WO2010059808A2

WO2010059808A2 - Integrated process for producing bio-fuels, bio-fertilizers, cattle wastestock, meat and dairy products using a gas turbine generator system

Info

Publication number: WO2010059808A2
Application number: PCT/US2009/065120
Authority: WO
Inventors: Christianne Carin; Alvin W. Fedkenheuer
Original assignee: Earthrenew, Inc.
Priority date: 2008-11-21
Filing date: 2009-11-19
Publication date: 2010-05-27
Also published as: WO2010059808A3

Abstract

The present disclosure provides methods and systems related to producing a bio-fuel from a source such as a grain or algae, whereby a residual source wastestock remains after the production of the bio-fuel, providing an animal feedlot including animal manure wastestock, anaerobically digesting at least a portion of the manure wastestock to produce a bio-gas, whereby a bio-gas byproduct remains after the production of the bio-gas, providing at least one gas turbine configured to produce exhaust gases, contacting the exhaust gases produced by the at least one gas turbine with at least a portion of the animal manure wastestock to produce a fertilizer, contacting the exhaust gases produced by the at least one gas turbine with the bio-gas byproduct to produce a fertilizer, and contacting the exhaust gases produced by the at least one gas turbine with the residual source wastestock remaining after the production of the bio-fuel to produce animal feedstock.

Description

INTEGRATED PROCESS FOR PRODUCING BIO-FUELS. BIO- FERTILIZERS. CATTLE WASTESTOCK, MEAT AND DAIRY PRODUCTS USING A GAS TURBINE GENERATOR SYSTEM

This application is being filed on 19 November 2009, as a PCT

International Patent application in the name of EarthRenew, Inc., a U.S. national corporation, applicant for the designation of all countries except the US, and Christianne Carin, a citizen of Canada, and Alvin W. Fedkenheuer, a citizen of the U.S., applicants for the designation of the US only, and claims priority to U.S. Provisional patent application Serial No. 61/116,916, filed November 21, 2008.

Technical Field

The present disclosure relates to an integrated process combining the production of bio-fuels, bio-fertilizers, cattle wastestock, meat and dairy products using a gas turbine generator system.

Background

American agriculture in general, and the livestock feeding industry in particular, face increasing pressures which pose challenges to traditional methods of doing business, and offer opportunities to those with improved methods. Trends in the marketplace have created a demand for meat and dairy products which are hormone-, antibiotics-, and E.coli- free. Cost effective methods for converting animal wastes into marketable fuels and products that are also generally sustainable, renewable, and environmentally friendly are in demand.

After cattle are fed, the non-digestible and water portions are passed as manure and urine which in conventional practice are typically dumped onto the ground. The pens are then occasionally cleaned by scraping the manure and dirt mixture into wind row piles where they are sun-dried. The mixture may eventually be field applied, sold as fertilizer or disposed of in some fashion.

Due to growing environmental concerns, however, manure management is rapidly becoming one of the most critical functions in commercial feeding operations. The sheer volume of cattle waste (12 times that of one adult human per day) is cause for considerable concern. Whereas human waste is treated in sewage disposal plants, septic tanks or by other approved methods, conventionally, cattle waste is not so treated. Commercial cattle feeding are the point source for numerous real and perceived environmental problems such as water contamination, airborne particulates, objectionable odors, fly and insect infestations, nitrogen and phosphorus buildup in the soil and major fish kills in rivers and streams. The troublesome greenhouse gas emissions of methane is another major environmental problem. Worldwide, cattle are the single largest animal source of methane release into the environment due to livestock flatulence. If the manure is left untreated, treated slowly, or washed away by rain, the waste byproduct can pollute the surrounding environment and the opportunity for odor and insect problems increases.

Another major environmental concern caused by commercial cattle feeding is the build-up of nitrogen and phosphorus in the soil under and around feedyards where manure is applied or disposed of. This build-up comes from the long-term consumption, and then concentration, of feed grain in the relatively small area encompassed by a feedlot. The feedyard must move these compounds back to local farm fields as replacement fertilizer needed for next year's corn crop. If the feedyard does not collect and remove these compounds from the land, the compounds end up in the environment. The nitrogen and phosphorous can remain in the land under the feedyard and be trapped there until the end of the feedyard's life cycle. Or, they can be transported off site via water runoff, airborne particulates, manure removal or disposal, etc. The principal environmental concern is that heavy buildup of nitrogen and phosphorus can enter the water system, as in the widely reported instances of runoff from

Midwestern states like Iowa and Illinois into the Mississippi River, and ultimate deposit in heavy concentrations in the Gulf of Mexico and elsewhere, causing immense "dead zones" which cause the death of marine life due to oxygen depletion. While anaerobic digestion of manure has been known for some time, it has never been practiced on a large scale basis in cattle feedlots due to poor economics, inability to prevent manure contamination by soil and water and limited outlets for the bio-methane. A new approach to cattle feeding is needed in order to address the concerns of environmental regulators, consumers, and the economic pressures facing the industry itself. Renewable bio-fuels such as ethanol and bio-gas using conventional methods are not cost competitive with fossil fuels, and new approaches are needed if the production goals are to be met. One of the most capital- and energy-intensive sections of modern-day ethanol plants is the spent mash (protein co-product) drying and handling section. The protein co-product is valued as an effective feed ingredient for the animals (cattle and dairy cows), but in traditional practice must be dried before it can be transported or stored. Satisfying this requirement in an efficient manner would result in substantial capital, energy and operating cost savings in ethanol production.

Summary

The present disclosure relates generally to an integrated process combining the production of bio-fuels, bio-fertilizers, cattle wastestock, meat and dairy products using a gas turbine generator system.

According to one aspect of the disclosure, the disclosure is related to a method comprising producing a bio-fuel from a source such as a grain or algae, whereby a residual source wastestock remains after the production of the bio- fuel, providing an animal feedlot including animal manure wastestock, anaerobically digesting at least a portion of the manure wastestock to produce a bio-gas, whereby a bio-gas byproduct remains after the production of the bio- gas, providing at least one gas turbine configured to produce exhaust gases, contacting the exhaust gases produced by the at least one gas turbine with at least a portion of the animal manure wastestock to produce a fertilizer, contacting the exhaust gases produced by the at least one gas turbine with the bio-gas byproduct to produce a fertilizer, and contacting the exhaust gases produced by the at least one gas turbine with the residual source wastestock remaining after the production of the bio-fuel to produce animal feedstock. Another aspect of the present disclosure relates to a system comprising a bio-fuel production facility configured to produce a bio-fuel from a source such as grain or algae, leaving a residual source wastestock as a byproduct of the bio- fuel production, an animal feedlot including animal manure wastestock, an anaerobic digester configured to digest at least a portion of the manure wastestock from the animal feedlot to produce a bio-gas and a bio-gas byproduct, and at least one gas turbine configured to produce exhaust gases to be contacted with any of the residual source wastestock, the bio-gas byproduct, or at least a portion of the manure wastestock to produce a converted material. Another object of the present disclosure is to provide a subsystem for a livestock feedlot which is integrated with an ethanol or bio-diesel production facility via a gas turbine generator system such that the economics of both the production facility and the feedlot operation are enhanced.

Brief Description of the Drawings

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate several aspects of the present disclosure and together with the description, serve to explain the principles of the disclosure. A brief description of the drawings is as follows: FIG. 1 is a diagrammatic view of an integrated process that combines the production of bio-fuels, bio-fertilizers, cattle wastestock, meat and dairy products using a gas turbine generator system, the process having features that are examples of inventive aspects in accordance with the principles of the present disclosure; FIG. 2 is a diagrammatic view of the gas turbine generator subsystem of the integrated process of FIG. 1; and

FIG. 3 is a diagrammatic view showing the processes for preventing emission of animal gases and greenhouse gases to the atmosphere using the gas turbine generator subsystem of the integrated process of FIG. 1.

Detailed Description

Reference will now be made in detail to the exemplary aspects of the present invention that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

FIG. 1 depicts a diagrammatic view of an integrated process that combines the production of bio-fuels, bio-fertilizers, cattle wastestock, meat and dairy products using a gas turbine generator system, the process having features that are examples of inventive aspects in accordance with the principles of the present disclosure.

According to one example embodiment of the present process, grain (e.g., corn) from a grain source is fed to a conventional ethanol plant, for preparing the feed for ethanol fermentation. The ethanol synthesis process may employ a variety of fermentation organisms, ranging from conventional yeast strains used in most modern ethanol plants, to advanced fermentation organisms such as Zymomonas mobilis, the benefits of which are described in U.S. Pat. Nos. 4,731,329 and 5,070,016, the entire disclosures of which are incorporated herein by reference.

As shown in FIG. 1, integration of animal feedlots and ethanol production facilities provides synergy. Both the feedlot and ethanol operations are able to utilize corn as their principal wastestock and the existing infrastructure is suited for both (i.e., grain storage, handling, treating and transporting).

The major products of the fermentation are carbon dioxide, ethanol, and wet distillers' grain. Wet distillers' grain by-products are the residual grain mash remaining after the starch has been extracted, converted to sugar and fermented into ethanol and carbon dioxide. Distillers' grain contains all of the fiber, proteins, oil, vitamins and minerals of the original wastestock. A majority of today's ethanol plants produce dried distillers' grain because their customers are removed from their plant, and wet distillers' grain cannot be transported long distances. Wet distillers' grain, with its high moisture content, is expensive to transport long distances, and will spoil unless used within several days, particularly in hotter climates.

In conventional practice, an efficient ethanol production facility will consume approximately 35,000 BTU's of energy to produce an average gallon of ethanol, spent grain and other products. Approximately 50% of this energy is used to dry the spent grain to form dry distillers' grain. Consequently, as will be shown, there are many cost and operational benefits to be gained from integrating an ethanol production/cattle feedlot facility with a gas turbine generator drying/energy production system.

