WO2002005932A1

WO2002005932A1 - Photosynthetic carbon dioxide mitigation

Info

Publication number: WO2002005932A1
Application number: PCT/US2001/022721
Authority: WO
Inventors: David J. Bayless; Morgan L. Vis-Chiasson; Gregory G. Kremer
Original assignee: Ohio University
Priority date: 2000-07-18
Filing date: 2001-07-18
Publication date: 2002-01-24
Also published as: AU2001280616A1

Abstract

A process and apparatus is provided for removing carbon dioxide out of a gas by passing the gas through a container housing at least one membrane which supports cyanobacteria.

Description

PHOTOSYNTHETIC CARBON DIOXIDE MITIGATION

At present, more than half of the electrical power generated in the United States is produced from coal combustion. The future of coal-based power faces serious challenges, especially with regard to greenhouse gas emissions. While some advocate mass replacement of coal with natural gas, such a solution fails to address the long term need to maintain a diversified fuel supply to ensure reliable delivery and competitive pricing of electrical power. Clearly, research is needed to develop a robust portfolio of carbon management options, such safe and effective photosynthetic carbon recycling, to enable continued use of coal in electrical power generation.

In response to this need, Ohio University has developed a novel biologically-based process to reduce CO₂ emissions from fossil generation units. Preliminary work on this process was partially funded by the Department of Energy. The high CO₂ content of fossil-fired exhaust is ideal for growing certain photosynthetic organisms. A conservative estimate indicates that a 1,000,000 m² facility (contained in approximately 10 acres) powered by collected solar energy could process 20% of the effluent CO₂ from a 500 MW coal-fired power plant, producing over 200,000 tons of dry biomass per year. Process improvements could potentially lead to nearly twice that removal rate for the same dimension reactor. Once dried, the biomass could be used in the production of fertilizer, fermented to produce alcohols and light hydrocarbons, or directly as a fuel to meet biomass mandates in pending deregulation legislation.

This process is unique in photosynthetic carbon sequestration. Previous efforts have been focused on viability of algal strains, photosynthetic mechanisms, or simply measurement of growth rates. This work focuses on developing a process for practical implementation at fossil generation units, using system-level design techniques to create a 'near-optimal' enhanced photosynthetic process. In this effort, photosynthetic organisms are attached to specially designed growth surfaces arranged in a bioreactor to minimize pressure drop. Hybrid lighting minimizes power consumption and enhances system performance. A harvesting system ensures maximum organism growth and CO₂ uptake rate. In addition, using innovations developed at the Ohio University Multiphase Corrosion Center, bicarbonate concentrations to the cyanobacteria are enhanced, further increasing growth rate and carbon utilization. This innovation also may hold the key expanding the applicability of this procedure from its original target of scrubbed units to all fossil generation units, because the process of bicarbonate enhancement increases moisture content and lowers exhaust gas temperature, which greatly stimulates CO₂ uptake by the cyanobacteria.

The proposed research program would build upon the. results already gathered to further optimize carbon recycling capability. Among the topics to be addressed include improving organism growth and reproduction rates through the optimization of membrane growth surfaces (material and configuration), processing chamber environment (temperature and nutrients) and harvesting procedure; optimizing bicarbonate concentration in the cyanobacteria growth media; enhancing light delivery using hybrid lighting consisting of fluorescence and large-core fiber optic solar collection (in collaboration with researchers at Oak Ridge National Laboratories); exploring the use of new thermophilic cyanobacteria isolated at Yellowstone National Park (in collaboration with researchers at Montana State University); and minimizing the total cost per unit of CO₂ reduction by using system-level design methods.

The integrated system for natural carbon recycling into potentially beneficial biomass that is presented in this proposal could be an important addition in the repertoire of CO₂ control techniques needed to meet the goals of Kyoto Accord. It is a relatively low-risk, low-cost, potentially widely applicable method that offers a viable alternative to separation and sequestration. TABLE OF CONTENTS

Public Abstract i

Table of Contents ii

List of Figures iii

List of Acronyms iv

General Technical Information

Introduction 1

Scientific and Technical Merit 1

Technical Approach and Understanding 11

Sequestration Potential 21

Likelihood of Commercial Application 25

Qualification of Organization and Key Personnel and Adequacy of Facilities Resources 27

Page Total 30

Appendices

A. Statement of Project Objectives Al

B. Resumes A2

C. Example Decision Matrices A3

D. Letters of Support A4

E. References A5

List of Figures

Figure 1. Photosynthetic conversion of CO₂ to biomass and oxygen 2

Figure 2. 60x microscopic image of Nostoc 86-3 grown in the CRF at Ohio University 5

Figure 3. Artist conception of the proposed biological sequestration system at a fossil generation plant 8

Figure 4. Solar collection system 15

Figure 5. The existing CRF with 4'x 4'x & test section 29

Figure 6. Proposed organizational chart 29

List of Acronyms

AEP American Electric Power

COTS Commercial off the Shelf

CRF Carbon Recycling Facility

OCDO Ohio Coal Development Office

ORNL Oak Ridge National Laboraties

TRIZ Theory of Inventive Problem Solving (Russian)

Enhanced Practical Photosynthetic C0₂ Mitigation

INTRODUCTION

Biological carbon sequestration offers many advantages. Photosynthesis is the natural way to recycle carbon. Biomass developed from photosynthesis has numerous beneficial uses, the most attractive being a replacement fuel. Despite the large body of research in this area, virtually no work has been done to create a practical photosynthetic system for greenhouse gas control, one that could be used with both new and existing fossil units. For example, raceway cultivator use ignores land availability limitations at existing fossil generation plants. Few existing generation plants could find 100⁺ acres of suitable land for siting a microbial pond, much less build and maintain one throughout a midwestern winter. Additionally, how would the CO₂ be introduced to the photosynthetic agents? Would expensively separated CO₂ (not direct flue gas) be sparged because stack emissions requirements would prevent dispersion of flue gas at ground level? In addition, a practical biological sequestration would require improved lighting and photon delivery, a harvesting process to remove non-viable organisms and promote maximum carbon utilization, consideration of deleterious effects of the flue gas temperature and composition, and a plan for utilizing the biomass. The proposal presented in this document attempts to address these relevant problems in the design and analysis of a practical system for using photosynthesis in carbon sequestration.

This proposal is in response to Program Solicitation Number DE-PS26-99FT40613, entitled "Research and Development of Technologies for the Management of Greenhouse Gases." A primary goal of the DOE Carbon Sequestration Program is to provide a range of "economically competitive and environmentally safe" carbon sequestration options that meet ambitious goals concerning implementation time, long-term cost, and magnitude of impact on CO₂ reduction. This proposal, to continue the design and development of an cost-effective engineered photosynthesis system for CO₂ recycling, directly addresses these program objectives and leverages design work completed by the Oak Ridge National Laboratory to better utilize full-spectrum solar energy. Proof- of-concept experimental test-beds, collectively referred to as the Carbon Recycling Facility (CRF), have already been constructed in work partially funded by the DOE. Testing and designing practical photosynthetic sequestration processes for low-cost, low-risk carbon recycling comes under Topic Area "Advanced Concepts-Biological Systems and Engineered Photosynthesis Systems."

SCIENTIFIC AND TECHNICAL MERIT

This proposal presents a comprehensive design and analysis plan for development of a viable, practical system for photosynthetic sequestration of carbon at fossil generation units. The proposal builds upon work, partially funded by the Department of Energy, already performed in our Center and an independent solar lighting design effort at the Oak Ridge National Laboratory. Photosynthetic sequestration, often referred to as "natural" sequestration, was chosen as the focus of this effort for several reasons. Biological systems and in particular engineered photosynthesis systems are the best near-to-intermediate term solution for reduced carbon emissions in the energy sector. First, in conversation with executives of a major regional electrical utility, the need for "other-than-ocean" sequestration for fossil units located in the Ohio Valley and the Midwest became readily apparent. First, the large capital and operating costsi complexity and energy required to transport CO₂ make ocean sequestration prohibitive. Second, the product of natural sequestration, biomass, has numerous practical uses ranging from fertilizer to fuel. Third, it is clear that no one sequestration technique will solve the enormous problem of limiting carbon emissions from fossil generation units. Fourth, engineered photosynthesis systems could be made attractive to industry because they require no high-risk scientific breakthroughs. Photosynthesis is well understood, but there are no integrated practical processes for using it at fossil units for carbon sequestration. For coal to remain competitive and ensure future fuel diversification, a portfolio of viable and practical sequestration techniques will have to be developed and applied in an optimal manner based on each plant's circumstances. Photosynthetic systems must be a part of the portfolio.

The concept behind affordable engineered photosynthesis systems is simple. Even though CO₂ is a fairly stable molecule, it is the basis for the formation of complex sugars (food) by green plants through photosynthesis. The relatively high content of CO in flue gas (approximately 14% compared to the 350 ppm in ambient air) has been shown to significantly increase growth rates of certain species of cyanobacteria. Therefore, this application is ideal for contained system engineered to use specially selected (but currently existing) strains of cyanobacteria to maximize CO₂ conversion to cyanobacterial biomass and thus not emitting the greenhouse gas to the atmosphere. In this case, the cyanobacteria biomass represents a natural sink for carbon sequestration.

Photons

Figure 1. Photosynthetic conversion of CO₂ to biomass and oxygen

Photosynthesis reduces carbon in the gas stream by converting it biomass. As shown in Figure 1, if the composition of "typical" cyanobacteria (normalized with respect to carbon) is CHι.₈No.ι₇Oo.₅₆, then one mole of CO₂ is required for the growth of one mole of cyanobacteria. Based on the relative molar weights, the carbon from 1 kg of CO₂ could produce increased cyanobacteria mass of 25/44 kg, with 32/44 kg of O₂ released in the process, assuming O₂ is released in a one-to-one molar ratio with CO₂. Therefore, a photosynthetic system provides critical oxygen renewal along with the recycling of carbon into potentially beneficial biomass.

Enhanced natural sinks are the most "economically competitive and environmentally safe" carbon sequestration options because they do not require pure CO₂, and they do not incur the costs (and dangers) of separation, capture, and compression of CO₂ gas. Among the options for enhanced natural sinks, the use of existing organisms in an optimal way in an engineered photosynthesis system is low risk, low cost, and benign to the environment. Additionally, this engineered photosynthesis system has the advantage of being at the source of the emissions to allow measurement and verification of the system effects, rather than being far removed from the emissions source, as is the case with forest-based and ocean-based natural sinks. Finally, the use of ocean-based sinks could present significant problems. It will be necessary to add large amounts of iron to the ocean to "use" the vast quantities of CO₂ that might be added. As a result, there will be no control over resulting growth. "Weed" plankton, the most likely organisms to grow, will not provide sufficient nutrients for the food webs and there is a high probability of significant negative environmental impact. In the case of CO₂ stored at the bottom of the ocean in "lakes," the adverse effects on the ocean-floor ecosystem can not be predicted, but are likely to be considerable. The system we are proposing has little or no adverse environmental impact.

For low concentration CO₂ streams (such as the 14% mean CO₂ concentration in waste flue gases from coal-fired power plants), the joint consideration of conversion of collected solar energy (using the Oak Rdige process) and natural carbon capture has the potential for significantly lowering carbon management costs. An engineered photosynthesis system can use (or recycle) waste CO₂ to generate a store of reduced carbon in the form of biomass that could be used as a fuel, fertilizer, feedstock or sink for disposal. Further, engineered photosynthesis systems appear to fit into DOE's long-term plan to integrate biological processes into energyplexes to sequester carbon and produce energy (via biomass). Finally, engineered photosynthesis systems will likely benefit from current research into enhancing the process of photosynthesis, either genetically or via catalysts. This synergistic effect could lead to significant CO₂ reductions not otherwise possible.

The process presented in this proposal would be suitable for application at existing and future fossil units. It also has several advantages compared to other natural sequestration techniques. For this project, optimization is based on design of a mechanical system to best utilize existing organisms rather than on optimizing the desirable features of an organism by genetic manipulation. Genetically engineered organisms are notoriously unstable, especially when forced to grow at the high rates expected in this application. The process also requires relatively small amounts of space (l/25 ^h of a raceway cultivator design) and most of the required energy is provided by passively collected sunlight. Because the organisms are grown on membrane substrates arranged much like plates in an electrostatic precipitator, there is little pressure drop. From a solar energy utilization standpoint, this proposal offers a unique and cost-effective alternative using a new hybrid system that leverages two decades of advancements and cost improvements in the solar, optical coating, and large-core optical fiber industries. This method far surpasses previous attempts at distributing sunlight to enhance cyanobacteria growth. Finally, this system could be used in virtually any power plant with the incorporation of translating slug flow technology to create favorable conditions for cyanobacteria growth, such as reduced temperatures and enhanced bicarbonate concentration.

Research Plan and Methodology

The overriding objective of our research plan is to design and develop an "optimum" engineered photosynthesis system for use at individual power plants, where the parameter optimized is the amount of CO₂ processed by the system per unit cost. Prior to this solicitation, researchers at Ohio University and Montana State University (with the encouragement of a local utility) developed a model-scale carbon recycling research facility as a proof-of-concept for engineered photosynthesis systems and as a test-bed for carbon recycling research. The basis for this ongoing research was the need for containable and sustainable methods of carbon management that may be applied in the near future by the power industry to show positive compliance with future regulations on carbon emissions. Because of our location in the Midwest, the effort underway at Ohio University has focused on the use of cyanobacteria-based photosynthesis systems to process CO from the effluent flue gas of scrubbed fossil-fired combustion units. Many of these units are located more than 200 miles from an ocean and would not be suitable for long-range CO₂ transport. Further, these scrubbed units are ideal for use with biological control of CO₂, as the outlet of the scrubber contains lower amounts of harmful particulates, lower temperatures, and high concentrations ofwater vapor. However, the techniques proposed for this expanded research effort and the creation of a next- generation CRF should in no way be considered limited to just scrubbed power plants. In fact, with translating slug flow technology, a CRF-like photosynthesis system could be applied to virtually any plant, if used downstream of the particulate control device. Translating slug flow creates zones of extremely high mass transfer, converting CO₂ into a bicarbonate solution in water. The model- scale CRF and the proof-of-concept tests that have been completed are therefore just one part of a rigorous system-level design effort that is underway to design and develop a next-generation CRF that establishes new performance levels for an engineered photosynthesis system in the area of CO₂ reduction per unit cost. Preliminary results from our research and model-scale testing indicate that additional research and experimentation is needed in a large number of areas in order to maximize the CO₂ fixation rate of the system per unit cost. This is clearly a system-level design objective that must ultimately be addressed by system-level design concepts, but for practical purposes the determination of an optimum system design is divided into a number subsystem evaluations followed by system integration and system-level optimization.

Independent of this work, ORNL researchers were tasked by the U.S. Department of Energy in FY 1999 to design a new type of lighting system that more efficiently uses sunlight to illuminate building interiors. ORNL's work led to the design of a novel collector that separates visible (for lighting) and infrared (for conversion to electricity using photovoltaics) portions of the solar spectrum for different end-use applications. Interestingly, the work proposed by Ohio University and described herein is an ideally-suited niche market for these hybrid solar energy systems because high-quality visible light is the primary end-use power requirement in engineered photosynthesis systems. By using roof-mounted hybrid solar collectors capable of tracking the sun across the sky, stacking cyanobacteria sheets vertically in the containment facility, and generating electricity with the otherwise wasted IR radiation, the efficiency and affordability of this approach surpasses passive techniques and requires much less space.

Phase I of the research plan involves rigorous lab-scale, proof-of-concept scale, and model-scale experimentation to evaluate the effects of the key factors in the optimization of the system. The key factors include 1) the type of biological/photosynthetic agent (cyanobacteria), 2) the deep- penetration light delivery subsystem (including cyanobacteria responses to lighting cycles, wavelengths, the spatial coefficient of light utilization, and intensities to maximize photosynthesis), 3) the growth surface subsystem, 4) the growth enhancing subsystem (including slug flow reactor performance and cyanobacteria responses to temperature and nutrients), especially examining how nitrates (from NOx) and bicarbonate (from CO₂) is enhanced using a novel mixing scheme, 5) the harvesting subsystem (to maximize the ratio of cyanobacteria with high CO₂ consumption rates in the system at all times), and 6) the post-processing system including appropriateness of the harvested cyanobacteria for high-value uses such as fuel, fertilizers, or feedstock.

The final task in Phase I of our research plan is to select an 'optimum' system design as the next- generation CRF for detailed Phase II evaluations. This task involves combining the best subsystem features from the results of the key factor testing into various alternative system designs. Each of these system alternatives would be evaluated via analysis and simulation when possible but also via system level experiments as required to differentiate between alternatives. The optimum system would then be selected via a cost-benefit/risk-reward decision methodology with the help of decision matrices. (Example preliminary matrices are included in the Appendix.) Phase II of the research plan then proceeds with implementation and verification of the optimum system. The next-generation CRF will be implemented as a scaled model, and long-term, full verification tests will be run to quantify CO₂ reductions and to estimate the CO₂ reduction per unit cost in a full scale system. In order to prepare for full-scale implementation we will perform scaling tests, working closely with industrial partners.

Phase II should conclude with the design of a theoretically optimal photosynthetic carbon recycling facility that could be tested (at pilot scale) at the Ohio University Lausche Heating Plant. (Please see the letter of recommendation from the Ohio University Facilities Management Office agreeing to this cooperation.) While funding for pilot scale testing is not requested in this proposal, it is the next logical step. Given the close ties of the Lausche Heating Plant and the Principal Investigator with the Ohio Coal Development Office, funding for this testing could easily come from sources other than the Department ofEnergy, should the results of this study warrant pilot scale testing.

Significant scientific and technically challenging concepts underlying the proposed approach

One of the great advantages of carbon sequestration via an engineered biological system is that the sequestration is performed by the well-understood and natural process of photosynthesis. The challenges are therefore more engineering-based than scientific. However, there are a number of challenging concepts that will be faced in this work.

Cyanobacteria, as shown in Figure 2, were picked for this application because they are one of only two groups of organisms capable of growing at the experimental temperatures of 50-75°C. Although the cyanobacteria are treated as a photosynthetic "black box" in that a mechanistic study of the photosynthesis process is not part of this work, maximizing certain behaviors is a key to long- term success of this application. For example, the optimal blend of nutrients (including nitrates and bicarbonates) that maximize growth and carbon fixation rates must be determined. Further, because the organisms are grown on vertical substrates to minimize the pressure drop of the flue gas, cyanobacteria that "cling" to these surfaces is critical. However, if the attachment is too strong, cleaning the surface and harvesting becomes problematic. In addition, growth characteristics must be characterized to design the optimal harvesting system. For example, if the organisms reach maturity (or die) they consume less carbon than if they are growing. Therefore, an identifiable characteristic of growth must be quantified to maintain maximum carbon fixation.

Figure 2. 60x microscopic image of Nostoc 86-3 grown in the CRF at Ohio University Another consideration is the potential effects of the cyanobacteria on local environments should containment be lost. While they are naturally occurring organisms, their effects on colder ecosystems must at least be considered. Thermophilic ("heat" loving) or mesophilic cyanobacteria were selected, in part, because their growth ceases or is drastically decreased when exposed to lower temperatures. However, growth rate data at lower temperatures for target species should be quantified for understanding potential adverse impact.

The distribution of photosynthetic photon flux (light energy in the visible spectrum - wavelength of 400-700 nm) is a key to promoting uniform and maximum growth. (Simply put, if growth is maximized, carbon fixation will be maximized.) Distributing light is not a simple task. Light intensity varies according to Beer's law. Thus, a particulate-laden flue gas can result in a large loss of photon flux due to scattering. As a result of the non-uniform distribution of light, growth rates could be decreased or more lighting capacity (to shorten the average transmission path) could be required, requiring more energy to achieve maximum photosynthetic response.

The specific challenges of the passive sunlight delivery system relate to: 1) the ability to simultaneously minimize cost and optimize the material dispersion and scattering properties of the large-core optical fibers so that a maximum amount of visible light emerges radially from the fibers (glowing much like a fluorescent lamp), and 2) design the illumination system to spatially illuminate all regions of the growth membranes evenly. In addition to these project-specific challenges, the practical matter of integrating readily available components into a practical working light distribution prototype has yet to be experimentally validated. These issues include optimizing the performance and cost of two-axis sunlight trackers, dish concentrators, UV Cold mirrors, and optical fibers. Similarly, the optical system design and management of wasted thermal energy residing in highly concentrated sunlight must be optimized.

Lighting methodology considerations do not stop at delivery mechanisms. Lighting cycle duration (duration of light exposure for the organisms) is also an important consideration. While some "rest" or "dark" period is required, the optimum length of the light and dark cycles to promote carbon fixation is not well known. It is estimated that the natural maximum for the lighting cycle (about 16 hours) might be optimal, but further testing is required to understand the effect of the wide range of lighting cycles that could be experienced.

Another concern regards growth substrate composition and orientation. The growth substrate must be resistant to wear in the harsh environment of the flue gas and corrosive potential of the growth media and offer a high degree of adhesion with the cyanobacteria because of the vertical position. However, the degree of adhesion can be too high, becoming problematic for harvesting.

Harvesting, or the process of separating young from mature cyanobacteria, and reapplication of growing (not yet mature) cyanobacteria to growth surfaces are other key concerns. Preliminary tests indicate that cyanobacteria, removed in "clumps" from the growth strata, are easily agitated into a diffuse state. At this point, mature or dead cyanobacteria can be removed and cyanobacteria that are maturing (and thus maximizing their consumption of carbon) can be repopulated on the growth strata. The harvesting process is also necessary to promote cell division arid to reap the benefits of post-processed biomass. Other engineering challenges include nutrient enhancement and delivery. Cyanobacteria mostly easily fixes carbon in the form of bicarbonate (HCO₃) and nitrogen in the form of nitrates or ammonium. Using translating slug flow technology from Ohio University's Institute for Corrosion and Multiphase Processes not only increases concentrations of nutrients, but also lowers flue gas temperatures and increases humidity. Slugs, create zones of greatly enhanced gas-liquid mass transfer, putting CO₂ and NOx into the water as valuable nitrates and bicarbonates for the cyanobacteria. Work remains to identify the optimal levels of these nutrients to maximize cyanobacterial growth.

Perhaps the single most important factor that could result from the use of the translating slug flow reactor would be the total elimination of direct exposure of the cyanobacteria in the bioreactor with the flue gas. If the water leaving the slug flow reactor contained more than enough bicarbonates and other nutrients to feed the cyanobacteria, further exposure to flue gas for more absorption of carbon species could be pointless for some cyanobacterial strains. This would offer the advantage of using less thermotolerant cyanobacteria, because the water temperature from the slug flow reactor would likely be between 35-40°C, and result in possible cost savings.

A schematic illustrating the integration of these concepts in the overall biologically-based greenhouse gas control system with a fossil-fired electric generation plant is shown in Figure 3. This illustration shows the bioreactor exposed to the flue gas, even after the flue gas is "scrubbed' of CO₂ by the slug-flow reactor. This arrangement was chosen because it is the anticipated configuration. As described above, it may be possible to totally bypass the flue gas from the bioreactor. However, translating slug-flow reactor technology has not been applied on a large scale, and resulting pressure drop and operational cost data are not available. Therefore, it is assumed, until this study could resolve such issues, that the flue gas will pass through the bioreactor.

The results of the research proposed here will definitely increase the knowledge base concerning many aspects of the use of engineered photosynthesis systems for carbon sequestration, and it has high potential for achieving an engineering breakthrough in this research area and achieving success in bringing a near-term carbon sequestration option to market.

Distinguishing features of the proposed research

Research Approach

Our two-phase approach to the investigation of the viability of an engineered photosynthesis system as a carbon sequestration technique has the benefit of greatly expanding the knowledge base for all factors associated with the effectiveness of engineered photosynthesis systems, then creating detailed validations/verifications for a specific system (the next-generation CRF) selected as the best currently possible engineered photosynthesis system, where currently possible refers to a system which requires no scientific breakthrough in order to be successful. The phase II tests will quantify costs per unit of CO₂ removed and provide realistic estimates for the potential CO₂ reduction achievable with an optimized photosynthesis system. In other words, the research plan is responsive to the technical goals of the DOE Carbon Sequestration Program in that it establishes the technical, economic, and environmental feasibility of an engineered photosynthesis system for sequestering the CO₂ present in the flue gas of coal-fired power plants.

Figure 3. Artist conception of the proposed biological sequestration system at a fossil generation plant.

After significant preliminary research we have identified the key issues r engineered photosynthesis system for CO₂ recycling and we have identifi alternative solutions for these key issues. Importantly, we have defined the experimentation necessary to develop a nearly optimal engineered photo preliminary work already completed in our laboratories on the first-gen research group in an excellent position to be able to complete the research eff

Advantages of the Existing Facilities

The Carbon Recycling Facility (CRF) test-bed at Ohio University contains that houses thermo-tolerant (or thermophilic) cyanobacteria on membrane fashion similar to plates in an electrostatic precipitator in order to mini through the system, thus reducing the need for additional fan power. As sho is a closed loop, internally heated system that circulates simulated flue chamber using an axial fan. The plates provide needed stability (fixed surface cyanobacteria. Stability has been shown to increase the growth rate of the The plates also facilitate harvesting by providing discrete areas of cyano treated without affecting other regions of growth and provide spacing for light delivery. Further, it is our intent to have the facility at multiple stages of depending on the location of the plates and the harvesting cycle. The vari should present optimal times for harvesting, while maintaining maximum CO

Gas Addition Port

Additio

Flow Anal Meter Damper _Fan

Galva

λ

Screen Water makeup ^lan?^e uπjer Mesh / Pressure

using a natural gas burner located in the ductwork downstream of the fans. The gas stream is saturated (with water), consisting of roughly 10% CO₂ and 3% O₂, with trace levels of SO₂ and NO₂, with the balance being N₂. The gas levels are adjusted by the addition of make-up gases through the injection port. The nominal plate surface area is approximately 2.5 m² in the largest of the CRF units and 0.1 m² in the smallest units.

Initial large scale testing will be done in Carbon Recycling Facilities, as described above. These units are the "first-generation" of bioreactors. It is anticipated that their design will change based upon accumulated knowledge of organism behavior. Also, several different CRFs will be utilized in this work to investigate size and scaling issues.

Utilization of Solar Energy

While other bio-remediation processes will certainly have a solar component to supply necessary photons, it is quite clear that few, if any research efforts have focused on effective collection and distribution of solar energy to optimize not only CO₂ utilization, but also to provide necessary process energy (such as power to run pumps, harvesting systems, and conveyors.) The use of hybrid lighting, developed by Oak Ridge National Laboratories, is ideal for providing the necessary photosynthetic photon flux (optimized in the visible spectrum), and for converting the filtered infrared radiation from the solar spectrum into electricity using photovoltaics. This combination, together with utilization of large-core fiber optics for even distribution of photons, is a vast improvement over previous efforts in this area.

Utilization of Translating Slug Flow

As previously mentioned, the use of a translating slug flow reactor will significantly increase the concentration of bicarbonates in the water used in the bioreactor. Research at Ohio University's Institute for Corrosion and Mutiphase Processes has already made great in-roads in this area, patenting the design. Use of the slug flow reactor will allow for not only greater concentrations of nutrients from scrubbed flue gas contaminant gases (CO₂, NOx, NH₃) at lower cost, and power consumption rates, but will also lower the growth surface temperature and possibly eliminate the need for direct contact of the cyanobacteria with the flue gas, although that can not be stated with certainty. What can be stated is that this feature is unique in bioreactor utilization for carbon sequestration and is predicted as the key to making this process commercially viable.

Comparison with Current Practices

In concluding this section, there are clearly advantages of our proposed carbon recycling process, including 1) it addresses emissions at-the-source and allows verification of compliance of individual power plants with emissions regulations; 2) it is containable and does not directly depend on utilization of rain forests or oceans for CO₂ control, 3) it is sustainable in that the carbon in the process could be recycled using extremely low energy inputs, generating biomass that has a number of practical end-uses, which could marginally offset the use of fossil energy; 4) it is based on enhancing a natural process and is therefore compatible with the environment and poses no risk to human health or sensitive ecosystems; 5) power plant auxiliary power needed for CO₂ removal can be kept to a small fraction of that required for liquefaction or other separation techniques by incorporating novel solar collectors (in other words, relative to energy use this is mostly a solar utilization process); 6) pressure loss can be virtually eliminated by proper design of the growth surface configuration (minimizing fan requirements); 7) the on-site recycling/reuse system fits into the "Vision 21 EnergyPlex" concept; and 8) A team from Oak Ridge National Labs will supply a solar collector and expertise on optimizing lighting in our system.

While there are other efforts involving biological control of CO₂, many of these attempts lack the expertise and experience in the power industry to adequately address this complex issue of creating a practical photosynthetic carbon sequestration process. By focusing on engineering a practical design for carbon sequestration based on photosynthesis, instead of basing work on specific organisms in raceway cultivators, several advantages are accrued. First, this approach will require far less land space (three orders of magnitude) for implementation. Next, the controlled hydraulic jump process (also known as a translating slug flow reactor) used to enhance bicarbonate and nitrate concentrations allows for greater potential uses by cooling the flue gas. Because this is a systems approach, it can utilize future improvement (such as genetic engineering of cyanobacteria) without complete redesign of the system. Because it is a process to be added to the flue gas stream (like a wet scrubber), any upstream improvement in thermal efficiency or carbon emissions reductions will only add to the total carbon reduction.

Finally, it is distinguished from other separation sequestration techniques because it does not need to separate all the CO₂ from the flue gas, avoiding energy intensive processes. Further, it does not need to put the separated products into a geological formation, aquifer or ocean for long term storage. Instead, it produces a product (biomass) that has many practical uses and a byproduct (oxygen) that is necessary for human life.

TECHNICALAPPROACHAND UNDERSTANDING

This section presents specific details of the research plan previously described in general terms. The proposed project scope is to research and develop an engineered photosynthetic carbon recycling system and to optimize levels for CO₂ uptake and for CO₂ reduction per unit cost. The overall objective is to design a containable and sustainable that optimizes the use of existing biological organisms for low-risk, low-cost CO recycling and reuse. When possible, direct measurements of CO₂ reduction will be used when quantifying the effects of various design options on system efficiency, but the relative impact of a design decision on CO reduction will occasionally be indirectly quantified by measuring its effect on organism growth rates or other indicators.

For clarity, details of the research plan are presented using the format of the tasks to be performed in the "Statement of Program Objectives." The reviewer is advised that it may be helpful to refer to the Statement of Program Objectives when reading the following section.

PHASE I - System Design to Create 'Optimum' System

While this research is already underway, much work remains to be completed. The intended result of Phase I research is a comprehensive understanding of the effects of key design factors on the overall performance of a CRF-based engineered photosynthesis system. Specifically, the research will focus on understanding the mechanisms by which thermo-tolerant cyanobacteria maximize their C0₂ fixation rates at conditions simulating those found in the flue g"as from a scrubbed coal- fired power plant. Among the factors to be examined for their effect on fixation rate include lighting and distribution, lighting cycles, temperature, CO₂ concentration, and harvesting. Task 1.0 - Evaluate and rank component and subsystem level alternative design concepts

This task involves conducting comprehensive research and experimentation regarding promising alternative design concepts. Because there are a large number of key factors (identified as subsystem design) and a large number of alternatives for each subsystem, design of experiments methodology will be used as necessary to manage the testing. Decision matrices are being used to combine all of the information gathered through research and experimentation to logically rank the subsystem design alternatives. Copies of two sample decision matrices for each of the key subsystems are included in the Appendix of this proposal.

Subtask 1.1 Investigate critical properties of alternative photosynthetic agents (cyanobacteria)

Cyanobacteria have been chosen as photosynthetic agents because they are one of only two groups of organisms capable of growing at the experimental temperatures of 50-75°C. Numerous reports of diatoms isolated from thermal areas exist, especially Yellowstone National Park, but in only one case was the organism grown in carefully controlled temperatures approaching 50°C. Fairchild and Sheridan (1974) succeeded in growing Achnanthes exigua at 44°C. This temperature is not high enough for this project. The only other phototrophs seen in hot springs over 50°C are species of Cyanidium calderium. These organisms grow at temperatures as high as 60°C, but not well; neither are they successful over pH 4 (Brock, 1978). This limits the field of potential microbes able to fix CO₂ under the conditioning of a flue gas remediation effort to the cyanobacteria that can grow at 70-75°C and at pH values ranging from 5-9. Although cyanobacteria are able to grow at these temperatures, their optimal temperatures are closer to 50°C. Cyanobacteria are small in size and grow attached to sediment particles in thermal streams. This is an essential property if they are to be used in a fixed cell bioreactor. Another advantage of cyanobacteria is amenabilty to manipulation in the laboratory and thus to a plant setting. Cyanobacteria in general are mechanically robust making them ideal organisms for use in bioreactors.

Thermotolerant strains of cyanobacteria will be tested to characterize their growth physiology, particularly their ability to take up carbon dioxide and bicarbonate ions in the environmental conditions of the CRF. Additionally, all organisms will be characterized with respect to their ability to adhere to surfaces of known surface energy, their ability to survive rapidly changing conditions in the CRF, the ease with which they can be harvested, their initial and maintenance costs, and their residual value in terms of end-use products after post-processing.

