Patent Abstract:
A thermolysis process for treating algal biomass, consisting substantially of dried algal cells, in which the algal biomass is heated from ambient to 460° C. in a flowing stream that contains one or more of carbon dioxide, acetic acid or other organic acids and that produces a condensable hydrocarbon product whose mass yield is greater than the dry, ash-free mass fraction of lipids in the starting algal biomass and whose higher enthalpy of combustion exceeds 25 MJ/kg plus a char, and a hydrocarbon-laden gaseous product. 
     In another feature, the present invention includes heating the previously dried, algal biomass in a readily available, waste acid gas, such as flue gas that is rich in carbon dioxide, or to intimately mix the algal biomass with a solid acid, such as a protonated, large pore zeolite, and then heating the mixture in a non-oxidizing sweep gas.

Full Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This patent application claims the benefit of provisional patent application No. 61/176,152, filed on May 7, 2009, which is incorporated by reference in its entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    None. 
       REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISC AND AN INCORPORATION BY REFERENCE OF THE MATERIAL ON THE COMPACT DISC 
       [0003]    None. 
       BACKGROUND OF THE INVENTION 
       [0004]    (1) Field of the Invention 
         [0005]    This invention relates generally to the production of fuels, chemicals, and soil amendments from biomass by means of thermolysis. More specifically, the invention relates to the acid-catalyzed thermolysis of algae. 
         [0006]    (2) Description of the Related Art 
         [0007]    The depletion of economically accessible petroleum and impending climate changes that follow from the accumulation of anthropogenic carbon dioxide in the atmosphere and the oceans, have motivated the search for carbon-neutral fuels that can be produced economically and domestically. Biomass, which derives its energy content from sunlight, and whose carbon comes from already oxidized carbon, promises to be a renewable feedstock from which to produce liquid fuels that can substitute for fuels derived currently from petroleum. 
         [0008]    Aquatic microalgae are widely distributed organisms that accumulate carbon dioxide and nutrients from their environment into a material, algal biomass, which can be harvested (separated from the water). Algal biomass grows more rapidly than do terrestrial plants, as evidenced by much higher areal productivities. It has long been thought that algae, which can grow very rapidly compared to terrestrial plants, might be a suitable source of biomass from which to produce liquid fuels. 
         [0009]    A much discussed route to convert algal biomass into liquid fuels is to extract lipids (plant fats), and to convert them into either biodiesel through transesterification with a light alcohol, or to hydrotreat the lipids to make what is termed “green” diesel. This route (oil extraction) leaves behind a large amount of protein and carbohydrate. In principle, that material can be employed as an animal feed, but comparison of the flows of mass to the fuel market with those to the feed market suggest that the feed market would be rapidly saturated once algae were converted routinely to renewable fuel by that process, generating a disposal problem rather than an economic opportunity. Moreover, each of those processes typically convert only a small (and, to date, uneconomic) fraction of the heating value of the algae into the heating value of the produced fuels—either because the target fraction (e.g. the lipids) is present at low concentration in the algae, or because the conversion process itself is not energy efficient, or both. 
         [0010]    A second route, steam reforming, produces synthesis gas that can be converted, for example, by the Fischer Tropsch reaction, into fuel range hydrocarbons. However, this route requires an investment in energy (both the steam reforming reaction and the Fischer-Tropsch reactions are typically carried out at high pressure), and is not very carbon efficient because some of the input carbon is diverted back to carbon dioxide or light hydrocarbons, which are frequently disposed by flaring. 
         [0011]    A third route, hydrothermal processing, produces a high yield of liquid hydrocarbon products, but also a large quantity of hydrocarbon-laden water that can present a disposal cost, and a dilution of some of the desired products. 
         [0012]    A fourth route, pyrolysis, is very general but has previously been carried out at high temperatures that exacerbate the corrosivity of the products and necessitates the use of expensive, refractory reactors. 
         [0013]    Other processes have also been explored, but none has yet offered compelling financial economics or attractive carbon efficiencies, despite research campaigns that seem to recrudesce about every thirty years. What is needed in the art is that the algal biomass-derived feed stocks be amenable to further refining together with conventional fuel feed stocks to take advantage of the existing capital investment in petroleum refining, and to make the algal biomass-derived fuel fungible with conventional petroleum-derived fuels. It is further desirable that any solid residuum from the production of the algal biomass-derived, liquid fuel feedstock also have economic value, for example as a solid fuel or as a soil amendment where minerals and heteroatoms (e.g., N, P) can be returned to the biosphere, albeit possibly in a different venue from which they came. 
       BRIEF SUMMARY OF THE INVENTION 
       [0014]    A thermolysis process for treating algal biomass, consisting substantially of dried algal cells, in which the algal biomass is heated from ambient to 460° C. in a flowing stream that contains one or more of carbon dioxide, acetic acid or other organic acids and that produces a condensable hydrocarbon product whose mass yield is greater than the dry, ash-free mass fraction of lipids in the starting algal biomass and whose higher enthalpy of combustion exceeds 25 MJ/kg plus a char, and a hydrocarbon-laden gaseous product. 
         [0015]    Another feature of the method of the present invention is heating the previously dried, algal biomass in a readily available, waste acid gas, such as flue gas that is rich in carbon dioxide, or to intimately mix the algal biomass with a solid acid, such as a protonated, large pore zeolite, and then heating the mixture in a non-oxidizing sweep gas. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0016]      FIG. 1  shows a temperature profile, illustrated by a solid curve, employed in TGA/GC/MS experiments detailed in Examples 1 and 2, discussed below. 
           [0017]      FIG. 2  shows chromatograms obtained at the sequence of the indicated sample temperatures (100° C., 290° C., 460° C.) in Example 1 during the thermolysis of a sample of algal biomass heated along the ramp shown in  FIG. 1  in a flowing stream consisting of 66.7 mol % CO 2  and 33.3 mol % N 2 . 
           [0018]      FIG. 3  shows an expanded view of a chromatogram obtained in Example 1 of the gas stream produced during the TGA/GC-MS experiment, sampled at 50° C. 
           [0019]      FIG. 4  compares the expanded chromatograms obtained in Example 1 at 100° C. during the thermolysis of a sample of algal biomass heated along the temperature trajectory shown in  FIG. 1  in a flowing stream consisting either of pure N 2 , as illustrated by a light weight curve or of 66.7 mol % CO 2  and 33.3 mol % N 2 , as illustrated by a heavy weight curve. 
           [0020]      FIG. 5  shows chromatograms obtained in Example 1 at the indicated sequence of sample temperatures (100° C., 290° C. and 560° C.) during the thermolysis of a sample of algal biomass intimately mixed with H-ZSM-5 heated according to the temperature ramp shown in  FIG. 1  in a flowing stream consisting of 66.7 mol % CO 2  and 33.3 mol % N 2 . The effluent stream from the sample was analyzed with the aid of a GC/MS at the end of the soak periods or when the temperature first reached the indicated value during the ramp periods. 
           [0021]      FIG. 6  compares chromatograms obtained in Example 2 at 50° C. heated according to the temperature trajectory shown in  FIG. 1  during the thermolysis in a flowing stream consisting of 66.7 mol % CO 2  and 33.3 mol % N 2  of a sample of algal biomass, as illustrated by a heavy curve, and another sample that had been previously, intimately mixed with H-ZSM-5, as illustrated by a light curve. 
           [0022]      FIG. 7  is a schematic diagram of a process in which the thermolysis of algal biomass is integrated with the flue gas and waste heat from an industrial process. 
           [0023]      FIG. 8  shows the temperature trajectory followed and the evolution of thermolysis products from the experiment described in Example 3, discussed below. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    The process of the present invention includes thermolysis that can be carried out at temperatures less than 460° C. when assisted by the presence of carbon dioxide or a solid acid catalyst. In one advantageous embodiment, dry biomass consisting substantially of algal cells is contacted in the absence of additional catalysts with a stream of hot gas containing carbon dioxide. In another advantageous embodiment, dry biomass is intimately mixed with a solid acid catalyst, such as H-ZSM-5, for example, and then contacted with a stream of hot gas. The hot gas may be carbon dioxide, diluted carbon dioxide, or any other suitable hot gas. The different advantageous embodiments provide a process that evolves thermolysis products at temperatures below 100° C. and even as low as 50° C. in the presence of a solid acid catalyst. As will be seen from the examples below, the thermolysis products span compositions that are different from those seen in the pyrolysis of cellulosic biomass. The high heating value of the oily product is an advantageous result in view of much lower values typically found for pyrolysis products from cellulose (Table 1). 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Comparison of the specific heating values of 
               
