Abstract:

The conversion of lignocellulose into biofuels or chemical products requires pretreatment, enzymatic hydrolysis and fermentation processes. Due to its complex chemical structure, pretreatment is usually performed before enzymolysis to destroy its dense structure and improve the accessibility of the enzyme and cellulose. Deep eutectic solvent (DES) is a new type of “green” solvent, which can effectively remove lignin from lignocellulose, while retaining most of the cellulose. In addition, DES has the characteristics of simple preparation, low cost, adjustable properties, biodegradable and recyclable, which shows great industrial application potential in the production of fuel and chemicals in the lignocellulose biorefinery. In this review, the types and physical and chemical properties of deep eutectic solvent were introduced. The effects of DES pretreatment on biomass components were summarized. Furthermore, the pretreatment effect factors such as the type of substrate and DES, the viscosity of DES, temperature, biological load, microwave and ultrasonic aids, two-stage pretreatment measure and so on were discussed. Then, the compatibility between DES and biology was also analyzed. At last, for the problems and disadvantages of DES, the opportunities and challenges of rational design and recycling of DES were put forward to realize low-cost pretreatment and high -value utilization of lignocellulose.

Key words: lignocellulose, deep eutectic solvent, removal of lignin, cellulose crystallinity, pretreatment

摘要：

木质纤维素生物质转化为生物燃料或化工产品一般需经历预处理、酶解及发酵过程，因其复杂的化学结构，在酶解前通常进行预处理以破坏其致密结构，提高酶与纤维素的可及性。深度共熔溶剂（DES）是一类新型的“绿色”溶剂，具有制备简单、价格低廉、性质可调、可生物降解、可循环使用等优势，可有效去除木质素组分，同时保留大部分纤维素，在生物质预处理方面具有巨大的潜力。本文介绍了DES的构成、分类及理化性质，总结了DES预处理对生物质组分的影响，并对预处理效果的影响因素如底物和DES的类型、溶剂黏度、温度、生物载量、微波及超声波辅助工艺和两阶段处理工艺等方面进行分析，探讨了DES和生物的相容性，最后针对DES存在的问题及缺点，提出了理性设计和大规模利用DES的机遇与挑战，本文可为实现生物质的低成本预处理和高价值利用提供新的思路。

关键词: 木质纤维素生物质, 深度共熔溶剂, 木质素去除, 纤维素结晶度, 预处理