Removal of Acidic Impurities from Corn Stover Hydrolysate Liquor by Resin Wafer Based Electrodeionization

Abstract

Dilute acid (sulfuric acid) pretreatment of lignocellulosic biomass releases monomeric xylose, xylo-oligomers, and acetic acid by degradation of hemicellulose. Acids inhibit both the enzymatic hydrolysis of cellulose to monomeric sugars and downstream fermentation of sugars to biofuels. Removal of acetic acid and sulfuric acid, as well as the nonionic toxic impurities, from the hydrolysate liquor prior to enzymatic hydrolysis may improve biofuel yields. Development of an efficient acid separation technique is essential for enhanced process performance and cost-effective biofuel production. We evaluated the use of an electrically driven membrane separation technique, resin wafer based electrodeionization (RW-EDI), for the removal of ionic impurities (acetic acid and sulfuric acid) from corn stover hydrolysate liquor. RW-EDI provides the capability to control solution pH in situ by voltage adjustment. In situ pH control enables pKa-selective recovery of acids (or bases). The results indicate that RW-EDI is ...