               
                 petrofuels and some biofuels: 
               
             
          
           
               
                   
                 Material 
                 HHV/MJ kg −1   
               
               
                   
                   
               
               
                   
                 Algae derived thermolysis-oil c   
                 36 
               
               
                   
                 Crude petroleum 
                 45-48 
               
               
                   
                 Jet fuel (minimum) 
                 43 
               
               
                   
                 Refined biodiesel 
                 38 
               
               
                   
                 Wood-derived py-oil 
                 ~20  
               
               
                   
                   
               
             
          
         
       
     
         [0025]    Because both CO 2 -assisted and solid acid-catalyzed thermolysis of algal biomass occur at comparatively low temperatures, a process deploying either embodiment can be integrated with an industrial facility to employ heat that would otherwise be wasted and/or deoxygenated flue gas from a combustion process that would otherwise be vented. A schematic of a process flow is shown in  FIG. 7 . Algae are grown in helioreactors ( 738 ), harvested continuously via flocculation ( 734 ) and pressed to remove bulk water ( 736 ). The partially dried algae are conveyed to a drying kiln ( 730 ) that can be heated using hot flue gas from the industrial partner. The temperature and flow rate of the flue gas is lowered by mixing a stream of gas from the flue ( 724 ), throttled by valve ( 728 ) and mixing the hot gas with ambient air whose inlet flow rate is controlled by the air mixing valve ( 732 ). The gases are drawn by the action of the induction fan ( 718 ) through the drying kiln and through the particle separator ( 720 ) and then a cooled in heat exchanger  722 . The now dry algae are conveyed to Kiln  710  where they are treated with hot, gas that has been deoxygenated by reaction with thermolysis char in kiln ( 714 ) and cooled in heat exchanger ( 712 ). The treated char is accumulated in storage vessel ( 716 ). The volatile products of thermolysis are condensed by passage through heat exchanger ( 702 ) and the condensibles are collected in storage vessel ( 704 ). The char is collected in vessel  706  before it is transferred to the inlet of the deoxygenation kiln ( 704 ). The hot thermolysis gas and the volatile products are transported through the kilns and heat exchangers by means of the induction fan ( 708 ), which also transports the noncondensable products of thermolysis to a flare ( 726 ) where they can be safely combusted. Because this process reuses heat from the industrial partner, there could be an allowance for the carbon dioxide that would have been produced had, instead, a carbon-based fuel been combusted to supply that heat. 
       Example 1 
       [0026]    A small quantity of unwashed algal biomass, about 30 mg was placed in the pan of a thermal gravimetric balance. The gas outlet of the TGA was connected via heat-traced stainless steel tubing to a 6-port sampling valve mounted on the inlet to an HP5890 gas chromatograph equipped with a capillary column and an HP mass selective detector. Either N 2  or a mixture of 66.7 mol % CO 2  plus 33.3% N 2  was flowed through the heated chamber at about 100 ml/min. The sample was then heated according to the trajectory shown in  FIG. 1 . When the sample had been heated to the temperatures indicated in  FIG. 2 , constant volume samples of the effluent stream were injected into the GC/Ms through the approximately 1 ml loop attached to the 6-port sampling valve. The identity of the eluted compounds was determined by comparing the cracking pattern of the mass spectrogram of each peak against spectra drawn from the library of the instrument. 
         [0027]      FIG. 1  depicts the weight losses in Example 1 by a sample of algae heated in either pure nitrogen, as illustrated by a short dashed curve or in a mixture consisting of 66.7% CO 2  and 33.7% N 2 , as illustrated by a long dashed curve. As indicated in  FIG. 1 , the sample heated in the gas stream that contained carbon dioxide lost more weight than did the sample heated in the stream containing only dinitrogen. Buoyancy effects are suppressed in this presentation of the data because we normalized the initial weights of the samples (also measured in the reaction gases) to 100%. 
         [0028]    The effluent stream obtained in Example 1 from the sample was analyzed with the aid of a GC/MS at the end of the soak periods or when the temperature first reached the indicated value during the ramp periods. 
         [0029]    At the end of the first 50° C. soak period, the gas stream consisted of the compounds listed in Table 2, which eluted through the GC at times and in amounts illustrated in  FIG. 3 . In particular, four compounds, which appeared at this low temperature at significantly greater abundance when the sweep gas contained CO 2  than when the sweep gas was pure N 2 , include indole, methylindole, trimethyl-bicyclo[3.1.1]heptanes, and propylcyclohexanol. 
         [0030]    In Table 2, shown below, are compounds identified in the GC/MS chromatogram of the TGA effluent from an algae sample treated in 60 ml/min CO 2 —F30 ml/min N 2  flow gas sampled at 50° C. In  FIG. 3 , the numbers labeling the peaks correspond to the compounds listed in Table 2, depicted below. 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
               
               
                 Peak # 
                 RT/min 
                 Compounds 
                 Formula 
               
               
                   
               
             
             
               
                 301 
                 4.681 to 4.754 
                 Pyrrolidinedione 
                 C 4 H 5 NO 2   
               
               
                 302 
                 5.177 to 5.236 
                 Butenoic acid, ethyl ester 
                 C 6 H 10 O 2   
               
               
                 303 
                 5.604 to 5.691 
                 Indole 
                 C 8 H 7 N 
               
               
                 304 
                 6.041 to 6.119 
                 Methyl-1H-Indole 
                 C 9 H 9 N 
               
