Abstract:
The production of jet fuel, diesel and gasoline components from lipid rich biomass is described. This process includes a hydrothermal pyrolysis step followed by catalytic conversion of biovapors to the fuel product. Biochar is a co-product of the process. This process avoids capital intensive investment in oil extraction technologies, and instead incorporates the oil extraction and oil conversion in one step.

Description:
INCORPORATION BY REFERENCE 
       [0001]    All patents, patent applications and publications cited herein are hereby incorporated by reference in their entirety in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described herein. 
       FIELD OF THE INVENTION 
       [0002]    This invention relates to a method for producing jet fuel, diesel, and gasoline from lipid-containing feedstock. 
       BACKGROUND OF THE INVENTION 
       [0003]    Several processes exist for the conversion of biomass to liquid fuels, including both thermo-catalytic processes, biologically based processes, or a mixture of the two. The thermo-catalytic processes entail pyrolysis, gasification, and catalytic conversion of the decomposed biomass. Biologically based processes typically involve algae systems, where the algae are cultured to produce oils which are refined to produce diesel and jet fuel components. These processes are characterized by intensive capital expenditures and high energy input. Simpler processes are sought that attain the efficient conversion of biomass to these complex liquid fuels. 
         [0004]    Lipids are long chain aliphatic hydrocarbons used by plants and animals for energy storage. Lipid rich biomass exists throughout the world, and they may comprise seeds, algae, jatropha, industrial grease and animal fats. Seeds in particular can be categorized into vegetable seeds, sunflower seeds, fruit seeds, and legume seeds. Worldwide seed production in 2013 was over 500 million tons. Very lipid rich seeds include rape seeds, an oil crop of the Brassica family, which can contain lipids in the 30-60% range, with protein and cellulosic compounds. Palm and soybean are lower containing lipid plants which, together with rape seed, account for the majority of global seed production. Other lipid containing biomass include ground nuts such as walnuts, cotton, peanut, coconuts, olive, cocoa and corn. These oils from this biomass is characterized by alkenes, of type n=1,3, and 6, as well as saturated compounds. Significant capital has been invested in extracting oils and fats from the biomass sources in order to render them suitable for subsequent reaction processes. 
         [0005]    Extracted lipids are used in the production of biodiesel involving the reaction of alcohols with lipids (of plant or animal origin) to produce long chain alkyl esters. Methods such as transesterification with methanol provide over 6 billion gallons of biodiesel produced worldwide and production continues to increase at a rapid pace. Fuel quality remains a major issue in the production, with inconsistencies arising from fuel gelling, clouding, viscosity, moisture content and particle content. 
         [0006]    Other methods for producing renewable diesel from biomass involve hydrotreating which involves the introduction of hydrogen in the presence of a catalyst at high temperatures and pressures. The lipids are also known to undergo a hydrogenation process to diglycerides, monoglycerides, acids and aliphatic compounds which is followed by a catalytic conversion process to produce linear hydrocarbons compounds. Fischer Tropsch (FT) processes also exist which first gasify the biomass to synthesis gas and then convert the syngas to long chain alkyl compounds. The various methods used in the prior art to convert extracted lipids into biodiesel are shown in  FIG. 1 . 