Laboratory scale work at Montana State University (Cooksey Lab) will isolate and deliver cultures of thermotolerant cyanobacteria for testing in an engineered photosynthesis system. These organisms may also be thermophilic, but obligate thermophilicity is not a required property for the organisms to function at 50-75°C. It is not possible to predict the number of organisms to be delivered or their cellular type, although both single cell and filamentous types will be used.

The Cooksey lab has easy access and collecting permits for Yellowstone National Park (YNP) as well as the cooperation of the rangers. This will be one of our primary collecting areas. In particular we will take samples from thermal streams where the temperature ranges from 50-75°C. and the pH from 5-8. However we are not restricted to YNP. The State of Montana has published a map showing the thermal sites in the state. There are dozens of sites with useful pH and temperature ranges. Samples will be transported to the laboratory (2hr journey) in insulated containers. The pH and temperature of the site water will be recorded. Temperature will be monitored after transport also. This will be important when obligate thermophiles are cultured.

Samples of sediment and small rocks colonized with obvious cyanobacterial mats (biofilms) will be returned to the laboratory. They will be stored at the sample site temperature under illumination until sub-sampled for the enrichment procedure (usually the same or within one day). The sediment of rocks will first be washed by decantation to remove unattached cells or those only lightly attached. We wish to culture only firmly attached cells. The biofilm will be scraped from the rocks and used to inoculate small volumes of media directly (5mL or less). Sediment will be treated with ultrasound to remove attached cells and the supernatant cells suspension used as inoculum as above. These techniques are standard in this laboratory to isolate attached eucaryote algae and heterotrophic bacteria from freshwater and marine sources. It is essential to provide an inoculum volume of at least 10% to achieve an initial cell count of at least 5000 cells/mL, otherwise it is unlikely that the inoculum will develop. Other means of isolation are given in Castenholz (1988) and Rippka (1988). Above 60°C, it will be necessary to use Gelrite for solidified media, since agar will liquify at these temperatures.

As an alternative source of inocula we will place glass slides in areas where cyanobacteria are seen and allow their colonization. This will allow a selection procedure to be applied in situ. Further we are able to generate wettability gradients on such slides (Wigglesworth-Cooksey and Cooksey, 1999) and thus potentially select cells from the environment capable of attaching to surfaces of particular surface chemistry. This information is needed to select growth surfaces for the bioreactor.

The constituents and pH of the water at the sampling site will dictate to some extent the initial chemistry of the medium we will use. Ultimately we will have to formulate media that can be used in the bioreactors at Ohio University, however initially it is important to bring organisms into culture. It will be possible to select clones capable of being used at a later date. Previously selected algae from non-marine habitats have been grown in traditional marine media. Our initial efforts at isolation of cyanobacteria will utilize the BG-11 media buffered at the pH of the sampling site (Vaara et al 1979; Allen and Stanier, 1968) and/or those found in (Castenholz, 1988; Rippka, 1988; and Ferris and Hirsch 1991). Most published media are not buffered. Where desirable to detect contaminating hetreoptrophic bacteria, 0.05% yeast extract and glucose will be added.

Incubation conditions will consist of temperatures from the from the sampling sites, light levels in the range 100-150 μmoles m^"2 sec^"1 of photosynthetically active radiation (PAR) and photo-period of 16hr light/8hr dark. We will use quiescent (non shaken) and shaken cultures (100 rpm in baffled flasks). Shaking is preferable, but some organisms will not grow if treated in this manner. CO₂ absoφtion rate is more a factor of the pH of the medium than it is the mixing conditions, but removal of potentially inhibitory levels of O₂ (photorespiration) is a function of mixing. We will use an air/CO₂ mixture as the atmosphere.

Stock cultures after purification will be kept at the temperatures used for isolation until it is determined that it is possible to keep them more conveniently at mesophilic temperatures. Experience of one of our colleagues is that some cultures of thermophilic organisms sent to Type Culture Collections die in culture at mesophilic temperatures, but according to Castenholz (1988), some species can be frozen in liquid N₂. Growth can be measured in several ways, depending on the type of cell and how the sample for measurement can be taken. Single cell suspension can be sampled by pipette and the cells can be counted using a hemocytometer (400 cells counted gives a coefficient of variation of 10%). Cell count can be correlated with dry weight of the biomass from a calibration curve. This method provides considerable sensitivity. Again if the cells are dispersed, chlorophyll can be measured (spectrophotometrically or as fluorescence) and related to biomass and or cell number. Care with this measurement is essential since cyanobacteria produce increased chlorophyll/cell as cell density (and thus cell self-shading) increases. (Cooksey, 1981). As the cell counting method requires a single cell suspension, severe clumping or filamentous cells will dictate that biomass be measured as dry weight after filtration and washing of the sample on a glass fiber filter.

Although the final use to which these isolates will be put precludes their use of axenic (heterotrophic bacteria free) cultures, it is essential that stock cultures be maintained this way. Furthermore, for the experiments outlined below, axenic clonal cultures are preferable. Clones will be selected from those cells growing well on mineral agar plates. They will be purified by plating and selection of fast-growing colonies well separated from non-pigmented heterotrophic bacteria. Although the medium we will use contains no added substrates for heterotrophic growth, heterotrophic bacteria and fungi grow as satellite colonies utilizing the secreted products of cyanobacterial photosynthesis. Antibiotics against fungi (cycloheximide) and bacteria will be necessary. Because of their peptidoglycan cell wall, cyanobacteria are susceptible to the action of β-lactam antibiotics, but only when growing. This can be exploited in the removal of heterotrophic bacteria. Mixed cultures will be treated with a broad spectrum β-lactam antibiotic such as imipenem at concentrations to be determined (Ferris and Hirsch, 1991). The media will also contain 0.05% glucose/yeast extract and the mixture incubated in the dark where the heterotrophs, but not the autotrophs, will grow and be killed. After washing away the antibiotic, the surviving cyanobacteria will be able to be cultivated. Details have been provided by Ferris and Hirsch (1991). Growth rates in flasks at 50-75°C and various CO₂ levels will be obtained.

Subtask 1. 2 Investigate deep-penetration light delivery subsystem

A light delivery subsystem capable of delivering sufficient quantity and quality of photosynthetic photons deep within the CRF is a critical component of the total system design. Because the cyanobacteria growth surfaces involve the use of many closely spaced membranes, the use of only a simple "open roof lighting source would not be able to deliver light to the majority of the cyanobacteria, because light penetration deep into the cavity is limited by shading and by attenuation due to scattering and absoφtion.

The light delivery subsystem includes the light source and light distribution, and selection of the optimum combination depends on optimum lighting system requirements such as light cycle duration, light intensity, and light wavelength, and on original system costs as well as energy costs and the ability of the system to function in the CRF environment. Some specific tests include examining CO₂ fixation of the cyanobacteria relative to different light sources (such as that delivered through fiber optical cable) and different lighting cycles.

It is known that many species of cyanobacteria optimize CO₂ utilizatioh at a light intensity flux level of 40-60 μmols m^"2 sec^"1 (Ohtaguchi, 1997.) Sunlight yields an approximate photon flux of 2000 μmols m^"2 sec^"1. As such, in natural sequestration systems, well over 90% of the sunlight is not utilized. Therein lies one benefit and value of using a cost-effective sunlight collection and delivery system that distributes the optimal wavelength band of visible sunlight evenly throughout an enclosed structure in the estimated photon flux range of 40-60 μmols m^"2 sec^"1. The otherwise wasted infrared radiation would also be converted into electrical power using concentrating photovoltaic systems.

The collection system, shown in Figure 4, is a result of significant design work already performed at Oak Ridge National Laboratories. In Figure 4, the following components are identified: (1) A ~0.75 meter radius primary mirror (with an approximate 2 meter curvature radius); (2) A ~0.125 meter radius secondary optical element with accompanying concentrating PV cell. The front surface of the optical element is a complex-shaped, convex cold mirror that focuses the visible light onto several separate large-core optical fibers and either rejects the IR radiation or directs it to a concentrating PV or very small solar thermal system; (3) concentric fiber mount assembly; (4) approximately eight 18 mm large-core optical fibers. Note: The size of primary mirror will dictate the actual number of fibers required; (5) angled, hollow mount to reduce range of motion needed for altitude tracking (+40° required tracking motion); and (6) a conventional rotational tracking mechanism.

Figure 4. Solar collection system

This new hybrid solar lighting design approach provides several advantages. First, there are fewer, more easily assembled system components integrated into a smaller and more compact design configuration. Second, there is vastly improved improved IR and UV spectrum removal and management. Third, improved optical fiber placement/articulation (bundled and pivoted about a radial axis) has been developed. Fourth, a longer optical path for incoming visible light that enables a lower entrance angle of light into large-core optical fibers. Fifth, lower transmission losses are found in the light delivery system. Sixth, concentrated IR radiation promotes implementation of other solar technologies. Finally, smaller roof penetrations allow for less-costly installations and flexibility during space reconfigurations. These improvements coupled with continued cost reductions provide more than a five-fold improvement in cost and performance when compared to earlier sunlight collection/distribution attempts developed by Himarawi Coφ. in the 1980's. ι

We propose to utilize direct, non-diffuse, and filtered sunlight collected and piped via collection optics and large-core optical fibers. Using this approach, visible light reflected from 1.5 meter diameter dish collectors and secondary optics is launched into approximately thirty-five 15 mm optical fibers (seven rows of five fibers). Unwanted UV and IR energy is transmitted through a secondary optical element and eventually recovered by concentrating silicon-based photovoltaic cells to generate additional electrical energy. The visible light enters the CRF cavity through sealed, non-electrical optical fiber ports oriented based on the growth surface orientation. Using side- lighting techniques, incoming light is evenly distributed throughout the cavity to enhance the rate of carbon sequestration. Early estimates suggest that one such system could provide the required interior illumination needs for a prototype CRF system.

The primary focus of this task will be the definition of lighting system performance and cost requirements, lighting system design, computer modeling of the light distribution system, and technical support of the evaluation of lighting cycles on cyanobacteria growth rates.

Subtask 1. 3 Investigate growth surface subsystem

The factors which contribute to the growth surface subsystem include configuration of the surfaces, including whether they are fixed in place, movable in increments, or continuously movable, orientation of the surfaces, and growth surface material. Functions that the growth surface subsytem must provide at the least total cost include maximum surface volume, minimum power loss due to flow obstruction, and ability to function reliably in the CRF environment.

The material selection will be dictated by the mechanical properties necessary for the optimal design of the bioreactor. Preliminary investigations show that the substrata or growth surfaces should be inorganic to avoid problems with fungi growth. Currently, plastics have proven to be good candidates for growth surface material.

It is essential that clones supplied to the bioreactor be able to grow in the attached state. Selection for adhesive properties is planned at the sampling stage, but another selection means is also required. A second approach to assess the ability of clones to adhere to substrata has been developed in this laboratory (Cooksey, 1981), Briefly cells are allowed to attach to surfaces of defined surface chemistry (Wigglesworth-Cooksey et al., 1999), rinsed and the number attaching measured by the fluorometric signal of their chlorophyll . This method will be developed further for cyanobacteria. In recent reviews of the attachment mechanisms of marine microorganisms (Cooksey and Wigglesworth-Cooksey 1995: Geesey et al., in press), no suitable method for cyanobacteria was found. Studies of the attachment mechanism may lead to a method of harvesting cells from the surfaces carrying biofϊlms in the pilot scale CO₂ bioreactor. Most microorganisms have a cation requirement for adhesion, usually calcium (Cooksey and Wigglesworth-Cooksey, 1995; Geesey et al in press). Thus they can be removed from a surface with calcium ion complexing agents such as EDTA or EGTA (Cooksey and Cooksey, 1986). The requirement for calcium in the attachment mechanism will be researched using previously developed techniques (Cooksey 1981).

A preliminary decision matrix that summarizes the design criteria, a number of design alternatives and the types of testing requires is including in the Appendix.

Subtask 1. 4 Investigate enhancements resulting from the translating slug flow reactor.

Testing must be performed to analyze the response of the cyanobacteria to the conditions established by the translating slug flow reactor immediately upstream of the bioreactor. Translating slugs, which have leading edges of greatly enhanced mass transfer, increase the content of bicarbonates in the liquid used to grow the cyanobacteria. The bicarbonate forms because of the CO₂ being absorbed into the water. Slugs result when the gas to liquid flows reach unstable conditions in nearly horizontal pipes. In fact, a slight vertical inline can substantially increase slug frequency and thus increase the rate at which CO₂ is transferred to the water.

The process of inducing slug flow (gas-liquid mass transfer) not only results in vastly enhanced CO₂ ^; absoφtion in the water used to grow the cyanobacteria, it produces several other advantages. By absorbing CO₂ in the water in the slug flow reactor, the flue gas might never need to come directly in contact with the bioreactor. If the CO₂ is already in solution as bicarbonate ions, some cyanobacteria do not require gaseous CO₂ for photosynthesis. However, research performed in this subtask (specifically Subtask 1.4.3) will investigate if direct flue gas exposure is needed to further bicarbonate concentrations. However, regardless of results of these experiments, parallel experimentation will be conducted to examine the resulting temperatures of a larger scale bioreactor using the upstream slug flow reactor. The interaction of large volumes of cooled water with the flue gas, and the subsequent saturation of the growth surfaces with the enhanced bicarbonate containing water will create a lower temperature zone in the region of the growth surfaces than would be experienced in the flue-gas flow channels, the increasing growth rate.

Response of the cyanobacteria to these various conditions can be measured using an air lift bioreactor. It is difficult to change the atmosphere in growth chambers used for phototrophs because they are not sealed. Thus we will use a temperature controlled 2 L air lift bioreactor fitted with illumination (0-300 μmoles m^"2 sec^"1), an integrated light sensor and a gas mixing device to determine growth rates with variable CO₂ concentrations in the aeration stream. The photo-period used will be derived from earlier experiments. The sample port is fitted with a dip leg.

Subtask 1. 5 Investigate harvesting subsystem

This subsystem includes removal of cyanobacteria from growth surfaces, processing the harvested cyanobacteria, and recycling young cyanobacteria (repopulating the growth surfaces). Cyanobacteria harvesting must be examined for both understanding life cycle, as well as to determine factors that allow for selectivity of mature cyanobacteria.

As the growth rate of cyanobacteria levels off, the rate at which they consume CO₂ decreases. Therefore, mature cyanobacteria must be harvested (removed from the growth surfaces) to make room for young cyanobacteria to grow and to maximize CO₂ use. Many harvesting systems have been proposed, but the method currently used in the CRF involves selective spray washing of the plates at periodic intervals designed to ensure maximum uptake of CO₂ throughout the reactor. The cyanobacteria washed from the plates fall into the liquid slurry at the bottom of the chamber. This slurry is agitated to ensure that the cells are separated for later removal. Preliminary results indicate that cyanobacteria "clumps" are easily dispersed by low levels of agitation, indicating that a size selective process to optimize CO₂ uptake (through proper harvesting) might be possible. The use of sieves to remove larger, mature cyanobacteria is currently favored over cyclone-based techniques, however many size selection options are being investigated. The mature (large) cyanobacteria would be removed and the remaining slurry would be recirculated to the plates for repopulation.

However, a potential problem with sized-based separation is that certain strains may exhibit no clear size distinction among young and mature cells. In that case, the photosynthetic efficiency of the cyanobacterial biomass in the pilot CO₂ bioreactor will be determined by the number of active and living cells. There will come a time when the CO₂ removal rate will fall due to the die off of the biomass. This can be detected using an infra red gas analyzer in the flue gas stream when the configuration is one of gas re-circulation. Harvesting then becomes a matter of removing dead cells.

Therefore, it is necessary to have a test that provides information on the number of living cells in the growth substrates of the bioreactor. We propose to make this measurement using fluorescent probes that react differently with dead and living cells. These chemicals (fluorophores) are cell permeant when the cells have compromised cell membranes (dead) and excluded when they are intact (alive). Many compounds are currently in use for this p pose, but most are not useful for cells containing chlorophylls, or other photosynthesis related pigments, since the fluorophores and these molecules often have similar excitation and emission wavelengths. However, we have determined that Sytox Green (excitation 488nm, emission 523nm) will stain dead cells but not live ones and the fluorescence of the chlorophyll can be excluded by using a band pass filter that cuts fluorescence above the emission wavelength of the dye. The optical filter set for Calcium Green 1, which we have already used, will provide the necessary optical filtering for use on a Nikon microscope. If the use of this dye is successful, dead cells will stain bright green and live cells will not stain. Live cells can be quantified when the Calcium Green filter is removed from the optical path. This section of the proposal cannot be so defined as the other parts because we cannot predict in advance the quantitative fluorescence properties of the cells we will isolate. They will all contain chlorophylls, carotenoids and anthocyanins in various proportions - but more than that we cannot say. There is no doubt that given the hundreds of potential stains available, one will be suitable.

A preliminary decision matrix that summarizes the experiments planned for this subtask is included in the Appendix.

Subtask 1. 6 Investigate high-value uses for processed cyanobacteria

The use of mature cyanobacteria, while not part of this specific research, must eventually be considered. It is envisioned that mature cyanobacteria would be used to produce value-added products and energy. One advantage that Ohio University possesses in the post-processing of cyanobacteria is an active biomass combustion research program studying the combustion of cyanobacteria and coal as a blended fuel in fluidized bed combustion to power Stirling cycle free piston engines. Other options for using the harvested cyanobacteria include fermentation or conversion to hydrocarbon fuels, as fertilizers, and if recovered and kept living, they have been proven to be excellent soil stabilizers in dry environments.

Task 2.0 - Select an 'optimum' system design

This final task in Phase I of the research plan is to select an 'optimum' system design as the next- generation CRF for detailed Phase II evaluations. This task involves combining the best subsystem features from the results of the key factor testing into various alternative system designs, evaluating these system alternatives via analysis and simulation when possible but also via system level experiments as required to differentiate between alternatives, and selecting the 'optimum' system using cost-benefit/risk-reward decision methodology with the help of ''decision matrices. Some additional detail is given in the subtasks below.

Subtask 2.1 Combine highly-ranked subsystem alternatives into novel systems Using the information gathered in Task 1 for screening, combine the best subsystem features into various system designs. This will be an activity performed by groups working together and using creativity methods such as TRIZ to enhance the number of alternative system designs.

Subtask 2.2 Evaluate alternative systems

Conduct analysis and simulation of alternative systems based on all information gathered through subsystem level research and experimentation, and conduct new system level experiments as required to differentiate between alternatives. All information would be used in a system-level decision matrices to select the 'near optimal' design solution to be implemented in Phase II.

PHASE II - Implementation and Verification of 'Optimum' system

The details here are sparse in terms of the system being tested, but it is clear what effects will be important. We will ultimately measure and quantify the CO₂ reduction per unit cost. Further, design to pilot-scale will be needed to advance this process to the commercial level.

Task 3.0 Implement the optimum system in scaled model

Upon completion of Tasks 1 and 2, modifications to the CRF would be built to incoφorate the optimal system design. Long-term testing of overall performance would be done to evaluate the soundness of the prior design analyses and to suggest modifications. Further, should data warrant such actions, testing to augment work done in Tasks 1.0 and 2.0 could be simultaneously conducted during work for Task 3.0.

Subtask 3.1 Collect system performance data for extended duration

This task would be exclusively performed in the optimized CRF at Ohio University. Extended operation is necessary to prove viability, especially with respect to CO₂ utilization, biomass production, and harvesting, as well as concerns about pressure drop and energy requirements. And while the reactor is relatively small, compared to the size needed for an actual power plant, it is large enough to provide baseline data needed for Task 4.0, design of the pilot scale unit.

Subtask 3.2 Evaluate system performance data

Three major subtasks will be addressed, including (1) evaluating data from Subtask 3.1 to suggest system modifications, (2) performing further experimentation to test necessary modifications, and (3) verifying that the system causes no significant environmental problems. Environmental testing will also include a controlled "spill" into a completely isolated test ecosystem to observe corresponding ramifications. Further, should testing from this subtask warrant, re-examination of the issues addressed in Task 1 and 2 would be pursued.

Subtask 3.3 Approximate the system's maximum level of CO₂ uptake and its long term operating costs based on the experimental results. '■

Task 4.0. Design system for pilot-scale testing The final task would be to design a comprehensive photosynthetic carbon utilization system for use with a local fossil-fired plant. Preliminary talks with Ohio University's Lausche heating plant indicate its three units might be suitable for such work. Further, such plans would be necessary to seek funding from the Ohio Coal Development Office, industrial partners, and potentially other units within the Department of Energy for construction.

Additional Benefits of this Process

Four major benefits, in addition to CO₂ mitigation, result from this process. These benefits are electrical power generation (from photovoltaics), oxygen production, reduction of gaseous pollutants including potential NH₃ slip (from selective catalytic reduction to control NOx) and NOx, and production of biomass that could be used for biomass utilization requirements specified in electric deregulation legislation currently pending Congressional action.

Oxygen is natural product of photosynthesis. If you assume that 1 mole of O₂ is formed for each mole of CO₂ consumed during photosynthesis, then for every kg of CO₂ consumed, (32/44) or 0.73 kg of O₂ are produced. While this may not seem terribly significant, one can not overestimate the importance of oxygen to our lives.

In terms of pollution control, this process offers real NOx control at no addition cost. First, the translating slug flow process used to enhance bicarbonate and nitrate concentration is a natural scrubber. Not only is NOx converted to nitrates, SOx is converted to sulfates and sulfites, any NH₃ that might 'slip' through an upstream SCR process for NOx reduction will be scrubbed as well. Both NOx and NH₃ scrubbing is not only an additional benefit of this process, it is actually beneficial to this process, as the cyanobacteria require nitrogen to grow. In fact, work by Yoshihara et al. (1996) shows considerable nitrogen fixation from NOx species bubbled through a bioreactor, one with poorer mass transfer characteristics than would be found in the process described here.

Finally, it should be noted that the resulting biomass (harvested cyanobacteria) has numerous beneficial uses. In addition to being a potential fuel, cyanobacteria has been used as soil stabilizers, fertilizers, and in the generation of biofuels, such as biodiesel and ethanol. However, it is the application as a fossil-fuel replacement that drives other research at Ohio University. With pending electric deregulation legislation requiring as much as 7.5% utilization rate of biomass, a viable biofuel and method for utilizing that fuel needs to be found. Dried cyanobacteria has been shown to have a suitable higher heating value, high volatile content, and in tests done at Ohio University, has suitable ignition characteristics to be cofired with coal in pulverized coal-fired generation units.

Discuss how this work relates to specific goals of the FETC Carbon Sequestration Program

As previously discussed, we believe this proposal is a necessary element in the national carbon sequestration portfolio, especially as a replacement for ocean-based sequestration when not economically or environmentally feasible. The process described in this proposal is low cost (less than $10 per ton of CO₂ removed) and inherently environmentally safe. Specifically, it addresses DOE technical objectives: (1) drive down the cost of CO₂ separation and capture from energy production and utilization systems, (2) establish the technical, environmental, and economic feasibility of carbon sequestration using a variety of systems, and (4) develop opportunities to integrate fossil energy technologies with enhancement of natural sinks. The main puφose of this research is to demonstrate that low-risk methods of CO₂ mitigation based on using existing biological organisms in an optimal way are capable of significant CO₂ uptake and offer a valid near-term solution for CO₂ sequestration. Specifically, we will demonstrate the technical and economic feasibility of using an "optimized" enhanced photosynthesis system to directly decrease CO₂ concentrations in the emissions of fossil generation units.

Comparison to State-of-the-Art Practices

The U. S. produces an estimated 1.7 billion tons of CO₂ annually from the combustion of fossil fuels (EIA, 1998.) U. S. industries consume only 40 million tons of CO₂, produced at a much lower price than possible by removing CO from flue gas. Therefore, increased consumption of CO₂ appears limited, and options for expanded use appear limited and costly. Consequently, sequestration in large bodies ofwater or in deep mines appears to be the most viable present option. However, sending CO₂ into the ocean or an abandoned mine is a limited solution, and may only keep the CO₂ from reaching the atmosphere for a few hundred years. In fact, no one really knows the exact time scale for "storage." It may be centuries, but it also may only be decades. At best, these are temporary solutions. Further, the transportation issues are considerable, even for the less than 30% of all U. S. fossil plants that are within 100 miles of an ocean. Existing power plants, with capital values in the hundreds of billions of dollars, are at risk if tens of thousands of miles of specialized pipelines must be installed to transport separated CO₂. Clearly, other approaches for CO₂ control must be developed to adequately address this challenge.

There are inherent inefficiencies related to growing cyanobacteria in ponds for CO₂ sequestration, primarily due to the amount of cyanobacteria that can be grown in a given volume. For example, if 2,000,000 m² of cyanobacterial surface area is required for 25% reduction of CO₂ emissions from a power plant, that is equivalent to almost 500 acres of surface. Very few existing plants have 500 acres available to them and fewer could afford to convert 500 acres to a shallow lake. Also, there are serious questions about how to distribute the flue gas (or separated CO₂) into the lake for maximum growth, not to mention what to do with the gas once it bubbles to the surface. Would it have to be collected again and redirected up a stack to meet other emission requirements? Clearly that while biological control offers many advantages, it also presents significant implementation challenges that we believe are addressed in this proposal.

There are size and scale problems with containable systems such as our CRF-based engineered photosynthesis system as opposed to ocean based systems. However, the ability to control, measure, validate, and optimize in the engineered system easily outweighs the scale issue, which can be overcome with careful design of the practical system.

SEQUESTRATION POTENTIAL

The following calculations are based in part on growth rate measurements of Synechococcus leopoliensis taken by Ohtaguchi et al. (1997). The sustainable growth rate used for this calculation was derived from their maximum (20-30 hour) attained growth rate. The assumed growth rate was considered sustainable at 67% of Ohtaguchi's maximum. Further, given the results of our current research on cyanobacteria growth on vertical substrates, we estimate a 0.968 kg-m^'2 organism mass per unit area, which compares well with Ohtaguchi's mass density (kg-m^"3) of almost the same numeric value. Of course, while the method by which the cyanobacteria was grown (liquid suspension versus substrate) is different, mass per unit area will be used instead of mass density. The following assumptions were used to used to calculate the bioreactor surface area to remove 25% of the effluent CO₂ from a 500 MW fossil-fired generation unit. The overall capacity factor includes loss of availability.

• Overall capacity factor = 0.65 • Heat rate = 10,000 Btu kW-hr

• Fuel HHV = 10,000 Btu/lbm • Fuel is 75% carbon by mass

• Growth rate of 0.1277 kg hr ' m^"2 • 12 hour lighting cycle

Calculation of carbon burned per hour fin 1000 kg (mt, or metric tons)] lOOOkW lOOOOBtu lbm ton 1000kg 0.75kg_c mtC

500MW = 170.25

MW kW-hr lOOOOBtu 20001bm l.l013ton kg^, hr

Calculation ofCC>2 sequestered in biomass released per year (in metric tons) mt_c 8766hr 44mt_co

170.25 (0.65) 2 _ ^mtCO,

889,000 ^" hr^" yr 12mtc yr

Surface area needed for the bioreactor

Bioreactor dimensions

While this may seem to be a daunting size requirement, note that only 9.7 acres of direct sunlight (at 2000 μmol m^"2 sec^_1)is needed to provide sufficient photosynthetic photon flux, if an optimal level of photon flux is assumed to be 60 μmol m^" -'2 „ se_α„c-l

If the reactor must have 39,000 m² of solar surface area, the reactor could be composed of any number of plates (say 2000) suspended in an arrangement similar to an electrostatic precipitator with a spacing of y meters, the height of the plates would be 26.67y meters. Using 2000 plates spaced 0.10 m apart, the required plate height would be 2.67 meters.

Compare this 9.7 acre facility with an equivalent lake or raceway cultivator. Such a facility would require 257 acres. Therefore, there is a 25:1 improvement in space required by employing a vertically-mounted system that uses deep penetration solar lighting. Also note that a 257 acre lake, even one only 2 meters deep, would require more than 257 acres to implement, because topography is rarely level.

Biomass generation per year (in metric tons) mt_cθ2 44mt_{cθ2 =} ^ ^ mt_biomass

889,000 yr 25mt_biomass yr Oxygen generation per year assuming 1 mol O2 released when 1 mol CO₂ consumed

To summarize, this process could reasonably convert 25% or more CO₂ from combustion to biomass. And while the size of the reactor required seems large, the size calculated in this example is only three times the surface area of the interior of a cooling tower at one of American Electric Power's 1300 MW supercritical coal-fired units (at fill level) and only l/50^th of the height. While a larger bioreactor would be required for a larger generating unit or for larger percentage removal, the size of the reactor is not expected to be a significantly limiting factor, as the containment building is a very simple design and requires little in special construction.

Auxiliary Lighting Concerns

No discussion of control capability of biological sequestration could be complete without a thorough discussion of light source. While the sun will be the primary source for photosynthetic photons (carried from the collectors to the cyanobacteria via large core fiber optics), the fact remains that the sun does not always shine. Two alternatives exist to this concern. First, the system could be designed to operate sufficiently on normal sunlight, which is our preferred approach. Solar availability in the central United States is approximately (7 kWh/m²/day). Of this, only 75% comes in the form of direct, non-diffuse sunlight, primarily due to cloud cover and scattered daylight. Direct sunlight consists of approximately 45% visible light with the remainder in the UV and near infrared. When used passively (such as in a lake), only the visible portion of sunlight is used while the remainder of the solar energy is wasted. Since the optimal photosynthetic photon flux rate (PPFR) is approximately 60 μmols m^"2 s^"1 for maximum cyanobacterial growth and the sun provides about 2000 μmols m^"2 s^"1 at ground level on a clear day, most of the visible light is wasted. Further, at low altitude angles (such as in the early morning and late afternoons), the surface reflectivity of the lake increases significantly, further reducing the sunlight-to-cyanobacterial growth efficacy. Our approach provides significant improvements over these conventional techniques by 1) distributing the visible portion of sunlight so that all cyanobacterial surfaces receive a photosynthetic photon flux rate (PPFR) of approximately 60 μmols m^"2 s^"1 thereby eliminating photon waste, 2) harvesting most of the nonvisible portion of sunlight and converting it into electricity rather than wasting it, and 3) tracking the sun with the system at low altitude angles so as to continually collect and distribute all available sunlight.

Further, it is important to note that capacity factors for daytime operation of most fossil generation units are far greater than at night, except for baseload units, even during the winter. In fact, most generating units operate at full capacity during the day and minimum load at night during the summer. The implication is that a greater amount of CO₂ is available for conversion to biomass during daylight hours, when the maximum photosynthetic flux is available.

Second, if auxiliary lighting were used, how would it operationally compare? Other bioreactor designs, such as raceway cultivator or bubble-through reactors would not be able to employ sufficient artificial lighting to sustain even minimal photosynthesis. Using the previous example's parameters and a photosynthetic photon flux rate (PPFR) of όOμmols m^"2 s^"1, the approximate power needed to provide this lighting level would be 44 MW (approximately 8.8% of the previous example plant net output) if one assumes perfect conversion of electrical energy to light. Given the inherent conversion losses in even the most efficient electric lighting systems, the power required is actually closer to 100 MW (or 20% of example net plant output.) The luminous efficacy of filtered, direct sunlight (~200 lumens/watt) far exceeds existing electric lamps (15-90 lumens/watt). As a result, the actual lighting requirement t grow the cyanobacteria would be even greater than the estimated 100 MW. Comparatively speaking, electric lighting simply can not compete with using solar photons on a net power usage or cost basis.

Finally, the issue of light delivery must be addressed, illustrating a clear advantage of this process. Large amounts (such as 100 MW as described above) of artificial lighting power could never be provided to an enclosed bubbling bioreactor, no matter how unreasonably large such a unit would be. Even if someone invented a way to place the lighting in an encased, transparent, wateφroof material, the biomass would eventually find this encasing the best place to grow. The encasing would become rapidly covered, and light transmission would decrease greatly at the expense of overall system performance. In the design proposed here, the photons are delivered deep into the processing chamber via large core fiber optics. Not only is this superior for distributing the light, it is amenable to a simple periodic cleansing procedure so that the light emission is not disrupted by the surfaces being covered with organisms.

Potential Impact

Original focus and motivation was on power plants in Ohio Valley and the Midwest, which sometimes use SO₂ scrubbers. However, the technology described in this proposal is applicable and easily extendable to all fossil generation plants. Using a translating slug flow reactor to convert CO₂ into bicarbonates in the water used to grow the cyanobacteria makes it possible to apply this technology at virtually any plant that employs particulate control devices. The large volume of water needed for the translating slug flow reactor lowers the temperature of the flue gas (similar to wet scrubbing) so that temperature can be adjusted to maximize the cyanobacteria growth rate.

In addition, most fossil generation units are located in clusters to share resources, such as coal piles, switchyards, and water source. Some units even share a common stack. (AEP's Amos 1 and 2, all the units a OVEC's Kyger Creek, and too many other examples to list here.) This proximity makes it possible to install one bioreactor for two or more units, reducing the cost of capital and increasing utilization of this technique.