               
                 305 
                 7.806 to 7.833 
                 TrimethylBicyclo[3.1.1]heptane, 
                 C 10 H 18   
               
               
                 306 
                 7.961 to 7.997 
                 Propylcyclohexanol 
                 C 9 H 18 O 
               
               
                   
               
             
          
         
       
     
         [0031]    Identifications of the compounds represented by peaks in the chromatographic analysis of the TGA effluent for this sample at successive temperatures along the trajectory shown in  FIG. 1  are presented in Tables 3-9. 
         [0032]    Table 3, shown below, is a GC/MS chromatogram of the TGA effluent from an algae sample treated in 60 ml/min CO 2 +30 ml/min N 2  flow gas sampled at 100° C. Entries in italics (Peaks 407-410) describe compounds that did not appear at 50° C. In  FIG. 4 , the numbers labeling the peaks correspond to the compounds listed in Table 3, depicted below. 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
               
               
                 Peak # 
                 RT/min 
                 Compounds 
                 Formula 
               
               
                   
               
             
             
               
                 401 
                 4.681 to 4.754 
                 2,5-Pyrrolidinedione 
                 C 4 H 5 NO 2   
               
               
                 402 
                 5.177 to 5.236 
                 2-Butenoic acid, ethyl ester 
                 C 6 H 10 O 2   
               
               
                 403 
                 5.604 to 5.691 
                 Indole 
                 C 8 H 7 N 
               
               
                 403 
                 6.041 to 6.119 
                 Methyl-1H-Indole 
                 C 9 H 9 N 
               
               
                 405 
                 7.806 to 7.833 
                 trimethyl-bicyclo[3.1.1]heptane 
                 C 10 H 18   
               
               
                 406 
                 7.961 to 7.997 
                 2-Propylcyclohexanol 
                 C 9 H 18 O 
               
               
                 
                   407 
                 
                 
                   4.789 to 4.844 
                 
                 
                   1,2,4-Triazine-3,5(2H,4H)-dione 
                 
                 
                   C 
                   3 
                   H 
                   3 
                   N 
                   3 
                   O 
                   2 
                 
               
               
                 
                   408 
                 
                 
                   6.491 to 6.532 
                 
                 
                   2,4,6-trimethyl-Benzonitrile, 
                 
                 
                   C 
                   10 
                   H 
                   11 
                   N 
                 
               
               
                 
                   409 
                 
                 
                   6.536 to 6.563 
                 
                 
                   2,7-dimethyl-Indolizine, 
                 
                 
                   C 
                   10 
                   H 
                   11 
                   N 
                 
               
               
                 
                   410 
                 
                 
                   7.955 to 8.001 
                 
                 
                   3,7,11,15-Tetramethyl-2-hexadecen-1-ol 
                 
                 
                   C 
                   20 
                   H 
                   40 
                   O 
                 
               
               
                   
               
             
          
         
       
     
         [0033]    Table 4, shown below, is a GC/MS chromatogram of the TGA effluent from an algae sample treated in 60 ml/min CO 2 +30 ml/min N 2  flow gas sampled at 200° C. Entries in italics (Peaks 11-12) describe compounds that did not appear at 100° C. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Peak # 
                 RT/min 
                 Compounds 
                 Formula 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 4.681 to 4.754 
                 2,5-Pyrrolidinedione 
                 C 4 H 5 NO 2   
               
               
                 2 
                 5.177 to 5.236 
                 2-Butenoic acid, ethyl ester, (E)- 
                 C 6 H 10 O 2   
               
               
                 3 
                 5.604 to 5.691 
                 Indole 
                 C 8 H 7 N 
               
               
                 4 
                 6.041 to 6.119 
                 Methyl-1H-Indole 
                 C 9 H 9 N 
               
               
                 5 
                 7.806 to 7.833 
                 trimethyl-,Bicyclo[3.1.1]heptane 
                 C 10 H 18   
               
               
                 6 
                 7.961 to 7.997 
                 2-Propylcyclohexanol 
                 C 9 H 18 O 
               
               
                 7 
                 4.789 to 4.844 
                 1,2,4-Triazine-3,5(2H,4H)-dione 
                 C 3 H 3 N 3 O 2   
               
               
                 8 
                 6.491 to 6.532 
                 2,4,6-trimethyl-Benzonitrile, 
                 C 10 H 11 N 
               
               
                 9 
                 6.536 to 6.563 
                 Indolizine, 2,7-dimethyl- 
                 C 10 H 11 N 
               
               
                 10 
                 7.955 to 8.001 
                 3,7,11,15-Tetramethyl-2- 
                 C 20 H 40 O 
               
               
                   
                   
                 hexadecen-1-ol 
               
               
                 
                   11 
                 
                 
                   5.037 to 5.142 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   12 
                 
                 
                   5.933 to 5.979 
                 
                 
                   1,2-dihydro-1,1,6-trimethyl 
                 
                 
                   C 
                   13 
                   H 
                   16 
                 
               
               
                   
                   
                 
                   Naphthalene 
                 
               
               
                   
               
             
          
         
       
     
         [0034]    Table 5, shown below, is a GC/MS chromatogram of the TGA effluent from a sample of algal biomass treated in 60 ml/min CO 2 +30 ml/min N 2  flow gas sampled at 290° C. Entries in italics (Peaks 13-15) describe compounds that did not appear at 200° C. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                   
                 Retention 
                   
                   
               
               
                 Peak # 
                 Time/min 
                 Compounds 
                 Formula 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 4.681 to 4.754 
                 2,5-Pyrrolidinedione 
                 C 4 H 5 NO 2   
               
               
                 2 
                 5.177 to 5.236 
                 2-Butenoic acid, ethyl ester, (E)- 
                 C 6 H 10 O 2   
               
               
                 3 
                 5.604 to 5.691 
                 Indole 
                 C 8 H 7 N 
               
               
                 4 
                 6.041 to 6.119 
                 Methyl-1H-Indole 
                 C 9 H 9 N 
               
               
                 5 
                 7.806 to 7.833 
                 2,6,6-trimethyl-bicyclo[3.1.1]heptane,, 
                 C 10 H 18   
               
               
                 6 
                 7.961 to 7.997 
                 2-Propylcyclohexanol 
                 C 9 H 18 O 
               
               
                 7 
                 4.789 to 4.844 
                 1,2,4-Triazine-3,5(2H,4H)-dione 
                 C 3 H 3 N 3 O 2   
               
               
                 8 
                 6.491 to 6.532 
                 Benzonitrile, 2,4,6-trimethyl- 
                 C 10 H 11 N 
               
               
                 9 
                 6.536 to 6.563 
                 Indolizine, 2,7-dimethyl- 
                 C 10 H 11 N 
               
               
                 10 
                 7.955 to 8.001 
                 3,7,11,15-Tetramethyl-2-hexadecen-1-ol 
                 C 20 H 40 O 
               
               
                 11 
                 5.037 to 5.142 
                 Dodecane 
                 C 12 H 26   
               
