生物质热溶萃取技术能够在温和条件下同时实现生物质的深度脱氧和脱灰，是一项非常有应用前景的生物质预处理提质技术。然而，生物质的复杂组成和结构导致生物质热溶萃取转化过程十分复杂，其转化反应机理及动力学特性尚不清晰，制约了生物质热溶萃取技术的发展。基于此，本项目将生物质解耦成主要有机组分（纤维素、半纤维素和木质素）以及少量无机组分（主要为碱金属和碱土金属）。首先，揭示热溶萃取反应条件下纤维素、半纤维素和木质素热解聚反应机理及三组分交互作用机制。然后，获得碱金属和碱土金属对生物质热溶萃取过程的影响规律及其迁移转化规律。在上述研究基础上，建立生物质中三组分和碱金属和碱土金属与萃取产物收率、组成及理化特性的关联关系，揭示生物质复杂大分子在热溶萃取过程中的反应机理，建立包含三组分交互作用和碱金属和碱土金属影响规律的热溶萃取转化过程的动力学模型，最终形成萃取产物收率、理化特性和品质的预测及定向调控方法。

Degradative solvent extraction of biomass can achieve deep deoxygenation and deashing of biomass simultaneously under mild conditions, and it is a very promising pretreatment and upgrading technology for biomass. However, the complex composition and structure of biomass result in the conversion process of degradative solvent extraction of biomass rather complicated. The reaction mechanism and kinetics of degradative solvent extraction of biomass is still unclear, which restricts the development of biomass degradative solvent extraction technology. Therefore, this project decouples biomass into major organic components (cellulose, hemicellulose and lignin) and a small amount of inorganic components (mainly alkali and alkaline earth metal). Firstly, the mechanism of thermal depolymerization of cellulose, hemicellulose and lignin and the interaction mechanism between the three components under degradative solvent extraction conditions will be revealed. Then, the influence of alkali and alkaline earth metals on the degradative solvent extraction process of biomass and the migration and transformation of alkali and alkaline earth metal will be obtained. On the basis of the above researches, the relationship between three components and alkali and alkaline earth metal in biomass with the yield, composition and physicochemical properties of the extraction products will be established. The reaction mechanism of the biomass complex macromolecules under degradative solvent extraction conditions will be revealed. The kinetic model of the degradative solvent extraction of biomass including the interaction of the three components and the effect of alkali and alkaline earth metal will be developed, and finally the prediction and directional regulation methods for the yield, physicochemical properties and quality of the extraction products will be developed.