In this work, we investigated the fractionation of raw biomass based on a “lignin-first” biorefinery strategy that enables the fractionation of corn stover into a stable lignin oil and a cellulose-rich pulp. Lignin fraction was completely disassembled into monomers with a yield of 25.1 wt% in methanol with a H₂WO₄ catalyst at 200 °C for 6 h. Higher temperature (≥220 °C) and longer reaction time (≥6 h) were in favor of higher delignification and hemicellulose removal, but led to lower cellulose retention and lignin monomer yield. Particle size of corn stover has minor impact on the delignification but significant for hemicellulose removal. A two-step mechanism is proposed for the fractionation of corn stover, in which ether and ester bonds between lignin and hemicellulose cleave to form oligomers through methanol solvolysis first, while the depolymerization of lignin oligomers to methyl hydroxycinnamates, e.g. methyl p-coumarate and methyl ferulate, as the major products happens in the catalytic steps.

在这项工作中，我们基于“木质素优先”生物精炼策略研究了原始生物质的分馏，该策略能够将玉米秸秆分馏成稳定的木质素油和富含纤维素的果肉。在具有H ₂ WO _4的甲醇中，木质素级分完全分解成单体，产率为25.1 wt％催化剂在200°C下放置6小时。较高的温度（≥220°C）和较长的反应时间（≥6h）有利于较高的脱木质素和半纤维素去除，但导致较低的纤维素保留和木质素单体收率。玉米秸秆的粒径对脱木素作用不大，但对半纤维素的去除作用很大。提出了玉米秸秆分级分离的两步机理，其中木质素和半纤维素之间的醚键和酯键先通过甲醇溶剂分解裂解形成低聚物，而木质素低聚物解聚为羟基肉桂酸甲酯，例如对-香豆酸甲酯和阿魏酸，因为主要产物发生在催化步骤中。