Finally, while this concept was conceived for fossil generation located far from viable water sequestration bodies (i.e. the ocean), it could serve virtually any unit, including ones that employed liquefaction and deep-ocean sequestration. While this may not be economically viable, it is still an option to reduce the amount of CO₂ that is put into the ocean should the life in the oceans be more sensitive to CO₂ levels than we anticipate.

Byproduct Sequestration and Energy Generation

While this proposal claims carbon sequestration as its goal, carbon is actually being recycled rather than sequestered in this process. Carbon recycling is fundamentally different than sequestration, with several advantages. In sequestration, the carbon is no longer available for use. While CO use for enhanced oil recovery has a benefit, CO₂ or carbon has little use in other forms of sequestration. With photosynthetic carbon recycling, useful carbon containing biomass and oxygen are produced from the carbon dioxide. As described elsewhere in this proposal, biomass has a number of beneficial uses, including as a fuel to offset the use of fossil fuels, as a soil stabilizer, fertilizer, or in the generation of biofuels (such as ethanol or biodiesel) for transportation use. In addition, the light collection and transmission system designed by ORNL would provide 3 MW of additional electrical power (using the previous example parameters) by converting the a portion of the filtered infrared spectrum using photovoltaics. This additional 3 MW of power reduces the overall example system's auxiliary load from 4.4 MW to 1.4 MW when fully operational.

Ability of the technology to address different types of emission sources.

In terms of pollution control, this process offers real NOx control at no addition cost. Algae and cyanobacteria have been found to fix nitrogen from NOx (Yoshihara et al., 1996) In these experiments, NOx at concentrations of 300 ppm was reduced up to 90% in simple bubble reactors. It was speculated that NO₂ formed nitrates in the water, which were then used by the cyanobacteria. The translating slug flow process used to enhance bicarbonate and nitrate concentration provides much greater mass transfer than found in a bubbling reactor. Not only is NOx readily converted to nitrates in the translating slug flow reactor, any NH₃ that might 'slip' through an upstream SCR process for NOx reduction will be scrubbed into the water. Both NOx and HN₃ scrubbing is not only an additional benefit of this process, it provides the cyanobacteria with vital nitrogen, enhancing their growth.

Feasibility of development of path-breaking means

Our proposed carbon sequestration method is based on enhancing naturally occurring photosynthesis and is therefore a very feasible procedure. Verification of costs and total impact on CO₂ levels in emissions are required to establish economic feasibility, but the main advancements required to make this option economically feasible are engineering-based rather than scientific, and therefore are very likely to be achievable.

LIKELIHOOD OF COMMERCIAL APPLICATION

Expected cost of commercializing in dollars per ton of carbon emission avoided

Assuming a plant lifetime of 30 years and the previous example parameters, a 8.8% auxiliary load for artificial lighting, pumping, and dewatering (which would be lowered to 2.8% when the photovoltaics were operational) at an average cost of $0,035 per kW-hr, a labor cost of $1 per ton (mostly for hauling the dry biomass) and a comparable production price of a similar sized ESP (scaled by a factor of five (5) for the solar collectors), yields a maximum cost of $15-$ 16 per ton of CO₂ removed. The breakdown costs, per unit ton of CO₂ removed assuming no cost of capital, are $4.50 capital cost, $10 for operating costs, and $l-$2 for associated operating labor.

However, if no auxiliary lighting is used, the potential long term cost drops to only $5-$8 per ton including only $1.50 per ton for power consumption because of the high level of self-generated (photovoltaic) power. Also note that the overall capital cost used in this estimate was approximately 40% greater than the estimate independently provided by the lighting team. If their estimate is used, the cost per ton of CO₂ removed decreases another $0.50. Finally, while these numbers are only estimates, they are consistent with prior assumptions. The calculations for cost also do not include any potential revenue from the sale or use of the biomass, which would further reduce overall costs.

Capability to compete with other commercial processes

Clearly, there is no one answer to CO₂ control. Even this process will not be able to address 100% of CO₂ generation. However, it does not have to. It clearly has a role to play in the suite of carbon control technologies. Even if this process performed no actual CO₂ conversion and recycling, the light delivery system designed by ORNL would generate 3 MW of usable electricity from solar power, reducing the need to use fossil-fuels and making this process nearly self-sustaining.

Consider the inherent cost of separation of CO₂. The primary option is liquefaction, which requires massive capital (for the refrigeration units) and a considerable auxiliary load on the plant, estimated to be 20-40% at best. Membrane technology and perhaps even some chemical additives could assist in lowering this costs, but it is fundamental to remember that CO₂ is a stable molecule, and thus no matter the final solution, it will require energy to remove it from flue gas.

Next, consider the cost of transport of the separated CO₂ for sequestration. It would be convenient if each power plant was located next to the ocean, or right on top of an oil field or old coal mine, but most are not. Whether it requires 10 miles or hundreds of miles, expensive pipelines will have to be constructed to deliver the separated CO₂. That literally means either refrigerated (or refrigeration stations) and pressurized lines to keep the CO₂ in the liquid phase or massive compressors to deliver the CO₂. In any case, there will be a number of fossil generating units that will not be able to use sequestration techniques because of these expenses will force the marginal price of its power far above the marketplace norm, resulting in closure of these facilities. This may not be acceptable, because significant capital has been, and remains, in many of these potential units.

Therefore, a widely applicable, biological based control technique is critical. Several advantages are accrued from biological control, as previously discussed, but the main one is a useful product (biomass) that could be used to generate revenue. For example, if the biomass was used as a cofiring fuel, the cost of fuel avoided would reduce the price per ton of CO₂ removed by $2-$6 per ton depending on the price of the avoided fuel.

Demonstrate the degree to which the activity identifies and makes progress on new concepts, thereby increasing the likelihood of a successful sequestration program.

The extensive experimentation program, focused at both component level concepts and system level concepts, will greatly increase the knowledge base relative to concepts and alternatives for the use of engineered photosynthesis systems for carbon sequestration.

Identify parties capable of commercializing in a timely manner

No current company could commercialize this technology. However, as work progresses, efforts will be made to bring this technology to commercialization. One possible company is Southern Environmental, Inc., which is currently working with researchers at Ohio University to commercialize new electrostatic precipitator technology. Of course, interest might also come from Wheelabrator, Babcock and Wilcox, or even Asea-Brown-Boveri. Development of the hybrid solar lighting & power system will initially be led by the Oak Ridge National Laboratory (ORNL). Once proven commercially-viable, ORNL's existing industrial partners in the U.S. Hybrid Lighting Partnership (Duke Solar, SAIC, Fiber Optic Technologies Inc., and others) will likely participate (and cost-share) in deployment of pilot-scale systems.

Estimate time before commercially successful

It would be a minimum of five years, more likely seven years to commercialization, given that pilot testing will require a minimum of 24 months.

Likelihood of obtaining patent or property rights.

This concept has already been disclosed to Ohio University's Technology Transfer Office (Disclosure 98104) in preparation for patent filing. A patent application for the hybrid solar collector system is being developed by ORNL. It is expected that a "continuation-in-part" for specific aspects related to lighting techniques of carbon sequestration applications will be jointly filed later. Work remains with regard the translating slug flow reactor from the Institute for Corrosion and Multiphase Technology, which are essential components to the overall program.

Identify the potential of securing cost sharing

Cost sharing for development of pilot-scale facilities is a reasonable goal. The Ohio Coal Development Office, which funds some of the Pi's current work, is funding a large portion of a $6.4 million demonstration project at Ohio University's Lausche Heating Plant. Because of the close cooperation between the plant's management, OCDO, and the proposing researchers, and the vast importance of CO₂ control to Ohio Coal, there is considerable potential for cost-sharing from OCDO. Additional cost share could be obtained through the Oak Ridge National Labs Hybrid Lighting program partners and through the Department of Energy's Office of Energy Efficiency and Renewable Energy because of the solar electric component of this project.

QUALIFICATIONS OF PERSONNEL AND ADEQUACY OF FACILITIES/RESOURCES

In order to create an engineered photosynthesis system which is practical enough to become an industrial solution and is cost-feasible, the interrelated issues of types of thermophilic cyanobacteria, light delivery, cyanobacteria harvesting to maximize CO₂ consumption, thermal environmental effects on the CO₂ absoφtion rate, effect of surface stability for cyanobacteria growth, and post-harvesting uses all must be considered. Our team possesses an excellent blend of scientific and engineering knowledge and practical experience in the power industry to adequately address these complex issues.

The principle investigator, Dr. David J. Bayless, P.E., has considerable experience in the fossil generation sector. A former employee and consultant for American Electric Power (AEP), involved in over 60 projects at numerous AEP fossil units, and frequent sponsored faculty member at the American Power Conference, Dr. Bayless understands the current fossil generation industry and what it would take to create a practical system for implementing an engineering photosynthesis system for carbon mitigation. Dr. Gregory G. Kremer has significant industrial experience as a Mechanical Design Engineer in the aircraft industry, and he also has some experience in the power industry, working as a summer engineering intern for the Cincinnati Gas & Electric Company at East Bend Power Plant. Dr. Kremer's research expertise is in the areas of mechanical system design (emphasis on large systems, nonlinear systems, and automotive systems) and design methodologies, including total life-cycle design, multi-objective design optimization, and design creativity and decision methods. Consistent with his areas of expertise, Dr. Kremer's primary contributions to this project will be 1) collecting and organizing the research and experimental results in Phase I into decision matrices so that logical cost-benefit decisions can be made, and 2) leading the system-level design and production of the large and complex mechanical system required to make photosynthetic CO₂ mitigation practical.

Drs. Cooksey and Vis will provide the biological expertise to utilize and understand the behavior of cyanobacteria. Dr. Vis will provide the needed expertise and facilities at Ohio University. However, most of the detailed biological studies will be performed at the Cooksey laboratory at Montana State University. Dr. Cooksey has over 50 publications concerning phototrophic metabolism of microorganisms. Currently he is teaching a course on industrial microbiology, which exposes microbiology and biochemistry students to the process engineering aspects of the subject. Before returning to academia, Dr. Cooksey ran a microbiological pilot plant for Shell International Chemical Coφoration. With Dr. W.G. Characklis, he was instrumental in forming the Institute for Biological and Chemical Analysis (IP A) at MSU - an organization devoted to working at the interface between microbiology and engineering. The Institute ultimately became the NSF-funded Center for Biofilm Engineering. Dr. Cooksey has extensive interdisciplinary experience gained in part while at IPA and also while Liaison Scientist for Europe and the Middle East for the Department of Defense (ONR) - a two year posting.

Mr. Jeff Muhs will be responsible for the solar lighting and delivery aspect of this work. He is the Photonics and Measurement Systems Group Leader at Oak Ridge National Laboratory. His experience and qualifications are listed in his resume, which can be found along with the resume's of all other key personnel in the Appendix.

Type, quality, and availability of the proposed equipment, materials, and facilities

The Ohio Coal Research Center has the infrastructure in place to initiate this proposed program, including burners, algal growth chambers, ultimate analyzers, CO₂, O₂, and NOx analyzers, mass flow controllers, temperature sensors, Licor photon flux sensors and precision microbalanced scales for mass measurement. The heart of the facility for this work is shown in Figure 5, the large test- section CRF. In addition to the capabilities of the Ohio Coal Research Center, the Institute for Corrosion and Multiphase Technology has extensive facilities for producing and testing translating slug flow reactors. A comprehensive list of this Center's capabilities would far exceed the 30 page limitation of this proposal. Interested reviewers should visit their website at the following URL - http://webche.ent.ohiou.edu//CorrosionCenter/.

Figure 5. The existing CRF with 4'x 4'x 6' test section

The Cooksey Laboratory at Montana State has, or has access to, all the usual facilities of a modern microbiology laboratory. In addition, the lab has lighted incubators (150 μmoles m^"2 s^"1) able to work to 50°C with a variable photo-period. Incubation facilities above this temperature are available in the newly formed Thermal Biology Institute that has initiation funding from the NASA. The Institute has been formed specifically to investigate life processes at elevated temperatures such as those found in the thermal areas of YNP and will develop systems for experimental biology at these temperatures. Two air-lift bioreactors (2 and 4 liter) with illumination levels to 300 μmoles m^"2 s^'1 can be dedicated to this program.

Proposed project organization chart

Ohio University !

Dr. John A. Bantle II Vice President for Research

Dr. Carol J. Blum Associate Vice President for Research

Dr. Michael E. Prudich Director, Ohio Coal Research Center

Dr. David J. Bayless Principal Investigator

Asst. Dir. Ohio Coal Research Center

Oak Ridge National Asst. Prof. Mechanical Engineering Montana State University Laboratories Time Commitment: 30%

Dr. Keith E. Cooksey

Jeff Muhs Research Professor of Research Engineer: Electro- Dr. Gregory G. Kremer Dr. Morgan L. Vis Microbiology Optical Sciences Asst. Prof. Mech. Asst Professor of Time Commitment: 25% Time Commitment: 25% Engineering Phycology

Time Commitment: 20% Time Commitment: 20%

Technician Time Commitment: Up to 75%

Graduate Students & Undergraduate Students Time Commitment: Up to 100%

Figure 6. Proposed organizational chart Provide justification for purchase or lease of facilities, equipment, or materials.

The main instrumentation needed for this work is a solar collector system, assembled by Oak Ridge National Laboratory, to be used with the facilities shown in Figure 5. Additional funding for transport and installation are included in the subcontracting budget prepared by the lighting team at Oak Ridge. The purchase of this system is absolutely critical to mission success. Further, because the technology developed by Oak Ridge laboratories is unique, it would be impossible and impractical to waste time trying to develop a similar system.

Enhanced Practical Photosynthetic CO₂ Mitigation

Statement of Project Objectives

OBJECTIVES

The main puφose of this research is to demonstrate that low-risk methods of CO₂ mitigation based on using existing biological organisms in an optimal way are capable of significant CO₂ uptake and offer a valid near-term solution for the CO₂ sequestration problem. Specifically, we will demonstrate the technical and economic feasibility of using an "optimized" enhanced photosynthesis system that (a) separates and uses various spectral regions of direct, non-diffuse sunlight to maximize cyanobacteria growth, (b) directly decreases CO₂ concentrations in the emissions of fossil generation units, (c) reduce the required space needed (compared to other biological techniques) by a factor of 25, and (d) simultaneously produce enough electrical energy to nearly self-power the entire sequestration system

Phase I Objectives

The main objectives of the first phase of the research are to determine which individual factors have the most significant effect on CO₂ uptake in an enhanced photosynthesis system, determine the preferred deep-penetration hybrid solar lighting design configuration for this application, and optimize the combination of these factors in a practical and effective system with maximum carbon utilization and minimum external power requirements. An additional objective in this phase is to demonstrate synergy with the enhanced mass transfer CO₂ absoφtion technique (which converts CO₂ to bicarbonate for cyanobacterial utilization) developed by the Multiphase Corrosion Research Center at Ohio University.

Phase II Objectives

The main objective of the second research phase is to determine the potential sequestration capability of an "optimized" enhanced photosynthesis system at a level greater than laboratory bench-scale. An additional objective is to demonstrate how this on-site recycling and reuse biomass system fits into the "Vision 21 EnergyPlex" concept.

Scope of Work

The proposed work would focus on optimization and design of a process to practically use photosynthesis to sequester CO₂ in potentially beneficial biomass (thermotolerant cyanobacteria). The first effort will be to study the effect of individual factors on carbon utilization and growth rates of the cyanobacteria. The individual factors to be studied include slurry-based recycling and harvesting, lighting cycles, solar-based spatial and temporal photon delivery, HCO₃ concentration enhancement, growth surface design, and examination of new strains of thermotolerant cyanobacteria. Using this data, optimal sub-system designs will be developed from combinations of the key factors and will be further tested for interactions and compatibility in a model-scale test bed. Phase I will culminate in the identification of an optimal system design, and Phase II research will involve the detailed testing of this design and the preparation for pilot-scale studies. While Phase I testing would last nearly two years, the data collected will be used both for evaluating enhanced photosynthesis as a candidate for CO₂ sequestration, and for optimizing our system design. The ultimate goal of this work is the development of a practical enhanced photosynthesis system that can meet the need for CO₂ sequestration in any fossil generation unit.

TASKS TO BE PERFORMED

PHASE I: Design of an "Optimum " Enhanced Photosynthesis System

Task 1.0. Evaluate and rank component and subsystem level alternative design concepts.

This task will include research and experimentation necessary to gather sufficient data to evaluate design worthiness of promising alternatives. The larger scale CRF would be used as the primary test-bed, with the smaller CRFs used for proof-of-concept testing. Decision matrices would be used to combine all information gathered through research and experimentation in order to logically rank the alternatives.

Subtask 1.1 Investigate critical properties of alternative photosynthetic agents (cyanobacteria) Subtask 1.1.1 Quantify agent growth rate characteristics in controlled experiments as a function of temperature, bicarbonate concentration, moisture content and nutrient level Subtask 1.1.2 Quantify adhesion characteristics Subtask 1.1.3 Quantify growth characteristics (size when mature and average time to mature) for harvesting considerations Subtask 1.1.4 Quantify growth characteristics at low temperatures for analysis of environmental impacts should there be loss of containment. Subtask 1.2 Design deep-penetration light delivery subsystem

Subtask 1.2.1 Define spatial photon delivery (lighting) requirements and model design configurations incoφorating large-core optical fibers using COTS lighting design tools Subtask 1.2.2 Determine preliminary solar-based photon delivery (lighting) systems spatial effect on cyanobacteria growth rates. Subtask 1.2.3 Test lighting cycle durations on growth rates. Subtask 1.3 Investigate growth surface subsystem design

Subtask 1.3.1 Examine surface configuration for effects on growth and harvesting Subtask 1.3.2 Examine surface composition for effects on growth and harvesting Subtask 1.4 investigate the use of a hydraulic jump to improve the system's overall CO₂ conversion efficiency Subtask 1.4.1 Examine effect of hydraulic jump on HCO₃ (bicarbonate) concentration Subtask 1.4.2 Examine effect of hydraulic jump on exhaust gas temperature Subtask 1.4.3 Examine effect of hydraulic jump on need for direct flue gas exposure to promote photosynthesis in the bioreactor. Subtask 1.4.4 Quantify costs / negative effects of hydraulic jump on the system Subtask 1.5 Design harvesting subsystem

Subtask 1.5.1 Examine harvesting methods for efficiency of biomass removal Subtask 1.5.2 Examine harvesting schedules for maximizing the percentage of young

(developing) cyanobacteria in the system Subtask 1.5.3 Examine methods for differentiating and separating cyanobacteria (live from dead and mature from those still growing) Subtask 1.5.4 Examine methods for processing harvested algae for end use and/or reuse in the CRF Subtask 1.5.5 Examine methods for repopulating growth surfaces Subtask 1.6 Quantify properties (higher heating value, elemental composition, volatile content) of dried biomass for potential end-uses

Task 2.0. Evaluate subsystem combinations and select an "optimum" system design

Create alternative system designs from combinations of the leading alternatives identified in Task 1, and implement and test them in the large CRF to verify compatibility and to quantify interaction effects. Evaluate the alternatives and select the 'best' system using cost-benefit/risk-reward decision methodology.

Subtask 2.1 Combine highly-ranked subsystem alternatives into novel systems

Subtask 2.1.1 Using the information gathered in Task 1 for screening, combine best subsystem features into various system designs scaled for testing in large CRF Subtask 2.1.2 Fabricate, install, and test system components (lighting system, etc.) based on optimized design selected Subtask 2.1.3 Modify the large CRF as required for utilization of subsystems

Subtask 2.2 Evaluate alternative systems

Subtask 2.2.1 Conduct analysis and simulation of alternative systems based on all information gathered through subsystem level research and experimentation Subtask 2.2.2 Conduct new system level experiments as required to differentiate between alternatives Subtask 2.2.3 Combine information into system-level decision matrices and select the system with the best combination of high performance, low cost, and low risk.

PHASE II - Implementation and Verification of "Optimum" system

Task 3.0 implement the optimum system in scaled model

Once the analysis indicates which combination of subsystems is the best for maximum CO₂ utilization and the design work in Task 2.0 has been completed, a new facility would be built to incoφorate this optimal system. Then, long-term (at least 1000 hours) testing of overall performance would commence. Note that data collected from the long-term test would be used to evaluate the soundness of the prior design analyses and to suggest modifications. Further, should data warrant such actions, testing to augment work done in Tasks 1.0 and 2.0 could be simultaneously conducted during work for Task 3.0. Subtask 3.1 Collect system performance data for extended duration (>30 days) Subtask 3.1.1 Collect data including rate of biomass production Subtask 3.1.2 Evaluate system operating and energy consumption

Subtask 3.2 Evaluate system performance data

Subtask 3.2.1 Evaluate data to suggest system modifications

Subtask 3.2.2 Perform further experimentation to test modifications

Subtask 3.2.3 Verify that the system causes no significant environmental problems

Subtask 3.3 Approximate the system's maximum level of CO₂ uptake and its long term operating costs based on the experimental results

Task 4.0. Design system for pilot-scale testing

The final task would be to design a comprehensive photosynthetic carbon utilization system for use with a local fossil-fired plant. Preliminary talks with Ohio University's Lausche heating plant indicate its three units might be suitable for such work. Further, such plans would be necessary to seek funding from the Ohio Coal Development Office for construction.

TIMELINE

The project timeline is attached (next page), giving approximate scheduling for program progress. This timeline is only an estimate, as research programs are inherently variant, depending on the results discovered during the process of the work.

DELIVERABLES

1. Periodic, topical, and final report are to be submitted in accordance with the "Federal Assistance Reporting Checklist" and any instructions provided by DOE point of contact.

2. Detailed briefings, for presentation shall be given by the Contractor to explain the plans, progress, and results of the technical effort to the COR at the COR's facility located in Pittsburgh, PA or Morgantown, WV.

3. Technical paper(s) would be presented at the DOE/FETC Annual Contractor's Review Meeting to be held at the FETC facility located in Pittsburgh, PA or Morgantown, WV.

₄. Additional updates and data will be made immediately available for review at http://www.ent.ohiou.edu/~ohiocoal/CO₂

David J. Bayless, Ph.D, P.E.

Email: bayless@ohio.edu Asst. Professor of Mechanical Engineering Phone: (740) 593 0264 www.ent.ohiou.edu/~bayless Asst. Director, Ohio Coal Research Center Fax: (740) 593 0476

Ohio University Athens, OH 45701-2979

Research Interest

Recycling of CO₂ emissions by biological sources; combustion of solid fuels, and slurries; study of the formation and control of SO₂, NO_x, PCDD/F, and particulate emissions from of coal and waste combustion; intrinsic reaction rates of single pulverized coal particles, waste-to-energy (incineration) combustion; use of mass spectroscopy and Fourier Transform Infrared spectroscopy for detection of gaseous compounds through gas chromatography.

Education

1995 Ph.D. University of Illinois at Urbana-Champaign

1992 M.S. University of Central Florida

1987 B.S. University of Missouri-Rolla (summa cum laude)

Professional Experience

1998-current Assistant Director of the Ohio Coal Research Center

1995-current Assistant Professor of Mechanical Engineering Ohio University

1996-current Consultant American Electric Power

1994- 1995 Link Foundation Energy Research Fellow University of Illinois

(Department of Mechanical Engineering)

1991 - 1994 National Science Foundation Fellow University of Illinois

(Department of Mechanical Engineering)

1987-1991 Nuclear Propulsion Officer and Instructor Naval Nuclear Power School

Professional Memberships

Combustion Institute

Air and Waste Management Association

American Society of Mechanical Engineers (Industrial Relations Chair - ASME Region V)

American Society for Engineering Education

Selected Awards

1997, 1999 Outstanding Mechanical Engineering Professor, ENT Student Council

1996- 1999 Sponsored Faculty to the American Power Conference

1994- 1995 Link Foundation Energy Fellow

1991-1994 National Science Foundation Fellow

1990 Navy Achievement Medal, U.S. Navy

Registration

Registered Professional Engineer (Missouri E-24997) David J. Bayless, Ph.D, P.E., (page 2 of resume) Patents

Membrane Electrostatic Precipitator No. 60,089,640 filed June 17, 1998.

Selected Publications

Bayless, D.J., "Analysis of the Evolution of Surface Voids Affecting Char Burning Rates at

Diffusion-Limited Conditions", accepted for publication in Combustion Science and

Technology, 1999 Bayless, D.J., Using Industrial Summer Intern Programs as a Tool for Engineering Education, accepted for publication in the Journal of Engineering Education, 1999 Bayless, D.J., Khan, A.R., Tanneer, S., and Birru, R., "An Alternative to Additional SO₃ Injection for Fly Ash Conditioning," paper 98-130 accepted for publication in the Journal of the Air and

Waste Management Association , 1999. Bayless, D.J., and Khan, A., "Effects of Gas Stream Temperature on Homogeneous SO₂ to SO₃

Conversion via Natural Gas Reburning," Proceedings of the International Joint Power

Generation Conference, pp. 147-153, 1998. Bayless, D. J., "American Electric Power's Project Probe^SM - Academic-Industrial Cooperation to

Improve Power Engineering Education," Proceedings of the International Joint Power

Generation Conference, pp. 467-471, 1998. Bayless, D.J., and Pawliger, R.I., "American Electric Power's Project Probe - Enhancing Power

Engineering Education Through Industrial- Academic Cooperation," Proceedings of the

Frontiers in Education Conference, pp. 873-878, 1997. Bayless, D.J., and Pawliger, R.I., "American Electric Power's Project Probe - Enhancing Power

Engineering Education Through Industrial-Academic Cooperation," Proceedings of the

Frontiers in Education Conference, -pp. 1230-1235, 1998. Bayless, D.J., and Brumfield C.A., "American Electric Power's Project Probe - Power Engineering

Education through Internship," Proceedings of the American Power Conference, pp. 146-150,

1998 Bayless, D.J., "Revitalizing Power and Power Generation Engineering Education at Ohio

University," Proceedings of the American Power Conference, pp. 151-154, 1998 Bayless, D.J., Wismer, M., and Sheidler, R., "American Electric Power's Project Probe - A Unique

Summer Intern Engineering Program," Proceedings of the American Power Conference, pp.

493-498, 1997. Bayless, D.J., and Clark, L., "Using CEMS Data to Estimate Instantaneous Heat Rate" Proceedings of the American Power Conference, pp. 987-992, 1997. Bayless, D.J., Schroeder, A.R., Peters, J.E., and Buckius, R.O., "The Effects of Surface Voids on the

Burning Rates of Coal Particles at Diffusion-Limited Conditions", Combustion and Flame, (108),

1997, pp. 187-198. Bayless, D.J., Schroeder, A.R., Olsen, M.G, Johnson, D.C, Peters, J.E., Krier, H., and Buckius, R.O.,

"The Effects of Natural Gas Cofiring on Sulfur Retention in Ash", Combustion and Flame, (106),

1996, pp. 231-240. Bayless, D.J, "Effects of Natural Gas and Coal Cofiring on Sulfur Retention in Ash", Research

Reports of the Link Energy Fellows, (11), pp. 25-44, 1995. David J. Bayless, Ph.D, P.E., (page 3 of resume)

Bayless, D.J., Schroeder, A.R., Johnson, D.C, Peters, J.E., Krier, H., and Buckius, R.O., "Effects of Natural Gas Cofiring on Ignition of Coal and Coke Particles", Combustion Science and Technology, (98), 1994, pp. 185-196.

Recent Research Projects

Role and Fate of Sulfur in Gas Reburning for NOx Control. Ohio Coal Development Office,

$287,000, 9/1/96 through 9/30/00 Carbon Dioxide Mitigation through Controlled Photosynthesis. U.S. Department of Energy (FETC)

$50,000, 9/1/99-8/31/00 Membrane-based Wet Electrostatic Precipitation, sponsored by the Ohio Coal Development Officer,

$150,000, 9/1/98 through 9/30/00 (Rudy Pasic PI) Greenhouse Gas Mitigation, funded through the Ohio University 1804 Fund, $28,000, 9/1/99. Enhanced Air Pollution Control using Electrostatic Precipitators. funded through the Ohio University

1804 Fund, $28,500, 9/1/98. Development of Air Sampling Laboratory, sponsored by the Stacker Foundation, $12,000, 11/1/96. Combustion of Solid-Fuels in Recirculating Fluidized Beds, sponsored by the Ohio University

Research Committee, $6,750, 4/1/96 through 4/1/97 Fluidized Bed Combustion, sponsored by the Ohio University Office of Research, $27,700, 9/1/95 through 6/30/97.

Gregory G. Kremer, Ph.D

Email: kremer@ohiou.edu Asst. Professor of Mechanical Engineering Phone: (740) 593 1561 www.ent.ohiou.edu/~kremer Ohio University Fax: (740) 593 0476

Athens, OH 45701-2979

Research Interest

Recycling of CO₂ emissions by biological sources; Large-scale mechanical systems; Advanced automotive technologies; Design, analysis, modeling, simulation, and control of nonlinear mechanical systems; Design methodologies, including total life-cycle design, multi-objective design optimization, and design creativity and decision methods; Web-based instructional technologies.

Education

1998 Ph.D. University of Cincinnati 1994 M.S. University of Cincinnati

1989 B.S. Rose-Hulman Institute of Technology

Professional Experience

1998-current Assistant Professor of Mechanical Engineering Ohio University 1997-1998 Mechanical Engineering Consultant Ganymede Corporation

1994- 1998 Research and Teaching Assistant University of Cincinnati

1989-1993 Mechanical Design Engineer General Electric Aircraft

Engines

Professional Memberships

American Society of Mechanical Engineers (ASME) American Society for Engineering Education (ASEE) Society of Automotive Engineers (SAE) Institute of Electrical and Electronics Engineers (IEEE)

Selected Awards

1999 Inducted into Athletic Hall of Fame, Rose-Hulman Institute of Technology

1993 GE Engineering Achievement Award: for design and analysis of a new compressor rotor spool-shaft for a major field retrofit program. 1992 GE Managerial Award: for development and substantiation of an electron-beam weld repair to salvage scrapped compressor rotor shafts.

1990 - 1993 GE Special Recognition Letters: for exceptional support of manufacturing cost reduction efforts, continuous improvement, and concurrent engineering. Gregory G. Kremer, Ph.D, (page 2 of resume) Selected Publications

Kremer, G.G., "Robust Stability Analysis of Large-Scale Hydraulic Control Systems," Proceedings of the American Control Conference, San Diego, California, June 1999. Thompson, D.F. and Kremer, G.G., "Parametric Model Development and Quantitative Feedback

Design for Automotive Torque Converter Bypass Clutch Control," Proceedings of the Institute of Mechanical Engineers, In Press. Kremer, G.G. and Thompson, D.F., "A Bifurcation Based Procedure for Designing and Analyzing

Robustly Stable Nonlinear Hydraulic Servo Systems," Proceedings of the Institute of

Mechanical Engineers, (212 Part I), 1998, pp. 383-394. Thompson, D.F. and Kremer, G.G., "Quantitative Feedback Design for a Variable Displacement

Hydraulic Vane Pump," Optimal Control: Applications & Methods, (19), 1998, pp. 63-92. Kremer, G.G., "Robust Stability of Nonlinear Hydraulic Servo Systems Using Closest Hopf

Bifurcation Techniques," Proceedings of the American Control Conference, Philadelphia,

Pennsylvania, June 1998. Kremer, G.G., "Designing an Automobile for Maximum Recyclability: Technological and

Economic Considerations for 100% Recyclability", Presented at the SAE Aerospace Atlantic

Conference, Dayton, Ohio, May 1995.

Recent Research Projects

Carbon Dioxide Mitigation through Controlled Photosynthesis. U.S. Department of Energy (FETC)

$50,000, 9/1/1999-8/31/2000 (Dave Bayless PI) Reducing Greenhouse Gas Emissions through Controlled Photosynthesis, funded through the Ohio

University 1804 Fund, $27,000, 7/1/1999 - 6/30/2001. Carbon Dioxide Mitigation through Controlled Photosynthesis, sponsored by the Stocker Foundation,

$12,000, 7/1/1999 - 6/30/2000. Dynamics on the Web - An Interactive Problem Solver to Enhance Student Learning. Ohio University

Technology Incentive Package, $17,060, 3/1/1999 - 6/30/2000. Research in Propulsion Systems For Future Vehicles. Ohio Board of Regents — Hayes Investment

Funds, $100,000, Pending.

