WO2010033512A1

WO2010033512A1 - Improved process for preparing bio-oils from biomass

Info

Publication number: WO2010033512A1
Application number: PCT/US2009/057009
Authority: WO
Inventors: Rongsheng Ruan; Changyan Yang; Bo Zhang; Xiangyang Lin; Ling Chen; Yiqin Wan
Original assignee: Regents Of The University Of Minnesota
Priority date: 2008-09-16
Filing date: 2009-09-15
Publication date: 2010-03-25

Abstract

The invention described herein provides an improved process for preparing bio- oils from biomass using pyrolysis. The process can comprise a step of acid pre-treatment of biomass prior to microwave assisted pyrolysis, and comprise a reformation step prior to condensation. The process of the invention can be used to produce simpler higher quality bio-oil compositions from a given biomass input, and with greater liquid percent yield relative to starting biomass solid weight. Resultant bio-oil output can comprise a water- soluble fraction and insoluble oil fraction, the components of which can be further separated to provide various useful compounds.

Description

IMPROVED PROCESS FOR PREPARING BIO-OILS FROM BIOMASS

STATEMENT OF GOVERNMENT INTEREST

The invention has been funded by the U.S. Federal government and the State of Minnesota. Accordingly, the U.S. government and the State of Minnesota may both have interests in this invention.

BACKGROUND OF THE INVENTION

Declining supplies of fossil energy sources and adverse effects of fossil energy usage on the global environment have prompted a strong growing interest in renewable energy. A variety of renewable energy technologies are being researched, including biomass-based energy technologies. Such technologies include conversion processes for corn to ethanol, soybean to biodiesel, lignocellulosics to bioethanol or bio-oils, and the like. In response to the rising prices of corn and soybean sources, focus and attention have increased in relation to conversion of lignocellulosics into biofuels (such as ethanol and bio-oils) and syngas.

Also of significantly increasing interest to various populations around the world is reducing or eliminating the ecological and environmental harm caused by industry and consumer behavior and activities. From an economic standpoint, there is also much interest in technologies which can utilize waste generated by certain industries and convert such waste into useful products. Technologies which can develop useful materials from raw materials have thus become a focus of interest to researchers and companies worldwide.

Raw input or biomass can be used to prepare useful materials, including bio-oils. Pyrolysis, a thermochcmical conversion process, is an attractive way to produce liquid fuels from solid biomass feedstock. The process typically employed to extract bio-oils from biomass is pyrolysis, which generally involves rapid heating of biomass material in oxygen-free condition. Conventional processes typically involve a fractionation step of the raw biomass to prepare the biomass in advance of the pyrolysis steps. It is known, for instance, that the compound furfural is included among the compounds that can be recovered and prepared from certain biomass input materials, such as corn stover. The result is a mixture of various chemicals and compounds, among them furfural. Furfural is a liquid aldehyde and an intermediate commodity chemical used to synthesize a wide array of other chemical products. Furfural can be produced from waste biomass or biomass containing pentosans, and has the molecular formula C₅H₄O₂. Furfural can also referred to as 2-furancarboxaldeliyde, furaldehyde, 2-furanaldehyde, 2- furfuraldehyde, fural and furfurol.

Synthesis using furfural alcohol or tetrahydrofuran (TIIF) is described in Australian Government Report on Furfural Chemical and Biofuels from Agriculture {November 2006), for example. Obtaining furfural from waste is described in Win, Au. J. T₁ 8(4) (April 2005). Furfural can be used in resin production useful as a binding agent in foundry technologies, which constitutes about 70 percent of the market for furfural use.

Such resins can be used to make fiberglass, aircraft components and automotive brakes.

Furfural can also be used as a solvent in the manufacture of petroleum-based lubricants.

Various attempts have been made to improve pyrolysis. Acid prc-treatments of biomass to improve pyrolysis are known. Pre-treatment of cellulose-containing raw materials to produce high yields of 1,6-anhydrosaccharides is described in Dobele et al., L Anal. Appl. Pyrolysis, Vol. 68-69, pp. 197-211 (2003).

Biomass technologies such as pyrolysis face many technical challenges. For example, the liquid fuels produced from pyrolysis of biomass are often compositionally complex and highly unstable in terms of physical consistency, chemical properties, and combustion characteristics. Downstream processing is typically required to further isolate the useful compounds. Current bio-oil products are a complex mixture of dozens of chemicals. Typically, the resulting bio-oils require substantial further downstream refinement, extraction and/or purification in order to obtain simpler bio-oil compositional profiles, or to obtain the other compounds of interest within the mixture, that are practical and useful. Furthermore, as a result of the heat and time parameters associated with known pyrolysis techniques, investigating energy efficiency poses a challenge for pyrolysis as well.

There exists a need for improved processes for obtaining useful materials such as bio-oils from raw input materials. There further exists a need for processing biomass which increases cost-effectiveness and energy efficiency of the process. Further yet, there is a need in biomass pyrolysis processes for improved quality, purity and simplicity of the resulting yielded bio-oils and bio-compositions that reduce the extent of downstream processing to isolate compounds of interest. Efforts and advancements that improve the practicality of the pyrolysis option to produce bio-oils are still needed.

SUMMARY OF THE INVENTION The invention provides an improved process for preparing bio-oils from biomass which yields a compositionally simplified and purer bio-oil profile. The invention can be used to provide enhanced predictability and correlative information between particular input biomass profiles and the corresponding bio-oil output product composition profile. Thus, the invention can be employed in systems to produce bio-oils from natural biomass with greater selectivity. The process of the invention can be associated with cost-effective and waste-reducing and byproduct-reductive bio-oil production systems. It has been discovered that the overall time required to prepare bio-oils can be significantly reduced, yet surprisingly, at the same time produce a relatively simplified composition profile of the resulting bio-oil. In addition to providing industry with correlative information between the input biomass material and the resultant output compositional bio-oil profile corresponding to the particular biomass input, the process of the invention further provides a significant qualitative improvement as to output bio-oil composition, e.g., selectivity and purity of bio-oil ingredients.

The invention can be used to enhance the front-end production of stable bio-oils as opposed to reliance upon downstream post-conversion processing of bio-oils to improve their stability. Strategic employment of catalysis within the process steps alongside pyrolysis is an important advance associated with the invention. These and other advantages of the invention can lead to more cost-effective commercial production and use of pyrolysis to produce bio-oils. The invention provides a process for preparing a bio-oil composition frem- biomass, the process comprising the steps of: a) introducing a biomass material; b) pre- treating said biomass material; c) subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; d) subjecting the pyrolyzed material to catalytic reformation; e) subjecting the catalytically reformed material to condensation; and f) obtaining resultant bio-oil-containing composition. In one embodiment, the biomass comprises corn stover and aspen wood pellets, and the bio-oil comprises furfural.

