深度共熔溶剂预处理对木质纤维素生物质作用机制的研究进展

深度共熔溶剂（DES）是一类可再生、对环境友好的新型混合溶剂体系,用于预处理木质纤维素生物质可有效去除半纤维素及木质素组分,并可保留较为完整的纤维素组分。本文综述DES预处理对木质纤维素生物质作用机制的研究进展。通常情况下,大部分DES对纤维素溶解性较差,但可改变纤维素的外貌形态;一些酸性DES对半纤维素具有良好的溶解性能;碱性DES及部分酸性DES对木质素具有优异的溶解性能,在预处理过程中木质素的结构发生解聚或缩合反应;三元DES体系在木质素提取、分离及回收等方面均展现出更多优势。DES对木质素的去除效果及作用机制受DES的构成、摩尔比、生物质类型及预处理条件如温度等多种因素的影响。理解DES在木质纤维素生物质预处理中结构与功能的关系,研究DES在预处理过程中对木质素及半纤维素去除的作用机制,有助于合理设计新的DES体系并为实现生物质三大组分的高效分离及转化奠定理论基础与技术指导。

Research Progress on Mechanism of Deep Eutectic Solvent Pretreatment of Lignocellulosic Biomass

Deep eutectic solvent (DES) is a new type of renewable and environmentally friendly mixed solvent system, which can effectively remove hemicellulose and lignin components and can retain relatively complete cellulose component during pretreatment. The mechanism of DES pretreatment on lignocellulosic biomass was reviewed in the paper. Most DES has poor solubility to cellulose, while can alter the appearance of cellulose. Some acidic DES has good solubility for hemicellulose; alkaline DES and some acidic DES have excellent solubility for lignin. During pretreatment, the structure of lignin may undergo depolymerization or condensation reactions. The ternary DES systems showed more advantages in lignin extraction, separation and recovery. The removal effect and mechanism of DES on lignin were affected by many factors such as DES composition, molar ratio, biomass type and pretreatment conditions such as temperature. Understanding the relationship between the structure and function of DES in the pretreatment of lignocellulosic biomass, and studying the mechanism of DES removal of lignin and hemicellulose would contribute to rationally design novel DES system and lay the theoretical foundation and technical guidance for the efficient separation and transformation of the three major components.