Freeze-thaw and sulfuric acid pretreatment of wheat straw for fermentable sugar release

摘要

Hydrolysis of cellulose and hemicelluloses of lignocellulosic materials to obtain reducing sugar can be used to produce ethanol by microbial fermentation. Effective pretreatment is necessary for optimal hydrolysis. This study investigated the positive effect of freeze-thaw treatment on low temperature sulfuric acid pretreatment for convert wheat straw to reducing sugar. Freeze-thaw treatment conditions were optimized: at -20°C for 12h, and at room temperature (25°C) for 1h, followed. After twice repeating of freeze-thaw treatment and pretreatment with 2wt% sulfuric acid for 16h at 80°C and enzymatic digestibility with 20U/g of cellulase loading, 67% cellulose and hemicelluloses were converted to glucose and xylose. The yield of furfural was decreased by 65% during sulfuric acid pretreatment. The time of acid hydrolysis was shortened by 20%.