The invention further provides a process for preparing a bio-oil containing furfural from pentosan-containing biomass, the process comprising the steps of: a) introducing a biomass material; b) pre-treating said biomass material; c) subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; d) subjecting the pyrolyzed material to catalytic reformation; e) subjecting the catalytically reformed material to condensation; and f) obtaining resultant bio-oil-containing composition. The invention additionally provides a process for converting biomass into a bio-oil composition, the process comprising: a) introducing a biomass material; b) prc-treating said biomass material; c) subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; d) subjecting the pyrolyzed material to catalytic reformation; c) subjecting the catalytically reformed material to condensation; and f) obtaining resultant bio-oil-containing composition.

In another aspect, the invention provides a method of determining the yielded compositional ingredients of a bio-oil composition corresponding to a given starting biomass, said method comprising: a) defining the initial composition of a starting biomass source; b) subjecting said biomass to a process for preparing bio-oil composition, said process comprising the steps of: i) introducing a biomass material; ii) pre-treating said biomass material; iii) subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; iv) subjecting the pyrolyzed material to catalytic reformation; v) subjecting the catalytically reformed material to condensation; and vi) obtaining resultant bio-oil-containing composition; c) analyzing the chemical content in terms of ingredients and respective amounts; d) comparing the resultant chemical composition content to said starting biomass composition to ascertain corresponding compositions information as to bio-oil content; and e) utilizing said corresponding bio-oil compositional information to forecast biomass input relative to correlative bio-oil output compositional content.

In an alternative embodiment, the invention can further include continuous process for preparing a bio-oil composition from biomass, the process comprising the steps of: a) introducing a biomass material; b) pre-treating said biomass material; c) subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; d) separating solid residue and char from the remaining pyrolized material; e) subjecting the remaining pyrolized material to condensation; and e) obtaining resultant bio-oil- containing composition; wherein the above process steps are structured as a continuous process. Using this embodiment, the reformation step prior to condensation is preferred though optional. The invention can be used to obtain liquid bio-oil output from input biomass. The bio-oil can be composed of two condensable fractions: a water-soluble phase or fraction; and insoluble (heavy) oil phase or fraction. The water-soluble fraction can comprise a mixture of compounds - some of which can be used as industrial chemicals, such as furfural. The compounds present in the water-soluble fraction can be separated from its water content. The heavy oil fraction can contain a mixture of hydrocarbon-based heavy oils which can be further refined downstream and used as a source of fuel.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further illustrated by the following drawings - none of which are intended to be construed as necessarily limiting the invention.

Figure 1 is a flow diagram of a microwave-assisted pyrolysis biomass catalytic process and reforming for chemicals and fuel production, according to one embodiment.

Figure 2 is a schematic diagram of apparatus arrangement for microwave assisted biomass catalytic pyrolysis and reforming, according to one embodiment of the invention.

Figures 3, 4 and 5 show liquid fraction gas chromatography data, quantified as integration area of peaks, for the primary water-soluble compounds as separated from water content and oil phase of the bio-oil product.

Figure 3 is the gas chromatography composition profile for the water-soluble components (minus water) from Test Processes A through D and Control described in Example 1.

Figure 4 is the gas chromatography composition profile for the water-soluble components (minus water) from Test Processes E, F and Control described in Example 1.

Figure 5 is the gas chromatography composition profile for the water-soluble components (minus water) from Test Processes C, G and Control described in Example 1.

Figure 6 is a diagram of a continuous catalytic microwave pyrolysis system according to one embodiment of the invention. Figure 7 is a comparative gas chromatography profile of bio-oil obtained from corn cob biomass subjected to the continuous microwave assisted pyrolysis process with and without acid pre-treatment.

Figure 8 is a table showing the bio-oil components obtained from corn cob starting biomass with 4% acid pre-treatment and continuous microwave assisted pyrolysis. DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term "pyrolysis" is meant to refer to the chemical decomposition of organic materials by heating in the absence of oxygen. Within the context of the invention, the term is meant to refer to the conversion of complex materials including biomass and waste into substances that are desirable, useful, and/or less harmful. For instance, biomass heated to about 35O⁰C in the absence of oxygen can form gases (e.g., CO, CO₂, H₂, H₂O, CH₄), vapors, bio-oils, organic acids, charcoal and inert materials. Within the context of the invention, bio-oils are the primary product of interest from pyrolysis.

As used herein and unless explicitly limited by context, the term "bio-oil" is meant to refer to organic liquid fuels or chemicals that can be produced through pyrolysis, in which biomass is rapidly heated in an oxygen- free environment to produce liquid, char and gas. Within the context of the invention, the process of the invention can be used to obtain liquid bio-oil output from input biomass. The bio-oil can be composed of two condensable fractions: a water-soluble phase or fraction; and insoluble (heavy) oil phase or fraction. The water-soluble fraction can comprise a mixture of compounds — some of which can be used as industrial chemicals, such as furfural. The compounds present in the water-soluble fraction can be separated from its water content. The oil fraction can contain a mixture of hydrocarbon-based heavy oils which can be further refined downstream and used as a source of fuel. As used herein and unless specifically limited by context, the term "biomass" is meant to refer to living or recently dead biological materials (e.g., plant materials and animal waste) that can be used for fuel or industrial purposes. Biomass can be derived from a variety of materials, including miscanthus, switchgrass, hemp, corn, poplar, willow, sugarcane, oil palm, aspen, and the like. As used herein and unless explicitly limited by context, the term "biofuel" is meant to refer to solid, liquid or gas fuel derived from biological material.

The term "comprising" means the elements recited, or their equivalent in structure or function, plus any other element(s) which are not recited. The terms "having" and "including" are also to be construed as open ended unless the context suggests otherwise. Terms such as "about," "generally," "substantially," and the like are to be construed as modifying a term or value such that it is not an absolute, but does not read on the prior art. Such terms will be defined by the circumstances and the terms that they modify are understood by those of skill in the art. This includes at the very least the degree of expected experimental error, technique error, and instrument error for a given technique used to measure a value.

The invention in general provides a process for preparing bio-oil compositions from biomass, the process comprising the steps of: introducing a biomass material; pre-treating said biomass material; subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; subjecting the pyrolyzed material to catalytic reformation; subjecting the catalytically reformed material to condensation; and obtaining resultant bio-oil-containing composition.

An important aspect of the process of the invention is that particular modifications or adjustments made with respect to reagents and process parameters, in conjunction with the order of the process techniques and the associated equipment, not only enhance liquid percent yield of the output bio-oil-containing composition, but increase the compositional specificity and simplicity as well. Furthermore, the process of the invention provides improved and more definite relationships between: 1) input starting biomass type, reagents, process parameters and conditions; and 2) the corresponding output compositional profiles. Put another way, the process not only improves the pyrolysis for bio-oil production per se, but also provides useful information as to input-output which can be used to steer or guide pyrolysis techniques to "tailor" and direct more exacting product compositions.