The wet distillers' grain is generally around 80% in moisture content. Before being fed to the livestock, the wet distillers' grain may blended with original grain at a ratio of wet distillers' grain: original grain of 25:75 to 80:20 to decrease the moisture content for easier digestion by the livestock. However, according to a preferred embodiment of the process, the wet distillers' grain may be dried within a gas turbine generator system to reduce the moisture content from around 80% to around 15% to 20%. Once dried, the animal feed is brought to a pelletized form within the gas turbine generator system to improve the handling and the feeding operations. The operation of the gas turbine generator system will be explained in further detail below. Examples of gas turbine generator systems suitable for use with the present process can be found in U.S. Patent Nos. 7,024,796 and 7,024,800, the entire disclosures of which are incorporated herein by reference.

When corn is converted to ethanol, the resultant distillers' grain contains approximately 30% protein, on a dry matter basis. Corn alone can't provide all of the catties' protein needs. External sources of protein, such as urea, soybean meal, cotton seed meal and alfalfa hay may be added to the wastestock to improve the nutritional value thereof. Providing the animal wastestock in pellet form facilitates the addition of nutritional supplements to the wastestock.

Once the wet distillers' grain is dried, it can be stored or transported. One of the most capital- and energy- intensive sections of modern-day ethanol plants is the drying and the handling of the wet distillers' grain. As will be described in further detail, by utilizing the exhaust gases of a gas turbine generator to dry the spent mash animal feed and utilizing the electricity produced by the turbine generator, substantial capital, energy, and operating cost savings can be achieved. The gas turbine generator system of the present process efficiently and economically processes such high water content wastestocks to not only recover the waste content in the form of a high nutrient animal feed, but to also recover the process water, which can be recycled for other uses.

Once dried, the animal feed can then be passed to a feedlot where cattle or other livestock are fed prior to processing. The beef from the cattle feedlot is slaughtered and routed onward to meat packing plants or other facilities. Milk from a dairy feedlot may be handled in a similar conventional manner.

The manure collected from the feedlot play a major role in the synergies achieved with the present process. The manure collected from the feedlot may be fed to digesters to produce a bio-gas (principally methane). The manure digester may either be a mechanical continuous-flow digester or a plug-flow digester. Anaerobic digesters conventionally are mechanical devices that utilize biological organisms in the absence of oxygen to convert cattle or other manure into bio-gases. There are two basic types of digesters: plug flow, and mixed mechanical. A properly operated digester will eliminate manure odors, destroy the pathogens and convert the manure to methane gas leaving a liquid byproduct. If desired, the bio-gas (i.e., methane) may be routed on to an energy conversion plant which produces non-fossil energy.

In addition to the production of a bio-gas, according to a preferred embodiment of the process, the manure collected from the feedlot may be processed within a gas turbine generator system to convert the manure to fertilizer. The details of the process for converting the manure wastestock to fertilizer are found in U.S. Patent Nos. 7,024,796 and 7,024,800, the entire disclosures of which have been incorporated herein by reference. The sludge, which is a byproduct of the anaerobic digestion of the manure during biomethane production, can also be converted to fertilizer using the gas turbine generator system, described in further detail in U.S. Patent Nos. 7,024,796 and 7,024,800, the entire disclosures of which have been incorporated herein by reference. It should be noted that although the present disclosure details features related to an integrated process for the production of ethanol, the inventive features described herein may be applicable to the production of other types of bio-fuels such as bio-diesel. As commonly known, bio-diesel is made through a chemical process called transesterification, whereby the glycerin is separated from the fat or vegetable oil (e.g., canola). The process leaves behind two products - methyl esters (the chemical name for bio-diesel) and glycerin (a valuable byproduct usually sold to be used in soaps and other products). Thus, according to another embodiment of the present integrated process, the gas turbine system may be utilized to harvest the residual grain mash after the vegetable oil has been extracted. Once dried, the product can be brought to a pelletized form. The pellets can be stored or be utilized as animal feed as discussed previously. The electricity produced by the gas turbine generator can be routed to desired points along the bio-diesel production process or sold to a power company purchaser. According to another example embodiment of the present disclosure, instead of utilizing sources such as different types of grains (e.g., corn, vegetables, etc.) in an integrated process to produce bio-fuels (ethanol, bio- diesel, etc.) and animal feed, the source utilized may be algae. Algae are fast-growing plant-like organisms. The term "algae" as used herein refers to any of numerous groups of chlorophyll-containing, mainly aquatic, eukaryotic organisms. Algae are distinguished from traditional plants by their absence of true roots, stems, and leaves and by their lack of nonreproductive cells in the reproductive structures. Algae are comprised of, among other components, lipids (e.g., oils), carbohydrates, and proteins. Thus, algae have many potential commercial uses including, for example, making ethanol, bio-diesel, paper, and feed/food products. As a replacement for corn and other grains, algae biomass provides certain advantages such as being able to utilize a photosynthesis process similar to that of higher-developed plants to grow even faster than tradition grains. Example methods of converting algae to fuel are disclosed in U.S. Patent No. 7,135,308 entitled Process for the Production of Ethanol from Algae, U.S. Patent Application Publication 2007/0202582 entitled Process for the Production of Ethanol from Algae, U.S. Patent No. 4,351,038 entitled Oil Products from Algae, and U.S. Patent Application Publication 2007/0048848 entitled Method, Apparatus and System for Biodiesel Production from Algae. Example methods of converting algae to food/feed products are disclosed in U.S. Patent No. 5,715,774 entitled Animal Feedstock Comprising Harvested Algal Turf and a Method of Preparing and Using the Same and U.S. Patent No. 7,208,160 entitled Process of Treating Sea Algae and Halophytic Plants, the entire disclosures of which are hereby incorporated by reference.

Since, algae can be cultivated and harvested like a traditional crop, the present integrated process utilizing a gas turbine generator system can be incorporated into a "biorefmery" type process, where algae is the main utilized source of feed and bio-fuel.

Similar to the integrated process discussed above, the algae is converted into ethanol or bio-diesel. The remaining biomass mash may be dried or processed using the gas turbine generator system and brought to a pelletized form within the system to improve the handling and feeding operations of the algae similar to discussed above for wet distillers' grain. In certain applications, the algae may be mixed with external sources of protein or corn products to provide the desired feed mix and to improve the nutritional value thereof for feeding. Providing the algae in pellet form facilitates the addition of nutritional supplements to the wastestock.

Referring now to FIG. 2, a diagrammatic view of an example embodiment of a gas turbine generator system suitable for use in different applications within the present process is shown in further detail. In the exemplary system illustrated, gas turbine generator unit 100 comprises gas turbine 101 and electric generator 102. The gas turbine has air intake filter 104 (which can optionally include animal shelter ventilation air from enclosed feedlots) and fuel feed 103. If desired, optional bypass exhaust silencer 106 can be included for startup, shutdown or upset conditions during those times the gas turbine is running but the exhaust gases cannot be directed into the dryer vessel. However, dryer vessel 200 will function as the silencer in the normal operation of the system. Alternatively, instead of silencer 106, the exhaust gas bypass (see 908 in FIG. 3) around the dryer vessel can be directed to any appropriate downstream unit, such as separator 208 and/or separator 600, which can provide a temporary silencer function. This arrangement eliminates the cost of a separate silencer and the space required for a separate silencer. The gas turbine 101 exhaust is connected to the dryer vessel 200 by connector 105. An optional air inlet can be included for dryer vessel 200 in connector 105 or elsewhere for purging the dryer vessel or the system, for startup or shutdown or for other reasons, particularly when either the exhaust gases or the wastestock is not present in the dryer vessel 200. However, when both are present, any such air inlet is closed and not used in order to substantially preclude introduction of air into the dryer vessel and to preclude significant oxidation of materials being processed in the dryer vessel 200. Optional burner 107 can also be included to provide supplemental heat source and combustion gases for the dryer vessel, which can be provided for input in connector 105 or elsewhere. The optional supplemental heat source may be useful during startup, shutdown, process upset, turbine outage or to maintain desired throughput when a peak load or unusually high water content wastestock is encountered. The wastestock (e.g., wet distillers' grain, spent algae mash, manure, bio- sludge, etc.) may be introduced into the system by mechanical means, such as a front end loader 201, which drops the wastestock into a rock separator, mixer, chopper unit 202. The wastestock can be further mixed and foreign objects separated in screw conveyers 203, 204 then fed to the dryer vessel 200 through 215. The wastestock can also be pre-mixed or conditioned for desired uniformity prior to loading into this system by loader 201, e.g., in storage windrows that can be combined and mixed.

The output from the dryer vessel 200 is transferred by conduits 205, 206 to separator 208 where the solids and gases are separated. The gases pass through 209 and blower 210 to the atmosphere via 211 or to other downstream processing via 212. Blower 210 can be operated to lower the pressure in separator 208 and in the dryer vessel 200, which will reduce the water boiling point in the dryer vessel and will reduce the water boiling point in the dryer vessel and will reduce the backpressure on the turbine exhaust and increase the turbine output and efficiency. Alternatively, blower 210 can be operated to maintain increased pressure in dryer vessel for higher temperature treatment, conversion or "cooking" of the wastestock, if desired. The output from dryer vessel 200 can pass through optional heat exchanger 207 for recovery of process heat for use downstream or in preheating the wastestock or turbine intake air. The solids output from separator 208 pass to ball mill or hammer mill 300 via conduit, conveyor or auger 301 and optional mixers and conditioners 302 and 303. In addition, recycled solids, such as fines, from recycle loop 305 can be mixed in at 303 via 304 to be combined for feeding to the ball mill or hammer mill 300. The fines and off spec material generated at various points in the system can be collected and recycled via loop 305 and reintroduced into the product processing system at any desired point for further processing, such as the milling unit 300 via 304, the pelletizing unit 400 via 404 or even the wastestock preparation 202, 203, 204 or other points. An important capability of the gas turbine generator system of this integrated process is the complete recycle via recycle loop 305 of all fines or off spec solids so that they are eventually incorporated in the final products. Thus, the system provides 100% conversion of the wastestock solids (except for rocks and other foreign objects that are not processible) into the desired products and does not produce a solids waste stream that must be otherwise disposed of, such as in a landfill.