               
                 12 
                 5.933 to 5.979 
                 Naphthalene, 1,2-dihydro-1,1,6-trimethyl 
                 C 13 H 16   
               
               
                 
                   13 
                 
                 
                   6.064 to 6.109 
                 
                 
                   1H-Indole, 3-methyl- 
                 
                 
                   C 
                   9 
                   H 
                   9 
                   N 
                 
               
               
                 
                   14 
                 
                 
                   6.310 to 6.341 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   15 
                 
                 
                   7.274 to 7.324 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                   
               
             
          
         
       
     
         [0035]    Table 6, shown below, is a GC/MS chromatogram of the TGA effluent from an algae sample treated in 60 ml/min CO 2 +30 ml/min N 2  flow gas sampled at 460° C. Entries in italics (Peaks 13, 16-38) describe compounds that did not appear at 290° C. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Peak # 
                 RT/min 
                 Compounds 
                 Formula 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 3 
                 5.604 to 5.691 
                 Indole 
                 C 8 H 7 N 
               
               
                 5 
                 7.806 to 7.833 
                 2,6,6-trimethyl- 
                 C 10 H 18   
               
               
                   
                   
                 Bicyclo[3.1.1]heptane 
               
               
                 6 
                 7.961 to 7.997 
                 2-Propylcyclohexanol 
                 C 9 H 18 O 
               
               
                 13 
                 6.064 to 6.109 
                 3-methyl-1H-Indole 
                 C 9 H 9 N 
               
               
                 
                   16 
                 
                 
                   1.383 to 1.501 
                 
                 
                   Pentane 
                 
                 
                   C 
                   5 
                   H 
                   12 
                 
               
               
                 
                   17 
                 
                 
                   2.515 to 2.606 
                 
                 
                   Toluene 
                 
                 
                   C 
                   7 
                   H 
                   8 
                 
               
               
                 
                   18 
                 
                 
                   2.656 to 2.707 
                 
                 
                   Cyclooctane 
                 
                 
                   C 
                   8 
                   H 
                   16 
                 
               
               
                 
                   19 
                 
                 
                   2.711 to 2.797 
                 
                 
                   2,4-dimethyl-Heptane 
                 
                 
                   C 
                   9 
                   H 
                   20 
                 
               
               
                 
                   20 
                 
                 
                   4.417 to 4.485 
                 
                 
                   3-methyl-Phenol, 
                 
                 
                   C 
                   7 
                   H 
                   8 
                   O 
                 
               
               
                 
                   21 
                 
                 
                   4.517 to 4.567 
                 
                 
                   Cyclododecane 
                 
                 
                   C 
                   12 
                   H 
                   24 
                 
               
               
                 
                   22 
                 
                 
                   4.567 to 4.617 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   23 
                 
                 
                   5.049 to 5.085 
                 
                 
                   1-methyl-2-octyl- 
                 
                 
                   C 
                   12 
                   H 
                   24 
                 
               
               
                   
                   
                 
                   Cyclopropane 
                 
               
               
                 
                   24 
                 
                 
                   5.085 to 5.122 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   25 
                 
                 
                   5.536 to 5.568 
                 
                 
                   1-Tridecene 
                 
                 
                   C 
                   13 
                   H 
                   26 
                 
               
               
                 
                   26 
                 
                 
                   5.581 to 5.604 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   27 
                 
                 
                   5.827 to 5.863 
                 
                 
                   4-Decene 
                 
                 
                   C 
                   10 
                   H 
                   20 
                 
               
               
                 
                   28 
                 
                 
                   6.004 to 6.032 
                 
                 
                   2-Tetradecene 
                 
                 
                   C 
                   14 
                   H 
                   28 
                 
               
               
                 
                   29 
                 
                 
                   6.036 to 6.063 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   30 
                 
                 
                   5.931 to 5.963 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   31 
                 
                 
                   6.291 to 6.314 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   32 
                 
                 
                   6.314 to 6.341 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   33 
                 
                 
                   6.441 to 6.468 
                 
                 
                   1-Pentadecene 
                 
                 
                   C 
                   15 
                   H 
                   30 
                 
               
               
                 
                   34 
                 
                 
                   6.473 to 6.500 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   35 
                 
                 
                   6.859 to 6.882 
                 
                 
                   1-Hexadecene 
                 
                 
                   C 
                   16 
                   H 
                   32 
                 
               
               
                 
                   36 
                 
                 
                   6.882 to 6.909 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   37 
                 
                 
                   7.273 to 7.371 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   38 
                 
                 
                   7.401 to 7.428 
                 
                 
                   Z-5-Nonadecene 
                 
                 
                   C 
                   19 
                   H 
                   38 
                 
               
               
                   
               
             
          
         
       
     
         [0036]    Table 7, shown below, is a GC/MS chromatogram of the TGA effluent from an algae sample treated in 60 ml/min CO 2 +30 ml/min N 2  flow gas sampled when cooled to 350° C. Entries in italics (Peaks 39-46) describe compounds that did not appear at 460° C. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Peak # 
                 RT/min 
                 Compounds 
                 Formula 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 3 
                 5.621 to 5.661 
                 Indole 
                 C 8 H 7 N 
               
               
                 13 
                 6.064 to 6.109 
                 3-methyl-1H-Indole 
                 C 9 H 9 N 
               
               
                 33 
                 6.445 to 6.463 
                 1-Pentadecene 
                 C 15 H 30   
               
               
                 34 
                 6.472 to 6.495 
                 Dodecane 
                 C 12 H 26   
               
               
                 35 
                 6.850 to 6.882 
                 1-Hexadecene 
                 C 16 H 32   
               
               
                 36 
                 6.882 to 6.909 
                 Dodecane 
                 C 12 H 26   
               
               
                 37 
                 7.273 to 7.371 
                 Dodecane 
                 C 12 H 26   
               
               
                 38 
                 7.401 to 7.428 
                 Z-5-Nonadecene 
                 C 19 H 38   
               
               
                 
                   39 
                 
                 
                   3.852 to 3.980 
                 
                 
                   Phenol 
                 
                 
                   C 
                   6 
                   H 
                   6 
                   O 
                 
               
               
                 
                   40 
                 
                 
                   4.303 to 4.380 
                 
                 
                   2-methyl-Phenol 
                 
                 
                   C 
                   7 
                   H 
                   8 
                   O 
                 
               
               
                 
                   41 
                 
                 
                   4.407 to 4.526 
                 
                 
                   4-methyl-Phenol 
                 
                 
                   C 
                   7 
                   H 
                   8 
                   O 
                 
               
               
                 
                   42 
                 
                 
                   4.685 to 4.730 
                 
                 
                   2,5-Pyrrolidinedione 
                 
                 
                   C 
                   4 
                   H 
                   5 
                   NO 
                   2 
                 
               
               
                 
                   43 
                 
                 
                   4.835 to 4.885 
                 
                 
                   2,4-dimethyl-Phenol 
                 
                 
                   C 
                   8 
                   H 
                   10 
                   O 
                 
               
               