Figure 1 illustrates a preferred embodiment of the invention including the sequence of process steps. The invention provides that certain and various modifications within the three "core" or essential process stages of the invention — 1) pre-treatment; 2) catalytic pyrolysis; and 3) catalytic reformation - can permit control as to cost-effective energy usage for the process and specificity of resultant (bio-oil) compositional profile. For example, the use of acidic conditions, alkaline conditions, and/or combinations of catalysts within each of these steps, as well as the various combinations between each of these steps, can affect compositional output and amount of energy required as to the overall process. In a preferred embodiment of the process, catalytic reformation is conducted prior to condensation. Referring still to Figure 1 , the process of the invention can be further described in terms of starting input biomass relative to output materials produced at various stages of the process. In general and comparing to a reference of input biomass quantified in terms of % dry weight biomass as 100% dry weight biomass (based on 100 grams), the amount of solid residues or char output produced from the microwave pyrolysis stage can be approximately 25% dry weight. Condensable output fractions produced from the condensation stage (shown in Figure 1 as "Chemical and fuels") can comprise two general fractions: water soluble fraction and heavy oil fraction. Measured in terms of grams weight of liquid, the condensation stage can yield approximately 30% water soluble compounds, and the heavy oil fraction can be approximately 20% grams weight of liquid output. Compositionally, the water-soluble fraction can comprise furfural, and the heavy oil fraction can be composed of a complex mixture of organic hydrocarbon compounds. Similarly, the amount of syngas or uncondensible gas (e.g., CO, CO₂, H₂, CH₄) generated from the condensation stage can be about 25% measured as a net remaining amount following the total 75% of other output products generated during the process in reference to the starting 100% biomass. Secondary ingredients introduced at different stages of the process, such as catalysts, can affect weight as well.

Biomass Material Biomass materials that can be used in conjunction with the invention can vary.

Common biomass materials that can be used in pyrolysis processes include, but are not limited to, living or recently dead biological plant materials such as miscanthus, switchgrass, hemp, corn, poplar, willow, sugarcane, sugar beets, oil palm, aspen, and the like. Biomass materials also include organic solid food waste and municipal solid waste materials. The process of the invention can be employed with a variety of biomass materials that generally contain cellulose, lignin, starch, oil and protein, and combinations thereof.

In the embodiment wherein furfural is the preferred bio-oil of interest as the resultant product yielded by the process of the invention, the biomass preferably is an organic material containing pentosan (a sugar aldehyde). For purposes of obtaining furfural compounds, the starting biomass material used in the invention can be corn stover, aspen wood pellets, or a mixture thereof, as well as other cellulosic biomass materials. Pre- Treatment of Biomass

One important aspect of the invention involves the pre-treatment of the biomass material prior to the pyrolysis steps. By pre-treating the initial raw biomass material(s) prior to the pyrolysis stage, the need for a separate or additional fractionation step can be eliminated. This advantage affords a significant simplification of the process and large- scale bio-oil manufacturing, as well as a significant reduction in energy usage and cost associated with pyrolysis. Pretreatment conditions that can be used include either acidic or alkaline conditions as created by the addition of acidic or alkaline ingredients, respectively, to the biomass and mixed therewith. According to one embodiment of the invention, the biomass material can be pre- treated with an acid. Acid pretreatment is preferred for starting biomass materials containing significant lignin content. Suitable acids that can be used for the pre-treatment step include, but are not limited to, an acid selected from the group consisting of dihydrogen sulfide (H₂S), hydrogen phosphate (H₃PO₄), hydrogen iodide (HI), hydrogen bromide (HBr), hydrogen chloride (HCl), hydrogen fluoride (HF), chloric (I) acid (HClO), hydrogen sulfate (H₂SO₄), perchloric acid (HClO₄), sodium carbonate (Na₂CO₃), sodium hydroxide (NaOH), nitric acid (HNO₃), and combinations thereof. Preferred for purposes of preparing furfural-rich resulting bio-oil compositions is the use with corn stover and/or aspen pellets as the starting biomass material, in conjunction with the use of sulfuric acid (H₂SO₄) in the pre-treatment step.

Generally, acidic pre-treatment conditions are preferred for lignin-containing starting biomass materials. It is believed that the presence of acids reduce or interfere with the chemical interactions of lignin, which may not be desirable as such may interfere with obtaining particular resulting composition ingredients. A pre-treatment step introducing acid can be carried out using a variety of equipment and techniques readily available to those skilled in the pyrolysis processing field. For example, the acid can be deposited onto the biomass material using a sprayer. The amount of acid (or base) to be added can vary according to the particular quantity and type of biomass material employed. In general, the amount of acid that can be added can range from between about 0.5% and about 10.0% w/w of the total solid biomass weight. The pre-treatment exposure time can vary as well according to the particular acid used and attributes of the specific biomass. In any case, pretreatment exposure time can be for a period sufficient to permit the chemical interactions between the biomass material content and acid or alkaline ingredient(s). In one example, the acid exposure time can range from between about 8 hours to about 16 hours, preferably about 12 hours.

The pre-treatment step can be carried out in ambient temperature conditions. However, as it can be desired to remove excess moisture and dry the biomass at this stage, the pre-treatment temperature can be between about ambient temperature to an elevated temperature sufficient to effect drying of the biomass. In one embodiment, the temperature can be raised to about 100⁰C to reduce moisture content. The combination of pre-treatment duration and temperature can be adjusted relative to one another for the particular desired pre-treatment objective. At the conclusion of chemical treatment, mixing and drying at the pre-treatment stage, additional preparative steps can be included at the conclusion of pre-treatment and prior to the pyrolysis step. Wherein microwave pyrolysis is the pyrolysis technique to be employed in the process of the invention, it is preferable to add microwave-absorbing materials into the biomass. Suitable microwave-absorbing materials that can be added at this juncture before pyrolysis include, but are not limited to, silica carbon, carbon powder, and salts such as manganese salts. Pre-treated biomass can be further combined with various additives and catalysts prior to being placed into the reactor. Additives and catalysts that can be used include, but are not limited to, manganese and other salts, SiC and carbon, for example. SiC is a solid coarse powder-like compound that can be added as a catalyst to facilitate absorption of microwave energy and speed up the biomass heating rate, since higher heating rate will help increase the liquid yield. Various amounts of additives and catalysts can be used as well, ranging from about 1% to about 10%.