The ball mill or hammer mill 300 is used to produce a uniform small particle size, short fiber length material called "meal" which is suitable for processing in pelletizer unit 400 to provide a product that has sufficient hardness and mechanical durability and stability for the conventional processing, packaging and storage normally used for dry products. The output of ball mill or hammer mill 300 goes through separator 310 where vapors are taken off and sent via 315 to separator 600 for recycle of solids via recycle loop 305 and venting of vapors to the atmosphere via blower 601 and vent 602. Separator 310 takes out fines or material suitable for recycle via recycle loop 305 and passes the meal to mixer 311. The meal is then sent via 312 to separator 401 and either direct to pelletizer 400 via 408 or to holding or surge bin 402 via 409a and 409b for mixing with other materials, recycle materials from 404 or additives or for holding in case of process startup, shutdown or upset. From surge bin 402 the meal is sent through mixer 403 and either directly to the pelletizer unit 400 via 417 or to mixer 311 via 412 for mixing with fresh meal when desired.

The pellets from pelletizer 400 are passed through heat exchanger, vapor removal unit 405 and from there sent via 406 and 414 either direct to final product cleaning in units 407 and 415 and finished product shipping or storage bin 500 via 416a, 416b, 501 and 503, or sent via 413 and surge bin 410 to a crumbier or granulator unit 411 then to final product cleaning units 407 and 415. The final product may be loaded in truck 502 via 501, 503 or via storage bin 500 for transport. The fines and off spec product separated out in final cleaning unit 415 can be recycled for reprocessing via recycle loop 305. The crumbier or granulator 411 converts the pellets to smaller particle or granular size having essentially the same hardness and mechanical durability and stability as the pellets. The solids can be transported between processing units of this invention by conventional augers, elevators, conveyor belts, pneumatic tube conveyors and the like, as appropriate for the material and for environmental considerations.

FIG. 3 illustrates a schematic process flow chart for an example gas turbine generator system that is used to process manure wastestock. It should be noted that a similar process may be followed for other types of wastestock (e.g., wet distillers' grain, spent algae mash, bio-sludge, etc.) resulting within the integrated process of FIG. 1. In a preferred operation, animal barns 900 and manure pits 901 are enclosed and ventilated with fresh air. The ventilation air from the animal barns or manure pits may be fed to the gas turbine 101 as part of the combustion air feed 904 through air filter 104. The manure pits can be within the same barn enclosure or can be separate holding tanks or lagoons that are enclosed so that all vapors given off by the manure can be contained and passed to the gas turbine 101 along with the barn ventilation air for combustion along with the conventional fuel 103, such as locally available natural gas. This prevents greenhouse and noxious or acrid gases from the animals and the manure from being released into the atmosphere, including biogases from any bioconversion that takes place before the manure can be processed in the gas turbine generator system of the present process. Not only does this provide the opportunity for commercial use of this process to obtain air quality credits for reduced greenhouse gas emissions, it also provides animal feeding operations a way to become acceptable neighbors with nearby residential areas, because all noxious and acrid odors from the animals and the manure can be contained within the system and incorporated in the final fertilizer product or converted to components that are not noxious or acrid before venting to the atmosphere. As noted in the DOE/EIA Report, the total methane given off by a livestock feeding operation, about two thirds is from enteric fermentation (animal gases) and about one third is bio-gas from bioconversion of manure. Thus, in most conventional bio-gas operations that use as fuel the methane from bioconversion of manure, two thirds of the methane from the livestock feeding operation is released into the atmosphere in the animal gases, while only the one- third from bioconversion is contained and utilized. Using a gas turbine generator to process the manure not only prevents the formation of unutilized methane during bioconversion, retaining all the nutrient values from the manure in the fertilizer product, but also contains and utilizes most or all of the other two- thirds methane in the animal gases as fuel and converts all other noxious and acrid gases from a livestock feeding operation to other compounds which are either absorbed or complexed in the fertilizer product or are not objectionable for release to the atmosphere.

As discussed previously, the gas turbine generator 101/102 produces electric power 905, which can be either sold to the local power company 906 or distributed by 907 for use in other processing units shown in FIG. 1. The economics of each commercial operation, fuel costs, selling price/purchase price of electricity and capital cost of equipment will determine whether the electricity is used internally, sold to the power company, used in other nearby operations or any combination thereof.

Preferably, the exhaust gases from the gas turbine 101 are passed to dryer vessel 200 by a connection 105 that precludes outside air from entering the dryer vessel. As disclosed herein, the gas turbine generator system is operated so that the oxidation of the wastestock in the dryer vessel 200 and elsewhere in the system is minimized and substantially avoided. The dryer vessel 200 also serves as silencer for the gas turbine. An optional bypass 908 can be provided so the exhaust gases can be sent to downstream equipment, such as separators/condensers 208, to silence the gas turbine exhaust when the dryer vessel is offline and to clean the exhaust gases before release into the atmosphere during such temporary operation. Or, the bypass 908 exhaust gases can be sent to a heat exchanger for water heating, animal shelter heating or other climate control or process energy requirements. This bypass eliminates the cost of having a separate silencer to satisfy noise restrictions on the gas turbine when the dryer vessel is offline. Manure wastestock 215 is fed to the dryer vessel 200 along with the exhaust gases from connection 105 and any auxiliary heat provided from alternate or auxiliary heat source 107. The manure wastestock preferable comes directly from the manure pits in animal barns so it is fresh and has little or no time for bioconversion. Other manure wastestock sources can be used or included in the system, such as stockpiled manure or manure from other operations that is brought in to be combined or mixed with the manure from the immediate animal barn. As disclosed herein, other green waste, organic materials, inorganic materials or additives can be combined with the manure for processing in the gas turbine generator system of the present process. The output from dryer vessel 200 is sent via 205 to the separators/condensers designed to separate the solids 912 for further processing downstream, to condense the water vapors as reclaimed water 913 and to clean the gases 914 vented to the atmosphere. The reclaimed water can be used downstream as process water, recycled for use in preparing or conditioning the manure wastestock, used for livestock water or used for crop irrigation. The solids output 912 from the separator units 208 is normally further processed by milling, pelletizing, granulating, bagging, etc. However, the solids 912 can be used as an intermediate to form other types of products. For example, it can be baled for use much like a peat material, it can be formed into bricks, rolls and other shapes for use in erosion prevention much like straw rolls are used (but having higher nutrient or soil builder value than straw), it can be used alone or in combination with other materials for incineration to utilize the fuel value of the material, it can be used in a bioconversion system to produce a methane or biogas fuel, it can be used as an animal feed, or it can be stored for any desired use or further processing at a later time. Similarly the meal/powder output 914 from the milling operation is normally further processed by pelletizing, granulating, etc., but can be used as an intermediate to form other types of products, such as slurry for spray application, hydro-mulching, etc. The final product 915 is preferred for use as a fertilizer, but is also useful as above for the intermediate products.

In each of the downstream operations, water vapor may be recovered and recycled to the separators/condensers 208 for reuse. As is apparent, the systems of this invention are adaptable to various configurations and various designs depending on the processing needs and economics of particular animal feeding operations. Various conventional heat recovery and recycle aspects, not shown in FIG. 3, can be designed into commercial installation of the gas turbine generator systems of the present process by using ordinary process engineering design skills, including the fines recycle 305 shown in FIG. 2, use of gas/vapor stream 914 for various heat recovery and pre-heating applications, insertion of binders, additives and blending materials at various desired points in the gas turbine generator system, cooling the combustion air and/or animal barn ventilation air, e.g., by water spray, to increase efficiency and power output of the gas turbines, dewatering very high water content manure wastestock, etc. The final pelletized, granulated or prilled product 915 can be bagged or shipped bulk for conventional end use applications.

As will be apparent to one skilled in the art, multiple gas turbines, other engines and/or burners of the same or varying types and sizes can be manifolded together to feed multiple dryer vessels of the same or varying types and sizes in a single installation. This can be done to not only provide increased wastestock processing capacity but also to provide operational flexibility for processing varying wastestock loads and for performing equipment maintenance without shutting down the operation. The gas turbine generator system of the present process reduces or eliminates the undesirable environmental impacts of wastestock treatment compared to the prior art processes and systems. One of the major advantages of the gas turbine generator system of the present process resides in the aspect that in most wastestock processing all waste solids are contained and become part of the final product useful as a fertilizer or animal feed material. Thus, the gas turbine generator system of the present process can completely eliminate the necessity of disposing of any remaining sludge or other solids in a landfill or by land spreading.

The term "manure wastestock" is used herein to mean and include waste matter excreted, from animals as feces and/or urine, such as but not limited to cattle (beef, dairy, buffalo, veal, etc.), horses, sheep, swine, poultry (chicken, turkey, ostrich, pigeon, etc.), goat, mink, veterinarian, stockyard, stable, race track, rodeo grounds, fairgrounds, feedlot, sale barn, zoo, aquatic (fish, shrimp, etc.), elk (and other game), llama, alpaca, as well as other operations and sources of waste or manure, and any mixtures thereof. Manure wastestock as used herein includes such matter along with other materials normally present in agricultural operations where such matter is produced, such as straw, bedding (which is typically shredded paper, wood chips, etc.), hair, feathers, insects, rodents, etc., whether the ratio of such matter to such other materials ranges from very low to very high. Manure wastestock as used herein includes such matter in its raw form, any prepared form and mixtures thereof with other materials such as other bio matter (yard waste, green waste, etc.), additives, process aids, bone meal, fish meal and the like, including where the matter is fresh, fully bioconverted by composting, digestion, etc., or is at any stage in between. It will be recognized that, when other components, such as bone meal, etc., are added to, mixed with or included in the wastestock for processing according to this invention, such additional components will also benefit from the thermal destruction or conversion of the undesirable components listed above, such as prions, etc., just as the manure wastestock does. Thus, it may be desirable to mix contaminated materials, such as straw containing pesticides, bone meal containing prions, etc., with the manure to be processed, so that those contaminants can be converted or destroyed during the processing of the manure wastestock according to the gas turbine generator system of the present process. This invention is useful in processing other types of waste products and waste streams.