                 
                   44 
                 
                 
                   4.903 to 4.971 
                 
                 
                   4-ethyl-Phenol 
                 
                 
                   C 
                   8 
                   H 
                   10 
                   O 
                 
               
               
                 
                   45 
                 
                 
                   7.250 to 7.273 
                 
                 
                   3-Heptadecene, (Z)- 
                 
                 
                   C 
                   17 
                   H 
                   34 
                 
               
               
                 
                   46 
                 
                 
                   7.396 to 7.437 
                 
                 
                   3,7,11-trimethyl-1- 
                 
                 
                   C 
                   15 
                   H 
                   32 
                   O 
                 
               
               
                   
                   
                 
                   Dodecanol 
                 
               
               
                   
               
             
          
         
       
     
       Example 2 
       [0037]    Algal biomass was comminuated with a commercial sample of H-ZSM-5 powder. A small quantity of that mixture or the algal biomass alone, about 30 mg in each case, was placed in the pan of a thermal gravimetric balance. The gas outlet of the TGA was connected via heat-traced stainless steel tubing to a 6-port sampling valve of an HP5890 gas chromatograph equipped with a capillary column and an HP mass selective detector. The samples were heated according to the temperature trajectory shown in  FIG. 1  while contacted with a 90 ml/min flow of N 2 . When the sample had been heated to 50° C., 100° C., 200° C., 290° C. and 460° C., constant volume samples of the effluent stream were injected into the GC/Ms through an approximately 1 ml loop attached to the 6-port sampling valve. The full chromatograms are shown in  FIG. 5  at the indicated temperatures. The identity of the eluted compounds was determined by comparing the cracking pattern of the mass spectrogram of each peak against spectra drawn from the library of the instrument. 
         [0038]    At the end of the first 50° C. soak period, the gas stream consisted of the compounds listed in Table 8. All twelve of the peaks listed in Table 8 appeared at this low temperature only when the sample contained the acid catalyst, in this example. 
         [0039]    In Table 8, shown below, are compounds identified in the GC/MS chromatogram shown in  FIG. 6  of the TGA effluent in Example 2 from an algal biomass and algal biomass+zeolite samples treated in 90 ml/min of N 2 , sampled at 50° C. In  FIG. 6 , the numbers labeling the peaks correspond to the compounds listed in Table 8, depicted below. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Peak #: 
                 RT (min) 
                 Compounds 
                 Formula 
               
               
                   
                   
               
             
             
               
                   
                 601 
                 4.345 to 4.545 
                 Phenol, 4-methyl- 
                 C 7 H 8 O 
               
               
                   
                 602 
                 4.691 to 4.754 
                 2,5-Pyrrolidinedione 
                 C 4 H 5 NO 2   
               
               
                   
                 603 
                 4.841 to 4.895 
                 2,4-dimethyl-Phenol 
                 C 8 H 10 O 
               
               
                   
                 604 
                 4.900 to 4.973 
                 4-ethyl-Phenol 
                 C 8 H 10 O 
               
               
                   
                 605 
                 5.623 to 5.664 
                 Indole 
                 C 8 H 7 N 
               
               
                   
                 606 
                 6.064 to 6.105 
                 4-methyl-1H-Indole, 
                 C 9 H 9 N 
               
               
                   
                 607 
                 6.856 to 6.883 
                 Cyclohexadecane 
                 C 16 H 32   
               
               
                   
                 608 
                 6.883 to 6.956 
                 Dodecane 
                 C 12 H 26   
               
               
                   
                 609 
                 7.081 to 7.115 
                 Dodecane 
                 C 12 H 26   
               
               
                   
                 610 
                 7.256 to 7.279 
                 3-Heptadecene, (Z)- 
                 C 17 H 34   
               
               
                   
                 611 
                 7.279 to 7.306 
                 Dodecane 
                 C 12 H 26   
               
               
                   
                 612 
                 7.816 to 7.838 
                 Phytol 
                 C 20 H 40 O 
               
               
                   
                   
               
             
          
         
       
     
         [0040]    Table 9, shown below, lists compounds identified in the GC/MS chromatogram of the TGA effluent from an algal biomass and algal biomass+zeolite samples treated in 90 ml/min of N 2 , sampled at 100° C. Lines in italics (Peaks 13-14) describe compounds that did not appear at 50° C. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Peak 
                 RT (min) 
                 Compounds 
                 Formula 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 4.345 to 4.545 
                 Phenol, 4-methyl- 
                 C 7 H 8 O 
               
               
                 2 
                 4.691 to 4.754 
                 2,5-Pyrrolidinedione 
                 C 4 H 5 NO 2   
               
               
                 3 
                 4.841 to 4.895 
                 Phenol, 2,4-dimethyl- 
                 C 8 H 10 O 
               
               
                 4 
                 4.900 to 4.973 
                 Phenol, 4-ethyl- 
                 C 8 H 10 O 
               
               
                 5 
                 5.623 to 5.664 
                 Indole 
                 C 8 H 7 N 
               
               
                 6 
                 6.064 to 6.105 
                 1H-Indole, 4-methyl- 
                 C 9 H 9 N 
               
               
                 7 
                 6.856 to 6.883 
                 Cyclohexadecane 
                 C 16 H 32   
               
               
                 8 
                 6.883 to 6.956 
                 Dodecane 
                 C 12 H 26   
               
               
                 9 
                 7.081 to 7.115 
                 Dodecane 
                 C 12 H 26   
               
               
                 10 
                 7.256 to 7.279 
                 3-Heptadecene, (Z)- 
                 C 17 H 34   
               
               
                 11 
                 7.279 to 7.306 
                 Dodecane 
                 C 12 H 26   
               
               
                 12 
                 7.816 to 7.838 
                 Phytol 
                 C 20 H 40 O 
               
               
                 
                   13 
                 
                 
                   7.392 to 7.433 
                 
                 
                   1-Heptene, 2-isohexyl- 
                 
                 
                   C 
                   14 
                   H 
                   28 
                 
               
               
                   
                   
                 
                   6-methyl- 
                 
               
               
                 
                   14 
                 
                 
                   7.956 to 7.988 
                 
                 
                   3,7,11,15-Tetramethyl-2- 
                 
                 
                   C 
                   20 
                   H 
                   40 
                   O 
                 
               
               
                   
                   
                 
                   hexadecen-1-ol 
                 
               
               
                   
               
             
          
         
       
     
         [0041]    Table 10, shown below, lists compounds identified in the GC/MS chromatogram of the TGA effluent from an algae and algae+zeolite samples treated in 90 ml/min of N 2 , sampled at 200° C. Lines in italics (Peaks 15-19) describe compounds that did not appear at 100° C. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Peak 
                 Retention 
                   
                   
               
               
                 #: 
                 Time (min) 
                 Compounds 
                 Formula 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 4.345 to 4.545 
                 Phenol, 4-methyl- 
                 C 7 H 8 O 
               