Pyrolysis While a variety of pyrolysis techniques and equipment can be used to process biomass, including fluidized bed pyrolysis, the advantages associated with the invention are better realized with the use of pyrolysis techniques and equipment that permit uniformity of reaction, and precision control of energy input in relation to heat rate. In addition to precision and uniformity, microwave pyrolysis further affords enhanced efficiency, as well as reduces the occurrence of undesirable localized burning or carbonization of the biomass material. Thus, it is preferred that the pyrolysis stage of the invention be conducted using a microwave pyrolysis reactor. One such available microwave reactor is PANASONIC^® Model NNSN667 (Panasonic, Shanghai, China). In this next (pyrolysis) stage of the invention, the treated biomass material is transferred to the pyrolysis reactor (preferably a microwave reactor). The microwave pyrolysis treatment should be conducted in an oxygen-free atmosphere. Thus, the microwave chamber and the inside of the reactor can be flushed with nitrogen to remove oxygen. Microwave pyrolysis is preferably performed in the presence of a catalyst.

The temperature parameter used in the pyrolysis stage is an important aspect of the invention. The specific temperature adjustment to be used can be variable and is coordinated according to the power input of the pyrolysis apparatus. In a preferred embodiment of the invention, the heat rate selected is ideally one which both reaches and maintains the desired heating temperature as fast as possible. As far as temperature per se, the temperature range for microwave pyrolysis stage can range from between about 300⁰C to about 700⁰C. A preferred temperature is approximately 500⁰C, which can be associated with the desirable increased percent liquid yield. Temperatures higher than about 500⁰C and within the range can be associated with undesirable increase in gas production, whereas temperatures lower than about 500⁰C and within the range can be associated with undesired increase in gas and char solid content.

Preferred catalysts for catalytic microwave pyrolysis stage of the invention include ferrous phosphate, ferrous sulfate, other salts, and combinations thereof. The catalyst(s) used is/are directly mixed with dry biomass to increase the microwave absorption, biomass heating rate, as well as catalyze the reactions. The amount of catalyst used can vary according to the heat rate to be used.

Catalytic microwave pyrolysis can be conducted for a period of time sufficient to process and dry the biomass material to a moisture content of about 10% or less. The duration of the pyrolysis step is affected by the moisture content of the biomass material following pre-treatment stage. In one embodiment, the pyrolysis time can range from between about 10 minutes to about 30 minutes. Throughout the pyrolysis stage of the invention, the pyrolysis vapors are transferred to the catalytic reformation apparatus. At the conclusion of the pyrolysis stage, the solid residues (char) can be removed and discarded. When aspen and corn stover are used as the starting biomass material, the liquid yields from the pyrolysis stage of the process of the invention can range from between about 45% to about 55% w/w relative to the original starting biomass weight. Catalytic Reforming

The pyrolysis vapors from the biomass are next subjected to the catalytic reforming stage. During the catalytic reformation step of the process, the volatile gases are reformed in the presence of a catalyst. An important aspect of the invention is that the reforming process occurs in advance of a condensation stage. This is in contrast to conventional pyrolysis techniques, wherein condensation occurs prior to reforming. As a result of catalytic reformation being conducted prior to condensation, the specificity of the resulting composition profile can be enhanced.

According to the invention, volatile gas reformation can be performed using a fixed bed catalytic reforming apparatus, which comprises a heater and catalysts through which the vapors are passed. An important aspect of this stage of the process is the ability to control the temperature of the fixed bed catalytic reforming apparatus.

Overall, the temperature conditions at the catalytic reformation stage are important to the process. Preferably, the temperature maintained during catalytic reformation should be sufficient to reduce condensation of the vapors within the apparatus, while facilitating the chemical interaction and reactions occurring between the gaseous compounds to permit conversion. The temperature that can be used for this stage of the process can range from between about 300⁰C to about 700⁰C. It is preferred that the temperature used for reforming be the same or similar to that employed in the microwave reactor pyrolysis apparatus.

In general, the duration of the catalytic reformation stage can be relatively short and quick. Hence, the duration of the catalytic reformation step can generally range from about 1 second to about 60 seconds, preferably between about 1 second and about 5 seconds. Catalyst used in the reformation stage is preferably an unmodified metal oxide that has been treated with a metal nitrite, Bronsted acid or Bronsted base, for example. Suitable unmodified metals that can be used include, but are not limited to, aluminum, titanium, zirconium, and hafnium. Suitable Bronsted acid or Bronsted bases include, but are not limited to, SO₄ ²VZrO₂, SO₄ ²VAl₂O₃, Al₂O₃, and the like. Additional catalysts include CoO/ZrO₂, NiO/ZrO₂, La₂O₃/ZrO₂, NiO/CaO-ZrO₂, Na₂O/ZrO₂, CaO/ZrO₂, MgO/ZrO₂ and a base, for example. Combinations of catalysts can be used as well.

Catalysts for use at the reformation stage can be prepared by wet impregnation. In one example, zirconium oxide supports were obtained from Alfa Aesar, Ward Hill, Massachusetts. Solid chemicals were dissolved in de-ionized water to a final concentration of 5%. Concentrated acids HCl and H₂SO₄ were diluted in de-ionized water to a final concentration of 5%. Active components were loaded onto supports by wet impregnation with solutions, followed by drying in a convection oven at 105⁰C for a period of 8 hours, and calcinated in a furnace at 57O⁰C for a period of 4 hours.

An important aspect of the invention is that it has been discovered that certain catalysts can "direct" the conversion of pyro lytic vapors to favor an ultimate specific bio- oil compound. For example, the use of solid acid catalysts such as ClYZrO₂ or SO₄ ²VZrO₂, can favor the conversion of vapors toward preparing 1 , 1 -dimethoxyhexane. Thus, the process of the invention may afford the capability of "tailoring" the relationship between the starting biomass material and the resulting products, including the bio-oil.

When aspen and corn stover are used as the starting biomass material, the liquid yields from the catalytic reformation stage of the process of the invention can be from about 80% to about 95% solely within the catalytic reformation stage alone relative to the liquid yield amount prior to this step. As far as percent liquid yield relative to starting solid biomass material weight, liquid yields following the catalytic reformation point of the overall process can range between about 45% to about 60%.

Condensation Following the catalytic reformation stage of the process, the intermediate product is then transferred to a condensing apparatus to prepare the bio-oil mixture. Referring now to Figure 2, condensing system equipment that can be used can include a spray tower, bio- oil tank containing a heat exchanger, recycling pathway between the tank and the spray tower, and exhaust pathway for removal of syngas. The bio-oil composition can be collected within a bio-oil tank which serves as a reservoir for the condensate bio-oils and other compounds.

