生物质水热转化为高品质燃料的基础研究

High-valued and selective transformation is the key for biomass energy utilization. Based on the hydrophily, thermal sensitivity and functionality of lignocellulosic biomass, this project focuses on the efficient conversion of all-components of biomass to high-valued biofuels (gasoline and jet fuel orientated hydrocarbons) in aqueous phase. The new processes for the efficient utilization of cellulose/hemi-cellulose and lignin are pointed out by combined hydrothermal depolymerization/reconstruction of biomass and increased carbon chain and energy capacity of products. By investigating the synergistic mechanism between multiphase (gas, water, oil and solid) flowing/miscibility and catalytic reaction, rules of structure and property evolution and product controlling methodology, during the hydrothermal depolymerization, carbon-carbon chain condensation, aromatization and hydrodeoxygenation upgrading processes to hydrocarbon fuels, this project will explore an efficient and new route for all component utilization of biomass in hydrothermal conditions. This project will also study the strengthened mass/heat transfer properties within multi-phase flowing and promoted conversion in the gas-liquid-solid reactors. Therefore, the key scientific issues including biomass depolymerization, carbon and energy increase of target products, structural recombination and energy/mass control can be resolved. The theoretical system for efficient and high-valued conversion of biomass to liquid hydrocarbon fuels will also be established. The investigation of this project will afford the theoretical horizon and technological support for the effective transformation and high-valued utilization of lighnocellulosic biomass.

生物质定向高值化转化是生物质能利用中的共性难点问题。本项目针对生物质聚合物结构的亲水性、热敏性及功能性，提出生物质水热解聚/重组的定向增碳增能新思路，在温和的水热环境下高效转化生物质制取高品质烃类燃料。通过对生物质解聚、碳链增长、芳构及脱氧提质等水热转化过程中复杂多相（气、水、油、固）流动混合与催化反应的协同机制、结构及物性演变规律与反应机制、以及转化选择性与高品质燃料能质调控机制的深入研究，探索出生物质全组分水热定向转化为高品质烃类燃油的高效转化新路径，以及复杂多相间热质传递与转化反应强化规律，明析生物质在水热环境下定向转化及增碳增能的调控策略，建立生物质合成高品质燃料的水热转化理论。为生物质在航空及道路交通能源领域的规模化高效利用提供理论基础和技术支撑。

木质纤维素生物质废弃物是一类重要的可再生含碳资源，将其定向水热转化为高品质燃料，对促进我国能源结构多元化、降低环境污染和实施低碳发展具有重要意义。然而，生物质复杂大分子结构、高热敏性和转化过程中的复杂反应环境导致其利用过程能效低、转化路径复杂和燃料产品质差，严重制约了生物质资源的高值高效利用。本项目围绕生物质高值高效转化为高品质燃料的目标，针对其利用过程中涉及的热质传递-反应协同机制、结构演变规律与反应机制、选择性及能质调控规律三个关键科学问题开展系统研究，获得了重要进展：（1）在热质传递-反应协同机制方面，提出了动态液膜效应理论，通过薄层限阈空间快速传质与脱水反应协同，攻克了平台分子易结焦的难题，大幅度提升平台分子收率；发展了基于LBM数值模拟研究的多种反应体系，建立了液-固、液-液-固和气-液-固等多个反应模型，系统阐述了单糖水热转化过程的温度场/浓度场特性及其对催化反应的促进效应，形成了传递促进反应的经验公式。（2）在结构演变规律与反应机制方面，系统阐释了植物细胞壁超微结构，揭示了生物质预处理过程中木质素从次生壁脱除，向细胞角隅富集的迁移及键联演变规律；发现了木质素选择性溶出过程中基于单体、二聚体解聚-重聚动力学的“振荡”行为。（3）在选择性与能质调控规律方面，发展了系列水热高效稳定的固体催化剂，拓展了多条全新转化路径，阐释了燃料分子定向制备的控制机理与协同催化作用机制，从元素组成、碳链与结构两方面对燃料的能量品质实现了精准调控，形成了规模化利用的核心技术。依托项目研究，共发表SCI论文106篇，申请专利36件，获得省部级奖励4项，获得“万人计划”科技创新领军人才等12人次。项目形成特色鲜明的生物质水热催化炼制理论体系，推动了生物燃料产业技术进步，研究成果被多家企业采用，新增销售额9.501亿元，新增利润6734万元，取得了较好的社会经济效益。