The gas turbine generator system of the present process provides a simplified, economically efficient alternative to the prior art and provides in its preferred aspects, a product 100% usable as fertilizer and/or animal feed products, and which provides 100% conversion of wastestock solids or liquids or sludge to useful products, which eliminates the problem unsolved by the prior art of disposal of waste left over from various treatments, such as composting and bio-gas production. As discussed above, the synergies provided by the integration of animal feedlots and ethanol or other bio-fuel production facilities with a gas turbine generator system are countless and the economics of both the ethanol production and the feedlot operation are enhanced.

According to the present process, the nutrient value of, for example, fertilizer produced from a manure wastestock can be maximized if composting, digestion, incineration and oxidation of the manure wastestock are avoided or at least minimized. In the gas turbine generator system of the present process, the high temperature treatment of the manure wastestock, preferably by direct contact with hot gases, e.g., >l,000degree F, destroys or converts to harmless forms substantially all undesirable components present in the manure wastestock, including organisms, microorganisms (including genetically modified organisms, bacteria, pathogens and other microorganisms), seeds, pesticides, antibiotics, hormones, prions and viruses, particularly when such heat treatment takes place for a sufficient time and without significant oxidation, incineration or pyrolysis of the manure wastestock. The treatment at sufficiently high temperatures for a sufficient amount of time in the absence of significant oxidation and/or pyrolysis "cooks" or otherwise converts or transforms the manure wastestock into a self-binding product, whereby it can be formed into conventional pellets, granules, prills or other forms, usually without the need for addition of binders or other agglomerating additives, which have sufficient physical hardness and strength to be formed into conventional shapes and sizes and to be used in conventional dry fertilizer application equipment and operations. As described above, gas turbine generator system of the present process also provides for recovering and recycling the water removed from the wastestock, which water can be used for livestock water, irrigation or other industrial uses, and for recovering and recycling all solids (fines or other) produced in the process, so that there are no significant solid products produced other than the desired products suitable for commercial use.

According to the present disclosure, as described above, a most efficient way of providing the hot gases for contact with the wastestock is the exhaust from a gas turbine, and preferably a gas turbine electric generator. According to the gas turbine generator system of the present process, the gas turbine may be fueled from locally available conventional fuel sources because conventional fuels provide the most efficient, reliable and controllable operation of the gas turbine. The electricity produced from the gas turbine generator is preferably sold back into the local power grid as a revenue source for the operation of the gas turbine generator system of the present process, but it can be used internally in the operation of the individual process units as shown in FIG. 1.

The gas turbine and the dryer vessel receiving the exhaust gas from the gas turbine are connected together such that induction of outside air into the dryer vessel is precluded and the dryer vessel preferably receives the exhaust gases directly from the gas turbine. It is preferred that 100% of the gas turbine exhaust gases are passed into the dryer vessel and, for most efficient operation, preferably without passing through any intervening heat exchanger, silencer or other equipment in order that the dryer vessel receives the maximum heating from the gas turbine exhaust. But, it is recognized that excess exhaust gases not needed for the dryer vessel operation can be diverted to provide heat required in other steps in the present integrated process or in other nearby operations. It is also preferred that the exhaust gases result from conventional and efficient combustion ratios in the gas turbine so that the exhaust gases contain minimum or limited amount of free oxygen, essentially no unburned fuel, no exposed flame and that the optimum exhaust gas temperature (EGT) is achieved, for maximum heat produced, per unit of fuel consumed. The combustion can also be at stoichiometric ratio for peak EGT operation at maximum temperature, and maximum heat input for the process. The absence of excess oxygen in the exhaust gases, precluding outside air induction into the dryer vessel, the absence of exposed flame and operation at the temperature set forth herein prevents significant oxidation of the wastestock in the dryer vessel, preserves the maximum nutrient value in the wastestock for containment in the end fertilizer or animal feed product, prevents the danger of fire damage to the equipment and provides an operation safe from flash fires in the dryer vessel. The absence of excess fuel in the exhaust gases prevents the exhaust gases from being a source of hydrocarbons that must be scrubbed from the vapor effluent from the operation of this invention before being released into the atmosphere. According to one example embodiment, wherein algae is the wastestock being processed, after the algae is treated, the end exhaust (containing CO2 from the natural gas combustion of the turbine) can be directed into algae growing tubes, houses, etc. to stimulate algae growth, hi this manner, the algae also absorbs CO2 from the exhaust reducing greenhouse gas emissions. The diversion of the exhaust gases can occur before/after or with/without water recovery from the exhaust stream as discussed above.

According to a preferred process, it is advantageous to condense and recover the water out of the exhaust stream before directing the exhaust wastestream CO2 toward the algae. This process concentrates the CO2 to a higher level in the remaining exhaust gas, which is more readily usable by the algae. hi the operation of the gas turbine generator system of the present process, it is preferred that the wastestock be as fresh as possible with a high moisture content, hi other words, the wastestock should have undergone no, or as little as practical, composting, digestion or other bioconversion prior to processing. This provides the highest nutrient value and organic matter content in the produced fertilizer/soil builder product or animal feed product.

For use in the gas turbine generator system of the present process, it is preferred that the wastestock have a high moisture content, such as at least 30% by weight water, preferably at least 50% and most preferably at least 70%. The high water content facilitates mechanized handling of the raw material and preparing it for use by blending and mixing for uniformity of wastestock. Typically the wastestock is moved by augers, front end loaders, back hoes, conveyor belts and the like, particularly in cattle and poultry operations. However, in some installations the wastestock may be prepared in the form of a pumpable slurry, particularly in dairy and swine operations, where barn cleaning may be done by water flooding and the water content of the wastestock may be as high as 90%, 95% or even 98%. Prior to the present process, such wastestocks could not be economically processed and were simply put in holding or settling ponds, or lagoons which have major air pollution, odor and environmental problems. The gas turbine generator system of the present process efficiently and economically processes such high water content wastestocks to not only recover the waste content in the form of a high nutrient fertilizer or animal feed, but to also recover the process water, which is decontaminated from pathogens, etc., and can be recycled for barn cleaning, for livestock drinking water or for crop irrigation. The gas turbine generator system of the present process can handle high water content wastestocks efficiently and economically due to the fact that excess steam produced in the dryer vessel can be used downstream, upstream or in other nearby operations, such as barn cleaning, preheating wastestock, greenhouse heating, etc. Instead of holding such high water content wastestocks in open ponds, the gas turbine generator system of the present process enables holding the wastestock in enclosures or tanks, which eliminates the air pollution, odor and environmental problems associated with open ponds.

It is recognized that raw wastestock will typically contain other material such as straw, twine, wire, gravel, rocks, jute or plastic bags, etc. Such materials are processable as part of the wastestock in the gas turbine generator system of the present process without detrimental effect, provided the levels of such other materials are not unusually high. However, it is normally preferred to separate out such materials, particularly rocks, wire and the like, that might damage the dryer vessel or downstream processing equipment. Otherwise, it may be desirable to prepare the wastestock by chopping, grinding or other preparation to comminute items such as twine, bags and the like into small pieces so they can be processed into the final product without significant interference with the normal operation of the process. It should be noted that such materials that are either inert or are biodegradable can be contained in the wastestock without detrimental effect, which may be particularly desired where it is not economically efficient to remove such materials from the wastestock. The wastestock preparation by grinding, chipping, chopping, crushing, etc., not only will improve the uniformity of the wastestock for processing, but will also facilitate addition of other materials into the wastestock, such as straw, woodchips, yard waste, etc., as referred to above. In addition the wastestock preparation can include a washing step, which may be useful in very dry manure, such as poultry, or to remove excess salt content that may not be desired in a final fertilizer/soil builder product.

The term "gas turbine" is used herein to mean and include any turbine engine having a compressor turbine stage, a combustion zone and an exhaust turbine stage that is capable of producing exhaust gas temperatures of at least 500degree F, preferably at least about 700degree F, more preferably at least about 900degree F and most preferably greater than about l,000degree F. Gas turbines are the heat source preferred for use in the gas turbine generator system of the present process because of their efficient operation and high heat output. The gas turbine generator is further preferred for use in the gas turbine generator system of the present process due to the production of energy by the generator, which energy can be utilized or sold to improve the economics of the operation of the integrated process. The generator will typically be an electric generator due to the convenience of using and/or selling the electricity produced. However, the generator can be any other type of energy generator desired, such as a hydraulic pump or power pack that can drive hydraulic motors on pumps, augers, conveyors and other types of equipment in the gas turbine generator system of the present process or equipment in other nearby operations. The heat requirements and the system economics will determine whether a gas turbine or gas turbine generator is used. If it is desired to have higher temperature exhaust gases and higher heat output from a given smaller size gas turbine, it may be desired to use a gas turbine instead of a similar size gas turbine generator. Compared to the gas turbine, the gas turbine generator further expands and cools the exhaust gases in absorbing energy to drive the generator, where in a gas turbine that energy is contained in higher temperature gases available for use in the dryer vessel. This can be an option when it is economically more important to have small (truckable) high temperature units than to have the revenue stream or economic benefit of the electricity or other energy production by the gas turbine. The gas turbine or gas turbine generator according to the present disclosure can be fueled from any available source with any suitable fuel for the particular gas turbine and for the process equipment designed accordingly. The preferred and conventional fuels are sweet natural gas, diesel, kerosene and jet fuel because the gas turbines are designed to run most efficiently on good quality fuels of these types and because of their common availability, particularly at remote agricultural operations, where the units of this invention are often most efficiently located. However, other fuels that can be used to fuel the gas turbine include methane, propane, butane, hydrogen and biogas and bioliquid fuels (such as methane, oils, diesel and ethanol). The bio-gas (e.g., methane) produced by the integrated process in the anaerobic digestion stage of FIG. 1 can also be used to power the gas turbine if the resulting methane is refined to a sufficient operable level.

