双功能离子液体中均相催化木质纤维素液化过程与机理研究

It is well known that great progress achieved in material civilization for human beings in the last few decades was mainly on the expense of non-renewable global resources, which has brought lots of realistic problems such as energy crisis, environmental pollution and climate change. Hence, the exploitation and development of novel and cleaner technologies for the efficient utilization of carbon neutral biomass have been recognized as one of the most predominated approaches for sustainable development of our society. Therefore, efficient and direct transformation of readily abundant and renewable biomass to high heating value biofuel and value-added biochemicals is of great significant and in good agreement with the concept of low carbon economy. In this project, a series of novel and bifunctional ionic liquid systems are going to be designed and constructed for the dissolution and catalytic liquefaction of lignocelluloses and/or their constituents. These bifunctional ionic liquid systems are composed of ionic liquids for the dissolution of lignocellulose constituents and acidic ionic liquid for in situ catalytic liquefaction of partly dissolved lignocellulose constituents homogeneously. The extraction of liquefaction products by the upper protection solvent is able to have the catalytic conversion equilibrium promoted and ulteriorly push the dissolution process forwards, resulting in the rapid and efficient transformation of sustainable lignocelluloses. Relationships among the liquefaction products distribution, composition of bifunctional ionic liquid systems and liquefaction process parameters, and liquefaction mechanism are hopeful to be recognized through systemically investigating of the dissolution and catalytic behavior of biomass. So obtained new knowledge is capable of giving beneficial reference and guidance for the future transformation of utilization of renewable lignocelluloses.

上世纪以来人类物质文明的快速发展主要是以消耗地球上不可再生资源为代价且带来诸如能源危机、环境污染及气候变迁等系列问题。可再生资源的开发及其高效与洁净利用技术的发展是解决人类社会可持续发展的主要手段之一。将来源丰富且可再生的生物质资源直接转化为生物质能源或化工原材料，意义重要且符合"低碳经济"的理念。本项目研究通过构建对生物质各主要组份具有溶解作用且具有酸催化功能的双功能离子液体体系，部分溶解的生物质被酸性离子液体原位均相催化液化，液化产物被保护溶剂萃取，同时打破生物质的溶解及催化液化平衡，有望实现生物质的快速与高效转化。通过系统考察双功能离子液体体系中生物质的溶解与催化液化行为，获得双功能离子液体体系的组成、催化液化工艺与液化产物分布之间的关联规律、液化过程机理并为离子液体体系中生物质高效转化过程提供借鉴与指导。

生物质是自然界中唯一含碳可再生资源，生物质也被认为是化石资源的天然替代品。然而，受制于其疏松的结构、复杂的化学键合方式以及大量分子间与分子内氢键，生物质催化转化过程通常面临转化率低，反应器效率低下等问题。针对上述技术难题，本项目研究基于化工过程耦合与强化的理念，设计并构建了系列兼具溶解与原位催化解聚性能的双功能化离子液体，并对其结构、离子液体溶剂与催化剂的协同作用机制、离子液体催化生物质及其主要组分转化性能进行了系统研究，获得了其反应历程、动力学行为、催化机理与过程强化与耦合机制，并在此基础上，采用计算机模拟的手段对复合离子液体原位溶解与催化纤维素解聚强化过程集成进行了研究。具体研究包括（1）：系列兼具溶解与催化性能的双功能化离子液体的设计、合成、表征及离子液体组分之间的协同作用机制研究；（2）双功能化离子液体催化纤维素转化制备化学品研究；（3）双功能化离子液体强化木质素催化解聚与过程消炭研究；（4）双功能化离子液体强化真实生物质中碳水化合物转化与原位脱木质素过程与机理；（5）双功能化离子液体催化生物质及其组分催化转化动力学行为与催化机理研究；（6）双功能化离子液体强化生物质催化转化过程集成。研究结果表明：在双功能化离子液体的协同作用下，生物质其组分的转化率与主要产物收率明显增大，极大提高了反应器效率。相关研究成果可为生物质能的高值化利用提供理论借鉴与技术支持。. 上述研究成果发表在Chem Eng Sci、Ind Eng Chem Res等本领域SCI/EI权威杂志上（11篇，其中SCI二区以上论文4篇），申请专利6项，授权4项。参加国际学术会议6次，国内学术会议5次，毕业博士生3名，硕士生3名。