         [0007]    Prior art in this space includes technology developed by NextFuels Inc. (Los Altos, CA), AliphaJet (San Francisco, Calif.), Greasoline, Inc (Overhause, Germany), and Renmatix, Inc. (King of Prussia, Pa.). 
         [0008]    Fast pyrolysis is a process in which organic materials (e.g., biomass) are rapidly heated in the presence of less than the stoichiometric amount of air needed for complete combustion. Under these conditions, organic vapors, pyrolysis gases and char are produced. The vapors are condensed to biomass-derived pyrolysis oil. Due to the oxygen content of ligno-cellulosic biomass, pyrolysis oils contain reactive oxygenated species that can continue to react, even after condensed and cooled. Most projected uses of biomass-derived pyrolysis oil require that it retain its physical properties during storage, shipment and use. Unfortunately, the biomass-derived pyrolysis oils are unstable, rapidly becoming more viscous and exhibit phase separation. In addition, the energy content of the pyrolysis oils is not as high as conventional fuels. 
         [0009]    Biomass-derived pyrolysis oil can be burned directly as fuel for certain boiler and furnace applications, and can also serve as a potential feedstock in the production of biofuels in petroleum refineries or in stand-alone process units. However, conversion of biomass-derived pyrolysis oil into biofuels and chemicals requires full or partial deoxygenation of the biomass-derived pyrolysis oil. 
       SUMMARY 
       [0010]    A system and method of making jet fuel, diesel fuel and gasoline from lipid-rich biomass feedstocks is described. The present invention particularly allows for the direct conversion of biomass with high lipid content into a blend of hydrocarbon compounds useful as fuels, including jet fuel, diesel, and gasoline. The method exposes lipid-rich biomass to an inexpensive catalyst to produce fuel in high yield with little capital investment. The fuel produced is mostly aliphatic in nature, containing only a small component of aromatic compounds. It is particularly well suited for use as a component of jet and/or diesel fuel. 
         [0011]    In one aspect, a method for the production of jet fuel, diesel and/or gasoline components from lipid rich biomass includes pyrolyzing lipid rich biomass in the presence of water to produce a biovapor and biochar; catalytically converting the biovapor to a biofuel having at least 15 wt % paraffin content; and collecting the biofuel as a liquid. 
         [0012]    In one or more embodiments, the method further includes producing C1-C5 noncondensable light gases in one or both of the pyrolyzing and catalytically converting steps. 
         [0013]    In any of the preceding embodiments, lipid rich biomass includes at least one of: edible seeds, non-edible seeds, algae, and cellulose-containing material and can be for example one or more of the following plant sources: soybeans, rapeseed, sunflower, palm, and optionally the non-edible seed may be selected from at least one of: jatropha and castor 
         [0014]    In any of the preceding embodiments, industrial grease or animal fat is pyrolyzed with the lipid rich biomass. 
         [0015]    In any of the preceding embodiments, lipid rich biomass includes at least 10 wt % lipids, or at least 20 wt % lipids. 
         [0016]    In any of the preceding embodiments, the biomass includes hydrocarbons, mono- and triglycerides, and fatty acids the range of C12-C40. 
         [0017]    In any of the preceding embodiments, the biovapor includes less than 50 wt % oxygen. 
         [0018]    In any of the preceding embodiments, the biofuel having at least 15 wt % paraffin content includes having at least 15 wt % C6-C20 paraffins. 
         [0019]    In any of the preceding embodiments, the biofuel includes at least 20 wt % paraffin content. 
         [0020]    In any of the preceding embodiments, the biofuel includes less than 50 wt % aromatic content. 
