PHP体系下基于内源灰分介导效应高效解构木质纤维素的机制及产物利用基础

基于生物转化路线，以木质纤维素开发生物能源或生物基产品的工艺中，高效解构细胞壁及其产物利用是该领域研究的热点。前期研究发现，生物质内源灰分在PHP（浓H3PO4+H2O2）体系中可形成自放热和多元氧化2个介导效应，并与磷酸溶剂效应构成解构细胞壁3个关键因子。为破解内源灰分介导效应及关键因子协同解构机制等关键科学问题，本项目利用植物定向水培体系，从元素-形态上寻求产生介导效应的关键内源物。以多原料预处理结合多元回归分析、模拟实验辅助理论计算等手段，明确介导效应的形成机制。基于7个模拟反应体系，借助多角度结构表征技术，利用3尺度模型物模拟实验，并辅以理论计算，从细胞壁结构变化、反应途径及产物特征角度，系统梳理3个关键因子的功能和协同解构机制。借助预处理对主要产物特征的调控，构建3类产物平台化利用技术，寻求高值化利用方案。通过本项目可有效提升生物质资源化水平，拓展产品形式，改善生物炼制综合成本。

In the biological route for conversing lignocellulosic biomass into bioenergy or biobased products, efficiently deconstructing lignocellulose and the derived products valorization are the hot topics in this field. Based on the previous findings in PHP (the concentrated H3PO4 plus H2O2) pretreatment, the endogenous minerals in various lignocellulosic biomass can induce 2 important mediating effects including the self-exothermicity and multi-oxidization. The solvent effect from the concentrated H3PO4 and the mediating effects are the key factors to deconstruct lignocellulosic biomass in PHP pretreatment. Obviously, the hidden mechanisms of the formation of mediating effects by the endogenous minerals and the synergisms of these 3 factors on efficiently deconstructing lignocellulose are the key scientific issues in this project. To elucidate these mechanisms, the water culture system is designed to harvest the biomass with certain minerals, we hope to clarify the key substances from element and chemical speciation in the endogenous minerals to substantially achieve the mediating effects. Meanwhile, the technical strategies of the diversified feedstocks for PHP pretreatment integrated with multivariate regression analysis, and simulation experiments assisted by density functional theory (DFT) calculation will be performed to reveal the forming paths of self-exothermicity and multi-oxidization. In addition, 7 simulation experiments will be constructed to elucidate the synergisms of self-exothermicity, multi-oxidization, and solubility on deconstructing lignocellulose, in which multi-visualization and characterization on lignocellulosic plant cell wall to reveal the structure changes during PHP pretreatment. The simulation experiments with 3-scale models for lignocellulose will be conducted with the aids of DFT calculation to clarify the key chemical paths during lignocellulose deconstruction and the distributions of derived products. Based on these investigations, we hope the functions of self-exothermicity, multi-oxidization and solubility on deconstructing lignocellulose can be elucidated in depth, as well as their synergisms. Besides, based on the investigations on the regulative strategies for the characteristics of recovered products by pretreatment parameters, the targeted utilizing platforms of the corresponding recovered products will be developed to achieve the proposal for high-value valorization of lignocellulosic biomass by PHP pretreatment. According to the anticipated results from these investigations, we believe this project can greatly improve the lignocellulosic biomass valorization, and diversify the potential biobased products and curtail the comprehensive costs of the biorefinery.