Examples of commercially available gas turbines and gas turbine generators useful in the gas turbine generator system of the present process include the following (rated megawatt (MW) outputs are approximate): Rolls Royce Gas Turbine Engines Allison 501-KB5, -KB5S or -KB7 having a standard condition rated output of 3.9 MW; European Gas Turbines Tornado having rated output of 7.0 MW; Solar Mars 90 having rated output of 9.4 MW and Solar Mars 100 having rated output of 10.7 MW; Solar Tarus 60 having rated output of 5.5 MW and Solar Tarus 70 having rated output of 7.5 MW. For a nominal product output capacity of 2.5 metric tons/hr. (2,500 kg/hr) a gas turbine generator size of about 4 MW can be used, depending on the heat insulation and heat recovery efficiencies designed into the overall system. For smaller product output systems, such as an 0.3 metric ton/hr product output, small gas turbines, such as Solar Saturn 0.8 MW, Solar Spartan 0.2 MW or Capstone 0.5 MW or 0.3 MW generators, can be used depending on system efficiencies and required heat input ranges.

The dryer vessel employed in the gas turbine generator system of the present process can be any type or configuration that is suitable for drying the wastestock available and that can be adapted for receiving the gas turbine exhaust gases and receiving the wastestock without allowing a significant amount of outside air to enter the drying chamber in the dryer vessel where the exhaust gases contact the wastestock. The objective of the design of the gas turbine exhaust connection to the dryer vessel is to preclude any significant outside air from entering the dryer vessel to help prevent significant oxidation of the wastestock. As previously pointed out, this is to preserve the organic matter, carbonaceous and/or nutrient values present in the wastestock, to prevent fires and to provide a safe operation. As used in this invention it is preferred and expected that the turbine will be operated at a conventional ratio of fuel to combustion air in order to produce the most efficient exhaust gas temperature (EGT) for the dryer vessel and to produce gases entering the dryer vessel that contain a minimum of free oxygen. It will be recognized in the operation of the gas turbine generator system of the present process, that not all outside air can be excluded and oxidation of the wastestock cannot be completely precluded, primarily because of the air present in and entrained in the wastestock, the air dissolved in the moisture present in the wastestock and excess oxygen that may be present in the turbine exhaust gases during periods that stoichiometric ratio of fuel and air is not achieved. In addition, in some cases oxygen may be produced or liberated from the organic or other materials present in the wastestock when the thermal treatment and conversion takes place and decomposes or converts such materials. Therefore, the terms as used herein which refer to "preclude introduction of air," "without significant oxidation," and the like, are used in the above operational context and with the recognition and intended meaning that the air or oxygen entering the system as part of the wastestock or exhaust gases or produced in the thermal conversion process is not intended to be precluded and that the oxidation that may occur as a result of that air entering the system with the wastestock is not intended to be prevented. However, such a level of oxidation is not considered significant within the scope, context and practice of the gas turbine generator system of the present process or the meanings of those terms as used herein. Similarly, "without significant pyrolysis" is used herein to mean that not more than an insignificant portion of the wastestock is pyrolized, e.g., as in U.S. Pat. No. 6,039,774. Pyrolysis products are undesirable in the processes and products of the present disclosure, and the processes and equipment of this disclosure are operated to achieve the desired drying of the wastestock and the desired conversion and destruction of various wastestock components, such as pesticides, prions, organisms, seeds, etc., but operated to avoid significant oxidation and preferably to avoid significant pyrolysis, or at least to minimize oxidation and minimize pyrolysis.

Following the disclosures herein, it will be apparent to one skilled in the art to control the exhaust gas temperatures, the contact times and/or residence times in the dryer vessel, the moisture content of the solids and of the vapor phase in the dryer vessel and other variables in order to process a particular wastestock to achieve these desired results and to maximize the nutrient value in the final products.

Dry or low moisture content wastestock is likely to have more air entrained in the interstices among the particles than wet or high moisture content wastestock, and elimination of such entrained air from a dry wastestock before introduction into the dryer vessel may not normally be economically practical. However, consistent with other operational aspects of the gas turbine generator system of the present process, it is therefore preferable to use high moisture, low air content wastestock, and may be preferable to add water to a dry wastestock to displace air therefrom before processing in the systems of this disclosure. Minimizing introduction of air and oxygen into the dryer vessel is preferred to prevent significant oxidation of the nutrient components of the wastestock, as well as other components of the wastestock, such as straw, dust, etc., that might pose a fire or safety hazard if excess air or oxygen were present in the dryer vessel.

Exclusion of outside air is also preferred for economic efficiency as well, because heating excess or outside air along with heating the wastestock reduces the efficiency of the gas turbine generator system of the present process. In some instances where the wastestock is very low in moisture content or too dry for preferred operation, water can be added to the wastestock, to the turbine exhaust, to the turbine intake or to the dryer vessel to raise the moisture level in the dryer vessel to a level for efficient operation and to produce a solids material from the dryer vessel with a desired moisture content and desired self-binding properties. Addition of water to a dry wastestock followed by mixing, kneading or pressing, such as in windrow mixing and pressing with a roller, can also serve to displace air from the wastestock before being introduced into the dryer vessel. In the case of very dry wastestocks, water may be considered a process aid added before entry into the dryer vessel. It will be recognized that the operation of the dryer vessel is normally to dry the wastestock, but it is to also achieve the high temperature heating of the wastestock to convert or destroy undesired components and to achieve a chemical or thermal alteration in the wastestock to provide binding and particle hardness profiles desired in the final product. As noted, an important aspect of the gas turbine generator system of the present process is the thermal conversion of the various components of the wastestock without significant oxidation from the outside air. Since the specific components of wastestocks are numerous and varied, it is not clearly understood what specific chemical reactions may be taking place in the thermal conversions, and applicants do not wish to be bound by specific theories or speculation regarding same. However, certain observations have been made, and the understanding of the following observations will further enable one skilled in the art in effectively and efficiently practicing the inventive aspects of the present disclosure. First is the thermal conversion and destruction of undesirable components, such as organisms, chemicals, etc., as discussed elsewhere in this disclosure. Second is the thermal conversion, chemically or physically, of the organic matter (animal waste, algae lipids, straw, bedding, etc.) in the wastestock that makes it essentially self-binding and enables the thermally treated or converted wastestock to be made into high physical strength pellets, granules or prills without the addition of binders or similar materials. While conventional binders for forming pelletized, granulated or prilled fertilizers can be used, it is preferred to operate at thermal treatment temperatures and residence times to produce a material that is self-binding and can be pelletized/granulated/prilled without added binders. It is believed that to some extent, when the organic matter in the wastestock is chemically altered and/or thermally converted, similar to being "cooked," it transforms ligands, cellulose, starch, carbohydrates, etc., into materials that can act as binders in the final product. This provides a binding profile to enable formation of a final product having particle strengths and free flowing anticaking and nonfriable properties that make it useful in conventional dry fertilizer handling and application equipment. In some operations of processing a very low moisture content wastestock, there may actually not be any significant drying taking place, i.e., the moisture content of the wastestock entering the dryer vessel may be essentially the same as the fertilizer or soil builder material exiting the dryer vessel, so the dryer vessel is essentially acting as an oven. In this case, the important processing taking place is the thermal treatment or conversion and/or chemical alteration ("cooking") of at least a portion of the organic matter present in the wastestock to enable the produced material to be sufficiently self-binding to provide a final pellet, granule or prill product having useful binding, agglomeration, hardness, anticaking, nonfriable, nondusting, free flowing and humidity tolerant profiles.

The types of dryer vessels that can be used in the gas turbine generator system of the present process are, for example, the following: Rotary drum with or without internal scrapers, agitation plates and/or paddles; Stationary

"porcupine" drum dryer with or without scrapers and/or agitator plates and/or paddles; Triple pass stepped drying cylinder or rotary drum dryer systems with or without scrapers and/or agitator plates and/or paddles; Rotary drum dryer systems with or without steam tubes and with or without scrapers and/or agitator plates and/or paddles; Turbo-dryer or turbulizer systems; Conveyor dryer systems with or without scrapers and/or agitator plates and/or paddles; Indirect or direct contact dryer systems with or without scrapers and/or agitator plates and/or paddles; Tray dryers; Fluid bed dryers; and Evaporator systems.

Examples of commercially available dryer vessels useful in or that can be adapted for use in the gas turbine generator system of the present process include: Scott AST Dryer™ Systems; Simon Dryer Ltd.-Drum dryers; Wyssmont Turbo Dryer systems; Duske Engineering Co., Inc.; Energy Unlimited drying systems; The Onix Corporation dehydration systems; International Technology Systems, Inc. direct or indirect dryer systems; Pulse Drying Systems, Inc.; and MEC Company dryer systems.

Further examples of dryer vessels useful in or that can be adapted for use in the gas turbine generator system of the present process are disclosed in U.S. Pat. Nos. 5,746,006; 5,570,517 and 6, 367,163, the disclosures of which are incorporated herein by reference in their entirety. As noted above the "dryer vessel" does not necessarily always function primarily as a dryer by removing moisture from the wastestock. The dryer vessel also functions as the thermal treatment/conversion/alteration vessel or oven in which the wastestock may be heated to sufficient temperatures for sufficient times to produce the desired final materials and products as disclosed herein. In addition, the dryer vessel need not provide direct contact of the turbine exhaust gases or other heat source and the wastestock, but can provide indirect heating of the wastestock to achieve the drying and/or thermal treatment/conversion/alteration desired. Another aspect of the dryer vessel adapted for use in the gas turbine generator system of the present process is that the dryer vessel preferably also functions as the silencer or muffler for the gas turbine or other engine providing the hot exhaust gases. Due to the connection between the gas turbine exhaust and the dryer vessel being closed to outside air, is that the dryer vessel functions effectively as a silencer for the gas turbine.

Another advantage provided by the gas turbine generator system of the present process is that the steam and off gases can be pulled from the discharge end of the dryer vessel by an appropriate fan, vent blower, etc., to provide a reduced pressure at the upstream entrance of the dryer vessel, thereby reducing the back pressure on the turbine exhaust. This increases the efficiency of operation of the gas turbine and is made possible because the connection between the gas turbine exhaust and the dryer vessel is not open to outside air.