         [0021]    In any of the preceding embodiments, the biovapors are introduced into a catalytic reactor without condensation. 
         [0022]    In any of the preceding embodiments, the catalytic conversion is performed using at least one catalyst selected from the group consisting of dehydration catalyst, decarboxylation catalyst and decarbonylation catalyst, and for example, the dehydration catalyst is at last one catalyst selected from the group consisting of silica alumina catalyst, acid catalyst, ion exchange catalyst, zeolite catalyst. 
         [0023]    In any of the preceding embodiments, the catalytic conversion is carried out in the absence of a hydrogen-rich co-reagent, and for example, the hydrogen-rich co-reagent is one or more compounds selected from the group of alcohols and ethers. 
         [0024]    In any of the preceding embodiments, the biofuel is a jet fuel component that contains at least one compound in the range of C6 to C18, or the biofuel is a diesel component that contains at least one compound in the range of C8 to C20, or the biofuel further comprises a gasoline component that contains at least one aromatic compound in the range of C6 to C12. 
         [0025]    In any of the preceding embodiments, the lipid rich biomass is pyrolyzed at a temperature between 200° C. and 800° C. 
         [0026]    In any of the preceding embodiments, the biochar retains 10-50% of the carbon of the lipid rich biomass. 
         [0027]    In any of the preceding embodiments, the water weight is 10-500% of the lipid rich biomass weight, and fore example, the input water attains supercritical condition. 
         [0028]    In any of the preceding embodiments, the pyrolysis is performed at a pressure between 1 and 200 bars. 
         [0029]    In any of the preceding embodiments, the fuel yield is greater than 20% of feedstock carbon input, or the fuel yield is greater than 30% of feedstock carbon input. 
         [0030]    The method and system provided herein efficiently convert lipid rich biomass in the presence of water to diesel, gasoline and jet fuel by avoiding extraction processes utilized in biodiesel and conventional renewable diesel conversion processes. 
         [0031]    These and other aspects and embodiments of the disclosure are illustrated and described below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]    The invention is described with reference to the following figures, which are presented for the purpose of illustration only and are not intended to be limiting. 
           [0033]      FIG. 1  is a diagram illustrating prior art methods for obtaining gasoline, diesel and/or jet fuel. 
           [0034]      FIG. 2  is a diagram illustrating a process employed according to one or more embodiments of the invention to obtain gasoline, diesel and/or jet fuel. 
           [0035]      FIG. 3  is a flow diagram illustrating a method of making jet fuel, diesel fuel and/or gasoline fuel components according to one or more embodiments. 
           [0036]      FIG. 4  shows a gas chromatograph data of raw fuel produced from rape seeds processed according to one or more embodiments of the present invention. 
           [0037]      FIG. 5  shows a gas chromatograph data of fuel obtained by distilling after obtaining raw fuel shown in  FIG. 4 . 
           [0038]      FIG. 6  shows a gas chromatograph data of raw fuel obtained from sunflower seeds processed according to one or more embodiments of the present invention. 
           [0039]      FIG. 7  shows an electron microscope picture of biochar remaining from fuel production process using (a) sunflower seeds, (b) rape seeds and (c) pine wood according to one or more embodiments. 
           [0040]      FIG. 8  is a bar plot showing the composition of a fuel derived from (a) high lipid biomass and (b) conventional woody biomass. 
       
