Enzymatic hydrolysis of autohydrolyzed wheat straw followed by refining to produce fermentable sugars

Wheat straw was pretreated using an autohydrolysis process with different temperatures (160-200 degrees C) and times (10-20 min) in order to allow the recovery of hemicellulose in the filtrate and help open up the structure of the biomass for improved accessibility of enzymes during enzymatic hydrolysis. Autohydrolysis at 190 degrees C for 10 min provided the highest overall sugar (12.2/100 g raw wheat straw) in the autohydrolysis filtrate and recovered 62.3% of solid residue. Before enzymatic hydrolysis, the pulps obtained from each pretreatment condition were subjected to a refining post-treatment to improve enzyme accessibility. Enzymatic hydrolysis was performed for all the pretreated solids with and without refining post-treatment at the enzyme loadings of 4 and 10 FPU/g oven dry substrate for 96 h. A total of 30.4 g sugars can be recovered from 100 g wheat straw at 180 degrees C for 20 min with 4 FPU/g enzyme charge. (C) 2013 Elsevier Ltd. All rights reserved.