In a preferred embodiment of the invention, the process avoids direct condensation applied immediately following pyro lysis. In the conventional direct condensation arrangement, vapors directly following pyrolysis are subjected to a compound-specific solution absorbent to collect the specific target compound, which can then be subsequently removed and contained for further processing. On the contrary, catalytic reformation occurs prior to condensation because it is believed that subjecting pyrolysis vapors to catalytic reformation first enhances advantages associated with the invention, including improved specificity of compositional profile and increased relative liquid percent yield.

Temperature conditions and duration of the condensation stage can vary. However, the temperature conditions of the condensation stage should be low enough to encourage condensation of vapors and gaseous compounds into the liquid physical state. In one embodiment, the condensation temperature can range from between about O⁰C to about 1O⁰C.

Duration of the condensation stage can vary according to the apparatus(es) used and routing or recycling architecture employed for this stage. In one embodiment, the condensation stage can occur over a period of time ranging from between about 1 second to about 10 minutes.

Bio-Oil Collection

The process of the invention can conclude with obtaining the resultant bio-oil containing composition. The process of the invention can be associated with two significant improvements in the biomass-to-bio-oil production processes. First, the process of the invention can improve bio-oil yield (i.e., increase liquid yield and reduce gas and solid residue yield) by as much as about 26% relative to starting biomass solid weight as compared to conventional processes using the same starting biomass material and conventional pyrolysis techniques.

Second, the process of the invention improves the specificity of the resultant bio-oil composition obtained. The process produces a more simplified bio-oil composition profile as compared to conventional pyrolysis techniques, thereby reducing the extent of further refinement and purification efforts to isolate the specific bio-oil of interest.

The bio-oil can be composed of two condensable fractions: a water-soluble phase or fraction; and insoluble (heavy) oil phase or fraction. The water-soluble fraction can comprise a mixture of compounds - some of which can be used as industrial chemicals, such as furfural. The compounds present in the water-soluble fraction can be separated from its water content. The oil fraction can contain a mixture of hydrocarbon-based heavy oils which can be further refined downstream and used as a source of fuel. Analytical Method

The specificity of the bio-oil composition prepared from the process of the invention for a given starting biomass material affords the ability to profile potential bio- oil compositions with enhanced specificity for various biological materials intended for pyrolysis. Put another way, the process of the invention gives rise to an analytical method and compilation of information useful in the pyrolysis, bio-oil and bio fuel industries. The accuracy of the input-output information, in this regard, is the direct result of the inventive process and its advantages.

Thus, the invention also provides a method of determining the yielded compositional ingredients of a bio-oil composition corresponding to a given starting biomass, said method comprising: defining the initial composition of a starting biomass source; subjecting said biomass to a process for preparing bio-oil composition, said process comprising the steps of: introducing a biomass material; ii) pre-treating said biomass material; iii) subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; iv) subjecting the pyrolyzed material to catalytic reformation; v) subjecting the catalytically reformed material to condensation; and vi) obtaining resultant bio-oil-containing composition; analyzing the chemical content in terms of ingredients and respective amounts; comparing the resultant chemical composition content to said starting biomass composition to ascertain corresponding compositional information as to bio-oil content; and utilizing said corresponding compositional information to forecast biomass input relative to correlative bio-oil output compositional content.

The invention is further illustrated by the following examples - none of which are to be construed as necessarily limiting the invention as covered by the subsequent claims. EXAMPLES

EXAMPLE 1 : Preparation of Bio-Oil Compositions from Aspen Wood A number of bio-oil preparation processes were performed using various starting biomass materials and with varying process parameters, conditions and catalysts/reagents. In these experiments, starting biomass materials associated with producing furfural- containing (specific) resultant compositions were used in the evaluation. The processes were identified as Test Processes A through J, with test subsets I) A through D and Control (varying amount of pre-treatment H₂SO₄; 2) E through G and Control (varying reformation catalysts); and 3) H through J and Control (different starting biomass). Specific experimental information is provided as follows. Control:

The pyrolysis of aspen was carried out in a microwave cavity oven by placing 250 g samples in a quartz flask, which was then placed inside the microwave cavity. Microwave treatment was performed for a period of about 20 minutes at a constant power input of 700 W at a microwave frequency of 2450 MHz at a temperature of 600 ⁰C.

Volatile pyrolizates (liquid fraction or bio-oils) were condensed in water-cooling columns, and collected in bottles. The solid reside or char was allowed to cool to room temperature before it was weighed. The condensates adhering to the interior wall of the quartz flask were washed with ethanol into the pyrolytic liquid collection bottle. All liquid collected was concentrated at 40 ⁰C using a ROTOVAP (Buchi R-141 , Flawil, Switzerland), and the final constant weight was recorded. The liquid yield was 45.1% of total starting biomass. The chemical content of the pyrolysis vapors was complex, including furfural, methoxy- furanethanol, acids, sugars, and miscellaneous phenols.

Test Process A: (temperature and amount of sulfuric acid) Before pyrolysis, aspen wood was pretreated with sulfuric acid solution which was about 0.5% of aspen sample weight. The mixed material was then air dried and/or oven dried at a range between 60 to 100 ⁰C until the moisture content of the sample was a bout 10%. The dried aspen sample was mixed with sodium carbonate powder using a weight ratio of 100:0.5 aspen to sodium carbonate. Pyrolysis temperature was measured at 400 ⁰C. All other experiment conditions were substantially the same as that of the Control Test Process above. The resulting liquid yield was 45.8% of total starting biomass. The chemical composition of pyrolysis vapors contained significant amounts of furfural and methoxy-furanethanol. Test Process B: (amount of sulfuric acid):

Before pyrolysis, aspen wood was prctreated with sulfuric acid solution which was about 1.0% of aspen sample weight. Pyrolysis temperature was measured at 450 ⁰C. All other conditions were substantially the same as Test Process A. Liquid yield was 48.6% of total starting biomass. The chemical content of the pyrolysis vapors contained significant amounts of furfural and methoxy-furanethanol. Test Process C: (amount of sulfuric acid)

Before pyrolysis, aspen wood was pretreated with sulfuric acid solution which was about 2.0% of aspen sample weight. Pyrolysis temperature was measured at 500 ⁰C. All other process conditions were substantially the same as Test Process A. The liquid yield was 49.7% of the total starting biomass. Chemical content of the pyrolytic vapors contained significant amounts of furfural and methoxy-furanethanol Test Process D: (amount of sulfuric acid):

Before pyrolysis, aspen wood was pretreated with sulfuric acid solution which was about 4.0% of aspen sample weight and SiC catalyst. Pyrolysis temperature was measured at a temperature of 550 ⁰C. Other process conditions were substantially the same as Test Process A. The liquid yield was 47.6% of starting total biomass. Chemical content of the pyrolysis vapors contained significant amounts of furfural and methoxy-furanethanol

