Pretreatment of Corn Stover by Acidic Electrolyzed Water for Enhancing Hemicellulose Degradation

Acidic electrolyzed water (AEW) pretreatment method was proposed and tested for deconstruction of recalcitrant corn stover. Results indicated low pH AEW significantly increased the hemicellulose degradation at temperature between 160 degrees C and 200 degrees C. It is an efficient way to remove hemicellulose and to improve the enzymatic digestibility of corn stover. Optimization of pretreatment condition was carried out through the study of the four main factors: pH value, liquid-to-solid ratio, temperature and reaction time. The optimum condition was at 180 degrees C for 10 min in the liquid-to-solid ratio 30:1 with pH 2.0 AEW. As this condition, about 92.4% of hemicellulose was removed and the recovery of monomeric and oligomeric xylose in liquid fraction reached 86.7%. Using 30 filter paper units of cellulose per gram cellulose, a digestibility of 82% was achieved by this method, which was higher than obtained from H2SO4 or HCl pretreatment at the same pH value under the same condition.