    
    
     DETAILED DESCRIPTION 
       [0041]    The process of the present invention provides a non-Fischer-Tropsch hydrothermal pyrolysis of lipid-containing biomass to generate both biofuel and biochar. The hydrothermal pyrolysis generates biovapors of high parafinnic content, thus allowing the production of carbon-negative diesel, jet fuel and gasoline. 
         [0042]    The term “biofuel” as used herein is understood to mean a composition derived from a non-petroleum biomass having a mixture of hydrocarbons in the correct chain lengths, chain conformations, and compound ratios to be used as a fuel or a fuel component. A “fuel” as used herein is understood to mean a composition useful as a fuel in internal combustion engines, such as commonly found in transportation vehicles (e.g., automobiles, airplanes, trains, and heavy machinery), the composition including, but not limited to, a composition classifiable as a jet engine fuel, a diesel engine fuel, or a gasoline engine fuel. A “fuel component” as used herein is understood to mean a composition containing some or all of the components of a fuel (in the same or different proportions from those found in a fuel) that can be blended with other ingredients to obtain a fuel. 
         [0043]      FIG. 2  shows a diagram illustrating the basic components of the method of the present invention in comparison with other commonly practiced methods for the production of diesel and jet fuel. Lipid rich biomass, such as seeds, algae and jatropha, is pyrolyzed in a water containing atmosphere under the presence of a cracking conversion catalyst to produce jet fuel, and/or diesel and/or gasoline components and biochar. Thus, the component lipids, as well as any accompanying ligno-cellulosic components of the biomass are processed into jet fuel, and/or diesel and/or gasoline components. 
         [0044]    In contrast, prior art methods (see  FIG. 1 ) first extract the lipid component from the biomass before any significant chemical transformation occurs. Thus, a feedstock that is essentially 100% oil or lipid is chemically transformed into biodiesel. 
         [0045]      FIG. 3  is flow diagram showing an exemplary embodiment of a method of making jet fuel, diesel fuel and/or gasoline from lipid-containing feedstocks. Lipid rich biomass  10  is pyrolyzed in pyrolysis process  20  to generate biochar  25  and biovapors  26 . The biovapors are routed without condensation to catalysis process  30  to generate fuel product  35  along with water, carbon dioxide, catalyst coke  33 , and light gases  34 . The light gases  33  comprise noncondensable gases, of composition selected from at least one of C1 to C5 compounds. 
         [0046]    Lipid-containing biomass feedstocks  10  refers to any plant material containing lipids to some extent. Lipid is used here in the conventional sense and includes without limitation fatty acids, glycerides, phospholipids, sterol lipids, glycolipids, animal fats, beef tallow and the like. A lipid-rich biomass feedstock refers to any plant material having a significant lipid content. 
         [0047]    Lipid-rich compositions may vary anywhere from 10 to 90%, and can be for example from 10% to 80% by weight. The lipid rich biomass can contain for example, at least 10% or at least 15% or at least 20% or at least 25% or at least 30% or at least 35% and up to 50% or up to 60% by weight lipid. The lipid content can fall into a range bounded by any of these values, e.g., 10-60%, 20-50%, etc. The remaining components can include protein, cellulose-containing material, hemicellulose, lignocellulose, and lignins. Lipid rich biomass may comprise one or more of plant seeds, algae, jatropha or other flowering plants. Plant seeds in particular can be categorized into vegetable seeds, sunflower seeds, fruit seeds, and legume seeds. Among the most important seeds available on large commercial scale are rape seeds, palm seeds and soybeans. Other lipid containing biomass include ground nuts such as walnuts, cotton, peanut, coconuts, olive, cocoa and corn. Jatropha seeds are also contemplated, as the seeds have high oil content (e.g., 27-40%). In addition, bio-derived industrial greases and animal fats can also be used as an additional component to the high lipid feedstock. These non-plant lipid sources are included in minor amounts and typically make up less than 50%, or less than 40% or less than 30% or less than 20% or less than 10% of the total feedstock. In one embodiments, the feedstock can be a mixture of jatropha and animal fats. 