Test Process E: (condensation catalyst) The pyrolysis of aspen was carried out in a microwave oven by placing 25Og samples in a quartz flask and placed inside the microwave cavity. Microwave pyrolysis was conducted for a period of about 20 minutes with constant power input of 700 W at a microwave frequency of 2450 MHz. Volatile pyrolyzates were first passed through a catalyst column of ClVZrO₂ where the temperature was measured at about 500 ⁰ C, and then condensed in water-cooling columns and collected in bottles. This fraction was called the pyrolytic liquid (bio-oil) fraction. The solid char residue was allowed to cool to room temperature before it was weighed. The condensates adhering to the interior wall of the quartz flask were washed with ethanol into the pyrolytic liquid collection bottle. All collected liquid was concentrated at 40 ⁰C using the ROTOVAP (Buchi R-141, Flawil, Switzerland) to a constant weight, and the weight was recorded. The liquid yield was 43.4% of total starting biomass. The chemical content of the pyrolysis vapors were converted to primarily 1 , 1 -dimethoxyhexane. Test Process F: (condensation catalyst)

Pyrolysis conditions were substantially the same as Test Process E. The volatile pyrolyzates were first passed through a catalyst column containing SO₄ ²VZrO₂ where the temperature reached was measured at about 500 ⁰C, and then condensed in water-cooling columns and collected in bottles. The liquid yield was 44.4% of total starting biomass. The chemical content of the pyrolysis vapors were converted to primarily 1,1- dimcthoxyhexane .

Test Process G: (sulfuric acid and condensation catalyst)

Before pyrolysis, aspen wood was pretrcated with sulfuric acid solution (4.0% of aspen sample weight). The mixed material was air dried and/or oven-dried at temperature of between about 60 to 100° C until the moisture content was about 10%. The dried aspen sample was combined with sodium carbonate powder according to a weight ratio of 100:0.5 aspen to sodium carbonate. Pyrolysis temperature was measured at 600 ⁰C. Other conditions were substantially the same as Test Process E. Volatile pyrolyzates were first passed through a catalyst column containing NaO-KOH/ Al₂O₃ where the temperature was controlled at about 400 ⁰C, then condensed in water-cooling columns and collected into bottles. The liquid yield was 44.0% of total starting biomass. The chemical content of pyrolysis vapors was mainly furfural.

Test Processes H. L J and Control: (different starting biomass) Test Processes H, I and J and Control were performed under similar conditions and parameters to Test Processes B through D and the Control, respectively, except that starting biomass was corn stover instead of aspen. Acid solutions (amount H₂SO₄ was used for biomass pre-treatment in 1.0%, 2.0% and 4.0% similar to Test Processes B through D, and temperature varied in a manner similar to Test Processes B through D and Control.

The apparatus set-up for the experiments of Example 1 is depicted in Figure 2. Using the process of the invention, biomass pellets (e.g., corn stover or aspen pellets obtained from Lone Tree Manufacturing, Bagley, Minnesota) were provided as the starting biomass material. The pellets were introduced into a vessel and mixed with an acid solution. The amount of acid solution varied, as did the particular acid.

The pre-treated biomass was maintained at varying temperatures - from air-drying ambient temperatures to oven drying at temperatures from 6O⁰C to 100⁰C. The duration of the drying was maintained until the moisture content of the mixture reached about 10%. Following pre-treatment, each experimental process continued with catalytic pyrolysis using a commercial scale microwave pyrolysis reactor (PANASONIC^® NNSN667, Shanghai, China). The microwave power input can be adjusted from a pre- calibrated or pre-set input power (e.g., 1 to 1.3 kW), and the microwave power input for the test processes was set to a power input of about 700 W and frequency of 2450 MHz. Prior to subjecting to microwaves, the oven and flask were flushed with nitrogen to ensure an oxygen-free atmosphere. The microwave reactor was then actuated for a heating period of about 20 minutes, and at temperatures reached and measured as described in the particular test process. The volatile pyrazolates from the pyrolysis reactor were then passed through a fixed bed filled with different catalysts as set forth in the tables. The reformation step base catalyst of Test Process G was prepared by directly mixing NaOZAL₂O₃, NaOH and KOH (available from Sigma Company, St. Louis, Missouri). Solid NaO and KOH were mixed with solid Al₂O₃ pellets according to a weight ratio of 1 : 1 :8. During the catalytic reformation stage, the temperature of the fluid bed was maintained to about 300⁰C to about 60O⁰C, and a residence time of about 1 second to about 10 seconds.

The gases exiting out from the fluid bed of the catalytic reformation step were then subjected to condensation. Condensation was performed using water-cooled columns at temperatures from about I⁰C to about 3°C for varying periods of time. The condensate was collected into bottles.

The various ingredients, catalysts, and process parameters and conditions for each of the experimental processes are summarized in the following tables.

Table 1 Summar of P rol sis Process Conditions/Factors usin As en as

Table 2 Summar of P rol s r

Table ummar of P ol s on i io s/Factors u in orn Stover as Biomass

As can be seen from the above, overall the liquid yields of aspen pellets and corn stover as the starting biomass following catalytic pyrolysis ranged from between 43.4% to 54.6% by varying certain process parameters, materials and conditions. When the biomass is pretreated with acid and subjected to microwave pyrolysis, the yield of bio-oil can generally be improved. It is believed that the liquid yield is a function of the mass of the starting biomass. The starting biomass material for experiments A, B, C and D was 250 grams, and the starting biomass material for experiments E and F was 100 grams. The experiments were repeated in Test Processes H, I and J using 250 grams of corn stover as the starting biomass (sec Table 3).

Chemical Analysis of Resulting Compositions

The initial resultant bio-oil was composed of two condensable fractions: a water- soluble phase or fraction; and insoluble (heavy) oil phase or fraction. The water-soluble fraction can comprise a mixture of compounds in addition to water, and the water-soluble compounds were further separated from the water content for analysis. The oil fraction can contain a mixture of hydrocarbon-based heavy oils which were further separated from the water-soluble fraction as well. Thus, the liquid samples from the bio-oil were collected and analyzed for their content using gas chromatography.

The liquid samples obtained from above experiments A through G and respective controls were analyzed using GC/MS to identify chemical content. Resulting compositions from each of A through F were obtained and samples for analysis were prepared by completely dissolving the composition in pure methanol solution at a volumetric ratio of 1 :9 (sample: methanol). Each of the samples was analyzed using liquid phase GC/MS.

