Novel biphasic DES/GVL solvent for effective biomass fractionation and valorization

Abstract

Numerous deep eutectic solvents (DESs) have been studied for effective saccharification of cellulose by removing hemicellulose and/or lignin. However, the removed fractions, including lignin and hemicellulose, have not been sufficiently characterized. For a successful biorefinery strategy, valorization of these fractionated portions is as important as cellulose utilization. In this study, a novel biphasic solvent process using DES and γ-valerolactone (GVL) was investigated for efficient glucan saccharification, furfural production, and high-quality lignin recovery. This process dramatically enhanced the enzymatic saccharification of cellulose by significantly removing lignin (88.61%) and xylan (98.67%). Remarkably, the recovered lignin exhibited a well-preserved lignin structure, and the furfural output reached a satisfactory yield of 50.90%. The fractionation mechanism of the biphasic system was comprehensively investigated. This study emphasized that the biphasic DES/GVL system is an ideal solvent to maximize the use of biomass components with high enzymatic saccharification yield, furfural yield, and high-quality lignin as co-products.