         [0048]    The high lipid content biomass is processed to obtain the product biovapors, biochar, light gases and water in a hydrothermal pyrolysis. Hydrothermal pyrolysis includes pyrolysis conducted in the presence of steam. Water and the lipid rich biomass  10  are co-fed to the pyrolysis process  20  which can comprise any thermochemical step that heats the biomass in non-oxidizing or an oxygen-free atmosphere. Typical temperatures used can range from about 200° C. to 800° C. or about 300° C. to 700° C., and typical operating pressures are 2-200 bars. Under these conditions, solid, liquid, and gaseous pyrolysis products are formed. The condensable portion (vapors) of the gaseous pyrolysis products is referred to as biovapors. Generally, lower temperatures and longer dwell times produce a higher content of biochar, while rapid heating to higher temperatures and shorter dwell times result in a higher production of biovapors. 
         [0049]    The pyrolysis process can be any conventional process used for the thermal treatment of biomass. Methods of introducing biomass into a processing station include introduction via conveyor belts, hoppers, and/or pulverizers. The pyrolyzer described herein may include these components enveloped in one system, where, for example, the pulverization and pyrolysis components are intimately connected. Biomass may be introduced in raw form or dry form, or may be dried within the pyrolysis chamber when the pyrolysis starts. Non-limiting examples include fluid bed reactors, auger reactors, rotating kiln reactors, and biomass fractionators. One pyrolysis process using heated platens to thermally treat the biomass is described in U.S. Pat. No. 8,293,958, entitled “System and Method For Biomass Fractioning”, which is incorporated in its entirety by reference. Another pyrolysis process using an auger screw reactor is described in U.S. Provisional Application No. 61/799,466, entitled “Staged Auger System,” which is incorporated in its entirety by reference. 
         [0050]    Ligno-cellulosic biomass refers to biomass comprising cellulose, hemicellulose and lignin as its major structural component. Conventional ligno-cellulosic biomass typically has less than 10 wt % lipid content. Conventional biomass-derived biovapors include oxygenated hydrocarbons in the gaseous pyrolysis products such as activated and reactive forms of cyclic oxygenated compounds due to the high oxygen content and cyclic structure of lignin and cellulose. Exemplary oxygenated compounds include carboxylic acids, phenols, cresols, aldehydes, etc.. The oxygen content of biovapors produced from conventional biomass can include more than 40 wt % oxygen. 
         [0051]    Lipids have a higher carbon and hydrogen content than cellulose and lignin. The pyrolysis of lipid rich biomass provides biovapors having a lower oxygen content than conventional ligno-cellulosic biomass. Thus, high lipid content biomass can produce biovapors with a higher carbon and hydrogen content (and lower oxygen content) than conventional biomass. Biovapors derived from lipid-rich biomass include long chain hydrocarbons, mono- and triglycerides, and fatty acids, typically in the range of C12-C40, although the exact distribution and nature of the fatty acids will depend on the input biomass. The biovapors will also include oxygenated products, but at a lower content due to the lower lingo-cellulose content of the input biomass. 
         [0052]    The pyrolysis process is conducted in the presence of water. Water can be added to the biomass before introduction of the feedstock into the pyrolysis unit. In other embodiments, water and biomass can be separately introduced into the pyrolysis unit. The input water to dry biomass ratio by weight can range from 10%-500%, and preferably from 20% to 200% by weight of biomass. During the pyrolysis process, the input water forms steam. In certain embodiments, the input water may attain supercritical condition. Lipids are more readily extracted into the water vapor environment than cellulosic and lignin components, making the use of supercritical water unnecessary. Although not wishing to be bound by theory, it is believed that water aids the decomposition and solubilization of the oils arising from lipid rich biomass. 
         [0053]    The co-product  25  is a carbonaceous product called biochar. This carbonaceous product is primarily carbon resistant to microbial degradation. It generally has a surface area between 50 m 2 /g and 1000 m 2 /g. These features enable biochar to be used as a long lasting soil amendment which retains water and nutrients, thus permitting increased agricultural yields. 