               
                 2 
                 4.691 to 4.754 
                 2,5-Pyrrolidinedione 
                 C 4 H 5 NO 2   
               
               
                 3 
                 4.841 to 4.895 
                 Phenol, 2,4-dimethyl- 
                 C 8 H 10 O 
               
               
                 4 
                 4.900 to 4.973 
                 Phenol, 4-ethyl- 
                 C 8 H 10 O 
               
               
                 5 
                 5.623 to 5.664 
                 Indole 
                 C 8 H 7 N 
               
               
                 6 
                 6.064 to 6.105 
                 1H-Indole, 4-methyl- 
                 C 9 H 9 N 
               
               
                 7 
                 6.856 to 6.883 
                 Cyclohexadecane 
                 C 16 H 32   
               
               
                 8 
                 6.883 to 6.956 
                 Dodecane 
                 C 12 H 26   
               
               
                 9 
                 7.081 to 7.115 
                 Dodecane 
                 C 12 H 26   
               
               
                 10 
                 7.256 to 7.279 
                 3-Heptadecene, (Z)- 
                 C 17 H 34   
               
               
                 11 
                 7.279 to 7.306 
                 Dodecane 
                 C 12 H 26   
               
               
                 12 
                 7.816 to 7.838 
                 Phytol 
                 C 20 H 40 O 
               
               
                 13 
                 7.392 to 7.433 
                 1-Heptene, 2-isohexyl-6-methyl- 
                 C 14 H 28   
               
               
                 14 
                 7.956 to 7.988 
                 3,7,11,15-Tetramethyl-2- 
                 C 20 H 40 O 
               
               
                   
                   
                 hexadecen-1-ol 
               
               
                 
                   15 
                 
                 
                   5.182 to 5.218 
                 
                 
                   1,4:3,6-Dianhydro-.alpha.-d- 
                 
                 
                   C6H8O4 
                 
               
               
                   
                   
                 
                   glucopyranose 
                 
               
               
                 
                   16 
                 
                 
                   5.241 to 5.273 
                 
                 
                   Phenol, 2-ethyl-6-methyl- 
                 
                 
                   C9H12O 
                 
               
               
                 
                   17 
                 
                 
                   5.296 to 5.332 
                 
                 
                   Benzene, 1-ethyl-4-methoxy- 
                 
                 
                   C9H12O 
                 
               
               
                 
                   18 
                 
                 
                   7.606 to 7.652 
                 
                 
                   1-Octadecene 
                 
                 
                   C18H36 
                 
               
               
                 
                   19 
                 
                 
                   7.652 to 7.697 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                   
               
             
          
         
       
     
         [0042]    Table 11, shown below, lists compounds identified in the GC/MS chromatogram of the TGA effluent from an algal biomass and algal biomass+zeolite samples treated in 90 ml/min of N 2 , sampled at 290° C. Lines in italics (Peaks 20-29) describe compounds that did not appear at 200° C. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Peak 
                 RT (min) 
                 Compounds 
                 Formula 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 4.419 to 4.519 
                 Phenol, 4-methyl- 
                 C 7 H 8 O 
               
               
                 2 
                 4.664 to 4.746 
                 2,5-Pyrrolidinedione 
                 C 4 H 5 NO 2   
               
               
                 3 
                 4.841 to 4.895 
                 Phenol, 2,4-dimethyl- 
                 C 8 H 10 O 
               
               
                 4 
                 4.900 to 4.973 
                 Phenol, 4-ethyl- 
                 C 8 H 10 O 
               
               
                 5 
                 5.623 to 5.664 
                 Indole 
                 C 8 H 7 N 
               
               
                 6 
                 6.064 to 6.105 
                 1H-Indole, 4-methyl- 
                 C 9 H 9 N 
               
               
                 8 
                 6.883 to 6.907 
                 Dodecane 
                 C 12 H 26   
               
               
                 9 
                 7.081 to 7.115 
                 Dodecane 
                 C 12 H 26   
               
               
                 10 
                 7.256 to 7.279 
                 3-Heptadecene, (Z)- 
                 C 17 H 34   
               
               
                 11 
                 7.279 to 7.306 
                 Dodecane 
                 C 12 H 26   
               
               
                 12 
                 7.816 to 7.838 
                 Phytol 
                 C 20 H 40 O 
               
               
                 13 
                 7.392 to 7.433 
                 1-Heptene, 2-isohexyl-6-methyl- 
                 C 14 H 28   
               
               
                 14 
                 7.956 to 7.988 
                 3,7,11,15-Tetramethyl-2-hexadecen-1-ol 
                 C 20 H 40 O 
               
               
                 15 
                 5.182 to 5.218 
                 1,4:3,6-Dianhydro-.alpha.-d-glucopyranose 
                 C 6 H 8 O 4   
               
               
                 16 
                 5.237 to 5.269 
                 Phenol, 2-ethyl-6-methyl- 
                 C 9 H 12 O 
               
               
                 17 
                 5.296 to 5.332 
                 Benzene, 1-ethyl-4-methoxy- 
                 C 9 H 12 O 
               
               
                 18 
                 7.606 to 7.652 
                 1-Octadecene 
                 C 18 H 36   
               
               
                 19 
                 7.652 to 7.697 
                 Dodecane 
                 C 12 H 26   
               
               
                 
                   20 
                 
                 
                   1.585 to 2.190 
                 
                 
                   Acetic acid 
                 
                 
                   C 
                   2 
                   H 
                   4 
                   O 
                   2 
                 
               
               
                 
                   21 
                 
                 
                   2.435 to 2.499 
                 
                 
                   Pyridine 
                 
                 
                   C 
                   5 
                   H 
                   5 
                   N 
                 
               
               
                   
                   
                 
                   Pyrrole 
                 
                 
                   C 
                   4 
                   H 
                   5 
                   N 
                 
               
               
                 
                   22 
                 
                 
                   2.513 to 2.563 
                 
                 
                   Toluene 
                 
                 
                   C 
                   7 
                   H 
                   8 
                 
               
               
                 
                   23 
                 
                 
                   2.631 to 2.708 
                 
                 
                   Propanoic acid, 2-oxo-, methyl ester 
                 
                 
                   C 
                   4 
                   H 
                   6 
                   O 
                   3 
                 
               
               
                 
                   24 
                 
                 
                   4.746 to 4.773 
                 
                 
                   Benzene, (2-methyl-1-propenyl)- 
                 
                 
                   C 
                   10 
                   H 
                   12 
                 
               
               
                 
                   25 
                 
                 
                   5.933 to 5.979 
                 
                 
                   Naphthalene, 1,2-dihydro-1,1,6-trimethyl 
                 
                 
                   C 
                   13 
                   H 
                   16 
                 
               
               
                 
                   26 
                 
                 
                   6.493 to 6.520 
                 
                 
                   Ethaneperoxoic acid, 1-cyano-1-(2-methyl 
                 
                 
                   C 
                   12 
                   H 
                   13 
                   NO 
                   3 
                 
               
               