It will also be recognized from this disclosure, that the operation of a gas turbine generator will preferably be controlled for optimal efficiency or economics for the wastestock drying, thermal conversion, chemical alteration and other processing needs, which may not be the optimal or best gas turbine operating conditions for electricity production. The electricity production is a cost recovery revenue stream for the system, but the overall economics of the operation may be better under gas turbine operating conditions that favor optimum exhaust heat output for efficient dryer vessel operation and downstream production of products having desired properties and disfavor electricity production. Determination of such operating conditions for a particular installation of the gas turbine generator system of the present process will be apparent to one skilled in the art following the teachings herein. Gas turbine control systems of this type are disclosed in commonly assigned copending U.S. patent application Ser. No. 10/894,875, filed on JuI. 19, 2004, the disclosure of which is incorporated herein by reference in its entirety.

Another advantage provided by the gas turbine generator system of the present process results from the contact of the gas turbine exhaust gas with the wastestock in the confined space of the dryer vessel without significant outside air present. The NOx and SOx emissions, and to some extent CO and CO2 emissions, in the gas turbine exhaust are substantially reduced, and in some cases reduced to zero, by absorbing or complexing of the NOx and SOx components into the wastestock, where they remain absorbed, complexed or fixed in the material exiting the dryer vessel and in the product after processing into granular, pellet or prill form. This provides the double advantage of lowering or eliminating the emissions of NOx and SOx (and CO/CO2) into the atmosphere and of adding the nitrogen, sulfur and carbon components to the nutrient value of the product produced by the process and apparatus of the present disclosure.

The typical turbine exhaust gas temperature entering the dryer vessel will be in the range of about 500 degrees F to about 1,500 degrees F, depending on moisture and other content of the wastestock and the desired condition of the material output from the dryer vessel. In smaller systems with smaller engines, the inlet exhaust gas temperature can be as low as about 300 degrees F or about 350 degrees F. A preferred range is from about 600 degrees F to about 1200 degrees F, and it is more preferred that the inlet temperature be at least about 650 degrees F and most preferably at least about 700 degrees F. The temperature and flow rate of the gas entering the dryer vessel will depend in part on the moisture content and other properties of the wastestock. Higher moisture content will obviously generally require higher inlet gas temperatures to reduce the moisture content. It is believed that an additional efficiency is achieved in the systems of the present disclosure where high moisture content wastestock is contacted with high temperature gases. Such contact causes the formation, sometimes instantly, of superheated steam as the moisture comes out of the wastestock, then that superheated steam heats and drives the moisture out of adjacent wastestock. It is believed that this mechanism is responsible for quick drying of the wastestock to a low moisture content so that the remaining residence time of the wastestock in the dryer vessel contributes to the desired thermal treatment/conversion/alteration or "cooking" thereof. Some wastestocks may require lower temperatures but longer residence time to achieve the conversion or "cooking" needed to produce a self-binding product having the other desired properties discussed herein. The temperature of the fertilizer/soil builder material or the animal feed material exiting the dryer vessel will typically be in the range of about 150 degrees F to about 450 degrees F and preferably between about 200 degrees F and about 350 degrees F. In some operations, the dryer vessel exit temperature of the fertilizer/soil builder material or animal feed material should be at least about 175 degrees F and preferably at least about 200 degrees F.

The self-binding properties of the materials and products of the gas turbine generator system of the present process are an important preferred aspect of this disclosure. While conventional binders and additives can optionally be used to provide desired physical strength properties of the granules, pellets or prills in desired shapes and forms, it is preferred that the operating conditions should be those that cook and convert the wastestock to produce a self-binding product. Those operating conditions will depend on the moisture content and the organic matter content of the wastestock that is capable of being converted to components having binding characteristics. While not understood and not being bound by any particular theory, it is believed that starch, protein, carbohydrate and sugar components are converted to glutenous-like materials that can act as binders and that oil and ligand-type components are polymerized to act as binders. As used herein the term "fertilizer material" is used to refer to and means the dried wastestock which is produced in the dryer vessel by reducing the moisture content of the manure from an existing level to a lower level achieving the chemical alterations and conversions referred to herein. The "fertilizer material" is considered an intermediate product that is suitable for further processing into a final fertilizer product suitable for consumer, commercial or industrial use. Typically the fertilizer material from the dryer vessel will be processed by milling to produce a powder or meal, followed by granulating, pelletizing or prilling of the powder or meal to produce the final fertilizer product or soil builder product suitable for dry application in a crop growing operation. The fertilizer material can also be milled or otherwise powdered and made into a slurry or other liquid or pumpable fertilizer product that can be applied to the soil or in a crop growing operation in wet form, or pressure applied to hills or cliffs in remediation or seeding type applications, such as hydro-mulching, hydro-seeding and hydro-sprigging, or can be used to coat seeds for such uses or for seed drills or aerial planting. Similarly, the material the dryer vessel produces may optionally be processed to form a product similar to natural peat, but typically much higher (by 20%, 30%, 40%, 50% or 60% or more) in organic matter and lower in moisture content than natural peat. In the case where the wastestock is partially or mostly bioconverted, the material produced by the dryer vessel can still be formed into a peat-like product which is useful as a soil builder product. Even though such product may not be as high in nutrient value, it will be high in organic matter. The raw output from the dryer vessel, whether from fresh or bioconverted wastestock, can be the final fertilizer or soil builder product which can be baled or packaged in a form desired and suitable for use in various agricultural and landscape operations. For example, it can be formed in long "snake" rolls, similar to the straw snake rolls, for use in erosion control at construction sites. Such rolls will be just as effective at erosion control as straw rolls, but due to the higher nutrient and/or organic matter compared to straw, such rolls will encourage and enable earlier and more vegetation growth at that site to resist erosion after the rolls are disintegrated and no longer effective. The material from the dryer vessel can also be combined with binders, such as molten urea, to form a product for agricultural use. As used herein "fertilizer material" and "fertilizer product" are intended to refer to materials and products higher in plant usable nutrient values (typically made from fresh manure wastestock). And, "soil builder material" and "soil builder products" are intended to refer to materials and products having lower plant usable nutrient values (typically made from bioconverted manure wastestock or a wastestock low in manure content and high in other content such as straw, nesting material, etc.), but are nevertheless high in organic matter that is beneficial as a soil conditioner, soil builder or soil amendment. It is recognized that these materials or products can be blended with other materials or chemicals as disclosed elsewhere herein. It is also noted that the products produced by the systems of this disclosure, while examples of which have been disclosed to be used for fertilizer/soil builder, or animal feed use, can also be used as fuel for heat or electricity production. Local economics will determine the end use made of the material produced from the dryer vessel or the final product produced from the gas turbine generator system of the present process. As used herein the term "granule," "granulating" and the like refer to any granular form of the material or product produced by the gas turbine generator system of the present process, including conventional granules, powder, dust, crumbs and the like, produced by conventional granulation processes and equipment, including crushing or crumbling previously formed pellets or prills. The term "pellets," "pelletizing" and the like refer to any pellet form of the materials or products produced by the gas turbine generator system of the present process, including cylindrical, bullet, spherical or other shape, typically made by conventional pelletizing processes and equipment, such as by extruding a slurry or paste and cutting, chopping, or breaking the extrudate to the desired size. The terms "prills," "prilling" and the like refer to any prill form of the materials or products produced by conventional prilling processes and equipment, including spray tower processes, freeze drying processes, etc.

An extrusion pelletizer is one of the preferred process units for use in the gas turbine generator system of the present process because it takes advantage of the self-binding properties of the material produced in the dryer vessel, and because it can be operated under temperature and pressure conditions that may further provide or contribute to the "cooking" of the material to produce the basic and/or enhanced self-binding properties of the desired product, hi a typical operation, the powder or meal from the milling unit may be mixed with steam or water, for example steam or condensed water vapor from the dryer vessel, sufficient to form material that is extrudable at high pressure and temperature to form pellets or other shapes. The temperatures in the extrusion pelletizer may be from heated screws, dies or drums or may be from the energy of high pressure compression. In either case the extrudable material is heated to a high temperature in the process. It is believed that for some wastestocks that the high temperature and pressure in the extruder pelletizer may further "cook" or convert certain components in the material to provide or contribute to additional or enhanced self-binding properties of the resulting pelletized, granulated or prilled product. Typical operating conditions for such an extrusion pelletizer will be an extrudable material having moisture content of up to about 20% by weight or higher, depending on the extruder equipment employed. Extruder temperatures and pressure will be those normally used in conventional extruder equipment.

Other operating conditions can obviously be employed depending on the wastestock being processed and the desired properties of the formed product. The pellets produced may be dried to reduce the moisture content to a level suitable for stable product storage, e.g., about 10% by weight. The moisture removed at this point in the process can be recycled for use in other steps and processes of the systems of this disclosure.

The wastestock will typically have a moisture content between about 50% and about 90% by weight, preferably between about 60% and about 80% by weight and most preferably between about 65% and about 75% by weight. (Percent by weight, as used herein, is in reference to percent of the component in question based on the total weight of the mixture referred to.) Although wastestock of lower moisture content, for example, as low as about 40% by weight or even about 30% by weight can be processed in the gas turbine generator system of the present process. The preferred wastestock has a moisture content of at least about 50% by weight, more preferably at least about 60% and most preferably at least about 70% by weight. When the wastestock has a high moisture content in this range, processing advantages are achieved from the essentially instant production of steam and superheated steam at the inlet of the dryer vessel where the l,000degree F exhaust gases contact the high moisture wastestock at atmospheric or subatmospheric pressure. The steam and superheated steam thus produced contributes to the drying, cooking and conversion of adjacent or nearby and downstream particles of wastestock, which enhances the efficiency of the process.

The temperature of the wastestock will typically be ambient, i.e., in the range of about 30 degrees F to about 100 degrees F, but can be lower than 30 degrees F, provided that any frozen agglomerations do not interfere with the wastestock preparation or the operation of the dryer vessel and wastestock feeder equipment. While wastestock is preferred to be at a low temperature to reduce or prevent composting or bioconversion of nutrients before processing, it may be advantageous for process economics or for throughput capacity to preheat the wastestock prior to introduction into the dryer vessel. If preheating is used, it preferably is done just before use in the gas turbine generator system of the present process so composting and bioconversion are kept to a minimum. If such wastestock preheating is employed, it may be done in any desired fashion, such as heat exchanger, solar heating, heated conveyers or augers or heated concrete slabs in the staging and wastestock preparation area.