Morgan L. Vis, Ph.D

Email: vis-chia@ohio.edu Asst. Professor ofPhycology Phone: (740) 593 1134 http://vis-pc.plantbio.ohiou.edu Director of DNA Analysis Facility Fax: (740) 593 1130

Ohio University Athens, OH 45701

Research Interest

Recycling of CO₂ emissions by biological sources (algae); culturing of algae for research purposes; the effects of acid mine drainage on stream biological communities; stream ecology of algae; evolution of algae in particular freshwater red algae;

Education

1995 Ph.D. Memorial University of Newfoundland, Canada

1991 M.S. University of Rhode Island, Rhode Island

1989 B.A. Kalamazoo College, Michigan

Professional Experience

1996-present Assistant Professor Ohio University

1995- 1996 Postdoctoral Research Position University of Guelph, Canada

1994- 1995 Postdoctoral Research Position Memorial University of

Newfoundland, Canada

1992 Lecturer Position University of Rhode Island

1990 Research Assistant University of Rhode Island

Professional Activities

Webmaster for Phycological Society of America (ad hoc executive committee member)

Director of Ohio University DNA Analysis Facility

Phycological Society of America Membership Committee 1998-2000

Editorial Board of European Journal ofPhycology 1999

Co-convenor for the 2000 meeting of the Northeast Algal Symposium

Selected Awards

1997 Elected to Sigma Xi

1994 Fellow of the School of Graduate Studies

Selected Publications

Vis, M.L. 1999. The applicability of inter- Simple Sequence repeats (inter- SSR) to distinguish individuals of Batrachospermum boryanum (Batrachospermales, Rhodophyta). Phycologia 38:

70-73. Vis, M.L. & Sheath, R.G. 1999. Systematics oϊSirodotia species (Batrachospermales, Rhodophyta) in North America based on molecular data. Phycologia 38: 261-266. Vis, M.L., Saunders, G.W., Sheath, R.G., Dunse, K. & Entwisle, TJ. 1998. Phylogeny of the

Batrachospermales (Rhodophyta) as infered from rbcL and 18S ribosomal RNA gene DNA sequences. Journal ofPhycology 34:341-350. Morgan L. Vis, Ph.D, (page 2 of resume)

Vis, M.L. & Sheath, R.G. 1998. A molecular and morphological investigation of the relationship between Batrachospermum spermatoinvolucrum and B. gelatinosum (Batrachospermales,

Rhodophyta). European Journal ofPhycology 33: 231-240. Vis, M.L., Carr, S.M., Bowring, R., & Davidson, W. 1997. Greenland halibut (Reinhardtius hippoglossoides) in the North Atlantic are genetically homogenous. Canandian Journal of

Fisheries and Aquatic Sciences 54: 1813-1821. Vis, M.L. & Sheath, R.G. 1997. Biogeography of Batrachospermum gelatinosum

(Batrachospermales, Rhodophyta) in North America based on molecular and morphological data. Journal ofPhycology 33: 520-526. Vis, M.L. & Sheath, R.G. 1996. Distribution and systematics of Batrachospermum

(Batrachospermales, Rhodophyta) in North America. 9. Section Batrachospermum: Descriptions of five new species. Phycologia 35: 124-34. Vis, M.L., Sheath, R.G. & Cole, K.M. 1996. Distribution and systematics of Batrachospermum

(Batrachospermales, Rhodophyta) in North America. 8b. Section Batrachospermum: excluding

B. gelatinosum. European Journal ofPhycology 31: 189-199. Vis, M.L., Sheath, R.G. & Cole, K.M. 1996. Distribution and systematics of Batrachospermum

(Batrachospermales, Rhodophyta) in North America. 8a. Section Batrachospermum: B. gelatinosum. European Journal ofPhycology 31 :31-40. Vis, M.L., Entwisle, T.E. & Sheath, R.G. 1995. Morphometric analysis of Batrachospermum

Section Batrachospermum type specimens. European Journal ofPhycology 30: 35-55. Vis, M.L., Sheath, R.G., Hambrook, J.A. and Cole, K.M. 1994. Stream macroalgae of the Hawaiian islands: a preliminary study. Pacific Science 48: 175-87. Vis, M.L. & Sheath, R.G. 1993. Distribution and systematics of Chroodactylon and Kylinella from

North American streams. Japanese Journal ofPhycology 41 : 231-5. Vis, M.L_; & Sheath, R.G. 1992. Systematics of the freshwater red algal family Lemaneaceae in

North America. Phycologia 31 : 164-79. Vis, M.L., Sheath, R.G. & Cole, K.M. 1992. Systematics of the freshwater red algal family

Compsopogonaceae in North America. Phycologia 31: 564-75. Vis, M.L., Carlson, T.A. & Sheath, R.G. 1990. The phenology oϊLemaneafucina (Rhodophyta) in a

Rhode Island River, USA. Hydrobiologia 222: 141-46.

Recent Research Projects

$50,000, 9/1/99 through 8/31/00 Greenhouse Gas Mitigation, funded through the Ohio University 1804 Fund, $28,000, 9/1/99. A Phylogeographv of a freshwater red alga. Batrachospermum helmentosum. funded through the

Ohio University Research Committee, $7,000, 1/1/99 through 8/31/99. An Automated DNA Sequencing Facility for Increased Research Productivity, funded through the

Ohio University 1804 Fund, $86,050 9/1/98. All Taxa Survey of Deep Woods. Hocking County. OH. Ohio Biological Survey, $2,500, 7/1/98 through 6/30/99. Aquatic Flora of the Hocking River Drainage Basin. Ohio Biological Survey, $500, 4/1/97 through

3/31/98. The Environment for the Next Millennium. Ohio Board of Regents Eisenhower Professional

Development Program, $45,070, 6/1/98 (K. Albertson PI) Keith E. Cooksey, Ph.D

Research Professor, Department of Microbiology, Letters and Science Montana State University-Bozeman Email: umbkc@montana.edu PO Box 173520 Phone: (406) 994 6136

Bozeman, MT 59717-3520 Fax: (406) 994-4926

Research Interest

Microbial physiology of phototrophs, Funded: Marine Microbial Biofilms, US Office of Naval Research 1996-1999; Thermophilic cyanobacteria and diatoms, NSF, 1999-2001.

Education

1959 B.Sc, Ph.D., Biochemistry, University of Birmingham, England.

Professional Experience

1985-present Research Professor of Microbiology Dept. of Microbiology, MSU

1993 -present Director, Montana Defense EPSCOR DEPSCOR

1995-1998 Deputy and Acting Head Dept of Microbiology, MSU

1991 External Examiner U. of Gothenberg, Sweden

1989-1991 Liaison Scientist U.S. Office of Naval Research

London, England

1983-1985 Co-Director, and Director of Operations MSU Institute for Biological and

Chemical Process Analysis

1975- 1983 Professor, Biology and Living Resources RSMAS, University of Miami

1978-80 Member, University Research Council University of Miami

1977- 1980 Chair, NIH Biomedical Research Committee University of Miami

1964-1968 Senior Scientist "Shell" Biosciences,

Sittingbourne, England

1962- 1964 Assistant Research Bacteriologist Dept of Bacteriology

U. California, Berkeley

1960- 1962 Assistant Research Biochemist Dept. of Biochemistry

U. California, San Francisco

1959- 1960 Post Doctoral Fellow National Research Council of

Canada

Professional Activities

Biofouling, Editorial Board, 1988-1996. [Algal adhesion]

Colloids & Surfaces B: Biointerfaces, Editorial Board, 1992-present. [microbial adhesion]

Biofilm Bulletin, Founding Editor

Applied and Environmental Microbiology, Editorial board 1993-2002 [All attached organisms, phototrophs] Reviewer: J. Phycology, Aquatic Microbial Ecology, Limnology and Oceanography, and Microbial

Ecology.

Selected Awards

1991 Federal Civil Service Outstanding Performance of Official Duties Award, Liaison Scientist for Europe and the Middle East, US Office of Naval Research Keith E. Cooksey, Ph.D, (page 2 of resume) Selected Publications [from 64 total and 84 published abstracts]

With G. Geesey and B. Wigglesworth-Cooksey, Influence of Calcium and Other Cations on Surface

Adhesion of Bacteria and Diatoms: A Review. Biofouling, in press With Wigglesworth - Cooksey, B., van der Mei, CH. and Busscher H. The Influence of Surface

Chemistry on the Control of Cellular Behavior : Studies with a Marine Diatom. J. Colloids and

Interface Science : Biosurfaces. 15 : 71-79(1999) Molecular Approaches to the Study of the Ocean, (1998). K.E. Cooksey [Ed]Kluwer/Chapman and

Hall, Editor, pp 549 With B. Wigglesworth-Cooksey. A Computer-Based System for Biocide Screening. Biofouling 10 :

225-237(1998) With B. Wigglesworth-Cooksey. Adhesion of Bacteria and Diatoms: A Review: Aquatic Microbial

Ecology 9:87-96 (1995) With B. Wigglesworth-Cooksey. The Design of Antifouling Surfaces: Background and Some

Approaches, in"Biofilms: Science and Technology", L.Melo et al (eds.) Kluwer Academic

Publishers, Dordrecht, The Netherlands, pp. 677-681, (1992) Extracellular Polymers in Biofilms, Ibid. With B. Wigglesworth-Cooksey. Can diatoms sense surfaces: State of our knowledge. Biofouling 5:

227-238 (1992) With D.R. Korber, J.R. Lawrence, B. Cooksey, and D.E. Caldwell. Computer Image Analysis of

Diatom Chemotaxis. Binary. 1:155-168, (1989) With B. Cooksey. The use of specific drugs in the dissection of the adhesive process in diatoms:

AIBS-ONR Symposium Volume, International Conference on Marine Biodeteriation, Goa,

India, 1986. Oxford and I.B.H., New Delhi, pp.337-34, (1988) With B. Cooksey. Chemosensing in diatoms of the genus Amphora, J.Cell Sci. 91:523-529, (1988) With S.D. Smith, B.R. McLeod, and A. Liboff. Calcium cyclotron resonance and diatom motility: a test of the cyclotron resonance theory. J. Bioelectromagnetics. 8: 215-217, (1987) With Cooksey, B. Cooksey. Studies on chemosensing in a tropical marine fouling diatom. AIBS- ONR International Conference on Marine Biodeteriation. Goa, India. Symposium volume,

Oxford and IBH, New Delhi, pp 325-335. (1986) With B. Cooksey. The adhesion of fouling diatoms to surfaces: Some biochemistry. AIBS

Symposium Volume. Ed: LN. Evans. Elsevier Press. Pp. 41-53 (1986) With others. Activity of Surfaces: Group Report. In: Microbial Adhesion and Aggregation. K.C.

Marshall (Ed.) Springer Verlag, Berlin, pp. 203-221, (1985) With D.R. Webster and R.W. Rubin. An investigation of the involvement of cytoskeletal structures and secretion in gliding motility of the marine diatom, Amphora coffeaeformis. Cell Motility

5:103-122,(1985). Cooksey, K.E., B. Cooksey, CM. Miller, J.H.Paul, R.W. Rubin and D. Webster. The attachment of microfouling diatoms. In: Marine Biodeteriation, An Interdisciplinary Study. (Eds.., J.D.

Costlow, R.C. Tipper). Naval Institute Press, pp. 167-171. (1983) With M.H. Turakkhia and W.G. Characklis. Influence of a calcium-specified chelant on biofilm removal. Appl.. Environ. Microbiol. 46: 1246-1238 (1983) With W.G. Characklis. Biofilms and microbial fouling. Adv. Appl.. Microbiol. 29: 93-138 (1983). With B. Cooksey, CA. Miller, and J.H. Paul. Attachment of diatoms to surfaces: field and laboratory studies. In: "Microbial Adhesion to Surfaces", pp. 526-528, (1981). A requirement for calcium in the adhesion of a fouling diatom to glass. Appl.. Env. Microbiol., 41:

1378-1382. (1981) Keith E. Cooksey, Ph.D, (page 3 of resume)

With B. Cooksey. Calcium is required for motility in the diatom Amphora coffeaeformis. Plant

Physiol.., 65:1229-131, (1980). With B. Cooksey. Growth influencing substances in sediment extracts from a subtropical wetland.

Investigations using a diatom bioassay. J. Phycol., 14: 347-352 (1978) With B. Cooksey. The influence of calcium on the morphology oϊ Phaeodactylum tricornutum.

J.Phycol., 10: 89-90. (1975)

Jeffrey D. Muhs

Email: muhsjd@ornl.gov Group Leader, Photonics & Fiber Optics Phone: (423) 574-9328 www.ornl.gov Director, Hybrid Lighting Partnership Fax: (423) 576-09279

Oak Ridge National Laboratory P.O. Box 2008, Oak Ridge, TN 37831-7280

Research Interests

The development of energy-efficient and cost-effective uses of photonics and fiber optics, particularly in hybrid solar lighting systems and sensor applications. Specific interests include optical design, modeling, and prototyping of lighting-based solar collectors, fiber-optic light distribution systems, and remote source electric lighting. Other research interests include silicone rubber fiber optic sensors, remote laser and electro-optic diagnostic systems, and fiber optic weigh- in-motion systems.

Education

1986 B.S. University of Houston (Electro-Optical Sciences; GPA - 3.9/4.0)

1984 A.S. Vincennes University (Laser Electro-Optics; GPA - 4.0/4.0)

Professional Experience

1997-current Group Leader, Photonics & Fiber Optics Oak Ridge National Laboratory

1997-current Private Optical Fiber Design Consultant Part-time (various clients)

1988- 1997 Research Scientist Oak Ridge National Laboratory

1993 Adjunct Professor (Fundamentals of Fiber Optics) Pellissippi State Comm. Coll.

1986-1988 Product Development Amphenol Fiber Optic Products

Professional Memberships

American Solar Energy Society (ASES)

Optical Society of America (OS A)

Society of Photo-Optical Instrumentation Engineers (SPIE)

Selected Awards

1998 Recipient of Industry Week Magazine's "Top 25 Technologies of the Year: Hybrid

Lighting Systems" 1997 ORNL "Scientist/Engineer of the Year" for pioneering research in fiber optics and fiber optic sensors (selected from over 2000 R&D staff members) 1989-1998 Recipient of over a dozen Technology Achievement Awards; Lockheed Martin

Energy Research Corp. 1989-1997 Recipient of 3 Special R&D Achievement Awards; ORNL - Engineering Tech.

Division

Patents (8)

5,627,934: Issued 5/6/97, "NOVEL MULTICORE OPTICAL FIBER"

5,568,582: Issued 10/22/96, "SMART MATERIAL FIBER OPTIC CONNECTING METHOD" Jeffrey D. Muhs Page 2

Patents (Cont.)

5,381,492: Issued 1/10/95, "FIBER OPTIC VIBRATION SENSOR"

5,374,821: Issued 12/20/94, "OPTICAL FIBER SENSORS AND METHOD FOR DETECTING AND MEASURING EVENTS OCCURRING IN ELASTIC MATERIALS"

5,701,370: Issued 12/23/97, "OPTICAL FIBER SENSORS FOR MONITORING JOINT ARTICULATION AND CHEST EXPANSION OF A HUMAN BODY"

5,639,749: Issued 5/2/97, "FIBER OPTIC VEHICLE IDENTIFICATION SENSOR SYSTEM"

5,959,259: Issued 9/28/99, "SYSTEM AND METHOD FOR ACCURATELY WEIGHING AND CHARACTERIZING MOVING VEHICLES"

5,998,741: Issued 12/7/99, "SYSTEM AND METHODS FOR ACCURATELY WEIGHING AND CHARACTERIZING MOVING VEHICLES"

5,260,520: Issued 11/9/93, "FIBER OPTIC VEHICLE IDENTIFICATION SENSOR SYSTEM"

Publications

"Hybrid Lighting Partnership - FY 2000 Strategic Business Plan", Muhs, J.D., issued by ORNL to the U.S. Department of Energy, Dec. 1999 "Fiber Optic Holography with Fringe Stabilization and Tunable Object and Reference Beam

Intensities," Muhs, J. D. et. al. Optical Fibers in Medicine II, S.P.I.E. Vol. 713, pp. 105-112,

1986 "Multiple Beam Fiber Optic Holography with Fringe Stabilization," Muhs, J. D. et. al. Fiber Optic and Laser Sensors V, S.P.I.E. Vol. 838, pp. 353-359, 1987 "Coupling Limitations of Asymmetric Multimode Couplers," Muhs, J. D.; Components for Fiber

Optic Applications II, S.P.I.E. Vol. 839, pp. 31-37, 1987 "Fiber Optic Holography Employing Multiple Beam Fringe Stabilization and Object/Reference

Beam Intensity Variability," Muhs, J. D.; Applied Optics, Vol. 27, No. 17, pp. 3723-3727, 1988 "Fiber Optic Sensors for Composite Cure Analysis and Lifetime Nondestructive Analysis," Muhs. J.

D. et. al., ICALEO 89, Orlando, FL, 1989 "Multiplexed High and Low Sensitivity Fiber Optic Strain/Temperature Sensor," Fiber Optic and

Laser Sensors VII, S.P.I.E. Vol. ??? pp. ???, 1989 "Fiber-Optic Sensors for Composite Cure Analysis and Lifetime Nondestructive Evaluation," Muhs,

J.D.; Int. Congress on Application of Laser and Electro-optics, Orlando, FL, Oct. 16-20, 1989 "Multiplexed, High- and Low-Sensitivity Fiber-Optic Strain/Temperature Sensor," Muhs, J.D., Proc. 7th Soc. Photo-Opt. Instrum. Eng. Meet, on Fiber Optic and Laser Sensors,

Boston, MA Oct. 1 5-20,1989, SPIE, 1990 ORNL/ATD-26; "Material Evaluation of Optical Fibers and Payout Bobbins - An Overview,"

Adams, D.J.; Muhs, J. D. et. al.. ORNL/ATD-31; "Engine Testing of Thermographic Phosphors. Part 1: Pratt & Whitney Fixed- Blade Test. Part 2: Virginia Polytechnic Institute Turbine-Blade Test," Tobin, K.W.; Muhs, J.

D. et. al. "Single Port, Two Color Particle Sensing System for Characterizing Wet Stearn,"; Simpson, M.L;

Muhs, J. D., et. al.; SENSORS Expo 90, Chicago, Sept. 11-13,1990 "Single Port, Two Color Particle Sensing System for Characterizing Wet Steam," Simpson, M .;

Muhs, J. D. et. al. pp. 107c-2-9, Proc. SENSORS Expo 90, Chicago, IL Sept. 11- 1 3,1990 ORNL/ATD-43; "Dynamic High-Temperature-Phosphor Thermometry," Tobin, K.W., Jr.; Muhs, J.

D. et. al. ORNL/ATD-42; "Composite Heat Damage Spectroscopic Analysis - Part 1. Mechanical Testing of

IM6/3501-6 Laminates, Part 2. Laser-Pumped Fluorescence Spectroscopic Studies on

IM6/3501-6 Laminates, Part 3. Diffuse Reflectance Infrared Fourier etc.," Janke, C.J.; Muhs, J.

D. et. al. "Fiber-Sensor Design for Turbine Engines," Tobin, K.W., Jr. and Muhs, J. D. et. al@ Workshop on

Fiber-Optic, Sensor-Based Smart Materials and Structures, Virginia Polytechnic Inst. and State

Univ., Blacksburg, VA Apr. 3-4, 1991 "Results of a Portable, Fiber-Optic, Weigh-in-Motion System," Muhs, J.D.; Fiber Optics and Laser

Sensors VII, S.P.I.E. Vol. 1584, pp. 374-386, 1991 "An Overview of Silicon-Rubber, Fiber-Optic Sensors and Their Applications," Muhs, J.D.;

Distributed and Multimplexed Fiber Optic Sensors, S.P.I.E. Vol. 1586, pp. 107- 116, 1991. "Algorithm for a Novel Fiber-Optic, Weigh-in-Motion Sensor System,"; Tobin, K.W., Jr. and Muhs, J. D. et. al. Soc. Photo-Opt. Instrum. Eng. Symp., OE/FIBERS'91, Boston,

Sept.3-6, 1991 "Results of a Portable, Fiber-Optic, Weigh-in-Motion System," Muhs, J.D.; MMES K/ITP-455,

1991. "Algorithm for a Novel Fiber-Optic Weigh-in-Motion Sensor System," Tobin, K.W., Jr.; Muhs, J.

D., et. al. Proc.Opto-Electronies/FIBERS, OE/FIBERS'91, Boston, N4A Sept. 3-6,1991 (1991) ORNL/M- 1 693; "Development and Testing of Fast-Response Fiber-Optic Pressure Sensors,"

Smith, D.B., Muhs, J. D. et. al. ORNL/M- 1692; "Operation, Maintenance, and Safety Manual for a Shock Tube Pressure

Calibration Facility," Smith, D.B., Muhs, J. D. et al "Silicone Rubber Fiber Optic Sensors: A Novel Optical Fiber, Silicone Rubber, Opens New

Avenues for a Variety of Sensors," Muhs, J.D., Photonics Spectra. July 1992; Page numbers unknown "Applications of Silicone-Rubber Fiber-Optic Sensors," in Proceeding of Distributed and

Multiplexed Fiber optic Sensors," Muhs, J. D. et. al. (SPIE, Bellingham, Washington, 1991), p.

107. "Fiber Optic Sensor Integration and Multiplexing Techniques for Smart Skin Applications,"

Proceedings from the ADPA/AiAA ASME/SPIE Conference on Active Materials and Adaptive

Structures, pp. 895-899, 1992. "Overview of Fiber Optic Weigh-in-Motion Technology," Muhs, J. D., Proceedings from the

National Traffic Data Acquisition Conference, pp. 230-240. Oct. 1992 "Embedded Silicone Rubber Fiber Optic Sensors," Muhs, J. D., Smart Structures, S.P.I.E. Vol.

1918, pp. 223 -231, 1993 "Fiber Optic Sensors: Providing Cost-Effective Solutions to Industry Needs," Muhs, J. D. APTICS

Overview Short Course Notes, S P.I.E. OE/Aerospace Sensing Symposium, 1994 "Intelligent Material Systems and Structures," Muhs, J. D., ASM International, Oak Ridge Chapter,

Educational Symposium, 1993 "Fiber Optic Sensors: Providing Cost-Effective Solution to Industry Needs," Muhs, J. D. S.P.I.E.

Symposium, Orlando, FL. 1994 "Results of Advanced In-Road and On-Board Sensors for IVHS-CVO Applications," Muhs, J. D.

S.P.I.E. Proceedings Vol. 2344, Boston, NIA. 1994

Ongoing and Recent Research Projects

Hybrid Lighting Systems R&D. U.S. Department of Energy, FY 1999 - $214,000, 4/1/99 through

12/31/99. FY 2000 tentative commitment - -$750,000. Development of Ultra-Low Attenuation Large-Core Optical Fibers for Light Distribution Systems.

$800,000, U.S. Department of Energy and Fiber Optic Technologies, Inc., 9/1/99 - 9/1/2001 Development of Fiber Optic Wei h-in-Motion Systems. $2,500,000, Air Mobility Battle Lab, Air

Force PRAM Office, U.S. Department of Energy, FHWA, TN Department of Transportation,

Defense Nuclear Agency, and others, 9/1/92 - 9/1/99. Development of Low-Cost OTDR-Based Fiber Optic Security Seals. $750,000, U.S. Department of

Energy, 9/1/95 - 10/1/99 Development of Silicone Rubber Fiber Optics Sensors. $200,000, Several sponsors including industry and gov , 9/1/90 - 7/1/96.

Subtask 1.3 Preliminary Decision Matrix: Growth Surface Subsystem

Will be determined with experimental research

Will be determined with analytical/theoretical research

Note: Alternatives are evaluated based on each criterion and are assigned relative values, with 100% representing the best alternative relative to a particular criterion

Growth surface material and composition has an impact on costs and functions and will be evaluated as part of each alternative

Measure, or focus on minimum flow area as an indicator of flow obstruction. Subtask 1.5 Preliminary Decision Matrix: Harvesting Subsystem

determined with experimental research

determined with analytical/theoretical research

*: Depends on the particular end use selected, but can be estimated in general or for an assumed end use

Note: Alternatives will become more specific as information is gathered in phase 1 REFERENCES

http://www.eia.doe.gov/

Allen M.M., and Stanier R.Y. "Selective isolation of blue-green algae on plates". J.Gen

Microbiol. Vol.51 pp.203-209. Aresta, M., Tommasi, I., "Carbon Dioxide Utilisation in the Chemical Industry," Energy

Conversion and Management, Vol.38 (Supplemental Issue), 1997, pp. 373-378. Bacastow R., and Dewey, R., "Effectiveness of CO₂ Sequestration in the Post Industrial Ocean",

Energy Conversion and Management, Vol. 37(6-8), 1996, pp. 1079-1086. Benemann J., "CO₂ Mitigation with Microalgae Systems", Energy Conversion and Management,

Vol.38 (Supplemental Issue), 1997, pp. 475-479. Brock, T.D., Thermophilic Microorganisms and Life at High Temperatures, Springer- Verlag,

New York, 1978. Castenholz R.W. "Culturing methods for cyanobacteria". Methods Enzymol. Vol 167 (1988) pp.

68-93. Cooksey, K.E., "Requirement of calcium in adhesion of a fouling diatom to glass", Appl.Env.

MicrobiolVol 41 (1981) pp. 1378-1382. Cooksey K.E. and Cooksey B. "Adhesion of fouling diatoms to surfaces : Some biochemistry" In

Algal Biofouling. Eds Evans LN and Hoagland K.D.(1986), pp. 41-53. Cooksey K.E. and Wigglesworth-Cooksey B., "Adhesion of bacteria and diatoms to surfaces in the sea : a review". Aquatic Microbial Ecol. Vol 9 (1995) pp.87-96. Fairchild E.,and Sheridan R.P. "A physiological investigation of the hot spring diatom,

Achnanthes exigua",J. Phycol. Vol 10, (1974) pp. 1-4. Ferris MJ. and Hirsch, CF."Method of isolation and purification of cyanobacteria".4pρ/.EHv

MicrobiolVol 57(1991) pp. 1448-1452. Fisher, A., "Economic Aspects of Algae as a Potential Fuel," Solar Energy Research, 1961,

University of Wisconsin Press, pp. 185-189. Geesey G.G, Wigglesworth-Cooksey, B. and Cooksey , K.E. "Influence of calcium and other cations on surface adhesion of bacteria and diatoms : A review." Biofouling (1999) in press. Hanagata, Ν., Takeuchi, T., Fukuju, Y., Barnes, D., Karube, I., "Tolerance of Microalgae to

High CO₂ and High Temperature," Phytochemistry, Vol.31(10), 1992, pp. 3345-3348. Hirata, S., Hayashitani, M., Taya, M., and Tone, S. "Carbon Dioxide Fixation in Batch Culture oϊChlorella sp. Using a Photobioreactor with a Sunlight Collection Device, "Journal of

Fermentation and Bioengineering, Vol.81, 1996, pp.470-472. Kajiwara, S., Yamada, H., Ohkuni, Ν., and Ohtaguchi, K., "Design of the Bioreactor for Carbon

Dioxide Fixation by Synechococcus PCC7942," Energy Conversion and Management,

Vol.38 (Supplemental Issue), 1997, pp. 529-532. Kaplan, A., Schwarz, R., Lieman-Hurwitz, J., and Reinhold, L., "Physiological and Molecular

Aspects of the inorganic Carbon-Concentrating Mechanism in Cyanobacteria," Plant

Physiology, Vol. 97, 1997, pp. 851-855. Kondo J., T Inui, T., and Wasa, K. (Editors), Proceedings of the Second International

Conference on Carbon Dioxide Removal, Oxford: Pergamon Press, 1995. Maeda, K., Owada, M., Kimura, Ν., Omata, K., Karube, I., "CO₂ Fixation from the Flue Gas on

Coal-Fired Thermal Power Plant by Microalage," Energy Conversion and Management,

Vol.36(6-9), 1995, pp. 717-720. Matsumoto, H., Shioji, N., Hamasaki, A., Ikuta, Y., Fukuda, Y., Sato, M., Endo, N., and

Tsukamoto, T., "Carbon Dioxide Fixation by Microalgae Photosynthesis Using Actual Flue

Gas Discharged from a Boiler," Applied Biochemistry and Biotechnology, Vol.51-52, 1995, pp. 681-692. Miyairi, S. "CO₂ Assimilation in a Thermophilic Cyanobacterium," Energy Conversion and

Management, Vol.36(6-9), 1995, pp. 763-766. Nagase, H., Eguchi, K., Yoshihara, K., Hirata, K., Miyamoto, K., "Improvement of Microalgal

NOx Removal in Bubble Column and Airlift Reactors," Journal of Fermentation and

Bioengineering, Vol. 86(4), 1998, pp.421-423. Ohtaguchi, K., Kajiwara, S., Mustaqim, D., Takahashi, N., "Cyanobacterial Bioconversion of

Carbon Dioxide for Fuel Productions," Energy Conversion and Management, Vol.38

(Supplemental Issue), 1997, pp. 523-528. Rippka R. "Isolation and purification of cyanobacteria". Methods Enzymol.V ol. 167 (1988) pp.

3-27. Vaara, T., Vaara,M., and Niemela, S. "Two improved methods for obtaining axenic cultures of cyanobacteria". Appl. Env Microbiol. Vol.38 pp. 1011-1014. Wigglesworth-Cooksey, B.van der Mei, H., Busscher H.J. and Cooksey K.E. "The influence of surface chemistry on the control of cellular behavior : Studies with a marine diatom. Colloids

Surfaces : Biosurfaces (1999) Vol 15 pp. 71-79. Yoshihara, K., Nagase, H., Eguchi, K., Hirata, K., Miyamoto, K., "Biological Elimination of

Nitric Oxide and Carbon Dioxide from Flue Gas by Marine Microalga NOA-113 Cultivated in a Long Tubular Photobioreactor," Journal of Fermentation and Bioengineering, Vol.

82(4), 1996, pp.351-354.

CHAPTER 4

EXPERIMENTAL RESULTS

4.1 Experimental overview

Different sets of experiments were performed on Nostoc 86-3 microalgae species to determine the algae growth performance against flue gas containing approximately 8.0% CO₂, temperature ranging from 150°F to 120°F, and light intensity.

Experimental evidence described here examines the effect of simulated flue gas on culture growth and biomass accumulation as a measure of carbon assimilation. First, two experiments were conducted to quantify temperature's effect on Nostoc 86-3 growth under fixed conditions of CO₂ concentration and light intensity. Growth performance characteristics were studied over a fixed temperature with varied light intensity. Experimental results are presented to quantify the "healthiness" and growth of cyanobacteria samples. Experimental measures for healthiness and growth of algae samples quantifying the effect of temperature are viewed in terms of: a) visible change in color of cyanobacteria samples b) cellular structure and cellular density c) difference in the amount of light intensity supplied to that passing through the screens over the course of experiment d) difference in sum of dry weight of screens and inline filter cartridge against the amount of algae sample loaded.

4.2 Experimental work

First two of experiments were carried out to study the effect of temperature (150°F as found in flue gas emission from power plants) and the rest were conducted to study the growth characteristic for a fixed temperature. ' 4.2.1 High temperature experimentation

Two sets of experiments were attempted to study the ability of microalgae species to sustain temperature of 150°F. First of these experiments was carried out for 150 hours with experimental containment illuminated by a bank of 60W cool- white fluorescent light of intensity 33μmol-s^"1nϊ² measured over the top cover of experimental containment. The simulated flue gas contained 3.4% CO₂, 14.8% O₂, 650ppm CO, 2.28 slpm natural gas and 22.95 slpm air.

Wet weights of the screens before and after firing are expressed in Table 4.1. Table 4.1 Difference in wet weight of screens for trial at 150°F (Experiment I).

Before trial After trial Difference

Screen #1 204.7gm 168.1gm -36.6gm

Screen #2 224.6gm 192.3gm -32.3gm

Screen #3 240.7gm 201.0gm -39.7gm

Screen #4 242.3gm 198.8gm -43.5gm

It was observed from this experiment that cyanobacteria samples were green colored until approximately 100 hours and later changed their color from dark green to brown. The density of cyanobacteria samples over the screens was drastically reduced, as is evident from the difference in the weight of the screens. It is important to note that there was no significant rate of growth observed indicated from microscopic analysis. Microscopic images of the algae samples were not healthy enough because of broken filaments, as presented in Figure 4.1.

Figure 4.1a Original microalgae sample under 60x magmfication.

Screen #1 Screen #2

Screen #3 Screen #4

Figure 4.1b Treated microalgae samples from four screens under 60x magmfication.

Figure 4.1 Microscopic images of algae samples, original and those from four screens, before and after treating at 150°F. Since the instantaneous carbon delivery rate did not appear to be limiting, it was other key parameters, such as amount of cyanobacteria species loaded over the screens, period of dosing and the light intensity were considered for study. Further these results indicated that the cyanobacteria were not able to handle either the high temperature, the thermal shock resulting from the transition from room temperature, or combination of both.

The next experiment was conducted at the same conditions of 150°F under the light intensity 33μmol-s^{" 2} measured at the top cover of experimental containment. However, for this experiment, the algae culture was preheated at 110°F in sampling containment. Also, for this experiment, a more formal methodology of deteirnining the mass of cyanobacteria loaded on the screens was adopted. As previously described, densities of algal solutions were measured out used to calculate the mass loaded on the suspension screens. Table 4.2 gives the weight analysis of five numbers of 25ml samples drawn through paper filter elements for calculation of weight of algae used for testing. Table 4.2 Dry weight analysis for test samplesfor Experiment II.