                 
                   27 
                 
                 
                   6.529 to 6.570 
                 
                 
                   1H-Indole, 2,5-dimethyl- 
                 
                 
                   C 
                   10 
                   H 
                   11 
                   N 
                 
               
               
                 
                   28 
                 
                 
                   6.857 to 6.884 
                 
                 
                   3-Hexadecene, (Z)- 
                 
                 
                   C 
                   16 
                   H 
                   32 
                 
               
               
                   
                   
                 
                   7-Hexadecene, (Z)- 
                 
                 
                   C 
                   16 
                   H 
                   32 
                 
               
               
                 
                   29 
                 
                 
                   7.207-7.230 
                 
                 
                   3-Heptadecene, (Z)- 
                 
                 
                   C 
                   17 
                   H 
                   34 
                 
               
               
                   
               
             
          
         
       
     
         [0043]    Table 12, shown below, lists compounds identified in the GC/MS chromatogram of the TGA effluent from an algae and algae+zeolite samples treated in 90 ml/min of N 2 , sampled at 460° C. Entries in italics (Peaks 30-44) describe compounds that did not appear at 390° C. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Peak 
                 RT (min) 
                 Compounds 
                 Formula 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 4.419 to 4.519 
                 Phenol, 4-methyl- 
                 C 7 H 8 O 
               
               
                 5 
                 5.623 to 5.664 
                 Indole 
                 C 8 H 7 N 
               
               
                 6 
                 6.064 to 6.105 
                 1H-Indole, 4-methyl- 
                 C 9 H 9 N 
               
               
                 10 
                 7.253 to 7.275 
                 3-Heptadecene, (Z)- 
                 C17H34 
               
               
                 11 
                 7.279 to 7.306 
                 Dodecane 
                 C 12 H 26   
               
               
                 12 
                 7.816 to 7.838 
                 Phytol 
                 C 20 H 40 O 
               
               
                 14 
                 7.956 to 7.988 
                 3,7,11,15-Tetramethyl-2- 
                 C 20 H 40 O 
               
               
                   
                   
                 hexadecen-1-ol 
               
               
                 18 
                 7.606 to 7.652 
                 1-Octadecene 
                 C 18 H 36   
               
               
                 19 
                 7.652 to 7.697 
                 Dodecane 
                 C 12 H 26   
               
               
                 22 
                 2.499 to 2.581 
                 Toluene 
                 C 7 H 8   
               
               
                 
                   30 
                 
                 
                   1.908 to 1.999 
                 
                 
                   Benzene 
                 
                 
                   C 
                   6 
                   H 
                   6 
                 
               
               
                 
                   31 
                 
                 
                   3.141 to 3.181 
                 
                 
                   Ethylbenzene 
                 
                 
                   C 
                   8 
                   H 
                   10 
                 
               
               
                 
                   32 
                 
                 
                   3.186 to 3.241 
                 
                 
                   p-Xylene 
                 
                 
                   C 
                   8 
                   H 
                   10 
                 
               
               
                 
                   33 
                 
                 
                   3.341 to 3.400 
                 
                 
                   Styrene 
                 
                 
                   C 
                   8 
                   H 
                   8 
                 
               
               
                   
                   
                 
                   Xylene 
                 
                 
                   C 
                   8 
                   H 
                   10 
                 
               
               
                 
                   34 
                 
                 
                   3.796 to 3.832 
                 
                 
                   Benzene, 1-ethyl-2-methyl- 
                 
                 
                   C 
                   9 
                   H 
                   12 
                 
               
               
                 
                   35 
                 
                 
                   3.987 to 4.023 
                 
                 
                   Benzene, 1,3,5-trimethyl- 
                 
                 
                   C 
                   9 
                   H 
                   12 
                 
               
               
                 
                   36 
                 
                 
                   4.319 to 4.355 
                 
                 
                   Benzene, 1-propynyl- 
                 
                 
                   C 
                   9 
                   H 
                   8 
                 
               
               
                 
                   37 
                 
                 
                   4.787 to 4.887 
                 
                 
                   Benzyl nitrile 
                 
                 
                   C 
                   8 
                   H 
                   7 
                   N 
                 
               
               
                 
                   38 
                 
                 
                   4.901 to 4.937 
                 
                 
                   Benzene, (1-methyl-2- 
                 
                 
                   C 
                   10 
                   H 
                   10 
                 
               
               
                   
                   
                 
                   cyclopropen-1-yl)- 
                 
               
               
                 
                   39 
                 
                 
                   4.937 to 4.969 
                 
                 
                   2-Methylindene 
                 
                 
                   C 
                   10 
                   H 
                   10 
                 
               
               
                 
                   40 
                 
                 
                   5.078 to 5.110 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   41 
                 
                 
                   5.110 to 5.160 
                 
                 
                   Naphthalene 
                 
                 
                   C 
                   10 
                   H 
                   8 
                 
               
               
                 
                   42 
                 
                 
                   5.656 to 5.711 
                 
                 
                   Naphthalene, 2-methyl- 
                 
                 
                   C 
                   11 
                   H 
                   10 
                 
               
               
                 
                   43 
                 
                 
                   6.311 to 6.343 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                 
                   44 
                 
                 
                   6.470 to 6.493 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                   
               
             
          
         
       
     
         [0044]    Table 13, shown below, lists compounds identified in the GC/MS chromatogram of the TGA effluent from an algal biomass and algal biomass+zeolite samples treated in 90 ml/min of N 2 , sampled at 350° C. Entries in italics (Peaks 46-51) described compounds that did not appear at 460° C. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Peak 
                 RT (min) 
                 Compounds 
                 Formula 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 4.419 to 4.519 
                 Phenol, 4-methyl- 
                 C 7 H 8 O 
               
               
                 2 
                 4.664 to 4.746 
                 2,5-Pyrrolidinedione 
                 C 4 H 5 NO 2   
               
               
                 3 
                 4.841 to 4.895 
                 Phenol, 2,4-dimethyl- 
                 C 8 H 10 O 
               
               
                 4 
                 4.900 to 4.973 
                 Phenol, 4-ethyl- 
                 C 8 H 10 O 
               
               
                 5 
                 5.623 to 5.664 
                 Indole 
                 C 8 H 7 N 
               
               
                 6 
                 6.064 to 6.105 
                 1H-Indole, 4-methyl- 
                 C 9 H 9 N 
               
               
                 10 
                 7.253 to 7.275 
                 3-Heptadecene, (Z)- 
                 C 17 H 34   
               
               
                 11 
                 7.279 to 7.306 
                 Dodecane 
                 C 12 H 26   
               
               
                 12 
                 7.816 to 7.838 
                 Phytol 
                 C 20 H 40 O 
               
               
                 13 
                 7.392 to 7.433 
                 1-Heptene, 2-isohexyl-6-methyl- 
                 C 14 H 28   
               
               
                 14 
                 7.956 to 7.988 
                 3,7,11,15-Tetramethyl-2-hexadecen-1-ol 
                 C 20 H 40 O 
               