         [0054]    The evolved gases  26  from the pyrolysis process are passed through catalysts in catalysis process  30  without condensation or collection as a pyrolysis oil. Biomass-derived pyrolysis oil is generally thermally unstable and acidic (as measured by the total acid number (TAN)), making it corrosive, with low energy density. Directly upgrading the biovapors into fuel provide at least the following advantages: (1) it provides a higher quality fuel than pyrolysis oils; (2) the biovapors contain reactive species which can be more readily converted into jet fuel, diesel fuel and gasoline components; (3) the biovapors exiting the pyrolysis unit are hot and require less heating (energy input) to sustain the catalytic activity in the catalyst process; and (4) the higher carbon and hydrogen content of the biovapors permits conversion to high paraffinic content fuels without addition of co-reagents. 
         [0055]    The catalysis process  30  can be performed by conversion catalysts and can include dehydration catalysts, decarboxylation catalysts, decarbonylation catalysts or any acid catalyst. Catalysis can be carried out at temperatures ranging from 300° C. to 700° C. The biovapors can be rich in high hydrocarbon content species such as fatty acids and glycerides. The catalysts can crack the fatty acid and glyceride content into smaller units to provide, for example, a fuel product ranging from C6-C20. The catalyst are also selected to reduce the oxygen content of the fatty acids and glycerides by decarboxylation, decarbonylation, and dehydration. In addition, the catalysts are capable of deoxygenating the oxygen-containing decomposition products derived from the lignin and cellulose components of the biomass to form C6-C12 aromatic compounds. 
         [0056]    In some embodiments, oxygenated hydrocarbons present in the biovapors are deoxygenated by contacting the pyrolysis gases with a catalyst selected to convert the oxygenated hydrocarbons into hydrocarbons. In some embodiments, biovapors are converted to biofuel having a high paraffinic content. Catalytic deoxygenation of such species can provide fuel that contains significant levels of paraffinic, olefinic and alkyl compounds. In one embodiment, deoxygenation can be accomplished by catalytic decarboxylation. In another embodiment, deoxygenation can be carried out by catalytic decarbonylation. In another embodiment, deoxygenation can be carried out by catalytic dehydration. Over the catalyst temperatures used, the same catalyst is effective to deoxygenate fatty acids and glycerides, as well as deoxygenate the oxy-aromatic compounds and promote cyclization of smaller olefins to produce a biofuel that has a high paraffinic content well suited for use as a jet fuel component or a diesel fuel components, as well as an aromatic content useful as a gasoline component. 
         [0057]    Suitable acid catalysts for the present invention are heterogeneous (or solid) acid catalysts. The at least one solid acid catalyst may be supported on at least one catalyst support (herein referred to as a supported acid catalyst). Solid acid catalysts include, but are not limited to, (1) heterogeneous heteropolyacids (HPAs) and their salts, (2) natural clay minerals, such as those containing alumina or silica (including zeolites), (3) cation exchange resins, (4) metal oxides, (5) mixed metal oxides, (6) inorganic acids or metal salts derived from these acids such as metal sulfides, metal sulfates, metal sulfonates, metal nitrates, metal phosphates, metal phosphonates, metal molybdates, metal tungstates, metal borates, and (7) combinations of groups 1 to 6. 
         [0058]    Suitable HPAs include compounds of the general Formula X a M b O c   q− , where X is a heteroatom such as phosphorus, silicon, boron, aluminum, germanium, titanium, zirconium, cerium, cobalt or chromium, M is at least one transition metal such as tungsten, molybdenum, niobium, vanadium, or tantalum, and q, a, b, and c are individually selected whole numbers or fractions thereof. Methods for preparing HPAs are well known in the art. Natural clay minerals are well known in the art and include, without limitation, kaolinite, bentonite, attapulgite, montmorillonite and zeolites. Suitable cation exchange resins are styrene-divinylbenzene copolymer-based strong cation exchange resins such as Amberlyst® (Rohm &amp; Haas; Philadelphia, Pa.), Dowex® (for example, Dowex® Monosphere M-31) (Dow; Midland, Mich.), CG resins from Resintech, Inc. (West Berlin, N.J.), and Lewatit resins such as MonoPlus™ S 100 H from Sybron Chemicals Inc. (Birmingham, N.J.). When present, the metal components of groups 4 to 6 may be selected from elements from Groups I, IIa, IIIa, VIIa, VIII, Ib and IIb of the Periodic Table of the Elements, as well as aluminum, chromium, tin, titanium and zirconium. Fluorinated sulfonic acid polymers can also be used as solid acid catalysts for the process of the present invention. 
