Low-pressure flow-through fractionation of Quercus mongolica for highly selective cellulose and reactive lignin recovery: a lignocellulosic biorefinery approach

Abstract

The utilization of lignocellulosic biomass (LCB) is the subject of intensive research and development due to the growing demand for sustainable, non-food-competitive alternatives to fossil fuels. Flow-through fractionation systems have shown potential for fully utilizing LCB, but the high-pressure requirements hinder their industrial implementation. This study investigated a low-pressure flow-through fractionation system for Quercus mongolica, designed for continuous-scale biorefinery operations. Results showed a 48.8% fractionation yield and 87.9% delignification, with a significant increase in enzymatic hydrolysis efficiency. Notably, the fractionated lignin exhibited substantially greater preservation of β-O-4 linkages than commercial Kraft lignin. A strategy to reduce solvent use was proposed based on the reactor temperature profile to further optimize the process. These results confirm the viability of this system as a lignocellulosic biorefinery pretreatment, enabling selective lignin separation and providing a scalable, continuous pathway for the complete valorization of LCB.