Enhanced hemicellulose retention in lignocellulosic biomass fractionation with ethylene glycol-regulated deep...

Fractionation of lignocellulosic biomass into carbohydrates (cellulose, hemicellulose) and lignin is essential for advancing biorefinery processes. However, achieving high retention of hemicellulose during pretreatment remains a significant challenge. In this study, an ethylene glycol (EG)-regulated deep eutectic solvent (DES) strategy was employed for corncob fractionation. The addition of EG increased hemicellulose retention from 55.7% to 77.9%. Additionally, delignification and cellulose retention reached up to 88.8% and 88.1%, respectively. Density functional theory analysis indicated that strong hydrogen bonds between DES-EG and lignin are the primary driving force for delignification. Molecular dynamics simulations demonstrated that the incorporation of EG significantly weakens the interaction energies between solvent and hemicellulose. This protective effect preserves the structural integrity of glycosidic linkages and hydroxyl groups in hemicellulose. This work presents a sustainable solution to mitigate hemicellulose loss, offering a promising advancement for eco-friendly biomass pretreatment.