Filter Volume Weight before Weight after Difference number filtering sample filtering sample

#1 25ml 1.8036gm 1.8219gm 0.0183gm

#2 25ml 1.7522gm 1.7744gm 0.0222gm

#3 25ml 1.8213gm 1.8450gm 0.0237gm

#4 25ml 1.7275gm 1.7502gm 0.0227gm

#5 25ml 1.7050gm 1.7283gm 0.0233gm

Total = 125ml 0.1102gm

1088ml of algal slution containing cyanobacetria was added each screen, giving total of 4352ml of algae solution used in the test. The effective amount of algae species used in the experiment was calculated as: 0.1102 . . _Q„ * 4352 = 3.837 gm

125

With CO₂ and O₂ concentration parameters constant from Experiment I, the cyanobacteria species started showing change in color from green to brown after 90 hours with reduced effective algae density over the screens. Microscopic analysis of the samples revealed similar images as from experiment I. Table 4.3 presents the dry weights of screens before and after firing for experiment II fired at 150°F. The screens were dried to remove moisture at 150°F for 6 hours each time. It was observed from the weight analysis of the screens that there was no effective algae growth over the screens.

Table 4.3 Difference in dry weight of screens for trial at 150°F (Experiment II).

Before trial After trial Difference

Screen #1 151.1gm 151.2gm O.lgm

Screen #2 149.8gm 149.5gm -0.3gm

Screen #3 150.5gm 150.0gm -0.5gm

Screen #4 150.3gm 150.8gm 0.5gm

It was concluded from experiments I and II that Nostoc 86-3 are not able to handle high temperatures of the order of 150°F when exposed under illumination of 33μmol-s^~1m^"2. This leads to the next series of experiments at lower temperature. 4.2.2 Lower temperature study

The next set of experiments were carried out at temperatures lower than 150°F with each set of experiment quantified for specific weight of algae sample used for test. In addition to changing experimental parameter, the cyanobacteria were preheated in their incubation container to minimize thermal shock upon transfer to the bioreactor. Experiment III was carried out at 130°F under an illuminance of SSjimol-s^{' 2} measured at the top cover of experimental the containment for 120 hours. The amount of algae loaded over each screen was 2000ml giving total loading of 8000ml in reactor. Table 4.4 gives the weight analysis of five numbers of 25ml samples drawn through paper filters for calculation of weight of algae used for testing.

Table 4.4 Dry weight analysis for test samples for Experiment III.

#1 25ml 1.6941gm 1.7052gm 0.01 llgm

#2 25ml 1.7275gm 1.7398gm 0.0123gm

#3 25ml 1.8165gm 1.8259gm 0.0094gm

#4 25ml 1.7423gm 1.7514gm 0.009 lgm

#5 25ml 1.7347gm 1.7438gm 0.0092gm

Total = 125ml 0.051 lgm

For 8000ml, the effective amount of algae loaded was 3.270gm. The simulated flue gas at 130°F contained 6.3% O₂, 7.9% CO₂, 1155ρρm CO, 2.56 slpm natural gas and 22.95 slpm ofair. Difference in dry weight of four numbers of screens and inline filter was calculated and the effective weight was compared with the weight of algae samples loaded. Table 4.5 tabulates the measured dry and differential weights.

Table 4.5 Weight analysis of screens and filter for Experiment III.

Before trial After trial Difference

Screen #1 157.2gm 157.7gm 0.5gm

Screen #2 138.9gm 139.1gm 0.2gm

Screen #3 143.8gm 144.1gm 0.3gm

Screen #4 152.3gm 152.5gm 0.2gm

Filter 168.0gm 168.2gm 0.2gm

Total = 1.4gm

It was again observed that total differential weight of screens and filter was less than the loaded weight of algae samples over the screens before experiment. It is evident that there was no significant growth in Nostoc 86-3. The microalgae species showed change in color form green to brown after 96 hours again with reduced effective algae density over the screens.

Because of poor growth performance at 130°F, the next experiment (Experiment IV) was carried out at 120°F under an illuminance of SSμmol-s^m^"2 measured at the top cover of experimental containment. The amount of algae sample loaded over each screen was again 2000ml giving total loading of 8000ml in reactor. Table 4.6 gives the weight analysis of five 25ml samples drawn through paper filters for calculation of weight of algae used for testing.

Table 4.6 Dry weight analysis for test samples for Experiment IV.

#1 25ml 1.7249gm 1.7538gm 0.0289gm

#2 25ml 1.6523gm 1.6796gm 0.0273gm

#3 25ml 1.7137gm 1.7422gm 0.0285gm

#4 25ml 1.7773gm 1.8068gm 0.0295gm

#5 25ml 1.6787gm 1.7086gm 0.0299gm

Total = 125ml 0.1441gm

The effective amount of algae loaded was 9.22gm. The simulated flue gas composition at 120°F was identical to one for Experiment III. After the experiment was ran for 120 hours, the growth screens and filter were removed and dried. Table 4.7 tabulates the measured dry and differential weights.

Table 4.7 Weight analysis of screens and filter for Experiment IV.

Before trial After trial Difference

Screen #1 151.3gm 154.6gm 3.3gm

Screen #2 151. lgm 151.6gm 0.3gm

Screen #3 156.2gm 156.4gm 0.2gm

Screen #4 154.9gm 156.3gm i 1.4gm

Filter 154.3 gm 155.7 gm 1.4 gm

Total = 6.6gm An analysis was carried out over the light intensity that was captured by Nostoc 86-3 over the screens. Table 4.8 presents the intensity level available inside the containment against supplied.

Table 4.8 Light intensity measurement against distance inside the containment.

Outside Inside Light intensity containment containment mV μmol-s^{' 2}

15" 89.2 33.43

16" 69.8 26.16

20" 51.8 19.41

24" 11.3 4.23 base 4.8 1.79 base 3.2 1.19

(Light source = 60watts cool white fluorescent lamps)

It can be observed from Table 4.8 that the light intensity passing into the containment was reduced by 96% as against the one available over the top cover of the containment.

The test results infer that the differential weight of algae samples after trial were less than he loaded weight and the algae species showed change in color from green to brown after 110 hours. However, the microscopic analysis of the algae samples taken from the screens revealed notably different results. Although not conclusive, Experiment IV indicated that 120°F was a more suitable temperature for growth of Nostoc 86-3. However, it was clear other parameters had to be adjusted to promote a positive increase in biomass. The samples were found to be healthy with cells still forming chains although

the average cell size was }_ of the original culture.

With the results from Experiment IV in mind, Experiment V was carried out at same temperature of 120°F but with higher light intensity and greater algae loading. Experiment V was carried out at 120°F with higher illuminance of SSu ol-s^m^"2 measured at the base of the experimental containment, after the growth samples were loaded over the screens. The amount of cyanobacteria over each screen was 3000ml giving total loading of 12000ml in reactor. Table 4.9 gives the weight analysis of the 25ml samples drawn through paper filters for calculation of cyanobacteria mass. Table 4.9 Dry weight analysis for test samples for Experiment V.

#1 25ml 1.7858gm 1.7916gm 0.0058gm

#2 25ml 1.7568gm 1.7623gm 0.0055gm

#3 25ml 1.6728gm 1.6773gm 0.0045gm

#4 25ml 1.7447gm 1.7502gm 0.0055gm

#5 25ml 1.8452gm 1.8509gm 0.0058gm

Total = 125ml 0.0271gm

The effective amount of cyanobacteria loaded was 2.602gm. The simulated flue gas at 120°F contained 10.0% Q, 5.7% CO₂, 380ppm CO, 1.87 slpm natural gas and 20.69 slpm air. The difference in dry weight of the screens and inline filter was calculated and the effective weight was compared with the weight of samples loaded. Table 4.10 tabulates the measured dry and differential weights.

Table 4.10 Weight analysis of screens and filter for experiment V.

Before trial After trial Difference

Screen #1 149.4gm 149.6gm 0.2gm

Screen #2 151.6gm 150.7gm O.Ogm

Screen #3 152.4gm 151.9gm O.Ogm

Screen #4 153.2gm 153.7gm 0.5gm

Filter 183.0 gm 183.9 gm 0.9 gm

Total = 1.6gm

It was observed during the experiment that Nostoc 86-3 changed color form green to brown within 80 hours. The experiment was stopped at 90 hours. It can be inferred that the growth performance of algae species not only depends upon the temperature but also the light intensity. Cyanobacteria are adapted to lower light environments. With higher light levels, the cyanobacteria cannot harvest themselves.

The next experiment was again aimed at 120°F but under reduced light intensity with controlled parameters of CO₂ concentration. Experiment VI was illuminated at 18.25μmol-s^"1m^"2 measured at the base of experimental containment after the algae samples were loaded over the screens in containment. Again the amount of algae sample loaded over each screen was 3000ml giving total loading of 12000ml in reactor. Table 4.11 gives the weight analysis of 25ml samples drawn through paper filters for calculation of weight of algae used for testing.

Table 4.11 Dry weight analysis for test samples for Experiment VI.

^' #1 25ml 1.7282gm 1.7435gm 0.0153gm

#2 25ml 1.6294gm 1.6455gm 0.0161gm

#3 25ml 1.8189gm 1.8368gm 0.0179gm

#4 25ml 1.7889gm 1.8066gm 0.0177gm

#5 25ml 1.7488gm 1.7663gm 0.0175gm

Total = 125ml 0.0845gm

The effective amount of algae loaded was 8.112gm. The simulated flue gas at 120°F contained 10.0% O₂, 5.7% CO₂, 700ppm CO, 1.87 slpm natural gas and 23.92 slpm air.

The light intensity passing through the containment was measured (at the bottom of the reactor), as shown in Table 4.12. Tables 4.12 Light intensity passing through the containment for Experiment VI.

Time Light intensity

(hours) mV μmol-s^"'m^"2

0 48.7 18.25

21 51.2 19.19

45 57.6 21.58

58 67.8 25.41

70 79.2 29.68

77 83.8 31.41

83 88.1 33.02

93 89.8 33.65

97 91.6 34.33

109 92.6 34.70

118 93.6 35.08

120 94.2 35.30

The Difference in dry weight of four numbers of screens and inline filter was calculated out and effective weight was compared with the weight of algae samples loaded. Table 4.13 tabulates the measured dry and differential weights.

Table 4.13 Weight analysis of screens and filter for Experiment VI.

Before trial After trial Difference

Screen #1 149.1gm 150.5gm 1.4gm

Screen #2 155.6gm 157.3gm 1.7gm

Screen #3 - 149.7gm 151.3gm 1.6gm

Screen #4 151.7gm 151.4gm -0.3gm

Filter 189.1 gm 193.6 gm 4.5 gm

Total = 8.9gm

It was observed during the experiment that Nostoc 86-3 did not change color and remained green, but still with reduced density on the screens. In addition, it was observed that amount of light intensity passing through the containment showed a continuous rise with time. The observation also supports the decrease in microalgae density over the screens as more and more light passed through. However, the amount of cyanobacteria obtained after trial was more than that initially loaded, indicating a positive growth. The next experiment was conducted at 120°F under the illumination of 22.11μrnol-s^"1nϊ² measured at the base of experimental containment after the algae samples were loaded. Again the amount of algae samples loaded over each screen was 3000ml giving total loading of 12000ml in the reactor. Table 4.14 gives the weight analysis of 25ml samples drawn through paper filters for calculation of weight of algae for testing.

Table 4.14 Dry weight analysis for test samples for Experiment VII.

#1 25ml 1.7666gm 1.7921gm 0.0255gm

#2 25ml 1.701 lgm 1.7266gm 0.0255gm

#3 25ml 1.7402gm 1.7668gm 0.0266gm

#4 25ml 1.8402gm 1.8677gm 0.0275gm

#5 25ml 1.6527gm 1.6778gm 0.0251gm

Total = 125ml 0.1302gm

The effective amount of algae loaded was 12.500gm. The simulated flue gas at 120°F contained 9.5% Ch, 6.0%CO₂, 500ppm CO, 1.73 slpm natural gas and 21.33 slpm air.

For this experiment, the illumination was maintained under ON-OFF mode (12 hours cycle) to support the light and dark reaction of cyanobacterial photosynthesis. The light intensity passing through the containment was measured after every 12 hours (at the bottom of the reactor), as shown in Table 4.15. Tables 4.15 Light intensity passing through the containment for Experiment VII.

Time Light intensity

(hours) mV μmol-s^"Im^"2

0 59.0 22.11

12 74.6 27.96

24 73.4 27.51

36 76.4 28.64

48 77.7 29.12

60 77.5 29.05

72 74.0 27.74

84 80.4 30.14

96 84.5 31.67

108 88.6 33.21

After the experiment was run for 120hours, the growth screens and filter were removed and dried. Table 4.16 tabulates the measured dry and differential weights. Table 4.16 Weight analysis of screens and filter for Experiment VII.

Before trial After trial Difference

Screen #1 146.8gm 151. lgm 5.3gm

Screen #2 148.1gm 151.5gm 3.4gm

Screen #3 150.1gm 152.8gm 2.7gm

Screen #4 148.3gm 151. lgm 2.8gm

Filter 137.6 gm 145.9 gm 8.3 gm

Total = 22.5gm

It was observed that the light intensity passing through the containment showed a continuous but gradual rise in jumps at various intervals. It was also observed that the Nostoc 86-3 changed color to light brown. Cellular study testified that, the species were of consistent size with the batch culture of algae and is maintaining the filamentous morphology of Nostoc. The species were found to be maintaining healthy coloration and were not dying off. These results indicated that species Nostoc 86-3 can tolerate 120°F as observed from the color of the samples after the experiment. The species were found to be quite healthy based on visual observations. OHIO UNIVERSITY TECHNOLOGY TRANSFER OFFICE

Disclosure of Invention

Or Copyrlfihtable Material

Your invention, software program, or idea is important (1) to your professional development; (2) to your department, college and the University; and, if applicable, (3) to your research sponsor. It is essential that it be reported promptly, so that it can be evaluated to determine if it can or should be patented or copyrighted and reviewed for commercial potential to justify an industry licensing program. Por additional information about the OU commercialization policy see Policy and Procedure 17.001, Do not send this information through e-mail.

1. Full names(s) and addresses) of the invcntσr(s):

Name and Title Office Address Home Address a. Dr. David J Bayless 248 Stocker Center 9 Applceate Dr. Athens OH 45701 b. Dr. Morgan L. Vis-Chiasson 400 Porter Hall 9 Briarwood Dr. Athens OH 45701

2. Type of Material: Invention ft Software Program____

3. Tide of Invention or Software Program: Biolo^gical remediation of greenhouse ftas cmjssinn.? μsing thermophilic entities

4. Date when you first conceived the Invention or Software Program: September 24. 199^

5. Date when you actually reduced the Invention or Software Program to practice, if this has been' done: Not done vet

6. State in general terms the purpose or objective of the Invention or Software Program:

The purpose of this invention is "remove" a portion of the CO₇ in the gaseous effluc _, of scrubbed fossil-fired power plants using thermophiiic al ae located in a separate chamber downstream of the scrubber. The aleae would be grown on fabric sheets and exposed to the effluent ^gas stream, suitable lightin^g conditions and nutrients. The mature algae would fre harvested to maximize CO; consumption.

7. In a joint invention or authorship of a software program, were different aspects of the Invention or Software Program made by different inventors?

( ) yes ( x ) no ( ) uncertain

8. Provide a relatively detailed description of the Invention or Software Program - attach narrative description of the invention, methods, programs, flow chart, photographs, drawings, sketches, patent applications, or any other descriptive material, A draft journal article or narrative report to a funding agency often will suffice for this description. The description should include the construction, showing the changes, additions, and improvements over existing embodiments of the technology. Also indicate the principles involved, the details of operation, and alternative

Nm. of Invention ptφto_B|cιιl *m≠\ * °f Q^hP»»ffiteflι^^

methods of construction or operation, including the following points:

a. Problem to be solved; b. Solution; c. New features of the Invention or Software Program; d. State-of-the-art/practice of forming the function of the Invention or Software Program; e. Disadvantages of the state-of-the-art/practice overcome by the Invention or Software

Program; f . How the Invention or Software Program overcomes these disadvantages ; and g. Disadvantages of this Invention or Software Program. h. Where applicable, illustrate the Invention with sketches, drawings, or photographs, where parts referred to in the description are identified by reference number or name.

The Kyoto Accord on greenhouse gas emissions may result in the reduction ofU.S.-bwco^* CO) omissions to 1990 levels in the years of 2008-2012. The bulk of the CO} emissions reduction likely will be shouldered by the fossil-fired power generation industry, due to α combination of numerous factors, Including low gasoline prices. Compounding the problem, the mass replacement of cool with natural gas would eliminate the diversity in the fuel supply necessary to ensure reliable deli_very an competitive pricing of electrical power. Given these considerations, the need to reduce COj emissions from coal combustion presents a formidable and critical challenge.

This scope of the problem, is enormous. The U.S. produces an estimated 1.7 billion tons or COj annually [1], U.S. industries consume only 40 million tons of COi, produced at a much lower price than could be dono by removing CO* from flue gas (2). Therefore, increased consumption of CO» appears limited, and options for expanded use appear limited and costly. Consequcndy, sequestration in large bodies of water or In deep mines appears to be the most viable option. While this could offer an increased window for developing an ultimate control technology, sending C fe into the ocean or α cavern is at best a limited solution, and may only keep the COj from reaching the atmosphere for about a few hundred years. Further, (he transportation issues are considerable, even for the less than 30% of all U.S. fossil plants that are within 100 miles of an ocean [1], Clearly, other approaches for COi control roust be developed to comprehensively address this challenge.

One method of CO* control that has been proposed is through the use of biological agents. Even though COj is a fairly stable molecule, It is the basis for the Formation αf complex sugars (food) by green plants through the process of photosynthesis {3]. If αlgne were used to convert A portion of COj from power plants, the algae, once dried, could be used as biomass fuel, fertilizer, animal feed, or could be fermented to produce alcohols and light hydrocarbon fuels [4.5],

The effort proposed here by Ohio University would focus on the use of specially designed algal growth chambers to process COi from the effluent (flue gas) of scrubbed fossil-fired combustion units. Approximately 15% of coal-fired capacity is currently scrubbed for SO* control Many of these units are located more than 200 miles from an ocean and would not be suitable for C0₂ transport to aα ocean [1]. Further, these scrubbed units are ideal for use with biological control of C0₂, as the outlet of (ho scrubber contains lower amounts of harmful particulates, lower temperatures, and high concentrations ofwater vapor [3J.

A key to developing a practical oarbon dioxide conversion process is cost. CO2 is & stable molecule, making it expensive to use in the manufacture of fuels [2], It is also relatively expensive to separate and transport over long distances [6,71. Conversion of CO_j to biomass using a thexαtophllic photosynthetic organism offers low cost possibilities for reducing CO> emissions [4,8]. In 1951, Arthur D. Little Inc. designed 0 405,000m* facility for the production of 236 kg/hr of Chlorellu pyrsnoidon_tα (5). The resultant power production was no more than 600 k W and the costs were approximately five times the equivalent cost of coal combustion. Numerous studies since that effort, Including Ohtaguchi et at,, have found ways to reduce the cost [4], However, the focus of meso efforts was to use massive artificial lakes imprαctlcatly εized for most existing power plants.

The approach proposed hero would be to create a chamber that would permit optimal growth of the algae, within the constraints resulting from the flue gas. Tho chamber would contain algae on membrane plates arranged to minimize the

Name of Invention Bicjogical Remediation of Greenhouse Gas Emigj|l_Tπg Uaiπp

.. . - .ϋ . ,_*,w,_n<r nϋPffpri fnn oower. The nlatcs would also provide much needed stability

S b Si without afffcting other regions of growth, and **A be ideal for fiber opttc cable-based ghc dcuvevy

K ft_M»W surface area to reduce emissions by 20% from a 500 MW plant, estimated using the wouW b nc^ ΪSo mVsuch _{R s} stem could annually produce an estimated 20 ,000 tons of dry mature algae btomass wflh » esrimaid HHV of 17.7 MJ/kg. While such a system may sound impractical, only 1250 plates would be needed ⁱf contained in a 20*20 meter cross section. Spacing plates every 3 centimeters would require less than 40 meters of linear space. Further, it may bo possible to increase algae C02 consumption through longer lightⁱng cycles, focused light spccu-ums, and effective harvesting, thus reducing the surface area requirements {8].

The proposed work would focus on two objectives. The first objecUve would be to test CO* consumption rate of thermophilic algae under conditions simulating t ose found in Λe flue gas from a scrubbed coal-fired power plant. The second objective is to test the effectiveness of algal harvesting using the proposed slurry-based technique. While t e long term plans for this research effort would subsequently Include a detailed analysis using continuous testing, optimization of the process through parametric testing, and integration with biomass combustion and utilization, the narrow timeframe of this proposal requires those issues w be considered al a later time.

The research would involve experimentation ith thermophilic (heat loving) algae to convert COj to biomass through photosynthesis. Testing would occur in the Carbon Recycling Facility (CRP) at Ohio University. As shown in Figure I, the CRF is a closed loop internally heated system thai circulates simulated flue gas through a reaction chamber using an axial fan. A variety of gases, primarily COj, can be added at tbc gas addition pott Water and other chemicals can be drained or returned to the conulπmenl section, depending on the needs of the algae and the harvesting cycle,

Figure 1, Carbon Recycling Facility Schematic

The algae would be grown on membranes of fabric arranged as plates. This design not only minimizes the pressure drop across the chamber, it provides a Used surface for the algae to attach. This is critical, BS it will Increase the growth rate and stability of the algal colony. Further, it Is our Intent to have die facility at multiple stages of algal growth, depending on the location of the screen (plate) and the harvesting cycle. The^'variadon in growth states should present optimal times for harvesting, while maintaining an population that maximizes COj consumption.

rVα e of Inve ^tion flpjogical RBCTedjajon l Ore nhouse Qas Emissions

Al_gae s_trains _thai typically grow in the desert attached to soil havo been chosen for initial experimen^tation. These algae ha_ve adapted to ₍rela_tively) low moisture, high temperature conditions, thus are an ideal candⁱdate tor this research. In a_ddition, these algae readily grow attached to a substrate and they have a fairly long lifespan.

The flue gas in the CRP would be monitored for concentrations of NO* SO_b CO* 0^ and H_zO, and ^temperature would be maintained be_tween 130-170^βF using a natural gas burner located in the ductwork downstream of the fans. The gas stream would be satura_ted (wi_th water), consisting of roughly 10% CO_z and 3% 0₂₍ with trace levels of S0₂ and NO with the _balance being N». The gas loyels would be adjusted by the addition of make-up gases through the Injection port, The nominal screen (plate) surface area will be approximately 3 tn .

Because any practical appUcation of this technology would Iileely confine the algae in an opaque enclosure, light must be delivered to the algae to promote photosynthesis. Two options lhat would be explored Include the use of fiber-optic cables or by halogen lighting resistant to me harsh environment of the scrubber exhaust. Fiber optic coble delivery allows for multiple sources of light, such as focused sunlight during the day and artificial lighting at night However, the cost of such a sys_tem may not be practical, so conventional artificial lighting would also be used. Initial experimentation wirh external ligh_ting sources would bo done to provide baseline data. However, quantifying the performance of the algae using Internal lighting (sucb as thai delivered by fiber optical cable) would be the primary focus αf this effor The intensity and duration (to examine the lighting cycle) of the light delivered to various surfaces in the reaction chamber would be monitored to quantify their effect on the algal growth rate. In addition to comparing lighting techniques, two different lighting cycles (one short, i.e. 9 hours, and one long, i.e. 15 hours) would also be investigated for (heir effect on algal growth and CO_! consumption rales.

The second objective would be to test harvesting techniques. As the growth nte of algae levels off, the rale nt which they consume CO_z decreases. Therefore, the mature αlgαe must be harvested to assure maximum CO. absorption. The proposed harvesting technique would involve spray washing of the plates. The algae washed into the liquid slurry at the bottom of the chamber would be pumped through a size selective process. The use of sieves is currently favored over cyclone-based techniques, however both will be investigated. The mature (large) algae would bo removed and the remaining slurry would be sprayed on the plates (at a much slower rate) to assist in repopulotion.

The use of mature algae, while not part of this specific research, must eventually be considered. Ii Is envisioned that mature algae would be used to produce value-added products and energy. One advantage that Ohio University possesses in the posl-proccasiπg of algae is an active biomass combustion research program studying the combustion of algae and coal as a blended fuel in fluidized bed combustion to power Stirling cycle free piston engines. Other options for using the harvested algae include fermentation or conversion to hydrocarbon fuels and fertilizers.

While there are other efforts Involving biological control of CO., many of these attempts lack the expertise and overall vision to adequately address this complex Issue. Issues of types of thermophilic algae, light delivery, algae harves_ting to maximize C0₂ consumption, thermal environmental effects on the CO] absorption rate, effect of surface stability for algal growth, and post-harvesting uses all must be considered if any hope of practicality can be achieved.

9. If the Invention relates to composition of matter, attach the following additional points to the disclosure: a. Show the general properties required for each class of materials used. If possible, list at least three examples in each class. Explain the method of preparing any new material for which a method of preparation is not already known. This part of the disclosure should enable one skilled in the art to make proper selections of alternative materials of each class. b. Set forth proportions of materials, and conditions, expressed in the form of the widest reasonable ranges that will work. Also, mention narrower limits within these ranges that will provide optimum results. State the disadvantages of using proportions or conditions outside the ranges selected. c. Give specific examples of practice of the invention, in various modifications, and with the preferred proportions and conditions. The examples should illustrate diverse

Name of Invention Mrf I gBa tf fl^^ _Vajπ, T^anpπhjl^n_tj^

conditions under which the invention may be practiced. Inόtude eπou n examples of specific combinations to form the basis for as broad of claims as possⁱble^, d Describe any surprising results that would not have been forecast by the mythⁱcal "expert in the art." Explain the surprising results, if possible. Emphasize any results lhat are contrary to what was to have been expected. 0 a Source of funding applicable to this Invention (indicate grants or contracts);

b. Subcontracts applicable to this Invention or Software Program:

None known.

11. Indicate further R&D necessary before discussing the Invention or Software Program to a potential commercial licensee:

This is discussed in #8, but briefly reviewing I) lighting cycle, 2) harvesting, 3) algal "bioengineering" to optimize C0₂ consumption and 4) post-harvesting disposal or recycling.

12. Names and addresses of potential manufacturers or commercial licensees (especially Ohio companies):

Asea Brown Bovftri P.O.Box 5308. Norwalk. CT 06856-5308. ⁽2Q3W50-2200

Foster Wheeler Corp. Perrwillc Corporate Park Clinton. NJ 08809-4000 Phone: 908-730-4000 Unfortunately. Babcock & Wilcox fnow known as M[cDermott Technologies') is not interested.

13. List key words for computerized patent and literature searches: Greenhouse gas control, thermophilic algae. CO? abatement or control.

14. Date of past publication or public use (if any) (ATTACH COPY) Where published or used: N/A a. If not yet published, has an article or manuscript been accepted? No b. If not yet accepted, has an article or manuscript been submitted? No c. If not yet submitted, will an article or manuscript be submitted? Yes

When ? „ January 2QQQ ? To Whom ^' ? JAWMA nr BflT ^?_

Name of Invention Biological *«nefoHm p Q»whouse- Qm Emission. ιj_si„_g

5. After the disclosure is prepared, it should be signed at the end by each inventor and initialed and dated on the bottom of each page, as well. The disclosure should then be read and witnessed by at least one other person, as indicated below.

Inventor David J Bayless

(First Name) (Middle Name) (Last Name)

Inventor . Morgan Lefav Vis-Chiasson (First Name) (Middle Name) (Last Name) Address 9 Briarwood Drive. Athens Off 45701

Date ιSX> lSut _,ΛάAH. jqqq

Witness

Upon completion of the disclosure, return the fonn and appendices to:

DO NOT SEND THIS FORM BY E-MAIL

Gary Meyer, Director

Technology .Transfer Office

Technology and Enterprise Building, #20, The Ridges

^Nam^e of Inven^tion Biol^ogical Rc^pigdiiUion of Greenhouse G_at fimfrwr-. __]_______•

Ohio University's Proposal for C0₂ Emissions Control Using Biological Agents

The future of coal based power faces enormous environmental challenges, especially with re ard to the emission of greenhouse gases. Nearly 1.7 billion tons of CO₂ are emitted annually by the U.S., of which most come from ibssil-luel combustion sources. While some advocate the mass replacement of coal with natural gas, such a solution fails lo address the long term need maintain a diversified fliel supply for reliable delivery and competitive pricing of electrical power. Clearly, research is needed to develop a robust portfolio of carbon management options lo ensure the continued use of coal in electrical power generation.

The Kyoto accord on greenhouse gas emissions may lead to the U.S. reducing its COz emissions to 1990 levels by the year 2008-2012. The bulk of the COj emissions reduction likely will be shouldered by the fossil-fired power generation industry, due to a combination of low gasoline prices and other factors. With the high probability that electrical demand will not decrease, the prospect of towering C0₂ emissions is a formidable challenge lo our nation's power producers.

Numerous approaches are being considered, but the primary option appears lo be sequestration in large bodies o ater or in deep mines. While this could offer an increased window for developing an ultimate control technology, sending COi into the ocean or a cavern is at besl a limited solution, and may only keep the CO* from reaching the atmosphere for about a hundred years. Further, the transportation issues are considerable, even for Ihe less than 30% of all U.S. fossil plants that are within 100 miles of an ocean. Clearly, other approaches for C0₂ control must be developed.

One method of COj control that has been proposed is through COj conversion using biological agents. While COj is a fairly stable molecule, it is readily used in photosynthesis by plants containing chlorophyll. Algae arc an excellent converter of C0₂ to complex sugars that act as food. If algae were used to convert some CO* emissions from power plants, the algae, once dried, could be used as biomass fuel, fertilizer, animal Teed, or could.ba fermented to produce alcohols and light hydrocarbon fuels. The effort proposed by Ohio University would focus on using algae growth chambers to process CU₂ ti-om the effluent (flue gas) of scrubbed fossil-tired combustion units. About 15% of coal tired capacity is currently scrubbed for S0₂ control. Most of these units are located a significant distance from an ocean and therefore, the costs for CO₂ transport would be enormous. Further, these scrubbed units are ideal for use with biological control of CO , as the outlet of the scrubber contains lower amounts of harmful particulates, lower temperatures and high concentrations o water vapor.

The research plan would involve experimentation with high temperature (130-170°F) thermophyllic algae to recycle cθ₂. Testing would occur in the Carbon Recycling Facility (CRF) at Ohio University. The CRF is a dosed loop, internally heated system that circulates simulated flue gas dirough a reaction chamber using an axial fan. The chamber would contain thermophyllic algae grown on thin plates of fabric to minimize the pressure drop across the chamber. The plate arrangement would be necessary to give the algae a stable surface upon which to grow, as algae do not readily grow in turbulent water.

COϋ & O, Analyaπ

Figure l_t Diagram of the Containment Facility

The fl„_{B eκ} would bo „_lwlit„_red for conception, of NO„ SO,, CO,, 0,, and H_A and ii, umper.,.™ would t,_e main*,,,*. b«,w._H1 1₅₀-_I60-F _{uώlg a} „_{atal gas flarø} ^ .__ ^ ductwork downstream of *, A» Th. , content of the ilu- gas in.o and out of the ^faction chamber would be continuously monitored. Q, level across the chamber would also be monitored ,o evaluate leakage. The intensity of d.c light delivered to various luiftc* In the reaction chamber would be m_onitored to determine its effect on the algal growth rate.

Because the algae would likely be contained in an opaque enclosure for any practical application, a system must be developed to deliver light to the interior of the box either via fiber-oplic cables or some other technique that would resist the harsh environment of die scrubber exhaust, Ailer initial experimentation with external lighting sources, the performance of the algae using inleinal lighting (such as that delivered by fiber optical cable) would be examined, especially focusing on the optimal duration of the lighting cycle, with a 24-hr exposure being the upper limit.

As algae reach maturity and the rate at which they consume COj decreases, die plates would be spray washed. The algae tl it fall into the liquid slurry at the bottom of the chamber would be pumped tlirough a size selection process, Mature (large) algae would be removed for later experimentation. If necessary, the remaining slurry would be sprayed over the su faces at a much lower rate) to repopulate the washed surfaces.

The use of mature algue, while not port of this specific research, must eventually be considered. It is envisioned that mature algae would be used to produce value-added products and energy. One advantage that Ohio University possesses in the post-processing of algae is an active biomass combustion research project that is studying the combustion of algae and coal as a blended fuel for use in fluidized bed combustion to power small engines, such as Stirling cycle free piston engines. Other options for using the harvested algae include fermentation for development of alcohol-based hydrocarbon fuels, use as animal feeds, and use in fertilizers.