         [0059]    Conventional biomass derived biovapors, e.g., woody biomass biovapors, require the use of a co-reagent in order to improve the yield of the biomass. A hydrogen-rich co-reagent is typically added to the high oxygen content biovapor to supplement the hydrogen deficient environment. Typical co-reagents include alkyl ethers and alcohols, such as dimethyl ether, methanol and the like. Without the addition of a hydrogen-rich co-reagent, fuel yields in conventional processes are low, e.g., 7-8% carbon based on input biomass. Addition of a co-reagent such as dimethyl ether (DME) on a 2:1 wt/wt % biomass: DME basis can increase fuel yields to about 15%. Addition of a co-reagent such as dimethyl ether (DME) on a 1:1 wt/wt % biomass: DME basis can increase fuel yields to about 20%. However, co-reagents add considerable cost and complexity to the process. 
         [0060]    Applicants have surprisingly found that high fuel yields can be achieved without additional co-reagent. In the method according to one or more embodiments, a high quality fuel is obtained without the addition of a hydrogen contributing co-reagent. The fuel  35  produced from the process of the present invention comprises renewable fuel components, in particular components that can be readily blended to produce specific fuels, such as jet fuel, diesel, gasoline or kerosene. Yield of fuel is high and can be greater than 20 wt % conversion of feedstock carbon, greater than 25 wt % conversion of feedstock carbon, or greater than 30 wt %, or greater than 35 wt %, and up to 40 wt % or up to 50 wt % of feedstock carbon. The fuel yield can fall into a range bounded by any of these values, e.g., 20-50 wt %, 25-40 wt %, etc. These yields are achieved in a process that does not use a hydrogen-rich co-reagent in the catalytic process. The ability to catalytically upgrade biovapors without use of co-reagents provides significant cost savings and processing efficiency. 
         [0061]    Furthermore, the fuel contains a high proportion of higher aliphatic hydrocarbon, making it suitable for use as a jet fuel or diesel fuel component. Jet and diesel fuel are a mixture of a large number of different hydrocarbons of varying carbon number (carbon atoms per molecule). Kerosene-type jet fuel has a carbon number distribution between about 6 and 18, while wide-cut or naphtha-type jet fuel has a carbon number distribution of between about 6 and 18. Jet fuel typically has a higher aliphatic hydrocarbon and lower aromatic hydrocarbon content than gasoline. Diesel gas is heavier than jet fuel, with a higher number of larger hydrocarbon chains, though both are primarily paraffin oils (kerosene). The carbon distribution in diesel components falls usually in the range between 8 and 20. Gasoline components fall in the range from C6 to C12. 
         [0062]    In one or more embodiments, the resultant biofuel comprises at least 15 wt % paraffin content (as used herein “paraffin” includes both linear and branched paraffins), or at least 16 wt % paraffin content, or at least 17 wt % paraffin content, or at least 18 wt % content, or at least 19 wt % paraffin content, or at least 20 wt % paraffin content. In one or more embodiments, the resultant biofuel comprises up to 60 wt % paraffin content or up to 70 wt % paraffin content. The paraffin content can fall into a range bounded by any of these values, e.g., 15 wt %-70 wt %, or 17 wt %-60 wt %. In one or more embodiments, the resultant biofuel comprises no more than 50 wt % aromatics, or no more than 45% aromatics, or no more than 40% aromatics. In one or more embodiments, the resultant biofuel comprises less than about 50wt % aromatics, less than about 45 wt % aromatics, less than about 40 wt % aromatics, less than about 35% aromatics, less than about 30% aromatics, or less than about 25wt % aromatics. The aromatic content can fall into a range bounded by any of these values, e.g., 25-50 wt %, or 30-40 wt % or 40-50 wt %, etc. 
         [0063]    In contrast, a biofuel derived from a conventional biomass typically comprises more than 50 wt % aromatics, and typically 60-90% aromatics, and the paraffin content is very low, e.g., about 1-10%. 
         [0064]      FIG. 8  is a bar graph that shows the relative compositions of (a) a biofuel prepared from a lipid-rich biomass according to one or more embodiments and (b) a biofuel prepared from a conventional wood pellet biomass DME as a co-reagent. The contents of the two compositions are set out in Table 1. The biofuel prepared from a lipid-rich biomass contains a considerably higher paraffinic content and lower aromatic content compared to biofuel prepared from a conventional woody biomass. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Relative Composition of Biofuel prepared 
               