               
                 41 
                 5.110 to 5.160 
                 Naphthalene 
                 C 10 H 8   
               
               
                 42 
                 5.656 to 5.711 
                 Naphthalene, 2-methyl- 
                 C 11 H 10   
               
               
                 45 
                 3.852 to 3.984 
                 Phenol 
                 C 6 H 6 O 
               
               
                 
                   46 
                 
                 
                   5.184 to 5.239 
                 
                 
                   1,4:3,6-Dianhydro-.alpha.-d-glucopyranos 
                 
                 
                   C 
                   6 
                   H 
                   8 
                   O 
                   4 
                 
               
               
                   
                   
                 
                   Benzofuran, 2,3-dihydro- 
                 
                 
                   C 
                   8 
                   H 
                   8 
                   O 
                 
               
               
                 
                   47 
                 
                 
                   5.339 to 5.398 
                 
                 
                   Benzenepropanenitrile 
                 
                 
                   C 
                   9 
                   H 
                   9 
                   N 
                 
               
               
                 
                   48 
                 
                 
                   6.126 to 6.158 
                 
                 
                   Amobarbital 
                 
                 
                   C 
                   11 
                   H 
                   18 
                   N 
                   2 
                   O 
                   3 
                 
               
               
                 
                   49 
                 
                 
                   6.176 to 6.212 
                 
                 
                   Pentobarbital 
                 
                 
                   C 
                   11 
                   H 
                   18 
                   N 
                   2 
                   O 
                   3 
                 
               
               
                 
                   50 
                 
                 
                   6.444 to 6.467 
                 
                 
                   1-Pentadecene 
                 
                 
                   C 
                   15 
                   H 
                   30 
                 
               
               
                 
                   51 
                 
                 
                   6.472 to 6.499 
                 
                 
                   Dodecane 
                 
                 
                   C 
                   12 
                   H 
                   26 
                 
               
               
                   
               
             
          
         
       
     
       Example 3 
       [0045]    A preparatory scale reactor constructed from a vertical alumina tube (7 cm OD) placed in the center of an electrically heated tube furnace was loaded with approximately 200 g of algal biomass and then connected to a gas cylinder. The gas cylinder permitted the interior of the vertical alumina tube to be swept with carbon dioxide that had bubbled at ambient temperature through an aqueous solution of 5% acetic acid and then in to the reactor tube at a flow rate of 0.2 standard L/min. The effluent from the reactor was directed into a glass receiver whose outside walls were cooled in an ice bath. The temperature of the reactor tube was ramped to 400° C., as shown in  FIG. 8 , and maintained at that temperature for 100 minutes, with CO 2  flowing at 45 ml/min. Approximately 100 ml of oily/waxy material was collected, from which was estimated a mass yield of 27 wt % in the oil fraction. During the heating, the nature of the effluent from the heated tube changed as indicated in Table 14. 
         [0046]    Table 14, shown below, shows changes in the character of the effluent from the preparatory scale reactor as the reaction temperature increases. 
         [0000]    
       
         
               
               
             
           
               
                   
               
               
                 Marker shown 
                   
               
               
                 in FIG. 8 
                 Character of the reactor effluent stream 
               
               
                   
               
             
             
               
                 802 
                 Smoke starts to appear 
               
               
                 804 
                 Smoke stops evolving 
               
               
                 806 
                 Clear liquid commences to collect in the chilled receiver 
               
               
                   
                 vessel. 
               
               
                 808 
                 White smoke appears in the receiver and flows out of the 
               
               
                   
                 receiver 
               
               
                 810 
                 Yellow smoke starts to fill the receiver and a yellow wax 
               
               
                   
                 collects on the sides of the receiver 
               
               
                 812 
                 An orange liquid starts to collect in the receiver as a 
               
               
                   
                 dense vapor 
               
               
                 814 
                 A thick, dark brown tar collects in the rceiver 
               
               
                   
               
             
          
         
       
     
         [0047]    Analysis of the initial algal biomass showed a lipid content of 3.5%. Subsequently, the enthalpy of combustion of the oil/wax was measured in a bomb calorimeter and found to be 36 MJ/kg, with a sulfur content of 0.22%. 
         [0048]    There are many advantages to the method of the present invention. This invention is directed at obtaining feed stocks from which to prepare liquid fuels from a renewable source, such as algal biomass that grows rapidly, with little impact on available water or food resources. 
         [0049]    The different advantageous embodiments provide a process that converts biomass, consisting substantially of whole, dry algae cells, into an oily material that exhibits a heating value approximating that of petroleum, along with a solid carbonaceous char, a hydrocarbon-laden gas stream, and an aqueous stream that contains polar organic compounds. 
         [0050]    In an advantageous embodiment, the algal biomass can be processed into the feedstock with a net decrease in carbon dioxide emissions, for example by using carbon dioxide and heat from an existing process that would otherwise be wasted. The process of the present invention converts a broad range of microalgae and the co-harvested micro-organisms, referred to as algal biomass, into three products: a hydrocarbon-laden gas, a carbonaceous char, a new oily material that exhibits many of the characteristics of crude petroleum, and an aqueous stream that dissolves polar compounds. The process produces significant quantities of oily product from algal biomass that does not contain high concentrations of lipids. Therefore, the process can be applied even to algal biomass that has not been selected or nurtured to generate lipids. 
         [0051]    The thermolysis produces a range of products that commence to evolve at unexpectedly low temperatures—as low as 50° C., i.e., hundreds of degrees lower than the temperatures at which cellulosic biomass must be heated to produce pyrolysis oils. The temperature range of the thermolysis of the algal biomass is low enough that the process can be carried out using waste heat generated by other industrial processes, for example cement manufacturing. The low temperature processing confers an economic advantage and offers a possible route to so-called carbon credits for the partner industry. Moreover, the oily material derived from the algae has an unexpectedly high enthalpy of combustion—around 36 MJ/kg, which approaches the heating value of petroleum (ca.  44  MJ/kg) and is about twice as large as the heating value of pyrolysis oils derived from cellulosic biomass (ca.  20  MJ/kg). 
         [0052]    In addition, the algal biomass-derived oily material can constitute more than 15 wt % of the original, ash-free, dry weight of the algae, even for starting material that contains less than 5 wt % lipids. Finally, the composition of the algal biomass-derived oily material suggests that it would be amenable to subsequent processing along side conventional petroleum-derived gas oil, unlike pyrolysis oils derived from cellulosic biomass. For example, the elemental analyses performed, and the heating value mentioned above, provide an inference that the oily material from the described thermolysis of algal biomass presents fewer oxygen-containing components than does cellulose-derived pyrolysis oil, along with a concentration of sulfur that is low enough to be considered for blending into low sulfur feed stocks, yet high enough to maintain the activity of conventional hydroprocessing catalysts. 
         [0053]    These conventional hydroprocessing catalysts can be used in conventional refinery processes to hydro-upgrade the oily material, for example to remove nitrogen, metals, and oxygen heteroatoms.

Technology Classification (CPC): 8