Sulfite pretreatment for biorefining biomass

Abstract

The present invention relates to a method using sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL). More specifically, it relates to a sulfite-based chemical process for pretreating biomass in solutions to reduce access barriers of enzymes to the lignocellulose, resulting in efficient conversion through enzymatic saccharification.

1 . A method for treating a cellulose-containing material comprising the steps of:
 (a) providing a material comprising cellulose; and   (b) treating the material in an aqueous solution comprising sulfite or bisulfite, wherein said treating is at a pH ranging from about 0 to about 10 at a temperature of about 130-250° C.   
     
     
         2 - 22 . (canceled) 
     
     
         23 . The method of  claim 1 , wherein the method further comprises a steam explosion step at the same time as step (b). 
     
     
         24 . The method of  claim 1 , wherein the method further comprises enzymatic hydrolysis of the material after step (b). 
     
     
         25 . The method of  claim 24 , wherein the enzymatic hydrolysis further comprises adding a surfactant. 
     
     
         26 . The method of  claim 25 , wherein the surfactant comprises PEG. 
     
     
         27 . The method of  claim 24 , where the method further comprises fermentation of glucose from cellulose into ethanol. 
     
     
         28 . The method of  claim 24 , wherein the method further comprises chemical conversion of cellulose. 
     
     
         29 . The method of  claim 28 , wherein chemical conversion produces a biofuel or biochemicals. 
     
     
         30 . The method of  claim 29 , wherein said biofuel is ethanol. 
     
     
         31 . A product comprising ethanol produced by the method in accordance with  claim 27 . 
     
     
         32 . The method of  claim 1 , wherein treating is performed for 0.1-120 min. 
     
     
         33 . The method of  claim 1 , wherein treating is performed for 0.5-30 min. 
     
     
         34 . A product comprising ethanol produced by the method in accordance with  claim 30 .