               
                 from lipid-rich and Woody Biomass 
               
             
          
           
               
                   
                 Aromatics 
                 Paraffins 
                 Iso Paraffins 
                 Olefins 
                 C15+ Paraffins 
               
               
                   
                   
               
             
          
           
               
                 Seeds 
                 40.33 
                 14.26 
                 3.92 
                 11.7 
                 29.79 
               
               
                 CPES 
                 92.6 
                 1.33 
                 2.17 
                 0.05 
                 3.68 
               
               
                   
               
             
          
         
       
     
         [0065]    The invention is illustrated in the following examples, which are presented for the purposes of illustration only and are not intended to be limiting of the invention. 
       EXAMPLE 1 
       [0066]    Production of fuel from rape seeds is described. 
         [0067]    200 g of rape seeds were placed into a fixed bed tubular reactor and brought to 300° C. in an atmosphere containing equal parts CO 2  (as a carrier gas) and H 2 O. The temperature was subsequently raised to 650° C. over a period of three hours in this atmosphere with a flow rate of 0.5 CFH. The resulting vapors were passed through 150 g of a silica alumina catalyst at 400° C. and cooled in ice water. 50-60 mL fuel, 165 mL of process water and light gases were obtained after a 6 hour run. The process described here is considered to be a slow pyrolysis process; however, comparable results are expected using known fast pyrolysis processes. 
         [0068]    A GC/MS analysis of the fuel in the range of C6 to C19 compounds using silica resin exchange column is shown in  FIG. 4  along with identification of peaks. A small component of light gases of C1 to C5 composition are also collected (not shown in GC spectra). It is noted in the GC spectra that all hydrocarbon compounds of formula C n H 2n+2  are detected, along with minor components comprised of branched aliphatic compounds and a variety of aromatic compounds. A total of 60 ml of fuel was collected, indicating a 30% conversion. The raw fuel was subject to atmospheric distillation in the temperature window of 60-380° C. using a laboratory scale distillation apparatus.  FIG. 5  shows a chromatogram of subsequently distilled fuel in the range of 60° C. to 380° C. Significant paraffinic content is apparent in the spectrum. A detailed analysis of the distilled fuel composition is shown below in Table 2. 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
             
             
               
                   
                 Paraffin&#39;s 
                 14.26% 
               
               
                   
                 (C 7  to C 15  only; GCMS, revealed up to C 21 ) 
               
               
                   
                 Iso-paraffins 
                 3.92% 
               
               
                   
                 Aromatics 
                 40.33% 
               
               
                   
                 Mono-aromatics 
                 27.48% 
               
               
                   
                 Di-aromatics 
                 12.86% 
               
               
                   
                 Olefins 
                 11.7% 
               
               
                   
                 Oxygenates 
                 0.15% 
               
               
                   
                 Sulfur 
                 &lt;0.1% 
               
               
                   
                 Other (C 15 +) 
                 31.18% 
               
               
                   
                   
               
             
          
         
       
     
         [0069]      FIG. 7   b  shows a SEM micrograph of the remnant biochar after rapeseed pyrolysis. The biochar surface area was measured as 120 m 2 /g with significant cellular structure. 
       EXAMPLE 2 
       [0070]    Production of fuel from sunflower seeds is described. 
         [0071]    200 g of sunflower seeds were placed into a fixed bed tubular reactor and brought to 300° C. in an atmosphere containing equal parts CO 2  and H 2 O. The temperature was subsequently raised to 650° C. over a period of three hours in this atmosphere with a flow rate of 0.5 CFH. The resulting vapors were passed through 150 g of a silica alumina catalyst and cooled in ice water. 50 mL fuel per obtained after a 6 hour run, representing a 25% carbon conversion. 
         [0072]    A GC/MS analysis of the fuel in the range of C6 to C19 compounds is shown in  FIG. 6  along with identification of peaks. A higher percentage of aromatic compounds are detected than in rape seed hydrothermal pyrolysis. 20% biochar was obtained on a carbon atom basis. A SEM of the biochar at 600×magnification is shown in  FIG. 7   a.    
         [0073]    It will be appreciated that while a particular sequence of steps has been shown and described for purposes of explanation, the sequence may be varied in certain respects, or the steps may be combined, while still obtaining the desired configuration. Additionally, modifications to the disclosed embodiment and the invention as claimed are possible and within the scope of this disclosed invention. As used in the specification, and in the appended claims, the singular forms “a”, “an”, “the”, include plural referents unless the context clearly dictates otherwise.