Method for the production of alcohol from a pretreated lignocellulosic feedstock

摘要

A process for the production of glucose from a pretreated lignocellulosic feedstock is provided. The method comprises enzymatically hydrolyzing the pretreated lignocellulosic feedstock with cellulase enzymes to produce a hydrolyzate slurry comprising glucose and unhydrolyzed cellulose and fermenting the hydrolyzate slurry in a fermentation reaction to produce a fermentation broth comprising alcohol. A process stream is obtained comprising unhydrolyzed cellulose, which is then subjected to a denaturing step, preferably comprising exposing the unhydrolyzed cellulose to elevated temperatures, thereby producing a heat-treated stream comprising the unhydrolyzed cellulose. The heat-treated stream comprising unhydrolyzed cellulose is then further hydrolyzed with cellulase enzymes to hydrolyze the cellulose to glucose.

主权项

1. A process for increasing the hydrolysis of cellulose in the production of alcohol from a lignocellulosic feedstock, comprising the steps of:
(i) pretreating a lignocellulosic feedstock under conditions to produce a composition comprising a pretreated lignocellulosic feedstock having a disrupted fiber structure and increased accessibility of the feedstock to being hydrolyzed; (ii) enzymatically hydrolyzing the pretreated lignocellulosic feedstock with cellulase enzymes to produce a hydrolyzate slurry comprising glucose and unhydrolyzed cellulose; (iii) fermenting said hydrolyzate slurry to produce a fermentation broth comprising alcohol and unhydrolyzed cellulose; (iv) separating the alcohol from the fermentation broth by distillation to obtain a stream comprising concentrated alcohol and a still bottoms stream comprising the unhydrolyzed cellulose and the cellulase enzymes, said distillation resulting in heat treatment of the unhydrolyzed cellulose, which heat treatment is conducted at a temperature between 70 and 200° C. so as to denature the cellulase enzymes; and (v) further hydrolyzing at least a portion of the still bottoms stream with cellulase enzymes to convert at least a portion of the unhydrolyzed cellulose present in said still bottoms stream to glucose, thereby increasing cellulose hydrolysis.