Chemical compositions of the light oils were determined using an HP 6890 GC/MS chromatography apparatus with a DB capillary column. The GC was programmed at 4O⁰C for 0.5 minutes, and then increased at 10°C/minute to 300⁰C, and finally held with an isothermal for 10 minutes. The injector temperature was 300⁰C and the injection size was 1 μL. The flow rate of the carrier gas (helium) was 0.6 ml/min. The ion source temperature was 23O⁰C for the mass selective detector. The compounds were then identified by comparing spectral data with the NlST Mass Spectral library data. The resulting composition profiles are shown in Figure3 for Test Processes A through D and Control, Figure 4 for Test Processes E and F and Control, and Figure 5 is directed to Test Processes C and G for comparison.

In general, relative to a starting mass weight as 100%, the process of the invention can produce about 25% by weight solid residue/char, 25% non-condensable gases, and about 50% condensable bio-oil mixture, of which about 30% can be condensable water- solubles and water by weight, and about 20% can be heavy oils. Based on the results of the above experiment, within the total bio-oil fraction itself as 100%, the process can produce about 60% by weight water soluble fraction including water, and about 50% by weight heavy oils. Therefore, the process of the invention can produce about 9% by weight water-soluble compounds absent water (which accounted for about 21% by weight of the bio-oil fraction) and about 20% heavy oils by weight relative to a starting input biomass as 100% weight. Furthermore, when acid pretreatment with H₂SO₄ is performed in combination with certain pyrolysis catalysts added prior to microwave pyrolysis, approximately 9% furfural can be obtained as a condensable water-soluble compound relative to the starting mass. The GC area percentage of furfural and methoxy-furanethanol in the resultant compositional profiles of the water-soluble fractions absent water are shown in Figures 3, 4 and 5. The water content of the resulting total bio-oil compositions (which do not appear in the Tables) can account for between about 10% and about 30% of the bio-oil fraction according to varying process conditions and parameters. Water content of the initial condensable water-soluble fraction can be between about 40% and about 70% of the fraction, with condensable water-soluble compounds per se being between about 30% and about 60% of the total water-soluble fraction. Thus, it may be possible to obtain furfural amounts ranging from between about 10 g to about 15 g relative to 100 g starting biomass weight. Heavy oil from the oil phase can be about 20% by wt of the bio-oil fraction content relative to 100% starting biomass.

Observations

As can be seen from the data in Figures 3, 4 and 5, the major liquid fraction compounds (absent water) identified from the various experimental process runs include furfural, methoxy-furanethanol, and a few phenols. Phenol content in the samples depended upon the catalysts in the biomass samples. The Area % and compounds depicted in the tables of Figures 3, 4 and 5 included only the significantly measured compounds, and additional minimal amounts of additional compounds were not specifically identified and set forth in the tables.

Referring to the control experiment shown that the water-soluble fraction composition of bio-oil (absent water) from aspen pyro lysis assisted by microwave heating with additives, when aspen wood pellets were pre-treated with 4.0% H₂SO₄ and 2% SiC catalyst, the pyrolysis liquid from catalytic pyrolysis (Test Process D) was composed of the two major compounds (furfural and methoxy-furanethanol) and a relative few other minor compounds (phenol, methyl-phenol, methoxy-phenol, etc.). When the pyrolysis gas passed through a catalytic reformation stage using a fixed bed filled with a solid base, such as NaOZAl₂O₃, NaOH, and KOH, the reforming liquid was mainly composed of furfural, as seen in Test Process G. The above experimental data substantiate the advantages associated with the invention by demonstrating that bio-oils having greater predictability, stability and specificity can be produced at earlier stages instead of greater reliance on improving the stability through post-conversion treatments of the bio-oils. The centralized and strategic placement of catalysis is also an important aspect of the invention affecting bio-oil compositional profile.

As can be seen from our results, pretreatment of biomass using acid and catalysts prior to the pyrolysis step changed the resulting chemical profile of the pyro lytic products significantly. We obtained a bio-oil composition having one predominant chemical component accounting for over 60% of the total water-soluble fraction chemical content, or about 100% of the water-soluble content absent water. Thus, the experimental data shows that employing the invention to pyrolysis technology effectively simplifies the compositional profile of the resulting bio-oil composition. Immediately following the pyrolysis step, the vapors exiting the reactor contain both condensable volatiles and non-condensable gases. When positioning a catalytic reactor apparatus directly and subsequently adjacent to the pyrolyzer, heated exiting vapors were catalytically reformed before they become liquid. The experimental data showed noticeable changes in chemical profiles of the pyrolysis oils caused by the catalytic reactions, thereby suggesting a great potential of manipulating the chemical composition and physical properties of bio-oils through catalytic reforming of pyrolytic vapors.

EXAMPLE 2: Continuous Microwave-Assisted Pyrolysis Process An alternative embodiment of the process of the invention can comprise a modified continuous microwave-assisted pyrolysis (MAP) process as illustrated in Figure 6 without reformation in advance of condensation. The construction of the components and arrangement appearing in Figure 6 are collectively referred to as, and collectively defining the phrase, "structured for continuous process." Referring to the diagram in the figure, prepared biomass materials (e.g., dried and acid pre-treated corn cobs) were manually or mechanically introduced into a feed silo having a maximum capacity of 50 kg at one time. The air-tight valve located at the top of the silo was sealed and locked, and the process was controllably initiated allowing a screw feeder drive by electric motor to feed enough material, 50 kg capacity per hour, into the MAP reactor. The heating of the reactor was conducted by multiple magnetrons (microwave generators), and the temperature was monitored by three thermocouples located at the front, middle and rear sections of the horizontal MAP reactor bed. Start time, screw shaft RPM, and temperature were monitored and logged and viewed on LCD display. Approximately 3 to 5 hours was needed for the target pyrolysis temperature of about 400 ⁰C to be reached when starting from room temperature. This varied with microwave heating power, feed amount, and moisture content, as well as other physiochemical properties. During the pre-heating period, it was necessary to keep the MAP reactor under vacuum conditions to prevent ingress of ambient oxygen into the reactor and maintain desired internal pressure. During the operation of the microwave pyrolysis stage, the condensation system was initialized for continuous operation through the process. Once the desired pyrolysis temperature was reached, the feed rate was adjusted to the desired scale as calibrated in blank tests. The biomass began to decompose into three fractions: non-condensable gases, condensable fraction (water soluble components and heavy oil), and residue char. Char5 was separated using a conventional splitter, transferring the char particles to a sealed char silo and subsequently cooled by indirect air. The bio-oil and non-condensable gases (NCGs) were quenched and separated in condensation columns and a gas scrubber. The primary components present in the non-condensable gas fraction were CO, H2, CO2 and CH4. CO2 and trace liquid droplets were captured and absorbed by basic absorbent, and the cleaned NCG stream was compressed and sent to the power generator as partial fuel or vented into a flare chimney. The quenched bio-oils were stored in the bottoms of the scrubber and condensation columns. Product yields were calculated based on the collected residual char, liquid bio-oils and consumed biomass feed amount.

