Systems and processes for producing bio-fuels from lignocellulosic materials

Abstract

A selective pyrolysis process for the production of bio-oils enriched in pyrolytic sugars and phenols and conversion of these compounds into second generation bio-fuels is disclosed herein. One embodiment of the process comprises pre-treating a biomass with superheated steam or gases in a selected range of temperatures, followed by fast pyrolysis using synthesis gas as a carrier, and a two-step condensation operation. The aqueous phase from the second condenser can then be reformed to produce hydrogen or can be gasified together with the charcoal to produce syngas.

1 . A process for processing a biomass, comprising:
 treating a biomass by heating the biomass at a first temperature;   thermally converting the treated biomass into a product having an oil portion and an aqueous portion via pyrolysis at a second temperature, the first temperature being lower than the second temperature; and   selecting the first temperature based on a correlation between the first temperature and a desired anhydrosugar content in the oil portion of the product.   
     
     
         2 . The process of  claim 1  wherein thermally converting includes using a synthesis gas as a carrier gas in a pyrolysis reactor. 
     
     
         3 . The process of  claim 1 , further comprising producing an oil phase in a first condenser and producing an aqueous phase in a second condenser, the first and second condensers are in a series. 
     
     
         4 . The process of  claim 1 , further comprising separating sugars from phenols in the oil phase via liquid-liquid extraction with a solvent. 
     
     
         5 . The process of  claim 1 , further comprising converting at least a fraction of sugars in the oil phase to ethanol. 
     
     
         6 . The process of  claim 1  wherein the oil phase contains sugars, and wherein the process further comprising converting at least a fraction of the sugars into lipids. 
     
     
         7 . The process of  claim 1  wherein treating a biomass includes treating a biomass by heating the biomass at a first temperature of about 200° C. to about 300° C. 
     
     
         8 . The process of  claim 1  wherein treating a biomass includes treating a biomass by heating the biomass at a first temperature of about 200° C. to about 300° C. for a period of time of about 3 minutes to about 10 hours. 
     
     
         9 . The process of  claim 1  wherein treating a biomass includes treating a biomass by heating the biomass at a first temperature of about 200° C. to about 300° C. for a period of time of about 1 minutes to about 10 hours, and wherein the first temperature is inversely related to the period of time. 
     
     
         10 . A process for processing a biomass, comprising:
 providing a biomass having a first crystallinity;   modifying a structure of cellulose in the biomass to have a second crystallinity higher than the first crystallinity; and   thermally converting the biomass with the increased crystallinity into a pyrolysis product containing anhydrosugar via pyrolysis.   
     
     
         11 . The process of  claim 10  wherein:
 the first crystallinity of the biomass corresponds to a first anhydrosugar content of the pyrolysis product; and   modifying the structure of cellulose includes modifying the structure of cellulose to have a second crystallinity and/or a degree of polymerization corresponding to a second anhydrosugar content higher than the first anhydrosugar content of the pyrolysis product.   
     
     
         12 . The process of  claim 10  wherein:
 the first crystallinity of the biomass corresponds to an anhydrosugar content of the pyrolysis product; and   modifying the structure of cellulose includes enhancing the anhydrosugar content of the pyrolysis product.   
     
     
         13 . The process of  claim 10  wherein modifying the structure of cellulose includes heating the biomass at a first temperature of about 200° C. to about 300° C. 
     
     
         14 . The process of  claim 10  wherein modifying the structure of cellulose includes heating the biomass at a first temperature of about 200° C. to about 300° C. for a period of time of about 1 minute to about 10 hours. 
     
     
         15 . The process of  claim 10  wherein modifying the structure of cellulose includes heating the biomass at a first temperature of about 200° C. to about 300° C. for a period of time of about 3 minutes to about 10 hours, and wherein the first temperature is inversely related to the period of time. 
     
     
         16 . A process for processing a biomass, comprising:
 heating a biomass at a first temperature;   thermally converting the heated biomass into a product via pyrolysis at a second temperature, the first temperature being lower than the second temperature; and   wherein the first temperature is selected to enhance an anhydrosugar content in the product from thermally converting the heated biomass.   
     
     
         17 . The process of  claim 16  wherein the first temperature is selected to be about 200° C. to about 300° C. 
     
     
         18 . The process of  claim 16  wherein the first temperature is selected to be about 200° C. to about 300° C., and wherein a heating period of time is also selected to enhance the anhydrosugar content in the product from thermally converting the heated biomass. 
     
     
         19 . The process of  claim 16  wherein the first temperature is selected to be about 200° C. to about 300° C., and wherein a heating period of time is also selected to enhance the anhydrosugar content in the product from thermally converting the heated biomass, the heating period of time being about 1 minute to about 10 hours. 
     
     
         20 . The process of  claim 16  wherein the first temperature is selected to be about 200° C. to about 300° C., and wherein a heating period of time is also selected to enhance the anhydrosugar content in the product from thermally converting the heated biomass, the heating period of time being about 1 minutes to about 10 hours and inversely related to the first temperature.