Fractionation of High-Yield Noncondensed Lignin and Glucan Oligomers from Lignocellulose in a Novel Biphasic System

作者：Xinyi Xie, Lifeng Li, Xiangyu Wang, Qiyu Liu, Xinping Ouyang, Xueqing Qiu · 发表于：Journal of Agricultural and Food Chemistry · 年份：2025 · DOI：10.1021/acs.jafc.4c12533 · 被引用次数：19 · 研究领域：Lignin and Wood Chemistry、Catalysis for Biomass Conversion、Biofuel production and bioconversion

Effective fractionation of lignocellulose into hemicellulose, cellulose, and lignin is the precondition for full-component valorization. Generally, harsh reaction conditions are used to improve fractionation efficiency, which leads to severe lignin condensation and inhibits its value-added applications. To address this issue, a novel biphasic system consisting of molten salt hydrates (MSHs) and n-butanol was developed for birch fractionation. After the removal of hemicellulose in dilute acid, the solid residue composed of cellulose and lignin was carried out in biphasic system conversion. Cellulose was selectively converted into 73.3% yield of glucan oligomers and 16.8% glucose in the MSH phase, while lignin was in situ-extracted into the n -butanol phase with a high yield of 98.1%. Mechanism studies revealed that the in situ extraction together with C α –OH group modification by n-butanol synchronously protected lignin β-O-4 linkages from cleavage, resulting in a high β-O-4 content of 53.7%, indicating that 87.7% of β-O-4 linkages in birch has been preserved. After depolymerization, a promising monophenol yield of 22.4% was obtained, which was 81.5% of the theoretical maximum monophenol yield obtained from birch. This fractionation strategy can also be used in softwood and herbaceous, showing a splendid separation efficiency as well as a high yield of noncondensed lignin production.