The contact time between the turbine exhaust gases and the wastestock will be determined by several variables including moisture content of the wastestock, moisture content desired in the dryer vessel output material, the chemical alteration/conversion desired, volume and temperature of the exhaust gases entering the dryer vessel and other factors. The contact time will be regulated to provide not only the drying desired, but also to elevate the particles of wastestock solids to sufficiently high temperatures to sufficiently destroy or convert to harmless forms, the undesirable components present in the wastestock, such as organisms, microorganisms, seeds, pesticides, antibiotics, hormones, prions, viruses and the like, when such conversion or destruction is desired, and to produce a self-binding product, when desired. The actual temperature attained by the particles is not important to determine, so long as the desired levels of said component destruction and conversion and the desired level of self-binding are achieved. The desired contact time can be varied and regulated by the dryer vessel volume and size and by the throughput volumes of the wastestock and exhaust gases. The heat transfer from the exhaust gases to the wastestock, and consequently the temperature to which the wastestock is heated, will mainly be a function of the mass ratio of exhaust gas to wastestock. An example of the dryer vessel operation with the gas turbine generator is a Rolls Royce Allison 501-KB5 generator (rated at 3.9 MW) having an exhaust gas output of about 122,000 Ib ./hr. at 1,000 degrees F and connected to a Scott Equipment Company, New Prague, Minn., USA rotary tubular dryer model AST 8424 having an internal volume of about 26 cubic meters (m³). The wastestock may be fresh cattle feedlot manure having a moisture content of about 70% by weight and a temperature of about 65 degrees F that is fed to the dryer vessel at a rate of about 6,500 kg./hr., which is about 10 m³/hr., (about 16,200 Ib ./hr.) to provide an average or nominal residence time of the solids in the dryer vessel of about 10 to about 18 minutes and a weight ratio of exhaust gases to wastestock of about 7.5. The dryer vessel output is at about 200 degrees F. The weight ratio of exhaust gas to wastestock will generally be between about 15:1 and about 1:1, preferably between about 10:1 and about 3:1 and more preferably between about 8:1 and about 4:1. The heat requirement may call for a ratio of at least about 20:1 or at least about 25:1 or higher where the wastestock is cold with a very high moisture content and the exhaust gas is not at a high or maximum temperature. The exhaust gas flow and the wastestock flow through the dryer vessel may be concurrent, countercurrent, single stage, multiple stage, etc., depending on results desired and various system designs and economic considerations.

The output from the dryer vessel comprises steam, water vapor, combustion gases and solids that are dried and/or thermally treated and converted to desired forms. Typical dryer vessel outlet temperatures of the gases and/or solids will normally range from about 200 degrees F to about 350 degrees F, but lower or higher temperatures may be selected and/or desired for economic, product quality and/or process efficiency reasons. The outlet temperatures can be from at least about 110 degrees F to at least about 500 degrees F, preferably at least about 180 degrees F and more preferably at least about 200 degrees F. It is generally desired that the solids material exiting the dryer vessel will generally have a moisture content between about 10% and about 15% by weight, but can range from about 5% to about 25% by weight. Again, lower or higher moisture content of the dryer vessel output solids may be selected and/or desired for similar reasons. The steam, water vapor and combustion gases exiting the dryer vessel may normally be routed through heat exchangers (for recovery of process heat usable downstream in granulating or pelletizing operations or upstream in wastestock or turbine intake air preheating), condensers (for recovery of process water for upstream or downstream use, for agricultural application or for disposal), scrubbers, filters or cyclones (for recovering solids entrained in gases or liquids and rendering gases and liquids environmentally acceptable for release) and other conventional process equipment.

The products and materials produced by the gas turbine generator system of the present process are useful for and include blends with other materials, products or chemicals, as may be desired for particular end uses requiring particular properties or characteristics. Such other materials and additives can be added and blended at any appropriate point in the process: blended with the wastestock, added to the dryer vessel, added in the process water at any point, added to the material exiting the dryer vessel, added as part of any milling, granulating or pelletizing processing or simply mixed with the final product or blended in before bagging or packaging or at the point of use. For example the fertilizer and soil builder products, while usually relatively odor free, can be blended with other materials that can either provide a pleasant odor or mask any unpleasant odor. Such materials can be synthetic (perfumes) or natural, with natural materials being preferred. Natural, organic materials can include sage, mint, fennel, garlic, rosemary, pine, citrus and similar materials that would not prevent certification as an organic input. Other materials for blending can include iron, minerals, carbon, zeolite, perlite, chemical fertilizers (urea, ammonium nitrate, etc.), pesticides and other materials to adapt, for example, the fertilizer or soil builder product for specialized use. It is well known in the art to make fertilizer products in desired granule or particle size having desired hardness and integrity in dry form, but readily dispensable when applied to an agricultural operation and treated with water by irrigation or rainfall. For example, see U.S. Pat. No. 4,997,469 to Moore and U.S. Pat. No. 5,676,729 to Elrod et al., the disclosures of which are incorporated by reference in their entirety.

The systems of the integrated process include configurations that can be used to reduce and in some operations essentially eliminate the emission into the atmosphere of noxious odors and greenhouse gases from animal feeding operations. As noted above, in addition to bioconversion of animal waste, one of the major sources of greenhouse gases (methane in particular) and noxious odors is from the gases produced in the enteric fermentation in the animals themselves and the release of those gases by the animals by eructation, emission of flatulence and the essentially immediate release of those gases from urine and feces upon evacuation from the animals, referred to herein as "animal gases." Animal feeding operations are coming under increasing regulation by federal and state agencies due to increasing pressure from population areas near the animal feeding operations. The regulation is directed to two aspects of air quality. The first is noxious odors from animal gases and bioconversion emissions, which contain mercaptans and many other organic compounds that have offensive odors and which are objectionable to residential communities. The second is greenhouse gas emissions that are harmful to air quality.

Greenhouse gases include CO2, CH4, and N2O and are usually referred to in terms of CO2 equivalent effect on the atmosphere. Methane has a CO2 equivalent factor of about 23 (as used by the USDOE), which means that 1 kg of CH4 released into the atmosphere is equivalent to 23 kg of CO2 released. (Some sources give the equivalent factor as about 21.) In the United States Department of Energy/Energy Information Administration Report # DOE/EIA-0573 (2002) released October 2003 (available at www.eia.doe.gov/oiaf/1605/ggrpt/) it is estimated that 8 million MT of CH4 (183 million MT CO2 equiv.) was released into the atmosphere in 2002 by agricultural operations, which was about 30% of all CH4 emissions in the U.S., the other sources including landfill and municipal sewage treatment operations. Of the agricultural CH4 emissions, 94% was from livestock operations, of which 67% (about 5 million MT) was from enteric fermentation (animal gases) and 33% (about 3 million MT) was from decomposition of livestock wastes. While CH4 is the main greenhouse gas produced by bioconversion of manure, CO2 and NOx gases are also produced. It is particularly desired to prevent NOx release into the atmosphere, because it is estimated that it has a CO2 equivalent of about 310. The gas turbine generator system of the present process can be used, as disclosed herein, to essentially eliminate the decomposition greenhouse gas emissions from animal feeding operations by containing and processing the animal gases, by processing the wastestock to prevent decomposition or bioconversion taking place and/or containing and processing emissions from decomposition or bioconversion that takes place before the wastestock can be processed.

The gas turbine generator system of the present process is particularly useful in essentially eliminating the animal gas emissions and odors from animal gases in certain existing animal feeding operations, hi the basic system of the integrated process, the gas turbine exhaust is connected to the dryer vessel. To control animal gases produced in an animal feeding operation, the gas turbine air intake may be connected to the animal shelter ventilation system so that the ventilation air exhausted from the animal shelter is directed into the gas turbine air intake where two processes normally will take place. First, the animal gases are burned along with the regular fuel supply, thereby converting the CH4 to H2O and CO2 and converting the mercaptans and other noxious or acrid compounds to H2O, COx, NOx and SOx. Second, the exhaust gases from the gas turbine are contacted with the wastestock, where the NOx and SOx and to some extent COx gases are absorbed into or complexed with the wastestock as it is dried and/or converted to a fertilizer or soil builder material, and preferably to a self-binding fertilizer or soil builder product. This aspect of the process prevents the animal gases from entering the atmosphere. Animal feeding operations that have free-stall or open barn structures can take advantage of the gas turbine generator system of the present process by pulling vent air from the top of the structure and ducting it into the turbine air inlet. This will capture a significant portion of the animal gas, particularly on zero wind days, because the methane in animal gases is lighter than air and will rise to the top of the structure, hi addition, such structures can be economically enclosed (e.g. by canvas walls) and ventilated by forced air (with or without climate control) to collect essentially all the animal gases from the animals in the structure and directing the exhaust vent air to the gas turbine air intake. Every kg of animal gas methane burned reduces the outside methane fuel requirement by one kg and reduces greenhouse gas emissions by CO2 equivalent of 23 kg. This aspect of the invention also provides the benefit of turbine inlet noise control.

Also as discussed previously, the end exhaust (containing CO2 from the natural gas combustion of the turbine) can be directed into locations such as algae growing tubes, houses, etc. to stimulate algae growth, hi this manner, the algae can absorb CO2 from the exhaust stream reducing greenhouse gas emissions.

