Processing biomass

Abstract

Biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) is processed to produce useful products, such as fuels. For example, systems can use feedstock materials, such as cellulosic and/or lignocellulosic materials, to proceed ethanol and/or butanol, e.g., by fermentation.

1 - 18 . (canceled) 
     
     
         19 . A mixture comprising:
 an aqueous solution comprising a low molecular weight sugar,   a fermenting microorganism, and   a lignocellulosic material that has been irradiated with at least 10 Mrad of electron beam radiation, the lignocellulosic material having a BET surface area greater than 0.1 m 2 /g and a porosity greater than 50%.   
     
     
         20 . The mixture of  claim 19 , wherein the low molecular weight sugar comprises xylose. 
     
     
         21 . The mixture of  claim 19 , wherein the lignocellulosic material has a porosity greater than 70 percent. 
     
     
         22 . The mixture of  claim 19 , wherein the lignocellulosic material has a BET surface area greater than 0.25 m 2 /g. 
     
     
         23 . The mixture of  claim 19 , wherein the lignocellulosic material has a BET surface area greater than 1.0 m 2 /g. 
     
     
         24 . The mixture of  claim 19 , wherein the lignocellulosic material is selected from the group consisting of wood, particle board, sawdust, agricultural waste, silage, grasses, rice hulls, bagasse, jute, hemp, flax, bamboo, sisal, abaca, straw, corn cobs, corn stover, switchgrass, alfalfa, hay, coconut hair, seaweed, and mixtures thereof. 
     
     
         25 . The mixture of  claim 24 , wherein the lignocellulosic material comprises corn cobs and/or corn stover. 
     
     
         26 . The mixture of  claim 19 , wherein the lignocellulosic material includes a plurality of saccharide units arranged in a molecular chain, wherein from about 1 out of every 2 to about 1 out of every 250 saccharide units includes a carboxylic acid group, or an ester or salt thereof.