Method of hydrolyzing cellulose slurry using cellulase and flocculent (as amended)

Abstract

A process for the enzymatic hydrolysis of cellulose to produce a hydrolysis product from a pre-treated cellulosic feedstock is provided. The process comprises introducing an aqueous slurry of the pre-treated cellulosic feedstock at the bottom of a hydrolysis reactor. Axial dispersion in the reactor is limited by avoiding mixing and maintaining an average slurry flow velocity of about 0.1 to about 20 feet per hour, such that the undissolved solids flow upward at a rate slower than that of the liquid. Cellulase enzymes are added to the aqueous slurry before or during the step of introducing. An aqueous stream comprising hydrolysis product and unhydrolyzed solids is removed from the hydrolysis reactor. Also provided are enzyme compositions which comprise cellulase enzymes and flocculents for use in the process. In addition, a kit comprising cellulase enzymes and flocculent is provided.

1 - 68 . (canceled) 
     
     
         69 . A method of hydrolyzing cellulose to glucose, cellobiose, glucose oligomers, or a combination thereof, comprising hydrolyzing a slurry comprising cellulose using cellulase and at least one flocculent. 
     
     
         70 . The method according to  claim 69 , wherein the flocculent is a cationic polymer. 
     
     
         71 . The method according to  claim 69 , wherein said cellulase enzyme is obtained from a plant, fungal or microbial source. 
     
     
         72 . The method according to  claim 69 , wherein the cellulase enzymes are produced by  Aspergillus, Humicola, Trichoderma, Bacillus  or  Thermobifida.    
     
     
         73 . The method according to  claim 69 , wherein the at least one flocculent is mixed with the cellulase enzymes to form an enzyme composition before addition to the slurry. 
     
     
         74 . The method according to  claim 73 , wherein the enzyme composition is produced by obtaining cellulase enzymes from a plant, fungal or microbial source, and combining the cellulase enzymes with one or more than one flocculent to produce the enzyme composition. 
     
     
         75 . The method according to  claim 70 , wherein the cellulase enzymes are produced by  Aspergillus, Humicola, Trichoderma, Bacillus  or  Thermobifida.    
     
     
         76 . The method according to  claim 75 , wherein the at least one flocculent is mixed with the cellulase enzymes to form an enzyme composition before addition to the slurry.