Processing biomass

Abstract

Biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) is processed to produce useful intermediates and products, such as energy, fuels, foods or materials. For example, systems are described that can use feedstock materials, such as cellulosic and/or lignocellulosic materials, to produce an intermediate or product, e.g., by fermentation.

1 . A method of processing biomass, the method comprising:
 pretreating biomass with electron beam irradiation;   saccharifying the pretreated biomass in an aqueous medium to produce sugars;   fermenting the sugars to produce an aqueous solution comprising a fermentation product; and   distilling the aqueous solution to concentrate the fermentation product;   wherein the aqueous medium comprises water removed during the distilling step.   
     
     
         2 . The method of  claim 1 , wherein the fermentation product comprises an alcohol. 
     
     
         3 . The method of  claim 1 , wherein the biomass comprises a cellulosic or lignocellulosic material. 
     
     
         4 . The method of  claim 1 , wherein fermentation is conducted in an aqueous fermentation medium and a portion of the water removed during the distilling step is used in the fermentation medium. 
     
     
         5 . The method of  claim 1 , wherein a portion of the water removed during the distilling step is sent to a waste water treatment process. 
     
     
         6 . The method of  claim 3 , wherein the biomass comprises a lignocellulosic material and the method further comprises recovering lignin after the saccharification and/or fermentation step. 
     
     
         7 . The method of  claim 6 , wherein the method further comprises utilizing the lignin to generate energy and utilizing the energy in one or more of the method steps.