Figure 7 is a comparative gas chromatography profile of bio-oil obtained from corn cob biomass subjected to the continuous microwave assisted pyrolysis process with and without acid pre-treatment. Figure 8 is a table showing the bio-oil components obtained from corn cob starting biomass with 4% acid pre-treatment and continuous microwave assisted pyrolysis. As can be seen from the above data in Figures7 and 8, continuous MAP using acid pre-treatment can produce significantly higher yields of furfural as compared to MAP in the absence of acid pre-treatment.

Industrial Applicability Bio-oils produced in accordance with the process of the invention have a wide variety of industrial uses. In the case of furfural, the process of the invention can be used to convert corn and aspen as a starting biomass, for example, to produce high purity grade furfural. The resultant furfural can be employed as a liquid boiler substitute "green fuel" or substituted for fuel oil or diesel in a number of static applications (e.g., stationary engines, gas turbines, boilers and furnaces). Furfural prepared according to the invention can also be used to prepare specialty chemicals, such as food flavorings and pharmaceuticals, and can be used as a phenolic replacement, and in asphalt binders (e.g., adhesives, road stabilizers). Furfural prepared according to the process of the invention possesses potential use in developing technologies as well. Such technologies include, but are not limited to, agrochemicals, clean fuels and biofuels, timber treatment, PLA performance plastics.

The invention hereinabove has been described with reference to various and specific embodiments and techniques. It will be understood by one of ordinary skill in the art, however, that reasonable variations and modifications may be made with respect to such embodiments and techniques without substantial departure from either the spirit or scope of the invention defined by the following claims.

Claims

CLAIMS What is claimed is:

1. A process for preparing a bio-oil composition from biomass, the process comprising the steps of: a) introducing a biomass material; b) pre-treating said biomass material; c) subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; d) subjecting the pyrolyzed material to catalytic reformation; e) subjecting the catalytically reformed material to condensation; and f) obtaining resultant bio-oil-containing composition.

2. The process according to claim 1, wherein said biomass is selected from the group consisting of corn stover, aspen wood, and combinations thereof.

3. The process according to claim 1, wherein step b) pre-treating comprises acid pre- treatment using FI₂SO₄ present in an amount of about 4.0% by weight starting biomass.

4. The process according to claim 3, further comprising adding a catalyst to said pre- treated material in advance of said microwave pyrolysis.

5. The process according to claim 4, wherein said catalyst is a SiC catalyst.

6. The process according to claim 1, wherein catalytic reformation comprises a NaO- KOH/A1₂O₃ catalyst.

7. The process according to claim 1, wherein said bio-oil comprises a condensable water-soluble fraction comprising furfural.

8. The process according to claim 1, wherein said bio-oil comprises a condensable insoluble fraction comprising a mixture of heavy oils.

9. A process for preparing a bio-oil containing furfural from pentosan-containing biomass, the process comprising the steps of: a) introducing a biomass material; b) pre-treating said biomass material; c) subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; d) subjecting the pyrolyzed material to catalytic reformation; e) subjecting the catalytically reformed material to condensation; and f) obtaining resultant bio-oil-containing composition.

10. The process according to claim 9, wherein said biomass is selected from the group consisting of corn stover, aspen wood, and combinations thereof.

11. The process according to claim 9, wherein step b) pre-treating comprises acid pre- treatment using H₂SO₄ present in an amount of about 4.0% by weight starting biomass.

12. The process according to claim 11, further comprising adding a catalyst to said pre-treated material in advance of said microwave pyrolysis.

13. The process according to claim 12, wherein said catalyst is a SiC catalyst.

14. The process according to claim 9, wherein catalytic reformation comprises using a NaO-KOH/Al₂O₃ catalyst.

15. The process according to claim 9, wherein said bio-oil comprises a condensable water-soluble fraction comprising furfural.

16. The process according to claim 9, wherein said bio-oil comprises a condensable insoluble fraction comprising a mixture of heavy oils.

17. A process for converting biomass into a bid-oil composition, the process comprising: a) introducing a biomass material; b) pre-treating said biomass material; c) subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; d) subjecting the pyrolyzed material to catalytic reformation; e) subjecting the catalytically reformed material to condensation; and f) obtaining resultant bio-oil-containing composition.

18. The process according to claim 17, wherein said biomass is selected from the group consisting of corn stover, aspen wood, and combinations thereof.

19. The process according to claim 17, wherein step b) pre-treating comprises acid pre- treatment using H₂SO₄ present in an amount of about 4.0% by weight starting biomass,

20. The process according to claim 17, further comprising adding a catalyst to said pre-treated material in advance of said microwave pyrolysis.

21. The process according to claim 20, wherein said catalyst is a SiC catalyst.

22. The process according to claim 17, wherein catalytic reformation comprises using a NaO-KOH/Al₂O₃ catalyst.

23. The process according to claim 17, wherein said bio-oil comprises a condensable water-soluble fraction comprising furfural.

24. The process according to claim 17, wherein said bio-oil comprises a condensable insoluble fraction comprising a mixture of heavy oils.

25. A method of determining the yielded compositional ingredients of a bio-oil composition corresponding to a given starting biomass, said method comprising: a) defining the initial composition of a starting biomass source; b) subjecting said biomass to a process for preparing bio-oil composition, said process comprising the steps of: i. introducing a biomass material; ii. pre-treating said biomass material; iii. subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; iv. subjecting the pyrolyzed material to catalytic reformation; v. subjecting the catalytically reformed material to condensation; and vi. obtaining resultant bio-oil-containing composition; c) analyzing the chemical content in terms of ingredients and respective amounts; d) comparing the resultant chemical composition content to said starting biomass composition to ascertain corresponding compositional information as to bio-oil content; and e) utilizing said corresponding compositional information to forecast biomass input relative to correlative bio-oil output compositional content.

26. A continuous process for preparing a bio-oil composition from biomass, the process comprising the steps of: a) introducing a biomass material; b) pre-treating said biomass material; c) subjecting the treated biomass material to microwave pyrolysis in the presence of a catalyst; d) separating solid residue and char from the pyrolized output to obtain remaining pyrolized material; e) subjecting the remaining pyrolized material to condensation; and f) obtaining resultant bio-oil composition; wherein the above steps are structured as a continuous process.

27. The process according to claim 26, wherein said remaining pyrolized material obtained from step d) is subjected to reformation prior to the condensation of step e).

28. The process according to claim 26, wherein said bio-oil composition comprises a water-soluble fraction comprising furfural.

29. The process according to claim 26, wherein said bio-oil composition comprises an insoluble oil fraction comprising a mixture of heavy oils.