While there are other efforts involving biological control of CO* many of these attempts lack the expertise and overall vision to adequately address (bis complex issue. Issues of types of thermophyllic algae, light delivery, algae harvesting to maximize CQ, consumption, thermal environment effect., on the CO* absorption rate, effect of surface stability for algal growth and post-harvesting „_Scs all mast be considered if any hope of practicably can he achieved Report Title: Enhanced Practical Photosynthetic CO₂ Mitigation Type of Report: Quarterly Technical Report

Period Start: 10/02/2000 Period End: 01/02/2001

Principal Authors: Dr. David J. Bayless Dr. Morgan Nis Dr. Gregory Kremer Dr. Michael Prudich

Dr. Keith Cooksey, Montana State University Dr. Jeff Muhs, Oak Ridge National Laboratories

Date Issued: 01/16/2001

DOE Award No.: DE-FC26-00NT40932

Organization: Ohio Coal Research Center Department of Microbiology Division of Photonics 248 Stocker Center LW-113B Oak Ridge National Labor Athens, OH 45701-2979 Montana State University P.O. Box 2009, MS-8058 bayless@ohio.edu Bozeman, Montana 59717 Oak Ridge, TN 32831 (740) 593 0264 voice umbkc@gemini.oscs.montana.edu um4@oml.gov (740) 593 0476 fax

Disclaimer: This report was prepared as an account of work sponsored by an agency of the

United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

Enhanced Practical Photosynthetic C0₂ Mitigation (R Abstract

This is the first quarterly report of the project Enhanced Practical Photosynthetic CO₂ Mitigation. The official project start date, 10/02/2000, was delayed until 10/31/2000 due to an intellectual property dispute that was resolved. However, the delay forced a subsequent delay in subcontracting with Montana State University, which then delayed obtaining a sampling permit from Yellowstone _; National Park. However, even with these delays, the project moved forward with some success.

Accomplishments for this quarter include:

Culturing of thermophilic organisms from Yellowstone

Testing of mesophilic organisms in extreme CO₂ conditions

Construction of a second test bed for additional testing

Purchase of a total carbon analyzer dedicated to the project

Construction of a lighting container for Oak Ridge National Laboratory optical fiber testing

Modified lighting of existing test box to provide more uniform distribution

Testing of growth surface adhesion and properties

Experimentation on water-jet harvesting techniques

Literature review underway regarding uses of biomass after harvesting

Plans for next quarter's work and an update on the project's web page are included in the conclusions.

Enhanced Practical Photosynthetic CO₂ Mitigation ( Table of Contents Page

Experimental Methodology 1

Algae Dry Mass Determination Test 7

Results and Discussion 9

Subtask 1.1 - Investigate critical properties of alternative photosynthetic agents....9

Summary of Test Run 10/18-24/00 11

Uncertainty Analysis 11

Summary of Test run 11/2-7/00 12

Uncertainty Analysis 13

Summary of Test run 11/14-19/00 13

Uncertainty Analysis 14

Subtask 1.2 - Design deep-penetration light delivery subsystem 14

Subtask 1.3 - Investigate growth surface subsystem design 17

Subtask 1.4 - Investigate the use of a hydraulic jumps to improve the system's overall CO conversion efficiency 18

Subtask 1.5 - Design harvesting subsystem 19

Subtask 1.6 - Quantify properties of dried biomass for potential end-uses 20

Webpage 20

Conclusion 21

Figures

Figure 1 - Schematic of the Carbon Recycling Facility 1

Figure 2 - Schematic flow diagram showing burner assembly 3

Figure 3 - Schematic flow diagram showing growth solution recirculation system 4

Figure 4 - Dimensional features of screens 5

Figure 5 - Results of 1^st Nutrient Assay Experiment 9

Figure 6 - Results of 2^nd Nutrient Assay Experiment 10

Figure 7 - Optimal Photosynthetic Photon Flux on Membrane 1 15

Figure 8 - Optimal Photosynthetic Photon Flux on Membrane 2 15

Figure 9 - Optimal Photosynthetic Photon Flux on Membrane 3 16

Figure 10 - Optimal Photosynthetic Photon Flux on Membrane 4 16

Figure 11 - Schematic of the fiber optic test facility 17

Figure 12 - Proposed Translating Slug Flow Reactor Modifications 18

Enhanced Practical Photosynthetic C0 Mitigation ( Experimental Methodology

The experimental and test facilities are designed to simulate the flue gas emission from fossil- fired power plants. Flue gases from fossil unit scrubbers for SO_x control contain 10-15% CO₂ and have a temperature around 150°F. It is likely that thermophylic cyanobacteria, which tolerate high CO₂ and elevated temperature, would be most suitable for reducing these CO₂ emissions. The effect of temperature, gas flow rate, CO₂ concentration in the simulated flue gas and light intensity over the growth characteristics of microalgae species were examined at the test facility shown schematically in Figure 1.

Figure 1. Schematic of the Carbon Recycling Facility

The facility aims to develop a high-density, large-volume photosynthesizing microalgal culture system to maximize the photosynthetic capacity As with any diverse group of organisms, algae

Enhanced Practical Photosynthetic C0₂ Mitigation (R vary in requirements, with different media and handling techniques from culture to culture. The experiment setup passes simulated flue gas over the vertically stacked screens inside the containment on which microalgae are grown. This assembly assists in reducing the pressure drop of flue gas as well as increasing the effective area for efficient trapping and bio-conversion of CO₂ in the flue gas. The experimental setup can be visualized as having the following subsystems; a flue gas recirculation system, a gas burner system, an algae grow solution recirculation system, and an analysis system.

The flue gas recirculation system is designed to circulate hot flue gas through the algae culture in the containment facility. The recirculating fan circulates through the ductwork and containment. The simulated flue gas is found in a typical power plant that is scrubbed to remove SOx.

The containment facility is an open cubical box made of V" thick Plexiglas with the top cover made of % " thick Plexiglas. Plexiglas was used because it can sustain high temperatures and also provides transparency that allows visual monitoring of any changes occurring in the algae growth inside the containment. The containment facility is provided with a 1" PNC flange at the top edges, having twelve % " holes. The top cover with matching holes is bolted to the flanged top. A rubber gasket is applied between the top cover and flange.

The two faces of the box (12" wide x 1 VA" high) are provided with two rectangular openings (9" wide x 8" high). These openings serve as the entry and exit of flue gas through the containment. The other openings provided in the box include one at the bottom (sized at J ") for solution drain and two (sized at V") on the top cover for the solution supply manifold and for insertion of a thermometer or thermocouple wire or light sensor. The openings are then sealed with thermal resistant glue and thermal sealing tape.

An inline centrifugal duct fan having variable speed control maintains the circulation of flue gas through the setup. Galvanized ductwork, 8" in diameter and with a total length of approximately 20', provides passageway for the circulation of flue gas through the experimental facility. The ductwork is made of galvanized sheet metal rolled into cylindrical rolls 8" in diameter x 2' in length. Each duct piece is connected to another with rivets. The ductwork is connected to the circulation fan with steel hose clamps and terminated at the containment facility with two transition pieces at either end.

Transition pieces, rectangular (9" wide x 8" high) to circular (8" diameter and 12" long), made of galvanized sheet metal are connected to the containment facility with fourteen V" nuts and bolts. Transition pieces are coupled to the ductwork with rivets. All the joints on the ductwork are thermally sealed with insulation tape. Two vent valves, sized V", are fitted before and after the recirculation fan. One of the vent valves serves as a gas sample collector point for the analyzer to assess the circulation gas for concentrations of CO₂, O₂₎ and CO.

The gas burner system is primarily designed to maintain a suitable operating temperature range for the recirculating gas while providing sufficient levels of CO₂. The gas burner system is designed as a part of the gas recirculation system to preheat the circulating gas, which then simulates the actual power plant flue gas. The idea of burning premixed natural gas with air is to create a steady flame. Figure 2 is a schematic of the features of the burner assembly.

Enhanced Practical Photosynthetic C0₂ Mitigation (R

Valve

Figure 2. Schematic flow diagram showing burner assembly.

The burner assembly consists of a 2" long burner nozzle covered with a galvanized cone so as to protect the root of the flame from the flow of circulating gas. The sub-assembly of burner nozzle, cone, and flame sensor is mounted inside the ductwork and serves as a combustion chamber. This particular section of the burner assembly is accessible by opening the ductwork at the joint. The flame sensor is a safety device that senses the flame/temperature at the burner nozzle and lets the pilot valve open, maintaining the flow of gas. When there's no flame, the valve snaps shut and kills the supply of gas, preventing leakage of natural gas into the combustion chamber. Prior to entering the burner nozzle, natural gas is premixed with air in a Y-shaped air-fuel mixer. To sustain the flame in the flow field of gas, pressurized air is supplied to the burner. The premixed gas and air are metered through a metering valve after the mixer and then burned in the nozzle. The metering valve helps to provide fine control of the flame at the nozzle.

Another additional safety feature provided in the burner system is the snap disc temperature control. This temperature control is preset to 200°F so that if the temperature exceeds the preset value, the controller kicks off the recirculation fan and shuts off the gas supply valve so that no fuel is supplied. This, of course, prevents overheating of the system. Simultaneously, the pilot shut-off valve closes when no flame is sensed, adding additional safety to the setup. An air

Enhanced Practical Photosynthetic C0₂ Mitigation (R pressure regulator with filter is provided in the air supply line to regulate the pressure of air supplied for burning. In addition, check-valves in the gas supply line and main shut-off valves are provided to manually shut off the system when not running.

A recirculation system is designed to circulate the culturing media through the algae culture, dispersed over screens, while they are subjected to the high temperature flue gas in the containment. The basic idea is to keep the algae cultures moist inside the containment and provide nourishment for them to grow even at high temperatures. Figure 3 illustrates in a schematic representation the features of the recirculation system.

Figure 3. Schematic flow diagram showing growth solution recirculation system.

Four screens made of polyester fabric cloth fastened within the frame and loaded with algae culture are placed inside the containment at an angle of 65°. Screens are 21" long x lO¹/^¹ wide with V" frame width. Figure 4 shows the dimensional features of the screens.

Enhanced Practical Photosynthetic C0₂ Mitigation (

Figure 4. Dimensional features of screens.

Screens are supported inside the containment by a slotted fixture covering the width of the containment. The slotted fixture has four slots cut at an angle of 65°. The growth solution (medium I) is dripped from a plastic upper 18 gallon holding tank through a solution dripping manifold over the screens. The manifold is a V_ⁿ PNC pipe system with the main supply line divided into four branches, 22" long for each screen. Each branch is provided with twenty " diameter holes to drip solution over the screens. Solution from the upper holding tank flows through the manifold under gravity, and flow can be controlled with the isolating valve provided in the supply line.

Solution collected in the containment is drained back to the steel lower 24 gallon holding tank. Both tanks are black to prevent any photosynthetic reaction in the solution due to external light. Algae solution from the lower holding tank is pumped back to the upper holding tank by a recirculation pump after passing through an inline 5 μm rated filter. The filter traps any algae passing through and circulates a clear solution free of algae. The upper holding tank is provided with a switch set to maintain the level of the solution in the tank so as to provide a continuous flow of solution over the screens. The float-type switch activates the recirculation pump on low level, and when the desired upper level is reached, shuts off the pump.

Analysis of the recirculating gas, growth solution, and light intensity inside the containment is performed to quantify the CO₂ absoφtion capacity of microalgae. The temperature of the flue gas is measured by inserting the thermocouple wire into the flue gas stream in the containment. Flue gas is then analyzed for CO, CO₂ and O₂ content using a Nova Analytical Systems Inc., model 375WP analyzer. The analyzer utilizes a sensitive infrared detector for CO₂ and disposable electrochemical sensors for O₂ and CO. A built-in sample pump draws in the sample gas from the probe for analysis. The electrochemical O₂ and CO sensors produce a small voltage, which is directly proportional to the respective gas concentration. This output is amplified and displayed on the front panel meter. A solid-state infrared detector detects CO₂, which is specific to CO₂. Flue gas after detection is vented into the atmosphere. All three gases are simultaneously detected and displayed on LCD readout meters, one for each gas. The pH of recirculating solution is measured using a Hanna Instruments made pH meter, model pHep. The range for the pH meter is from 0.0 to 14.0 pH with resolution of 0.1 pH and accuracy (@20°C) of ± 0.1 pH .

Enhanced Practical Photosynthetic CO _ Mitigation ( Photosynthetically Active Radiation (PAR) is measured using a Licor LI- 190S A quantum sensor. The quantum sensor measures PAR received on a plane surface. A silicone photodiode with an enhanced response in the visible wavelengths is used as the sensor. Licor radiation sensors produce a current proportional to the radiation intensity. The current output of the sensor is measured over a milli-volt recorder by connecting an amplifier between sensor and recorder. The special purpose amplifier converts the micro-amp level current output of Licor light sensor to a corresponding signal voltage. LI- 190S A sensor has a calibration constant of 6.67 or calibration multiplier of -149.93. The calibration multiplier is the negative reciprocal of the calibration constant and is always a negative number because the shield of the coaxial cable is positive instead of negative. This is expressed in radiation units per microamp.

The setup is provided with a cool white light bank with an effective capacity of 612W. The light bank capacity is adjustable by adding or removing the 32W tube lights from the fixtures. Nine total fixtures are fixed and a pair of tube-lights can be mounted on each. The light bank resembles an enclosed trough and can be slid over the containment.

The LI- 190S A is mounted at the base of the containment. The main idea is to measure the radiation from the artificial source of light (cool fluorescent light) passing through the screens and culture media. The output of the sensor from the millivolt adapter is boosted with an amplifier and measured over a millivolt recorder (multiplier).

An experimental investigation was carried out on Nostoc 86-3 microalgae species to determine temperature response, CO₂ absoφtion, and growth characteristics of the species under simulated flue gas conditions. For each experiment, the steps involved were:

1) preparing algae culture

2) sampling algae culture to determine mass of algae culture used for experimentation

3) preheating of containment facility and culturing solution

4) setup for gas analysis

5) measuring temperature and light sensor

6) trial of the experiment for a specific temperature and light intensity.

Microalgae species Nostoc 86-3 was isolated in pure culture from soil enrichment carried out under conditions of fixed nitrogen and selection of hormogonia induced by red light. The species were cultured in 20 gallons of culture medium I (described in Appendix A). The algae culture was illuminated by a 42W cool-white fluorescent lamp at an intensity of 64 μmol-s^" m^" and bubbled with air and CO mixed together in the ratio of 19:1. The fluidization created by the bubbled CO₂ helps in uniform defragmentation of algae samples and CO₂ transport via bulk flow diffusion.

The algae colonies so cultured are later transferred into 6-gallon plastic sampling containments, from where the algae samples are drawn out for experimentation. Each containment is provided with sample draw out isolation valve and a closed circuit heater to maintain the algae samples at 110°F and a pH level of 7.4. The reason for preheating the algae samples at 110°F arises from the effort to prevent algae samples from thermal shock when they are transferred from the culturing containment at ambient temperature to an experimental facility at test temperature. The algae samples in sampling containments are illuminated by a bank of 60W cool-white

Enhanced Practical Photosynthetic C0₂ Mitigation ( fluorescent lamps at an intensity of 64 μmol-s^",m^"2.

Algae Dry Mass Determination Test

This summary explains the procedure that was used to estimate the percent mass of dry algae from a wet weight basis. This is also the procedure that will be used to load the membranes in all the tests. A 100-ml algae sample (including growth medium) was poured across a very fine wire mesh to filter the algae from the growth medium. The algae sample remained on the wire mesh for 9 minutes to further reduce water content. Two oven-dried and weighed crucibles were each filled with approximately 6-grams of filtered algae. The samples were placed in an oven and dried for 116 hours at 107°C. The masses of the two samples were periodically measured during the drying process to determine when all the moisture had been removed from the samples. After 75 hours of drying, there was no measurable mass difference in subsequent mass measurements and the final mass measurement (116 hours) of each sample.

The percent dry mass of algae was determined by dividing the algae's dry mass by the algae's wet mass (mass loaded into the crucible). The first crucible's percent dry mass was 4.67% and the second's was 4.24%. These first two samples were taken as an initial test for the above- described method. Ten more samples were taken following the same procedure. The average percent dry mass of the ten samples was 4.46% with a standard deviation of 0.19%.

A specific amount of cyanobacteria culture is loaded over each screen, either by directly pouring the algae solution over the screens or by using a peristatltic pump to distribute it evenly over the screens. The pouring or distributing rate is adjusted so that the organisms get enough time to attach to the screen fabric.

For each trial experiment, the containment facility and algae growth solution (to be circulated through screens inside the containment) are preheated for 12 hours to the temperature at which the trial experiment is intended to be run. The containment facility's upper and lower holding tanks are cleaned off, and a new filter element is fitted to the inline filter. The filter cartridge is preheated at 180°F for 24 hours to remove any moisture content and is weighed before fitting.

To start preheating, a set of screens is fitted over the fixture at an angle of 65°. The top cover is fitted and bolted over the experimental facility and solution is dripped over the screens from the upper holding tank. The dripping rate is adjusted to maintain a level of ."-% " inside the facility. The solution is allowed to circulate between the upper and lower holding tank through screens, recirculation pump, and inline filter. The main shut off valves for air and gas are opened and air pressure is adjusted to 20 psi. The temperature rating of the snap disc temperature control is adjusted to the desired operating temperature. With flow control knobs for both the air and gas rotameters closed and metering valve half throttled, the flame sensing thermocouple for the burner is heated with an external propane torch through an opening in the duct work to open the pilot valve. Air and gas flows are then adjusted to get a shaφ blue flame at the burner tip. Slowly the metering valve is fully opened and again the rotameter knobs are adjusted to get a shaφ blue flame at the burner tip. At this time the flue gas recirculating blower is switched on. Flow control knobs of air and gas flow rotameters are again adjusted to obtain desired temperature for preheating.

Enhanced Practical Photosynthetic C0₂ Mitigation ( Once the experimental facility is preheated to the desired experimental temperature and samples are being cultured at 110°F, the top cover is opened and the required quantity of cyanobacteria is introduced in equal amount over each screen. While loading the algae samples over the screens, the circulation of hot gas is kept running. Once the samples are loaded over each screen, the screens are fitted back inside the containment. After the screens are inserted in the experimental containment, the top cover is fitted back and bolted down over the containment. The growth solution dripping rate is adjusted so that a level of 54"-% " is maintained in the bottom of the containment facility. The level of algae solution in the upper holding tank is maintained constant by the level switch and recirculation pump.

During each 120 hour trial experiment for specific amounts of algae samples and fixed temperature, readings for temperature, air and gas flow rotameter values, light intensity, O₂, CO₂ and CO concentration are recorded. After the experiment is complete, the algae samples from each screen are compared to the original algae sample for visible changes in color and/or molecular characteristics (like cellular density and cellular structure). This analysis provides information about algae samples regarding their health and growth characteristics at high temperatures, similar to those in power plant flue gas. Also after the experiment is over, the screens and inline filter element are dried and their weights are noted. The dry weight of screens and the filter is noted. Calculation of weight differences when compared to the original mass of algae samples loaded into the system gives information on the growth of algae when exposed to a particular temperature.

Enhanced Practical Photosynthetic C0₂ Mitigation ( Results and Discussion

1.1.1 Quantify agent growth rate characteristics in controlled experiments as a function of temperature, bicarbonate concentration, moisture content and nutrient level a. The published data about physiology and ecology of thermotolerant cyanobacteria ^; have been investigated. b. It was found that there is additional way to enhance photosynthetic CO₂ mitigation, i.e., to use thermotolerant strains of cyanobacteria with calcium deposition potential. Two thermotolerant strains of cyanobacteria isolated in Yellowstone National Park have been introduced in culture. Permission to supply to the Ohio group cultures of Cyanidium caldarium isolated from Nymph Cr. in Yellowstone National Park has been negotiated with park authorities. Efforts to allow the archiving of these cultures are being undertaken by this group and others at MSU working in YNP. d. 5-gallon cultures of 3 thermophillic organisms were initiated in a newly acquired 50 C incubator. These cultures are growing well and one is ready to be transferred to a larger container for mass culturing. Experiments on the effects of nutrient level were carried out for one thermophillic organism. The experimental design was as follows:

5 replicate cultures of each of 6 treatments were utilized for a total of 30 cultures. The treatments were 2X (double normal concentration), IX (normal cone), 0.5X (1/2 normal cone), 0.1X (l/10^th normal cone.) and 0.001X (l/100^th normal cone.) of Allen's Modified Medium that is used to grow the thermophillic organisms. We hypothesized that a higher nutrient concentration would promote growth. The cultures were sampled every three days and the number of cells per culture counted as a measure of growth. The results of our first test are presented in Figure 5.

Day3 Day6 Day9 Day 12

Figure 5. Results of 1^st Nutrient Assay Experiment. Error bars represent standard deviation.

Enhanced Practical Photosynthetic C0₂ Mitigation (R We had difficulties with the culture set-ups and evaporation at high temperatures. We modified the set-ups and re-ran the experiment. The results of the second experiment are shown in Figure 6. The conclusion from the second experiment is that the lower concentration of nutrients appears to favor growth of these organisms. This result is contrary to our hypothesis. One explanation may be that these organisms are adapted to low nutrient environments. We have used this information to alter our culture conditions for the organisms.

Day6 Day9 Day 12 Dayl5 Day 18 Day21

Figure 6. Results from 2 ,nⁿd Nutrient Assay Experiment. Error bars represent standard deviation.

1.1.2 Quantify adhesion characteristics No progress made this quarter.

1.1.3 Quantify growth characteristics (size when mature and average time to mature) for harvesting considerations a. A lab-scale glass fermenter for the examination of different physiological properties of cyanobacteria has been designed. b. Technical documentation for this glass fermenter has been sent to 3 potential vendors for a price quotation.

1.1.4 Quantify growth characteristics at low temperatures for analysis of environmental impacts should there be loss of containment.

No progress made this quarter.

Enhanced Practical Photosynthetic C0₂ Mitigation (R In addition to the work reported under Task 1, three test runs in the bioreactor were performed.

Summary of Test Run 10/18-24/00

The test specimen for Test Run 10/18-24/00 was the cyanobacteria, Nostoc 86-3. The target values for the gas concentrations were 3%, 10%, and less than 50 parts per million for oxygen, carbon dioxide, and carbon monoxide, respectively, with a temperature range between 120°F- 125°F. The gas concentration averages for the 120 hours were 2.90%, 10.05%, and 32.54 ppm for oxygen, carbon dioxide, and carbon monoxide, respectively. The 120-hour temperature average was 122.6°F. The lighting was not altered from Summary of Light Intensity Test (thru 10-10-00) and was cycled 12-hours on and 12-hours off.

Test Run 10/18-24/00 had a total dry algae mass gain of 1.25 grams, or a 29.8% increase over the estimated initial dry mass. The following table describes each membrane and final test results. More details are provided in Data Sheet Test Run 10.18-24.00.

Uncertainty Analysis

The uncertainty analysis is based on the results from the Algae Dry Mass Determination Test and the final results of Test Run 10.18-24.00. From the Algae Dry Mass Determination Test, the average percent dry mass of the initial twelve samples was 4.46% with a standard deviation of 0.19%. The same technique used to gather the twelve initial samples was used to load the membrane. An algae sample taken from the bulk tank was poured across a wire mesh to remove most of the water content, but still retaining the algae mass. The sample remained on the wire mesh for 9 minutes to further reduce water content. The remaining sample was scooped into a beaker and weighed. The algae sample in the beaker was then applied to the membrane and the beaker was weighed again to determine the algae loading weight. This was repeated for each remaining membrane. 4.4581% of the total loading wet weight was used as the estimated initial dry mass for each membrane.

Enhanced Practical Photosynthetic C0₂ Mitigation (R The following sample calculation is the uncertainty at 90% confidence in the estimated initial dry mass for membrane- 1. It is based on the 12 samples taken from Algae Dry Mass Determination Test, using Student's t-distribution and using only one sample to load the membrane.

Data from Algae Dry Mass Determination Test, Test Run 10.18-24.00 and Student's t- distribution: Mean = 4.46%, Std. Dev = 0.19%, and Degree's of freedom = 11 (based on Student's t-distribution for 12 samples), t₉₀ = 1.796 ( Student's t-distribution for 12 samples)

Uncertainty =

yfn t = Student's t-distribution for 12 samples at 90% confidence σ = Standard deviation of the 12 samples n = Number of samples applied to membrane- 1

Uncertainty₉₀ = 1.796x0.19% = 0.34%

Algae wet weight applied to Membrane- 1 = 23.44 grams

Uncertainty of estimated dry weight = 23.44 x 0.0034 = ± 0.081 grams

Estimated initial dry weight = 23.4396 x 0.044581 = 1.0450 ± 0.08136 grams

Mass gain for Membrane-1 = Membrane-1 dry weight - initial weight = 0.2838 grams

Uncertainty₉o = — x 100 = 28.7% (uncertainty of mass gain at 90% confidence)

0.2838

Summary of Test Run 11/2-7/00

The test specimen for Test Run 11/2-7/00 was the cyanobacteria, Nostoc 86-3. The target values for the gas concentrations were 3%, 20%, and less than 50 parts per million for oxygen, carbon dioxide, and carbon monoxide, respectively, with a temperature range between 120°F-125°F. The gas concentration averages for the 120 hours were 2.96%, 19.22%, and 16.90 ppm for oxygen, carbon dioxide, and carbon monoxide, respectively. The 120-hour temperature average was 122.3°F. The lighting was not altered from Summary of Light Intensity Test (thru 10-10-00) and was cycled 12-hours on and 12-hours off throughout the test.

Test Run 11/2-7/00 had a total dry algae mass gain of 0.90 grams, or a 28.0% increase over the estimated initial dry mass. The following table describes each membrane and final test results. More details are provided in Data Sheet Test Run 11.2-7.00.

Enhanced Practical Photosynthetic CO _ Mitigation (R

Uncertainty Analysis

The following sample calculation is the uncertainty at 90% confidence in the estimated initial dry mass for membrane-2. It is based on the 12 samples taken from Algae Dry Mass Determination Test, using Student's t-distribution and using two weighed samples to load the membrane.

Data from Algae Dry Mass Determination Test, Test Run 11.2-7.00 and Student's t-distribution: Uncertaintygo = 1.796x0.1933% = 0.2454%

Algae wet weight applied to Membrane-2 = 17.9094 grams

Uncertainty of estimated dry weight = 17.9094 x 0.002454 = ± 0.04395 grams

Estimated initial dry weight = 17.9094 x 0.044581 = 0.7984 ± 0.04395 grams

Mass gain for Membrane-2 = Membrane-2 dry weight - initial weight = 0. 2178 grams 0.04395g

Uncertainty₉o= x 100 = 20.2% (uncertainty of mass gain at 90% confidence)

0.2178g

Summary of Test Run 11/14-19/00

The test specimen for Test Run 11/14-19/00 was the cyanobacteria, Nostoc 86-3. The test run was performed under ambient conditions at an average temperature of 83.2°F. The lighting was not altered from Summary of Light Intensity Test (thru 10-10-00) and was cycled 12-hours on, and 12-hours off throughout the test.

Test Run 11/14-19/00 had a total dry algae mass gain of 2.0 grams, or a 59.2% increase over the estimated initial dry mass. The following table describes each membrane and final test results. More details are provided in Data Sheet Test Run 11.14-19.00.

Enhanced Practical Photosynthetic C0₂ Mitigation (

Uncertainty Analysis

The following sample calculation is the uncertainty at 90% confidence in the estimated initial dry mass for membrane-1. It is based on the 12-samples taken from Algae Dry Mass Determination Test, using Student's t-distribution and using four weighed samples to load each membrane.

Data from Algae Dry Mass Determination Test, Test Run 11.14-19.00 and Student's t- distribution:

Uncertainty₉₀ = 1.796x0.1933% = 0.174%

Algae wet weight applied to Membrane-1 = 17.15 grams

Uncertainty of estimated dry weight = 17.15 x 0.00174 = ± 0.030 grams

Estimated initial dry weight = 17.15 x 0.0446 = 0.765 + 0.030 grams

Mass gain for Membrane-1 = Membrane-1 dry weight - initial weight = 0. 465 grams

Uncertainty₉o = — — xlOO = 6.4% (uncertainty of mass gain at 90% confidence)

0.4652g

Subtask 1.2 Design deep-penetration light delivery subsystem

1.2.1 Define spatial photon delivery (lighting) requirements and model design configurations incoφorating large-core optical fibers using COTS lighting design tools.

1.2.2 Determine preliminary solar-based photon delivery (lighting) systems spatial effect on cyanobacteria growth rates.

1.2.3 Test lighting cycle durations on growth rates.

Enhanced Practical Photosynthetic CO ₂ Mitigation (R During this quarter, further testing was performed to determine if artificial lighting (without fiber optics) could be used to provide a uniform lighting source. Figures 7-10 show the optimum achievable distribution, which has been determined impossible to achieve in a scaled-up reactor (with a depth over three feet) due to the high rate of attenuation.

Figure 8. Optimal Photosynthetic Photon Flux on Membrane 2

Enhanced Practical Photosynthetic C0₂ Mitigation (R

Figure 9. Optimal Photosynthetic Photon Flux on Membrane 3

Figure 10. Optimal Photosynthetic Photon Flux on Membrane 4

Because of the poor distribution achievable with external artificial lighting, the researchers at Oak Ridge National Labs have designed a testing box for measurement of light distribution via

Enhanced Practical Photosynthetic C0₂ Mitigation (R fiber optic cables with growth membranes in-place. The box is described in Figure 11. The unit is currently under construction at Ohio University and it is hoped that the fibers can provide a more uniform distribution of photons within the bioreactor to achieve an optimal balanace between growth rate and surface area.

5.71" 5.71" 5.71"

Figure 11. Schematic of the fiber optic test facility

Subtask 1.3 Investigate growth surface subsystem design

1.3.1 Examine surface configuration for effects on growth and harvesting

1.3.2 Examine surface composition for effects on growth and harvesting

Enhanced Practical Photosynthetic CO ₂ Mitigation ( The polymer "Scotch Bright" has been tested for the sterilization properties. It was found that this polymer can be sterilized at 121°C for 30 min and there was no detectable damage.

Subtask 1.4 Investigate the use of a hydraulic jump to improve the system's overall CO conversion efficiency

1.4.1 Examine effect of hydraulic jump on HCO₃ (bicarbonate) concentration

1.4.2 Examine effect of hydraulic jump on exhaust gas temperature

1.4.3 Examine effect of hydraulic jump on need for direct flue gas exposure to promote photosynthesis in the bioreactor

1.4.4 Quantify costs / negative effects of hydraulic jump on the system

An early decision was made to utilize a previously designed and constructed slug flow reactor system currently housed at the Institute for Multiphase Technology at Ohio University. The current system was designed specifically for use in a situation, which was moderately different than the desired configuration. Subsequent efforts focused on the identification of system requirements for the slug flow reactor to be used for scrubbing of CO₂ from a synthetic flue gas and the modifications required in the present system. A schematic of the desired configuration is presented in Figure 12.

Figure 12. Proposed Translating Slug Flow Reactor Modifications

Enhanced Practical Photosynthetic CO ₂ Mitigation (R Identified modifications included:

(1) conversion of reactor from vertical configuration to horizontal flow

(2) addition of a second gas inlet stream for the ability to deliver 15% CO₂ in 85% N₂

(3) addition of gas sampling ports prior to the inlet and at the exit of the reactor

(4) addition of liquid sampling ports prior to the inlet and at the exit of the reactor

(5) addition of thermocouples prior to the inlet and at the exit of the reactor

(6) addition of a differential pressure transducer to monitor pressure drop in reactor

Piping for inlet gas lines has been purchased and the manifold system for gas delivery is under construction. High accuracy gas flow meters have been evaluated and appropriate units identified. These are currently in the process of being ordered. Acrylic piping for the horizontal flow configuration has been located and it is anticipated that this will be fitted with flanges and sized for installation prior to the end of January. A differential pressure transducer of the required sensitivity has been specified and an appropriate unit is being located. Location of all sampling and/or monitoring ports within the reactor system has been completed. Drilling of the reactor pipe and subsequent installation of these sampling/monitoring ports is awaiting the receipt of all units for concurrent installation.

Subtask 1.5 Design harvesting subsystem

Phase I research aims to determine which individual factors have the most significant effect on CO₂ uptake in an enhanced photosynthesis system. It also will evaluate and rank component and subsystem level alternative design concepts with respect to their ability to control or provide those factors which maximize CO₂ uptake. We have made progress in phase I level research for the harvesting subsystem as described in the following paragraphs.

We have researched the growth patterns and preferences of the various types of thermophilic organisms that are candidates for the bioreactor and have determined that a harvesting method that provides a frequent, gentle, and partial cleaning is desirable. Thorough cleaning methods (which would remove nearly 100% of the cyanobacteria in the cleaned area) are likely to result in a significant growth lag as the cleaned area is repopulated. Partial cleaning (which attempts to maintain a certain percentage of the organisms in the cleaned area) appears to be the better choice for an overall optimum level of CO₂ uptake. Research into cleaning methods has identified the commonly used water-jet cleaning method as the most likely to provide the controllability, flexibility, cost, and performance necessary for a successful harvesting system design. Therefore, experiments to date have focused on determining parameters that maximize the performance of a water-jet cleaning system for the carbon recycling facility experimental setup.

