An integrated strategy for corncob pretreatment and coproduction of furfural and monosaccharides based on p-toluenesulfonic acid and a deep eutectic solvent system

Abstract

High-value valorization of cellulose and hemicellulose fractions in lignocellulosic biomass is crucial for a feasible biomass refinery scheme. In this study, an integrated strategy was developed for pretreatment of corncob and coproduction of furfural and high-concentration fermentable sugars. The hemicellulose fraction in raw corncob was selectively extracted to produce a xylose-rich hydrolysate via pretreatment with dilute p-toluenesulfonic acid (p-TsOH) under optimal reaction conditions (0.5% p-TsOH, 160 °C, and 30 min). Thereafter, the xylose hydrolysate was subjected to catalytic conversion in a DES (TEBAC : LA = 1 : 4) system at 190 °C for 10 min. Notably, 78.6% furfural yield was achieved, and the corresponding xylose conversion was close to 100.0%. In addition, the pretreated corncob residue exhibited excellent enzymatic digestibility as the yields of reducing sugar and glucose were 90.7% and 97.0%, respectively, at a high solid loading of 12%. This proposed approach represents an integrated strategy for coproduction of multiple products from agriculture residues.