Processes utilizing pulp and paper mill equipment for enzymatic hydrolysis of cellulosic fibers to glucose

Abstract

A method for the production of alcohol and other bioproducts hemicelluloses extracted from biomass prior to thermal conversion of the biomass to energy. The process can be integrated with the host plant process to minimize the energy loss from extracting hemicelluloses. Also disclosed is a Stepwise enzymatic break down of cellulose fibers from a pulping operation which is performed with the redeployment of equipment and vessels contained within typical existing pulp and paper manufacturing mills. The preferred feedstock is highly delignified pulp from acid or alkaline pulping process or from bleaching stage.

1 - 24 . (canceled) 
     
     
         25 . A process that utilizes pulp and paper mill equipment to enzymatically hydrolyze cellulose to glucose, said process comprising:
 (a) providing a cellulose-containing pulp at a starting solids concentration from 3% to 12% by weight;   (b) providing an enzyme formulation comprising cellulase enzymes;   (c) mechanically mixing a first amount of said pulp with a first amount of said enzyme formulation, to promote enzyme contact with cellulose fibers in said pulp;   (d) hydrolyzing said cellulose fibers in a retention tank, while maintaining mixing, to produce a partially hydrolyzed pulp suspension, wherein from 25% to 50% of said pulp by weight is hydrolyzed;   (e) concentrating or diluting said partially hydrolyzed pulp suspension to a suspension solids concentration from 3% to 12% by weight;   (f) introducing a second amount of said enzyme formulation to said partially hydrolyzed pulp suspension, to maintain hydrolysis activity;   (g) introducing a second amount of said pulp to said partially hydrolyzed pulp suspension, to adjust said suspension solids concentration and to increase glucose production; and   (h) removing unhydrolyzed solids from said partially hydrolyzed pulp suspension, to produce a sugar solution comprising glucose,   wherein at least one of steps (c), (d), (e), (f), (g), or (h) utilizes pulp and paper mill equipment.   
     
     
         26 . The process of  claim 25 , wherein said process comprises utilizing a pulp and paper mill pulper to carry out step (c). 
     
     
         27 . The process of  claim 25 , wherein said retention tank in step (d) is selected from the group consisting of a pulp and paper high density storage tank, a pulp and paper low density storage tank, a pulp and paper machine stock chest, a pulp and paper bleach tower, a pulp and paper broke surge tank, and combinations thereof. 
     
     
         28 . The process of  claim 27 , wherein said retention tank in step (d) is a pulp and paper machine stock chest. 
     
     
         29 . The process of  claim 25 , said process comprising utilizing one or more of a pulp and paper side hill screen, a pulp and paper stock washer, a pulp and paper machine saveall filter, a pulp and paper fourdrinier wire section, and a pulp and paper machine press section for dewatering said partially hydrolyzed pulp suspension in step (e). 
     
     
         30 . The process of  claim 29 , said process comprising utilizing a pulp and paper machine saveall filter for dewatering said partially hydrolyzed pulp suspension in step (e). 
     
     
         31 . The process of  claim 25 , said process comprising utilizing one or more of a pulp and paper machine fourdrinier section, a pulp and paper stock washer, a pulp and paper screw press, and a pulp and paper machine press section, during step (h) to dewater said unhydrolyzed solids. 
     
     
         32 . The process of  claim 31 , said process comprising utilizing a pulp and paper machine fourdrinier section during step (h) to dewater said unhydrolyzed solids. 
     
     
         33 . The process of  claim 25 , wherein said enzyme formulation further comprises hemicellulase enzymes and wherein said enzyme formulation is less than 3% by weight of the total cellulose and hemicellulose content of said cellulose-containing pulp. 
     
     
         34 . The process of  claim 25 , said process further comprising introducing a third amount of said enzyme formulation to said partially hydrolyzed pulp suspension.