The advantages provided by the present integrated process are numerous, as described above. The same bushel of corn can be used to produce both meat/milk and fuel that results in extremely high conversion efficiencies, and substantially reduces petroleum consumption per bushel of corn produced (field preparation, cultivation, harvesting, fertilizers, chemicals, and transport). Bio- fertilizer production and pathogen extermination (odor removal) allows energy efficient surface application back to the fields, and reduces petroleum and natural gas requirements for fertilizer manufacture, transport, and application. Processing of both food and fuel (utilizing grains or algae) at the same location reduces overall transportation-related petroleum requirements. Cattle feedlot odor and water contamination are reduced by rapid transfer of the cattle waste into the gas turbine generator and the anaerobic digestion systems. The production of bio-fuels like ethanol, bio-methane, and bio-diesel becomes cost competitive with fossil fuels, by exploiting synergies to reduce capital and operating costs, and maximizing returns on all of the co-products. With the utilization of a gas turbine generator system, conventionally costly spent grain mash drying processes are used to provide supplemental energy for the ethanol or bio-diesel production plant. The economic costs, and fossil fuel consumption and emissions associated with the conventional practice of transportation between disaggregated production sites (e.g., corn fields, corn drying facilities, ethanol plants, and cattle feedlots) may be eliminated. Distillers' grain or spent algae mash, once dried and pelletized can be stored for long periods before being fed to the animals.

The integrated process can also provide advantages to any nearby located meat packing plants. Two of the major cost centers of a meat packing plant are electricity costs for refrigeration and freezing, and the treatment of wastes, both manure and waste- water. Both of these cost centers can be integrated into the operations of the overall feedlot/bio-fuel/gas turbine generator complex, and net costs greatly reduced. Excess electricity generated by the gas turbine generators can be used in the dedicated packing plants rather than sold to the grid if desired. Also, the continuous flow gas turbine generator system can be interconnected, and adapted to treat packing plant wastes for a modest incremental investment, as described in U.S. Patent Nos. 7,024,796 and 7,024,800, the entire disclosures of which have been incorporated herein by reference.

In summary, the present integrated process substantially reduces fossil fuel use, livestock methane emissions and other pollution, and transforms wastes such as spent grain mash and spent algae mash into valuable products and energy. As a result, substantial reductions in greenhouse emissions are achieved cost effectively, and efficiently.

The above specification, examples and data provide a complete description of the manufacture and use of the inventive aspects of the present disclosure. Since many embodiments of the inventive aspects can be made without departing from the spirit and scope of the disclosure, the inventive aspects reside in the claims hereinafter appended.

Claims

Claims:

1. A method comprising:

- producing a bio-fuel from a first source, whereby a residual source wastestock remains after the production of the bio-fuel;

- providing an animal feedlot including animal manure wastestock;

- providing at least one gas turbine configured to produce exhaust gases;

- contacting the exhaust gases produced by the at least one gas turbine with the animal manure wastestock to produce a fertilizer; and - contacting the exhaust gases produced by the at least one gas turbine with the residual source wastestock remaining after the production of the bio- fuel to produce animal feedstock.

2. A method according to claim 1, wherein the first source includes a grain.

3. A method according to claim 2, wherein the grain includes corn.

4. A method according to claim 1 , wherein the first source includes algae.

5. A method according to claim 1 , wherein the gas turbine includes a gas turbine generator for generating electricity.

6. A method according to claim 5, wherein at least a portion of the electricity produced by the gas turbine generator is used in producing the bio- fuel.

7. A method according to claim 1, wherein the bio-fuel includes ethanol.

8. A method according to claim 1, wherein the bio-fuel includes bio-diesel.

9. A method according to claim 1 , wherein either the animal manure wastestock or the residual source wastestock are contacted with the gas turbine exhaust gases in a dryer vessel without significant oxidation of the wastestock.

10. A method according to claim 9, wherein either the animal manure wastestock or the residual source wastestock are contacted with the exhaust gases to produce an end-product having a moisture content less than about 20% by weight.

11. A method comprising:

- providing an animal feedlot including animal manure wastestock; - anaerobically digesting the manure wastestock to produce a bio-gas, whereby a bio-gas byproduct remains after the production of the bio-gas;

- providing at least one gas turbine configured to produce exhaust gases;

- contacting the exhaust gases produced by the at least one gas turbine with the bio-gas byproduct to produce a fertilizer; and - contacting the exhaust gases produced by the at least one gas turbine with the residual source wastestock remaining after the production of the bio- fuel to produce animal feedstock.

12. A method according to claim 11 , wherein the first source includes a grain.

13. A method according to claim 12, wherein the grain includes corn.

14. A method according to claim 11, wherein the first source includes algae.

15. A method according to claim 11 , wherein the gas turbine includes a gas turbine generator for generating electricity.

16. A method according to claim 15 , wherein at least a portion of the electricity produced by the gas turbine generator is used in producing the bio- fuel.

17. A method according to claim 11 , wherein the bio- fuel includes ethanol.

18. A method according to claim 11 , wherein the bio-fuel includes bio- diesel.

19. A method according to claim 11 , wherein the bio-gas includes methane.

20. A method according to claim 11, wherein either the bio-gas byproduct or the residual source wastestock are contacted with the gas turbine exhaust gases in a dryer vessel without significant oxidation of the materials within the dryer vessel.

21. A method according to claim 20, wherein either the bio-gas byproduct or the residual source wastestock are contacted with the exhaust gases to produce an end-product having a moisture content less than about 20% by weight.

22. A method comprising:

- providing an animal feedlot including animal manure wastestock;

- anaerobically digesting at least a portion of the manure wastestock to produce a bio-gas, whereby a bio-gas byproduct remains after the production of the bio-gas;

- providing at least one gas turbine configured to produce exhaust gases;

- contacting the exhaust gases produced by the at least one gas turbine with at least a portion of the animal manure wastestock to produce a fertilizer; - contacting the exhaust gases produced by the at least one gas turbine with the bio-gas byproduct to produce a fertilizer; and

- contacting the exhaust gases produced by the at least one gas turbine with the residual source wastestock remaining after the production of the bio- fuel to produce animal feedstock.

23. A method according to claim 22, wherein the first source includes a grain.

24. A method according to claim 23, wherein the grain includes corn.

25. A method according to claim 22, wherein the first source includes algae.

26. A method according to claim 22, wherein the gas turbine includes a gas turbine generator for generating electricity.

27. A method according to claim 26, wherein at least a portion of the electricity produced by the gas turbine generator is used in producing the bio- fuel.

28. A method according to claim 22, wherein the bio-fuel includes ethanol.

29. A method according to claim 22, wherein the bio-fuel includes bio- diesel.

30. A method according to claim 22, wherein the bio-gas includes methane.

31. A method comprising:

- providing an animal feedlot including animal manure wastestock; - anaerobically digesting at least a portion of the manure wastestock to produce a bio-gas, whereby a bio-gas byproduct remains after the production of the bio-gas;

- providing at least one gas turbine configured to produce exhaust gases;

- contacting the exhaust gases produced by the at least one gas turbine with at least a portion of the animal manure wastestock to produce a fertilizer; and

- contacting the exhaust gases produced by the at least one gas turbine with the bio-gas byproduct to produce a fertilizer.

32. A method according to claim 31 , wherein the gas turbine includes a gas turbine generator for generating electricity.

33. A method according to claim 31 , wherein the bio-gas includes methane.

34. A method according to claim 31 , wherein either the manure wastestock or the bio-gas byproduct are contacted with the gas turbine exhaust gases in a dryer vessel without significant oxidation of the materials within the dryer vessel.

35. A method according to claim 34, wherein either the manure wastestock or the bio-gas byproduct are contacted with the exhaust gases to produce an end- product having a moisture content less than about 20% by weight.

36. A system comprising: a bio-fuel production facility configured to produce a bio-fuel from a first source, leaving a residual source wastestock as a byproduct of the bio-fuel production; an animal feedlot including animal manure wastestock; an anaerobic digester configured to digest at least a portion of the manure wastestock from the animal feedlot to produce a bio-gas and a bio-gas byproduct; and at least one gas turbine configured to produce exhaust gases to be contacted with any of the residual source wastestock, the bio-gas byproduct, or at least a portion of the manure wastestock to produce a converted material.

37. A system according to claim 36, wherein the first source includes a grain.

38. A system according to claim 37, wherein the grain includes corn.

39. A system according to claim 36, wherein the first source includes algae.

40. A system according to claim 36, further comprising a dryer vessel receiving the exhaust gases from the at least one gas turbine through a connection and drying or thermally treating any of the residual source wastestock, the bio-gas byproduct, or at least a portion of the manure wastestock to produce the converted material, wherein the connection between the at least one gas turbine and the dryer vessel substantially precludes the introduction of air into the dryer vessel.

41. A system according to claim 36, wherein the gas turbine includes a gas turbine generator for generating electricity.

42. A system according to claim 41, wherein at least a portion of the electricity produced by the gas turbine generator is used in producing the bio- fuel.

43. A system according to claim 36, wherein the bio-fuel includes ethanol.

44. A system according to claim 36, wherein the bio-fuel includes bio-diesel.

45. A system according to claim 36, wherein the bio-gas includes methane.

46. A system comprising: a bio-fuel production facility configured to produce a bio-fuel from a first source, leaving a residual source wastestock as a byproduct of the bio-fuel production; an animal feedlot including animal manure wastestock; and at least one gas turbine configured to produce exhaust gases to be contacted with either of the residual source wastestock or at least a portion of the manure wastestock to produce a converted material.

47. A system according to claim 46, wherein the first source includes a grain.

48. A system according to claim 47, wherein the grain includes corn.

49. A system according to claim 46, wherein the first source includes algae.

50. A system according to claim 46, further comprising a dryer vessel receiving the exhaust gases from the at least one gas turbine through a connection and drying or thermally treating either of the residual source wastestock or at least a portion of the manure wastestock to produce the converted material, wherein the connection between the at least one gas turbine and the dryer vessel substantially precludes the introduction of air into the dryer vessel.

51. A system according to claim 46, wherein the gas turbine includes a gas turbine generator for generating electricity.

52. A system according to claim 51, wherein at least a portion of the electricity produced by the gas turbine generator is used in producing the bio- fuel.

53. A system according to claim 46, wherein the bio-fuel includes ethanol.

54. A system according to claim 46, wherein the bio-fuel includes bio-diesel.

55. A system according to claim 46, wherein the bio-gas includes methane.