The water-jet system design parameters currently under investigation include

1. Nozzle types

2. Orientation angle of water-jet (relative to plate being cleaned)

3. Impact velocity of the water-jet on the area to be cleaned

4. Spray time, or the amount of time the spray is held on the area to be cleaned

Enhanced Practical Photosynthetic CO _ Mitigation ( Results to date show desirable cleaning performance from a water-jet system consisting of a 90° low-flow full-cone whirl nozzle with its centerline oriented at an angle of 46° relative to the growth surface, using 10-psi line pressure and a spray time of 5 seconds. The organisms remaining in the partially cleaned area after the spray cleaning were examined and were found to be healthy and capable of continued growth.

One of the difficulties encountered in this and other experiments is that the total mass of the cyanobacteria involved is small, and the change in mass (for instance before and after a cleaning operation) is even smaller, so special dry-weight methods for comparison are often required to make meaningful comparisons. Therefore, another focus of our efforts has been on developing improved test procedures to simplify data collection over the duration of this project. One alternative technique, being investigated for approximating changes in the mass of cyanobacteria on a growth surface, is comparative image analysis. Digital images of the growth surfaces taken at different times can be processed using image analysis techniques and characteristics of the images can be compared. If changes in certain characteristics (either color based or density based) can be reliably calibrated with measured changes in mass, then image analysis may be used to simplify and speed up the test process and ultimately automate the cleaning process (i.e. to provide a real-time determination of when the surface needs to be cleaned). We are currently working to establish the calibrations and to better understand the capabilities of the image analysis process (accuracy, sensitivity, etc.).

Only limited amounts of work have been completed on subtasks 1.5.2, 1.5.3, 1.5.4, and 1.5.5. Specifically, for subtask 1.5.2 we are waiting on more detailed results about the growth characteristics of specific thermophilic organisms before determining and testing harvesting schedules. Methods for differentiating between live and dead organisms (1.5.3) have been identified but have not been tested thoroughly, and separation methods (1.5.3) and repopulation methods (1.5.5) will be studied later in the project with reference to continuous harvesting systems. Examination of methods for processing harvested algae for end use and/or reuse in the CRF (1.5.4) have been started but there are no major findings to report.

Subtask 1.6 Quantify properties (higher heating value, elemental composition, volatile content) of dried biomass for potential end-uses.

A Ph.D. student involved in the project is currently researching this task. He has started by examining the literature on potential end-uses of biomass other than as a directly combustible fuel. Several potential end-uses have been identified, but more details are needed.

Webpage

The web page is running at http://www.ent.ohiou.edu/~bayless2/CO2. All parties involved in the project will receive e-mail instructions and the password to access the information.

Enhanced Practical Photosynthetic C0₂ Mitigation ( Conclusions

While the data collected this quarter is insufficient to draw strong conclusions, it has helped to direct the work for the upcoming quarter. Specifically, some of the tasks that will be undertaken in the next quarter include

• When culturing has sufficiently progressed, begin growth rate measurements under extreme (140°F⁺) conditions in various flue gas compositions

• Continue fundamental testing of growth surfaces, organism adhesion, and intrinsic growth rates

• Continue modification of translating slug flow reactor and begin basic testing of soluble carbon species concentrations versus flow conditions

• Deliver lighting system containment to Oak Ridge to begin fiber testing schemes

• Continue optical- and mass-based harvesting experiments with water spraying

Finally, because the rate of progress has increased greatly over the last two months, the web page with weekly progress reports to provide a greater level of project feedback.

Enhanced Practical Photosynthetic C0₂ Mitigation (R Report Title: Enhanced Practical Photosynthetic CO₂ Mitigation Type of Report: Quarterly Technical Report

Period Start: 01/03/2001 Period End: 04/02/2001

Principal Authors: Dr. David J. Bayless Dr. Morgan Vis Dr. Gregory Kremer Dr. Michael Prudich

Date Issued: 04/16/2001 DOE Award No. DE-FC26-00NT40932

Organization: Ohio Coal Research Center Department of Microbiology Division of Photonics 248 Stocker Center LW-113B Oak Ridge National Labora Athens, OH 45701-2979 Montana State University P.O. Box 2009, MS-8058 bayless@ohio.edu Bozeman, Montana 59717 Oak Ridge, TN 32831 (740) 593 0264 voice umbkc@gemini.oscs.montana.edu um4@ornl.gov (740) 593 0476 fax

Enhanced Practical Photosynthetic C0₂ Mitigation (R Abstract

This quarterly report documents significant achievements in the Enhanced Practical Photosynthetic CO₂ Mitigation project during the period from 1/03/2001 through 4/02/2001. Many of the activities and accomplishments are continuations of work initiated and reported in last quarter's status report.

Major activities and accomplishments for this quarter include:

• Three sites in Yellowstone National Park have been identified that may contain suitable organisms for use in a bioreactor

• Full-scale culturing of one thermophilic organism from Yellowstone has progressed to the point that there is a sufficient quantity to test this organism in the model-scale bioreactor

• The effects of the additive monoethanolamine on the growth of one thermophilic organism from Yellowstone has been tested

• Testing of growth surface adhesion and properties is continuing

Construction of a larger model-scale bioreactor to improve and expand testing capabilities is completed and the facility is undergoing proof tests

• Model-scale bioreactor tests examining the effects of CO₂ concentration levels and lighting levels on organism growth rates are continuing

• Alternative fiber optic based deep-penetration light delivery systems for use in the pilot-scale bioreactor have been designed, constructed and tested

• An existing slug flow reactor system has been modified for use in this project, and a proof- of-concept test plan has been developed for the slug flow reactor

• Research and testing of water-jet harvesting techniques is continuing, and a harvesting system has been designed for use in the model-scale bioreactor

• The investigation of comparative digital image analysis as a means for determining the "density" of algae on a growth surface is continuing

Enhanced Practical Photosynthetic C0₂ Mitigation (R Table of Contents Page Results and Discussion 1

Subtask 1.1 - Investigate critical properties of alternative photosynthetic agents 1

Subtask 1.1.1 - Quantify agent growth rate characteristics in controlled experiments as a function of temperature, bicarbonate concentration, moisture content and nutrient level 1

Subtask 1.1.2 - Quantify adhesion characteristics 2

Subtask 1.1.3 - Quantify growth characteristics for harvesting considerations 2

Subtask 1.1.4 - Quantify growth characteristics at low temperatures for analysis of environmental impacts should there be loss of containment 3

Subtask 1.2 - Design deep-penetration light delivery subsystem 3

High-Efficiency Holographic Diffusing Element 4

Design and Construction of an "Illumination Rod" 4

Design and Construction of an "Illumination Sheet" 5

Subtask 1.3 - Investigate growth surface subsystem design 8

Subtask 1.4 - Investigate the use of a hydraulic jumps to improve the system's overall

C02 conversion efficiency 8

Subtask 1.5 - Design harvesting subsystem 9

Subtask 1.5.1 - Examine harvesting methods for efficiency of biomass removal....10

Improving/Expanding the Experimental Facilities for Harvesting Tests 12

Comparative Digital Image Analysis to Improve the Experimental

Procedure 12

Subtask 1.6 - Quantify properties of dried biomass for potential end-uses 14

Other Experiments 14

Summary of Test Run 01/17-22/01 14

Summary of Test Run 02/28/01-03/05/01 17

Webpage 18

Conclusion ... 18

Figures

Figure 1 - Effects of monoethanolamine on the thermophillic organism from Yellowstone 1

Figure 2 - Alternative light delivery systems 3

Figure 3 - Illumination Rod 5

Figure 4 - Illumination

Sheet 6

Figure 5 - Intensity Distribution of Illumination 7

Figure 6 - Plate and nozzle orientations and parameters 11

Figure 7 - Full-cone nozzle coverage patterns 11

Figure 8 — Theoretical coverage pattern for Flat fan Nozzle 12

Figure 9 - Growth surface images before and after water-jet cleaning, used in the comparative image analysis 13-14

Enhanced Practical Photosynthetic CO _ Mitigation (R0 Results and Discussion

Subtask 1.1 Investigate critical properties of alternative photosynthetic agents (cyanobacteria) 1.1.1 Quantify agent growth rate characteristics in controlled experiments as a function of temperature, bicarbonate concentration, moisture content and nutrient level a. A 30-gallon tank of the Yellowstone organism was initiated. The culture is being grown in 1/2 strength Allen's media as per the results of the earlier tests nutrient concentration with growth. i. This culture is doing well and producing much biomass so that it will be ready for use in the next stage of experiments. The 5-gallon cultures of other potential organisms are being maintained. b. Experiments on the effects of the monoethanolamine were carried out for the thermophillic organism from Yellowstone. The experimental design was as follows:

6 replicate cultures of each of 3 treatments were utilized for a total of 18 cultures. The treatments were 10% monoethanolamine, 5% monoethanolamine and no monoethanolamine in Allen's Modified Medium that is used to grow the thermophillic organisms. We hypothesized that the monoethanolamine would have little effect on the growth of the thermophilic organisms. The cultures were sampled at Day 7 and 14. The results showed that the 10% killed the cells within a week (no cells counted) and 5% significantly inhibited growth compared with the control (Figure 1). Further testing of the monoethanolamine will be conducted in order to determine if very low levels can be tolerated.

Figure 1. Effects of monoethanolamine on the thermophillic organism from Yellowstone c. Yellowstone Park scientists who work with the park GPS database have been contacted . Sites have been selected which, given the temperature and pH requirements of the carbon dioxide mitigation system are likely to hold suitable organisms. Three sites have been identified.

Enhanced Practical Photosynthetic CO _ Mitigation (R0 d. Since the Yellowstone National Park is not open to foot traffic until May, we have obtained cyanobacterial strains from culture collections here and in other places. Dr. David Ward's lab [Montana State University] has helped us with some organisms, but the greatest potential source is the collection of Dr. Richard Castenholz at the University of Oregon. Dr. Castenholz is a Visiting Fellow at the Thermal Biology Institute at MSU and we expect to continue to collaborate with him. The strains we have received are : Synechococcus C-l, Synechococcus P-2, Oscillatoria sp. and K- Borgonia. Attempts to cultivate Oscillatoria sp. were unsuccessful. Synechococcus P- 1 showed very slow growth and therefore we have stopped working with this culture. The doubling time for Synechococcus C-l into media D and BG-11 is about 2-4 days. Now we are comparing the growth of K-Borgonia in media D and BG-11. e. Frozen stocks of Synechococcus C-l, P-2 and K-Borgonia have been prepared. Control re-growth experiments have been done. The cultures were recovered successfully. f. It was shown that Chi a extraction with methanol is to be better than with 90% acetone in water. This is now used routinely to determine chlorophyll as a biomass indicator. g. We have studied the effect of medium pH on the growth of Synechococcus C-l in buffered BG-11 media. This experiment showed that alkalinity stimulated the growth of C-l during lag-phase and initial log-phase. On the other hand the alkalinity stimulated the aging (death) of cultures. Neutral pH slows down the division of Synechococcus C-l. h. The addition of NaHCO₃ (1,5 and 10 mM) shortened the lag-phase of Synechococcus C-l in BG-11 medium, but dramatically stimulated the alkalinization of media and consequently the death of cyanobacteria. Since the addition of sodium bicarbonate had negative effects, we will investigate whether this could be a general effect of alkalinity or a negative effect of increased sodium ions.

1.1.2 Quantify adhesion characteristics a. We have carried out a survey of potential media gelling agents for thermotolerant cyanobacteria. Agar [Difco], Gelrite [Kelco-Merck ] and agarose [Seakem] were compared. Agarose appeared to have the best properties at 50deg C, although with care, agar is usable at this temperature. b. An initial experiment to measure the adhesion to a glass surface of Synechococcus C- 1 has been done. It appears that surface adhesion may involve calcium. c. In initial experiments, Synechococcus C-l appeared to have better adhesion [ greater biomass/area] on plastic than glass. Conditions for adhesion are being optimized. d. K-Borgonia adheres to both hydrophilic and hydrophobic surfaces.

1.1.3 Quantify growth characteristics (size when mature and average time to mature) for harvesting considerations a. The incubation facility [light, temperature control] has been constructed. We await delivery of the tubes that will fit in the incubation system. b. Because it will be important to know the viability of cells harvested from the CRF before they are used for re-inoculation puφoses, we have developed a live/dead test for microalgae The test depends on staining with the fluorescent dye Sytox Green The

Enhanced Practical Photosynthetic CO _ Mitigation (R dye binds to DNA and can only enter a cell if the cell membrane is compromised. Dead or dying cells stain with a yellow/green fluorescence. Live cells do not take up the stain and can be seen by their red [chlorophyll] fluorescence at another wavelength.

1.1.4 Quantify growth characteristics at low temperatures for analysis of environmental impacts should there be loss of containment. No progress made this quarter.

Subtask 1.2 Design deep-penetration light delivery subsystem

Development of a deep-penetration light delivery subsystem for use in a pilot-scale bioreactor setup is proceeding as scheduled. The three unique light delivery systems illustrated in Figure 2 are in various stages of construction and testing.

Diffuse Surface

(a) Holographic Diffusion of a Fiber Source (b) Fiber Illuminated Cylindrical Diffusing Rod

c) Side-Emitting Fiber Illumination Sheet

Figure 2. Alternative light delivery systems

Enhanced Practical Photosynthetic CO ₂ Mitigation (R Figure 2a illustrates a technique for the high-angle dispersion of light from an optical fiber using holographic diffusers. Holographic diffusers (Light Shaping Diffusers®) are used in combination with a collimating Fresnel lens to provide a potentially efficient (>85%) and controllable method for diffusing light across a large area. Figure 2b illustrates a technique for creating a fiber-illuminated cylindrical diffusing rod. This "illumination rod" is designed to mimic the dimensions of a standard T-8 fluorescent tube and creates diffuse illumination across a 180° angle below the rod. Figure 2c illustrates a technique for creating a planar sheet of near constant illumination. The "illumination sheet" utilizes a side-emitting fiber, which can be formed into various patterns, to produce various desired intensity distributions. All three techniques appear promising and the status of efforts to test and construct each device are described below.

High-Efficiency Holographic Diffusing Element

Design and construction of a high-efficiency holographic diffusing element is on hold pending the arrival of several Light Shaping Diffusers® from Physical Optics Coφoration. Expected delivery is end of April.

Design and Construction of an "Illumination Rod"

A design for the cylindrical diffusing rod, shown in Figure 2b, was developed using ZEMAX optical modeling software. The design consisted of a 2.54 cm. diameter, 1.0 meter long, optically clear cylinder with a polished lower hemisphere and a diffuse upper hemisphere. Light launched from a butt-coupled optical fiber scatters from the diffuse upper surface of the cylinder and escapes through the polished lower surface of the cylinder. To improve efficiency, upward- scattered light is redirected back toward the lower hemisphere of the diffusing rod through a silver coating on the rod's upper hemisphere. A silver-coated concave surface at the end of the rod is used to diverge low-angle incident light which has reached the end of the rod unscattered. This addition improves the optical efficiency of the diffusing rod while also improving the overall uniformity of the scattered light. A series of parallel illumination rods, placed within close proximity to one another, would provide an approximately uniform plane of light. The number of illumination rods required would be dependent on the amount of light desired and the total area to be illuminated.

An illumination rod was constructed from a 2.54 cm. diameter, 1 meter long, cast acrylic rod, with high optical clarity and optically smooth outer surface. The rod was diamond-machined on one end to create a concave surface with a radius of curvature of 4.0 cm, and polished on the other end to create a planar optical surface suitable for butt-coupling to a large-core optical fiber. The top hemisphere of the rod was sandblasted to produce a uniform scattering surface and both the top hemisphere and concave end-mirror were coated with aluminum.

Preliminary testing of the cylindrical diffusing rod revealed a discrepancy between the desired modeled surface scatter of the rod's top hemisphere and the actual surface scatter created by the sandblasting technique. Because optical scattering is often difficult to accurately pre-model in software, the result was not entirely unexpected. The difference in surface scatter unfortunately created a diffusing rod with an uneven illumination and low efficiency, see Figure 3.

Enhanced Practical Photosynthetic C0₂ Mitigation (R0 ill

Figure 3. Illumination Rod

However, now given the correlation between the modeled scattering values and the manufactured scattering values, it may be possible to re-simulate and re-design the current illumination rod to produce a more uniform intensity distribution. Before revisions are undertaken, additional factors related to optical efficiency, construction costs, and integration issues are first being evaluated.

Design and Construction of an "Illumination Sheet"

Greater success was achieved with the development of the "illumination sheet" shown in Figure 2c. The illumination sheet consisted of 10 meters of side-emitting optical fiber, which is sandwiched between two clear plexiglass sheets. . The optical fiber is formed into a seφentine pattern before being mounted in the plexiglass frame. Aluminum c-channels hold the assembly together. A mirror, fixed to the end of the optical fiber, reflects light back toward an optical source. The reflecting mirror greatly improves the efficiency and intensity distribution of the illumination sheet. The illumination sheet emits light from both sides of the sheet.

During construction, an additional 1/8" thick, 2' x 4' prismatic diffusing sheet was added to each side of the illumination sheet to improve diffusion. In addition, a 4" strip of highly-reflective tape was added across the top and bottom portions of the illumination sheet. The reflective tape redirected light being lost at the curved portions of the seφentined fiber. The finished 7/8" thick illumination sheet is shown in Figure 4.

Enhanced Practical Photosynthetic CO ₂ Mitigation (R0

a) Final Design of Illumination Sheet, b) Final Construction of Illumination Sheet

Figure 4. Illumination Sheet

A measurement of the illumination sheet's intensity distribution was acquired 2.75" above the surface of the illumination sheet. No algae screen or other diffusing material was placed in the plane of measurement. The normalized intensity distribution (normalized to produce a range from 0% to 100% illuminance) is shown in Figure 5. The white box in Figure 5 identifies the approximate location and size of a typical algae screen relative to the illumination sheet.

Enhanced Practical Photosynthetic C0₂ Mitigation (R Relative Intensity Distribution Illumination Sheet (Serpentine Design #1)

X Data (inches) Figure 5. Intensity Distribution of Illumination

Figure 5 shows areas of increased illuminance ("hot spots") corresponding to light leakage near fiber bends and near "scarred" portions of the fiber. Reductions in the occurrence and magnitude of these "hot spots" should be possible in future designs through more careful construction and assembly techniques. The average intensity difference across the sheet falls from 49% (far right) to 21% (far left). Ideally, a 1:1 intensity ratio across the width of the sheet is desired, however, the current 2.3:1 intensity ratio is very promising. Immediate improvements can be made to the current design, and are underway, to more closely approach a 1 :1 intensity ratio.

When a diffusing material such as an algae screen is placed in the plane of measurement, the current illumination sheet's intensity distribution is observed to become considerably more uniform across the surface of the screen. The screen's natural surface structure combines with the reflective properties of the illumination sheet's plexiglass housing, to act as a large optical integrator which effectively smoothes the intensity distribution shown in Figure 4. However, because the algae screen may exhibit various surface properties (sometimes wet, sometime dry, etc.), the optical properties of the algae screen must be considered but NOT depended upon for the proper performance of the illumination sheet. Therefore, design improvements and additional testing must still continue to create an illumination sheet which properly performs and exhibits a 1 :1 intensity under all circumstances.

Enhanced Practical Photosynthetic C0₂ Mitigation ( The 2' x 4' illumination sheet shown in Figure 4 is designed to be cascade-able. For example, three illumination sheets can be connected together to create one 4' x 6' illumination sheet. Each 2' x 4' section requires one optical fiber to supply the necessary amount of solar light. Consequently, a 4' x 6' illumination sheet would require three fiber connections to an outside solar collector. This scalable property greatly simplifies the requirements on the design of the solar collector.

Currently, the illumination sheet design appears to be the most promising technique for uniform illumination of close proximity algae screens. This technique will continue to be studied and improved with additional prototypes constructed and tested. Variations in the seφentine pattern of the side-emitting optical fiber, improvements to the method of mounting the optical fiber, and reductions in the optical loss associated with bend radius will be studied. Accurate efficiency measurements of all the techniques will be conducted with the arrival of new large-area camera- based optical measurement tools.

Subtask 1.3 Investigate growth surface subsystem design

1.3.1 Examine surface configuration for effects on growth and harvesting a. One of the first choices for a potential support for the biomass in the carbon remediation facility was Scotch Brite [3-M Co.]- a nylon based polymer with aluminum oxide grafted onto it. This product proved to be toxic to at least one cyanobacterial species with which we are working.

Subtask 1.4 Investigate the use of a hydraulic jump to improve the system's overall CO₂ conversion efficiency

All the modifications of the slug flow reactor system housed at the Institute for Multiphase Technology at Ohio University have been finished. Identified modifications included:

(1) Conversion of reactor from vertical configuration to horizontal flow;

(2) Addition of a second gas inlet stream for the ability to deliver 15% CO₂ in 85% N_2;

(3) Addition of gas sampling ports prior to the inlet and at the exit of the reactor;

(4) Addition of liquid sampling ports prior to the inlet and at the exit of the reactor;

(5) Addition of thermocouples prior to the inlet and at the exit of the reactor;

(6) Addition of a differential pressure transducer to monitor pressure drop in reactor;

(7) Addition of heater and its controller prior to the gas inlet of the reactor;

(8) Additions of N₂ and CO₂ flow meters prior to the gas inlet of the reactor.

In order to get a more accurate data of gas concentration changes, a decision was made to sample the gas continuously at the exit of the reactor, as well as at the inlet of the reactor. As a result, two problems appear, the first is that two gas analyzers are needed to detect two samples at the same time. The second is the liquid that goes out with gas when sampling at the exit end should be removed before entering the analyzer. To solve the first problem, another gas analyzer was

Enhanced Practical Photosynthetic CO ₂ Mitigation (R ordered and will arrive soon. As for the second problem, we have identified a continuous gas sampling system that not only removes the water but decreases the test error to a minimum as well.

Pure water and Sodium Hydroxide solution will both be used to scrub CO2 from flue gas in the coming experiments. 50Kg Sodium Hydroxide was bought to make the solution. To measure the actual concentrations of carbonate and bicarbonate ions, titration will be applied. Sulfiiric Acid, which will be used as titration solution, was ordered and already came to the lab. The essential equipment for titration, pH meters and burets were prepared.

Tests will be started in the weeks ahead. The experimental parameters were decided (see following tables).

(1) Liquid velocity: lm/s (125gpm), gas velocity: 6m/s (102scfrn), CO₂ concentration: 15%; liquid: water;

(2) Liquid velocity: lm/s (125gpm), gas velocity: 6m/s (102scfm), CO₂ concentration: 15%; liquid: NaOH + water solution;

(3) Liquid velocity: lm/s (125gmp), gas velocity: 2m/s (34scfrn), CO concentration: 15%; liquid: NaOH + water solution;

(4) Liquid velocity: lm/s (125gmp), gas velocity: lOm/s (170scfrn), CO concentration: 15%; liquid: NaOH + water solution;

For each above condition, we can achieve the following data from the meters, transducers and analyzers with the time change.

Note: * indicate the time to acquire data

Enhanced Practical Photosynthetic C0₂ Mitigation (R0 Subtask 1.5 Design harvesting subsystem

In an effort to develop a harvesting system for use in the model-scale to pilot-scale bioreactors we have continued our examination of alternative harvesting methods and have also focused on improving our test facilities and procedures to provide more meaningful experimental results. Specific activities supporting the design of the harvesting system are detailed below.

Subtask 1.5.1 Examine harvesting methods for efficiency of biomass removal

As previously reported, a harvesting method that provides partial cleaning (maintaining a certain percentage of the organisms in the cleaned area) appears desirable to avoid growth lag. The commonly used water-jet cleaning method is currently the leading alternative for providing a gentle and partial cleaning of the growth surfaces because of the wide variety of nozzle types available and the good controllability of the cleaning action via control of supply pressure, offset distance, and incidence angle. Current harvesting system experiments are focused on proving that the water-jet system will work well for this application and determining target parameter values that work best for specific combinations of organisms and growth surfaces.

Water-jet system design parameters currently under investigation, including a summary of experimental results to date

1. Nozzle types

A series of 12 tests have been completed investigating the cleaning performance of two different types of nozzles for removing Nostoc algae from polyester fabric growth surfaces. A 90 degree low-flow full-cone whirl nozzle and a 90 degree flat-fan nozzle have both been tested and their practical coverage area and percent algae removal have been determined for common spray conditions (incidence angle approximately normal to the surface, with 10 psi gage supply line pressure and a spray time of 5 seconds). See Figures 6-8 below for nozzle spray patterns. Results from these tests showed that: a) the full-cone nozzle provides a good balance between a large coverage area and a gentle partial cleaning for these test conditions, b) the flat fan nozzle could be effective in applications where it is rotated or swept but it is not appropriate for fixed nozzle applications because of its significantly reduced coverage area, and c) the actual coverage area for the full-cone nozzle is about 85% of the theoretical coverage area based on the manufacturer's specifications.

2. Incidence angle of water-jet centerline (relative to plate being cleaned) The original harvesting test experimental setup had the plates and the nozzles set at a fixed orientation angle. This setup has recently been modified to run a new set of experiments to determine the effect of the angle of incidence between the water jet and the growth surface on the cleaning effectiveness in the area of direct impact. Algae will be placed on the screens only in the area of direct impact (rather than completely covering the screens) so that a direct determination of percent of algae removed in the direct impact area can be found from a comparison of the dry mass of algae removed from the screens and the dry mass of algae remaining on the screens. Various incidence angles will be run and results of these tests will be used to inform the design of the harvesting systems for the CRF-1. and the pilot scale bioreactor. These experiments are underway and results will be reported when available.

Enhanced Practical Photosynthetic CO _ Mitigation (R 3. Impact velocity of the water-jet on the area to be cleaned

The required level of water-jet impact velocity is currently unknown, and it is expected that it will vary considerably for different combinations of organisms and growth surfaces due to differences in adhesion properties. Once more information is gathered on adhesion properties for specific organisms we will design and conduct experiments to test the required level of impact velocity. The experiments will have to account for the fact that impact velocity is a function of many factors, including nozzle type, offset distance, and supply pressure.

4. Spray time, or the amount of time the spray is held on the area to be cleaned This is an additional parameter that will eventually be tested, especially in relation to larger screen sizes. No experiments have been run yet for this parameter.

Spray distance

Figure 6. Plate and nozzle orientations and parameters

Enhanced Practical Photosynthetic CO ₂ Mitigation ( 90 degree Ml cone nozzfe withe O angle of rotation :

90 degree fuli cone nozzle with angle of rotation as thβta.

Figure 7. Full-cone nozzle coverage patterns

Area In gray (FGHI) Is the effective cleaning area every theoretical coverage of the 90 degree flat fan nozzle. Assmlng nozzles spaced transversely at every coverage width. Spray angle = 45 degree (according to the table below)

Area of FGHI = 140 cm²

Figure 8. Theoretical coverage pattern for Flat fan Nozzle.

Enhanced Practical Photosynthetic CO ₂ Mitigation (R Improving/Expanding the Experimental Facilities for Harvesting Tests The current harvesting system test setup is separate from the CRF test facility, which is fine for studying basic parameters and "proof-of-concept". Since an enlarged bioreactor test system (CRF-2) has been constructed, the original CRF will soon be available for harvesting system experiments. Testing harvesting systems in the CRF will lead to more realistic results since the algae will have time to grow and attach to the growth surfaces before the harvesting step is initiated, and the CRF system can be run continuously after harvesting to determine the sustained growth of the algae remaining on the screens. Various harvesting schedules and "removal percentages" will be tested. An analytic study of nozzle types, plate and nozzle spacings, and nozzle orientation angles based on existing experimental results has been completed to determine a preliminary harvesting system design. The proposed design for the CRF water-jet harvesting system uses full-cone whirl nozzles with fixed position and orientation, with the constraint that the number and the spacing of the growth plates should be kept the same as it has been in the previous tests. For the current CRF growth plates 9 nozzles oriented at an angle between 30 and 40 degrees (relative to the vertically suspended plates) are needed for each plate to achieve direct impact coverage of the entire surface. See Figures 1.5-1 and 1.5-2 for more information. The current CRF "processing chamber" that holds the plates will have to be modified to allow extra space for the water-jet equipment since we want to keep the screen sizes the same as in the previous CRF tests. The current plan is to build an extension on top of the current box large enough to house the water-jet harvesting system.

Comparative Digital Image Analysis to improve the experimental procedure As previously reported, comparative image analysis is being investigated because it appears to have the potential to simplify data collection over the duration of this project and to offer a means for automated monitoring of growth surface status during experiments which may allow for an intelligent harvesting system. We are still working to establish the calibrations and to better understand the capabilities of the image analysis process (accuracy, sensitivity, etc.), but preliminary results are encouraging.

An image similarity analysis was completed for three digital images of growth surface plates (shown in Figure 1.5-4), a new screen (with no algae loaded), a screen "fully loaded" with algae, and the same screen after a cleaning cycle with the full-flow cone nozzle setup. An Edge detected Radon transformation algorithm was used to compute similarity measures for the three images. The "fully loaded" screen had a similarity measure of 0.0026 relative to the new screen (meaning they are not at all similar), and the "cleaned area" of the screen had a similarity measure of 0.8306 relative to the new screen (meaning that they are about 83% similar). These results seem very meaningful relative to the area of the images being compared, so we will continue to investigate the correlation between image analysis similarity measures and the experimentally determined dry mass percentage differences using these images and images from future harvesting tests. For future tests we will focus on getting better pictures that are similar in all manners except the amount of algae on the screen, making sure the frame and background do not influence the results.

Enhanced Practical Photosynthetic C0₂ Mitigation (R

a) Corner of Original screen - Before algae applied

b) Corner of screen after algae was applied

c) Corner of screen after water-jet cleaning ,

Figure 9. Growth surface images before and after water-jet cleaning, used in the comparative image analysis

Enhanced Practical Photosynthetic CO ₂ Mitigation (R02 Subtask 1.6 Quantify properties (higher heating value, elemental composition, volatile content) of dried biomass for potential end-uses.

No experimental work has been completed in this area. The investigation of alternative end-uses of biomass other than as a directly combustible fuel is continuing. A detailed literature and internet search has been completed several potential end-uses have been identified, but more information is needed.

Other Experiments

In addition to the work reported above for the specific subtasks, a large amount of work went into development of improved model-scale experimental facilities as well as preliminary testing in the existing bioreactor facility (the Carbon Recycling Facility). The results of two bioreactor test runs in the existing bioreactor facility are summarized below.

Summary of Test Run 01/17-22/01

The test specimen for Test Run 01/17-22/01 was the cyanobacteria, Nostoc 86-3. The target values for the gas concentrations were 3%, 10% and less than 50 parts per million for oxygen, carbon dioxide, and carbon monoxide, respectively, with a temperature range between 120°F- 125°F. The gas concentration averages for the 120 hours were 3.53%, 9.90%, and 36.32 ppm for oxygen, carbon dioxide, and carbon monoxide, respectively. The 120-hour temperature average was 120.9°F.

The lighting was not altered from Summary of Light Intensity Test (thru 10-10-00) and was cycled 12-hours on, and 12-hours off. The intensity averages for the four membranes were 117.5 μmols/s-m² for membrane-1, 130.9 μmols/s-m² for membrane-2, 141.5 μmols/s-m² for membrane-3, and 150.3 μmols/s-m² for membrane-4

Test Run 01/17-22/01 had a total dry algae mass gain of 1.37 grams, or a 31.1 % increase over the estimated initial dry mass. The following table describes each membrane and final test results.

Enhanced Practical Photosynthetic C0 Mitigation (R The uncertainty analysis for this test run is based on the results from the Algae Dry Mass Determination Test and the final results of Test Run 01.17-22.01. From the Algae Dry Mass Determination Test, the average percent dry mass of the initial twelve samples was 4.46% with a standard deviation of 0.19%. The same technique used to gather the twelve initial samples was used to load the membrane. An algae sample taken from the bulk tank was poured across a wire mesh to remove most of the water content, but still retaining the algae mass. The sample remained on the wire mesh for 9-minutes to further reduce water content. The remaining sample was scooped into a beaker and weighed. The algae sample in the beaker was then applied to the membrane and the beaker was weighed again to determine the algae loading weight. This was repeated for each membrane. 4.4581% of the total loading wet weight was used as the initial estimated dry mass for each membrane.

Data from Algae Dry Mass Determination Test, Test Run 01.17-22.01 and Student's redistribution:

Mean = 4.4581%

Std. Dev = 0.1933%

Degree's of freedom = 11 (based on Student's t-distribution for 12 samples) tg₀ = 1.796 ( Student's t-distribution for 12 samples)

Uncertainty =

t = Student's t-distribution for 12 samples at 90% confidence σ = Standard deviation of the 12 samples n = Number of samples applied to membrane-1

Uncertainty₉₀ = 1.796x0.1933% = 0.1735%

Algae wet weight applied to Membrane-1 = 26.3690 grams Uncertainty of estimated dry weighty 26.3690 x 0.001735 = ± 0.04575 grams Estimated initial dry weight = 26.3690 x 0.044581 = 1.1755 ± 0.04575 grams Mass gain for Membrane-1 = Membrane-1 final dry weight - initial dry weight

= 0.1413 grams

Uncertaintyon = — x 100 = 32.4% (uncertainty of mass gain at 90% confidence)

0.1413

Enhanced Practical Photosynthetic C0₂ Mitigation ( The following table depicts the uncertainty of the mass gain for each membrane.

The second uncertainty analysis is on a total mass gain basis for the four membranes, instead of the mass gain for each membrane. The benefit of this uncertainty analysis is that the four membranes are looked at as four samples for the total mass gain, which will increase the number of samples in the uncertainty equation. All other values remain the same as in the above calculation.

Uncertainty₉₀ = 1.796x0.1933% = 0.1736% A^~ Total wet weight applied to membranes = 99.0896 grams Uncertainty of total estimated dry weight = 99.0896 x 0.001736 = ± 0.1720 grams Estimated initial dry weight = 99.0896 x 0.044581 = 4.4175 ± 0.1720 grams • Total algae mass gain (from membranes) for test run = 0.5758 grams 0.1720g

Uncertaintygo = x 100 = 29.9% (uncertainty of mass gain at 90% confidence)

0.5758

The following table depicts the uncertainty values on a total mass basis for the four membranes combined.

The results conclude with 90% certainty that the mass gain oϊ Test Run 01.17-22.01 was 1.3724 ± 0.4103 grams, i.e. the mass gain was between 0.9621 grams and 1.7827 grams.

The total uncertainty associated with the scale (used for mass measurements) is estimated as a root-sum-square of the repeatability uncertainty, the resolution uncertainty, and the calibration uncertainty. The following calculation is the uncertainty at 95% confidence.

Uncertainty₉₅= (2 0.00015g)² + (0.0001^ /2)² + (0.0002g)² = +0.00036g

This would be the uncertainty for a single measurement made with this device. Since the uncertainty associated with the scale is so small, with respect to the uncertainties calculated for the mass gains, the uncertainty in the scale is neglected.

Enhanced Practical Photosynthetic C0₂ Mitigation (R Summary of Test Run 2/28/01-3/5/01

The test specimen for Test Run 02/28/01-03/5/01 was the cyanobacteria, Nostoc 86-3. The target values for the gas concentrations were 3%, 10% and less than 50 parts per million for oxygen, carbon dioxide, and carbon monoxide, respectively, with a temperature range between 120°F- 125°F. The gas concentration averages for the 120 hours were 3.30%, 9.98%, and 42.58 ppm for oxygen, carbon dioxide, and carbon monoxide, respectively. The 120-hour temperature average was 120.2°F.

The lighting was not altered from Summary of Light Intensity Test for Test Run 2.28.01-3.5.01 and was cycled 12-hours on, and 12-hours off. The intensity averages for the four membranes were 47.3 μmols/s-m² for membrane-1, 54.0 μmols/s-m² for membrane-2, 50.9 μmols/s-m² for membrane-3, and 62.4 μmols/s-m² for membrane-4

Test Run 01/17-22/01 had a total dry algae mass gain of 1.33 grams, or a 33.6% increase over the initial estimated dry mass. The following table describes each membrane and final test results.

The uncertainty analysis was conducted following the same procedure outlined above. The following tables depict the uncertainty of the mass gain for each membrane and four the four membranes combined.

The results conclude with 90% certainty that the mass gain oϊ Test Run 02.28-3.5.01 was 1.3281 ± 0.6388 grams, i.e. the mass gain was between 0.6893 grams and 1.9670 grams.

Enhanced Practical Photosynthetic C0₂ Mitigation ( Webpage

The web page is running at http://132.235.19.45/DOE . All parties involved in the project will receive e-mail instructions and the password to access the information.

Conclusions

The activities and accomplishments detailed throughout this report indicate significant progress towards completion of project objectives. However, since we have just completed the second quarter of the project most of the test results are preliminary and the majority of the activities underway are focused primarily on development and improvement of test facilities rather than on definitive testing. The most significant preliminary test results and test facility developments are summarized below.

• Test results concerning organism responses to pH levels and chemical additives are being used in the selection of organisms for the bioreactor and for setting optimal conditions in the bioreactor.

• A side-emitting fiber illumination sheet has been identified as the leading alternative design for deep-penetration light delivery in the pilot-scale bioreactor.

• An improved model-scale bioreactor has been constructed and is currently undergiong proof testing.

• A slug flow reactor system has been modified and is nearly ready for proof-of-concept testing.

These activities and the others discussed in the report will be continued in the next quarter in support of the overall project objectives. Additionally, the search for appropriate thermophilic organisms in Yellowstone National Park will now be able to proceed since all regulatory impediments have been removed and the weather conditions will be favorable. Also, tests of one previously cultured Yellowstone thermophilic organism will be able to begin next quarter in the newly constructed model-scale bioreactor system since an adequate supply of the organism is now available, and longer duration model-scale bioreactor tests will be initiated in the original model-scale bioreactor after it has been retrofitted with a water-jet harvesting system.

Enhanced Practical Photosynthetic CO _ Mitigation (R Interim Report

(Economic Analysis is in the Appendix)

Report Title: Enhanced Practical Photosynthetic CO₂ Mitigation Type of Report: Quarterly Technical Report

Period Start: 04/03/2001 Period End: 07/02/2001

Principal Authors: Dr. Gregory Kremer Dr. David J. Bayless Dr. Morgan Vis Dr. Michael Prudich

Date Issued: 07/16/2001

DOE Award No.: DE-FC26-00NT40932

Organization: Ohio Coal Research Center Department of Microbiology Division of Photonics 248 Stocker Center LW-113B Oak Ridge National Laborato Athens, OH 45701-2979 Montana State University P.O. Box 2009, MS-8058 bayless@ohio.edu Bozeman, Montana 59717 Oak Ridge, TN 32831 (740) 593 0264 voice umbkc@gemini.oscs.montana.edu um4@oml.gov (740) 593 0476 αx

Enhanced Practical Photosynthetic CO ₂ Mitigation (R03 Abstract

This quarterly report documents significant achievements in the Enhanced Practical Photosynthetic CO₂ Mitigation project during the period from 4/03/2001 through 7/02/2001. Most of the achievements are milestones in our efforts to complete the tasks and subtasks that constitute the project objectives. Note that this version of the quarterly technical report is incomplete because reports were not received from subcontractors Montana State and Oak Ridge National Laboratories prior to the due date. A revised report will be issued after their reports are received.

The significant accomplishments for this quarter include:

• Development of an experimental plan and initiation of experiments to create a calibration curve that correlates algal chlorophyll levels with carbon levels (to simplify future experimental procedures)

• Completion of debugging of the slug flow reactor system, and development of a plan for testing the pressure drop of the slug flow reactor

• Design and development of a new bioreactor screen design which integrates the nutrient delivery drip system and the harvesting system

• Development of an experimental setup for testing the new integrated drip system / harvesting system

• Completion of model-scale bioreactor tests examining the effects of CO₂ concentration levels and lighting levels on Nostoc 86-3 growth rates

• Completion of the construction of a larger model-scale bioreactor to improve and expand testing capabilities and initiation of tests

• Substantial progress on construction of a pilot-scale bioreactor

Enhanced Practical Photosynthetic C0₂ Mitigation (R03

^ΓΠIHI ! I ! ! -"mni'i ι_rui(,_i'» (nπi.iliiπiiui n. in .uiila \ A

. I'lirnn I flllli ll .j) (.'* UJ >i HlHv l "II 1 -' U in OH

I o II r v IM ϋl II ' t uUl it I I

L'l i. i 1 ! _! - «^~»iι itini vlb HU lι n > i i m

i l ^"! -C'luntir <_r« h h rn, π n fr> ιiτ < MIL. <>Γ> ι» t >tm ~u{n ' 1 ^! -⁽ 'M) if ur th han.t ιι ti a i" ιcι ιp^">MU"u. loi Mil ' » HI L "Oi iti-m ii im v i »> uld ti ιt. I c '» '•.-ot „< m intjn.ni ' b I 1 , - rι I^»£I ΛΛJ r iru m»»ι» lij it ii.lt - "b kn ihJt-Lui i i Mi I » < _*(»!'/ r^>ι! >I HM EL u

P^"" 1JI ll' ^! I illl.M"llHl 'i llltl|ⁱ I I I"il f ( >J

P ! rt i i I * un irnϋini! oi in 111' n Hi f('< », ι

^ ιιbι ' 1 ^" - in t U-IIL - O ill HI iv υt> kind' »_cιι ^r'ftι r ' 1 11 - ^ t wn< writ.-' i lU iπuMn b i tr _' f» ι IT ^s HI _tm I liif tinj.

Itlu ' i -' - In 1l_e<ιι i H ,. t'f li ll tu||« (Hints l») flllliil'

_J ^fClil 'I ill!

^I'I <^•)<.⁾ i -M ι π Im < tm., ubs » m ¹(» uh > . > ^" I ~ C iirm I¹ ιr <, υi , ;n ιh <l i»n ill. ιι> _., J I JVM ,^« I HU «l In but ' ' t_^r r , i i i lu. _ji ,tj II in ,l f I iliin i i H >ι _ 1. * ι it ii ill Di-'t ' Ii 11L.. -¹ uαl ι I" [m[ u < ι!ι, fc. | .mat nl 1

l«ι ! * - πiιniι μi',L»iιc >^»ϊf ,ι U bu in » 101 } < jni l t ιJ-ι £

> til ii (i ui I i Pun »»'/1722 '11 ( nil i i n! |ι 1 T tilt <!„ . ,0 l ι )^"/(*

Win '

ΓJ-_ ire i - Ei d u>>sut Uh H 1 mini OIHW' Uunw hHjr < nv iti on > ι Ho t a ri_.nu _ - 'ι anti I Jit it ii » i.in ' llliihllll i r,ι I . if rι_feιnι - fl unin id ><i lv „ι

11 > JL ( i ' mill-, u 1 in ih oir m i

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) Results and Discussion

Task 1.0. Evaluate and rank component and subsystem level alternative design concepts Subtask 1.1 Investigate critical properties of alternative photosynthetic agents (cyanobacteria)

Efforts on this subtask continue both at Ohio University and at Montana State. Ohio University researchers are currently focused on developing improved procedures for quantifying organism growth rates on a large scale (for example in the bioreactor) by correlating algal chlorophyll levels with carbon levels. If successful, we only have to perform chlorophyll A measurements in the future rather than a more complicated, involved method for determining primary productivity. The experimental procedure that will be followed is included below. Step 1 (testing screens for heterogeneity) is currently underway. It is expected that actual test runs will begin the week of July 16^th.

Primary Productivity Protocol (PPP)

1. First, we must determine any heterogeneity of algal application within and among screens

- If there exists a zonation within the screens (i.e., more algae on the top than the bottom or vice verse), document that variation o As long as there is no vertical heterogeneity, horizontal patterns do not matter

- Using any zonation patterns, set up 4, 2x2 inch squares across the filters (see below)

- Employ three replicates up and down

1 whole screen

IA IB 1C ID

2A 2B 2C 2D

3A 2B 3C 3D

2. After a full test run (3 days), cut out all pre-selected areas

- samples A and C will be subjected to acetone extraction (see below)

- samples B and D will be subjected to C-analysis

3. Afterwards, correlation statistics will be performed

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) C-analysis

1. Ten non-inoculated, 2x2 inch squares will be placed in the C-analyzer to serve as blanks and determine variability within and between filters

2. Samples B and D from multiple filters (10 filters, for 60 total samples) will be dried at 50 C overnight and subjected to C analysis

Chlorophyll extraction

1. Soak each 2x2 filter piece in a cleaned test tube with 90% Mg-acetone solution

- continue for 24 h, with occasional agitation

2. Remove the filter, and measure the final volume of acetone

3. Filter the acetone mixture onto a GF/C filter

4. Place disks in aluminum foil, and freeze for later use

5. Send samples to BSA Environmental services for chlorophyll a analysis

Subtask 1.2 Design deep-penetration light delivery subsystem

No current report. Project status will be supplied by Oak Ridge National Laboratories and will be issued in a revised report.

Subtask 1.3 Investigate growth surface subsystem design

No current report. Project status will be supplied by Montana State and will be issued in a revised report.

The debugging work for the slug flow reactor has been finished, which includes checking the wiring of the transducers and flow meters and calibrating the pipeline pressure transducer, the differential pressure transducer and the orifice plate flow meter. Tests will begin as soon as test rig maintenance repairs are completed.

Considering the importance of pressure drop across the reactor, our first tests will focus on quantifying the pressure drop of the slug flow reactor and investigating how the gas and liquid velocities affect the pressure drop. The results of the pressure drop experiments will be used to optimize the gas and liquid velocities and understand the basic pressure drop of the slug flow reactor.

Once the pressure drop is understood we will begin the CO₂ solubility experiments, by which we will obtain CO solubility as a function of operating conditions such as slug frequency, CO₂ concentration additive, and pH. An operating condition that maximizes CO₂ solubility will be identified by these experiments.

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) The first additive that will be added to the water in order to improve the CO₂ solubility is sodium hydroxide. Titration will be applied to detect the concentration of OH^", HCO₃ ^" and CO₃ ^2". A carbon analyzer will be used to examine the total carbon content in the solution.

Subtask 1.5 Design harvesting subsystem

Results from preliminary tests of water jet harvesting systems have shown that sufficient cleaning can be obtained at relatively low flow velocities and shallow incidence angles. This information has caused us to shift our focus from nozzle-based water jet harvesting methods which spray water on the growth surfaces to differential pressure water supply systems that function as both nutrient delivery drip systems (at low delivery pressures) and algae harvesting systems (at high delivery pressures). The integrated system requires a special bioreactor screen design (shown in Figure 1) which delivers moisture to the screen via capillary action under normal operation, but which creates a high flow "sheeting action" of fluid which displaces a percentage of the algae clinging to the surface when the fluid delivery pressure is increased. The experimental setup constructed to allow testing of this new design is shown in Figure 2.

Figure la. Bioreactor screen with combined nutrient delivery drip system and harvesting system

Enhanced Practical Photosynthetic C0₂ Mitigation (R03)

Figure lb. Side view of header pipe and separation plate. Small holes in the plate separate the pressurized area above from the fabric bundle and slot opening below to create the desired capillary action.

Figure 2. Harvesting system experimental test facility

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) Subtask 1.5.1 Examine harvesting methods for efficiency of biomass removal

An experimental test plan is being developed for the new harvesting system design to quantify cleaning efficiency and system sensitivity to the control parameters. Recall that the goal of the harvesting system is to provide partial removal of the organisms in the cleaned area of the growth surface since total removal causes a lag in growth and CO₂ uptake. Initial experiments will quantify mass percentage of algae removed as a function of supply pressure, harvesting time, etc. for a Scotch Brite growth surface fabric and Nostoc algae.

The original CRF is now available for operation as a test bed for continual harvesting system experiments. The current CRF "processing chamber" is being modified to allow extra space for the water supply pipes necessary in the new bioreactor screen design. Tests in this facility are on hold until more information is known about the performance of the new harvesting system design. Plans are to install an "optimized" version of the new combined drip harvesting system once sufficient off-line tests have been completed.

No experimental work has been completed in this area, as current experiments are focused on identifying organisms with maximum rates of CO₂ uptake in the conditions of the bioreactor.

Task 2.0. Evaluate subsystem combinations and select an "optimum" system design

Model-scale bioreactor tests in the original Carbon Recycling Facility (CRF-1) have been underway throughout the project period in an effort to develop proper experimental procedures and to accumulate system-level experience in dealing with bioreactor systems. The organisms, growth surfaces, nutrient delivery systems, etc. currently being tested have not been optimized because the subsystem level experiments are still in process. However, tests to quantify gains in algae mass as a function of light intensity levels and CO₂ levels have been completed for Nostoc 86-3 cyanobacteria. Results from many of these experiments have been included in previous reports, and results from two recent light intensity test runs are summarized at the end of this section.

Two new system level experimental facilities are currently under construction, a new model- scale bioreactor and a pilot scale bioreactor. The pilot scale system is discussed in the Task 3.0 section of this report. The new model-scale bioreactor (CRF-2) is 4 times larger than CRF-1 in terms of growth surface area. Construction of CRF-2 is complete and debugging of the system is underway. Air line stability appears to be affecting the burner, so a surge volume (tank) is being added to damp out air pressure fluctuations. Also, work continues on improving the new bioreactor screen design (discussed above in the harvesting section). A new organism (cyanidium) will be tested in this bioreactor.

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) Summary of CRF-1 Test Run 4/4-9/01

The test specimen for Test Run 4.4-9.01 was the cyanobacteria, Nostoc 86-3. The target values for the gas concentrations were 3%, 10% and less than 50 parts per million for oxygen, carbon dioxide, and carbon monoxide, respectively, with a temperature range between 120°F-125°F. The gas concentration averages for the 120 hours were 3.6%, 10.1%, and 44.7 ppm for oxygen, carbon dioxide, and carbon monoxide, respectively. The 120-hour temperature average was 120.0°F.

The lighting was not altered from Summary of Light Intensity Test for Test Run 4.4-9.01 and was cycled 12-hours on, and 12-hours off. The intensity averages for the four membranes were 68.6 μmols/s-m² for membrane-1, 72.3 μmols/s-m² for membrane-2, 72.9 μmols/s-m² formembrane- 3, and 84.4 μmols/s-m² for membrane-4

Test Run 4.4-9.01 had a total dry algae mass gain of 1.38 grams, or a 44.4% increase over the initial estimated dry mass. The following table describes each membrane and final test results. More details are provided in Data Sheet Test Run 4.4-9.01.

Uncertainty Analysis

The uncertainty analysis is based on the results from the Algae Dry Mass Determination Test and the final results of Test Run 4.4-9.01. From the Algae Dry Mass Determination Testj the average percent dry mass of the initial twelve samples was 4.46% with a standard deviation of 0.19%. The same technique used to gather the twelve initial samples was used to load the membrane. An algae sample taken from the bulk tank was poured across a wire mesh to remove most of the water content, but still retaining the algae mass. The sample remained on the wire mesh for 9- minutes to further reduce water content. The remaining sample was scooped into a beaker and weighed. The algae sample in the beaker was then applied to the membrane and the beaker was weighed again to determine the algae loading weight. This was repeated for each membrane. 4.4581% of the total loading wet weight was used as the initial estimated dry mass for each membrane.

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) The following sample calculation is the uncertainty at 90% confidence in the estimated initial dry mass for membrane-4. It is based on the 12-samples taken from Algae Dry Mass Determination Test, using Student's t-distribution and using four weighed samples to load each membrane.

Data from Algae Dry Mass Determination Test, Test Run 4.4-9.01 and Student's t-distribution:

Mean = 4.4581%

Std. Dev = 0.1933%

Degree's of freedom = 11 (based on Student's t-distribution for 12 samples) t₉₀ = 1.796 (Student's t-distribution for 12 samples)

Uncertainty _ t x σ ft t = Student's t-distribution for 12 samples at 90% confidence σ = Standard deviation of the 12 samples n = Number of samples applied to membrane-4

Uncertainty₉₀ = 1.796x0.1933% = 0.1735%

Algae wet weight applied to Membrane-4 = 19.0884 grams

Uncertainty of estimated dry weight = 19.0884 x 0.001735 = ± 0.0331 grams

Estimated initial dry weight = 19.0884 x 0.044581 = 0.8510 + 0.0331 grams

Mass gain for Membrane-4 = Membrane-4 final dry weight - initial dry weight

= 0.2406 grams

0.033 lg

Uncertainty₉o xlOO = 13.8% (uncertainty of mass gain at 90% confidence)

0.2406g

The following table depicts the uncertainty of the mass gain for each membrane.

The second uncertainty analysis is on a total mass gain basis for the four membranes, instead of the mass gain for each membrane. The benefit of this uncertainty analysis is that the four

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) membranes are looked at as four samples for the total mass gain, which will increase the number of samples in the uncertainty equation. All other values remain the same as in the above calculation.

Uncertaintygo = 1.796x0.1933% = 0.1736%

Total wet weight applied to membranes = 69.9995 grams

Uncertainty of total estimated dry weight = 69.9995 x 0.001736 = ± 0.1215 grams

Estimated initial dry weight = 69.9995 x 0.044581 = 3.1206 ± 0.1215 grams

Total algae mass gain (from membranes) for test run = 1.0928 grams

0.1215g .

Uncertainty^ xl00 = 11.1% (uncertainty of mass gain at 90% confidence)

1.0928g

The results conclude with 90% certainty that the mass gain of Test Run 04.4-9.01 was 1.3864 ± 0.1539 grams, i.e. the mass gain was between 1.2325 grams and 1.5403 grams.

Uncertainty₉₅ = _*J(2x 0.00015g)² + (0.000 lg/2)² +(0.0002g)² = ±0.00036g

This would be the uncertainty for a single measurement made with this device.

Since the uncertainty associated with the scale is so small, with respect to the uncertainties calculated for the mass gains, the uncertainty in the scale is neglected.

Summary of Test Run 4/19-24/01

The test specimen for Test Run 4.19-24.01 was the cyanobacteria, Nostoc 86-3. The target values for the gas concentrations were 3%, 10% and less than 50 parts per million for oxygen, carbon

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) dioxide, and carbon monoxide, respectively, with a temperature range between 120°F-125°F. The gas concentration averages for the 120 hours were 3.6%, 10.1%, and 44.3 ppm for oxygen, carbon dioxide, and carbon monoxide, respectively. The 120-hour temperature average was 119.9°F.

The lighting was not altered from Summary of Light Intensity Test for Test Run 4.19-24.01 and was cycled 12-hours on, and 12-hours off. The intensity averages for the four membranes were 38.9 μmols/s-m² for membrane-1, 51.5 μmols/s-m² for membrane-2, 51.7 μmols/s-m² for membrane-3, and 55.4 μmols/s-m² for membrane-4

Test Run 4.19-24.01 had a total dry algae mass gain of 0.3827 grams, or a 14.5% increase over the initial estimated dry mass. The following table describes each membrane and final test results. More details are provided in Data Sheet Test Run 4.19-24.01.

The results conclude with 90% certainty that the mass gain of Test Run 04.19-24.01 was 0.3827 ± 0.3808 grams, i.e. the mass gain was between 0.0019 grams and 0.7635 grams.

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) Task 3.0. Implement the optimum system in scaled model

The pilot scale bioreactor test facility is under construction at the Ohio University Corrosion Center. Ohio University technician Shyler Switzer is leading the construction effort and is working closely with representatives of Oak Ridge National Laboratories to ensure proper placement of the solar collectors. The current status of the pilot scale bioreactor construction is detailed below.

Group Accomplishments:

(a) Met with Tonya McFadden (Oak Ridge Intern) on 5-17-01 and brought her up to speed on the bioreactor projects.

(b) Updated a map of the Corrosion Center including the existing McBee stack, true north, and the proposed bioreactor site and emailed it to Tonya on 6-4-01 for use with their sunlight simulation program.

(c) Pictures of the proposed bioreactor site taken and emailed to Tonya on 7-5-01 to aid in the generation of the sunlight program.

(d) Met with Al Schubert from the Corrosion Center to finalize acceptance for the location of the bioreactor outside the building.

(e) Manufactured eight frames utilizing the new integrated wicking/harvesting system. (ϊ) Modified the harvesting test chamber on 6-27-01 for trial of the new integrated wicking/harvesting frame system, (g) In the process of investigating alternate suppliers for a prefabricated shelter to house the bioreactor when moved to the Corrosion Center. Tasks to Complete:

(h) Complete drawings of the Corrosion Center building addition by 7-13-01. (i) Review final drawings with Al Schubert by 7-18-01 and break ground, (j) Dismantle the bioreactor for relocation to the Corrosion Center.

Webpage

The web page is running at http://132.235.19.45/DOE . All parties involved in the project have received e-mail instructions and the password to access the information.

Conclusions

The activities and accomplishments detailed throughout this report indicate significant progress towards completion of project objectives. Since we have just completed the third quarter of a multi-year project, most of the test results are still preliminary and the majority of the activities underway are focused primarily on development and improvement of test facilities and procedures. Some of the most significant accomplishments this quarter include:

• Completion of debugging of the slug flow reactor system, and development of a plan for testing the pressure drop of the slug flow reactor .

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) • Design and development of a new bioreactor screen design which integrates the nutrient delivery drip system and the harvesting system

• Substantial progress on construction of a pilot-scale bioreactor

These activities and the others discussed in the report will be continued in the next quarter in support of the overall project objectives.

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) Appendix A - Review of Photosynthetic System Efficiency and Practicality

There are several factors that make photosynthetic-based systems attractive for CO₂ mitigation.

1. The process works well in nature.

2. Use/ recycling of CO₂ is preferable to disposal.

3. Photosynthetic systems should be applicable to a variety of potential host units.

4. Multi-pollutant control, include metals and NO

5. Generation of valuable O₂.

In addition, focus on development of systems to make photosynthesis a potentially viable industrial process, not organism development, allows for focus on process optimization, cost reduction, land use reduction, and ultimately can use whatever organisms may be identified as optimal in the laboratory, or even (if perfected) could deploy artificial photosynthetic reactions.

Despite such promise, there are several objections to the use of photosynthetic systems in the control of CO₂ emissions. Many of these are explained well in Benemann, 1997.

1. Photosynthetic systems are inefficient.

True. When considering incident sunlight on rooted systems, conversion (on an energy basis) is about 1%. Microalgae and cyanobacteria do better. In full sun, they do about 1- 10%. But there is a reason for this. At full sun, 2000 μmols m^"2 s^"1 is too great an incident photon level for the plant to process. Most organisms/plants maximize their productivities at somewhat less than 200 μmols m^"2 s^*1. When kept at low photon intensities, conversion efficiency is routinely measured over 24% with levels as high as 38% reported. (If you will note, the reactor light distribution design will keep photon levels at or below 200 ^' μmols/ m^"2 sec.) Also, two other external factors should be noted: a. Even at 25% conversion, the power source is "free." b. Research and development into reduction of antenna pigment and even chemical simulation of photosynthesis could push this efficiency higher. And while this is not in the scope of our work, such projects are underway. (I will be visiting Australia's CSIRO lab where the artificial photosynthesis research is being conducted in December.)

2. Photosynthetic systems use up too much area.

This may well be true. Photosynthetic photon flux is only 2000 μmols m^"2 s^"1 (approximately a gigawatt per Km²) at peak, with much lower instantaneous (and of course average) values being typical. However, a carefully designed system can reduce that area by increasing incident photon flux and using vertical space.

• the use of solar collector keeps PPFD at a peak by always having the collector incident with the sun

• stacking vertical organism suspension plates reduces bioreactor footprint

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) Also, while it is doubtful that this process will be useful at all power generation units, most existing power plants are cited on large tracks of land, far from urban development. Most of the land at these sites is otherwise non-usable land.(except perhaps for landfill construction.) The conversion to a solar-based bioreactor would be as good a use of the land as any.

3. This process of photosynthetic carbon dioxide mitigation cost too much

At the present moment, YES. But you can say the same for every other option currently being studied. Who has a <$10/ ton solution ready to go? It is interesting that a "natural" solution is dismissed for cost, when membrane, amine, (or whatever) separation and later land or ocean sequestration systems are just as cost prohibitive, but are widely touted as the answer to CO₂ buildup.

In this section, the costs of sequestration are more closely examined, and various assumptions of process efficiency and subsystem costs are studied. The case being examined is for a powerplant with a gross capacity of 200 MW, a capacity factor of 65% operating as a load-following unit (peaking during the day when solar photons are available), with a heat rate of 9000 BTU/kW-hr, burning a coal containing 70% carbon by mass and a HHV of 12,000 BTU/lbm.

The bioreactor will be designed to remove 50% of all CO₂ during daylight hours (during peak use), and the incident photon flux on the solar collectors as delivered to the bioreactor is 1200 μmols m^"2 s^"1. (This value assumes that the directional control of the collector surface can collect approximately 2100 μmols m^"2 s^"1 without cloud cover and the effect of weather and fiber attenuation reduces the value to 1200.) r

A copy of the code used to implement the analysis based on these assumptions follows

Program Code for Engineering Equation Solver

P=200000 (Power generation output in kilowatts} cf-0.65 (Plant capacity factor}

HeatRate = 9000 {Btu/kw-h} {Fraction of the coal that is carbon}

(Ratio of molecular weights of carbon dioxide to carbon}

HHV=12000 (Higher heating value of coal in Btu/lbm} reduction=0.5 (reduction ofC02 emissions, divide this in two to get total} systemlife=30 (30 years of analysis} reflectorcost-500 (Cost per unit collector) m_dot_CO2=P*cfi^fHeatRate*f_C*MWr*reduction/(HHV*l/0.454)/3600

CO2=m_dot_CO2*8766*3600/1000*.5 reflectorarea =pi *2.5 *2.5/4 reflectorprice=500/reflectorarea

Enhanced Practical Photosynthetic C0₂ Mitigation (R03) (Lets say it takes 8 quanta (mole) of photons to convert one mole ofC02, then X=8 Absolute best efficiency you could expect of a biological agent isX=4 For an artificial process, the best would be about X=2.7}

Mole_Co2=M_dot_co2/44 photons=1000 *Mole_Co2 *X growtharea2=photons/200E-06 reactorwidth =500 platespacing=0.05 reactorlength=growtharea2/3/reactorwidth/(l/platespacing) collectorarea=photons/1200E-06 area2 =collectorarea^A.5 collectors2 -collectorarea collectorcost=collectors2 *reflectorprice '

PerTon -collectorcost/(C02 *systemlife)

Analysis of Results

Before discussing the graphs of costs for various assumptions, it should be noted that the key cost parameter is the cost of the solar collectors. Right now, it is estimated that the collectors, built by hand, would cost $90,000 a piece to install. Without mass production and economies of scale, $90,000 per collector would make the cost of one ton of CO₂ removed from the flue gas approximately $6000.

However, commercialization and mass manufacture of the solar collector technology ^' seems much more likely. The design team, headed by Oak Ridge National Laboratories, received $3 million from DOE to further their hybrid lighting work. Their technology, while extremely useful (if not absolutely necessary) for the bioreactor, is actually focused towards use as a lighting system in commercial buildings. More information on their program related to development can be found at http://www.ornl.gov/hvbridlighting/.

In order to examine the effect of photon conversion efficiency at a collector cost of $2000 per unit, Figure 1 was generated. Using the previously stated assumptions, the minimum cost for collection of one ton of CO₂ over the lifetime of the bioreactor, assuming continuous use with the unit, would be $44, with a more likely cost (assuming an optimistic 30% conversion efficiency) is $146 per ton.

At $500 per collector, the costs are more reasonable, as shown in Figure 2. Using the same assumptions used to generate Figure 2, except for the $500 per collector cost, the cost of removing one ton of CO₂ over the life of the bioreactor falls to a minimum of $11 and a more likely value of $37 per ton.

Enhanced Practical Photosynthetic C0₂ Mitigation (R03)

0% 20% 40% 60% 80% 100%

Photon Conversion Efficiency

Figure 1. Cost of one ton of CO₂ removed as a function of photon conversion efficiency for a collector price of $2000 per unit.

0% 20% 40% 60% 80% 100%

Photon Conversion Efficiency

Figure 2. Cost of one ton of CO₂ removed as a function of photoh conversion efficiency for a collector price of $500 per unit.

Enhanced Practical Photosynthetic C0₂ Mitigation (R03 If line losses (photon attenuation) is reduced and deployment of such a unit occurs in a "sunnier" location, the incident photon level could increase to approximately 1500 μmols m^"2 s^"1, the cost of CO₂ removal (per ton) at a conversion efficiency of 30% is $29.

While not all the analysis done on economics is presented here (it will be given in the final report), it is clear that current system design, even if deployed in "sunny" locations, will require a more efficient organism or process to carry out photosynthesis. It is important to note that the target economics, as described in the proposal ($8-$ 10 per ton), would require 50% conversion efficiency and a collector cost of $250 per unit.

Value of Byproduct (biomass)

Of course, another key parameter, and the one sought after by many proponents of photosynthetic control, is the value of the harvested biomass. It is well accepted that biomass could be used in a number of applications, including

• fertilizer • H₂ source • animal feed stock

• biodiesel • pigment/ dyes • Dietary supplement(beta carotene)

Work has not yet been done under this program to investigate other potential uses of the biomass. However, any positive revenue (or offsetting cost) of the biomass would positively influence the overall economics.

This aspect will also be discussed in more detail in the final report.

Enhanced Practical Photosynthetic C0₂ Mitigation (R03)

Claims

L A method for removing carbon dioxide from a flowing gas, the method comprising passing the flowing gas through a container housing at least one membrane on which a cyanobacteria is positioned.

2. A method in accordance with claim 1, further comprising the step of flushing said membrane with a liquid for removing at least some of said cyanobacteria.

3. An apparatus for removing carbon dioxide from flowing gas, said apparatus positioned along a flowing gas stream, the apparatus comprising: (a) at least one membrane positioned in said gas stream; and (b) cyanobacteria' on said membrane.

4. An apparatus in accordance with claim 3, further comprising means for placing liquid on said membrane for removing at least some of said cyanobacteria.