【作者】 任俊莉； 林琦璇； 王孝辉；

【Author】 Junli Ren;Qixuan Lin;Xiaohui Wang;State Key Laboratory of Pulp and Paper Engineering,School of Light Industry and Engineering,South China University of Technology;

【机构】 华南理工大学轻工科学与工程学院制浆造纸工程国家重点实验室；

【摘要】 半纤维素资源的高效转化及利用是目前国际的研究热点和难点。半纤维素是木质纤维细胞壁主要组分,约占细胞壁总重20%～35%。半纤维素被认为是构成细胞壁抗降解屏障的主要因素之一,在生物合成中其在纤维素微纤维表面,与木质素化学交联构成坚硬的细胞互通连接网络,形成结构复杂、性质稳定的具有结构抗性大的细胞壁,严重阻碍组分的有效分离与转化,这也是生物质研究领域公认的难题。此外,半纤维素结构复杂、性质多样限制了其规模化的工业应用。因此探索适用于工业化的半纤维素分离及转化有效策略具有重大的经济、社会和生态效益。基于十多年从事半纤维素的基础研究,从解析木质纤维细胞壁复杂结构和半纤维素结构特性出发,我们创立了半纤维素高选择性分离和定向催化转化的新途径和新方法,设计和制备了适用于半纤维素催化的高选择性催化剂,建立基于选择性C-O键断调控的半纤维素原位分离机制和可控催化转化理论体系,通过碳标记等先进测试手段深入解析了半纤维素及木糖转化为糠醛、木酮糖的反应路径。此外,通过研究催化过程中积碳副产物的形成条件和反应路径,探索出有效抑制副产物的催化体系,利用催化剂和溶剂效应实现糠醛、木酮糖的高效制备,糠醛最高产率达98%,木酮糖最高产率达28%,利用分子动力学模拟软件从理论层面进一步揭示了溶剂对反应的影响机制。该研究将为半纤维素的工业化应用提供重要的理论依据。更多还原

【Abstract】 The efficient conversion of hemicellulose resources is a hot focus and a big challenge in the world.Hemicellulose is the main component of the cell wall of lignocellulosic biomass,and is considered to be one of the main factors forming the anti-degradation barrier of cell wall,which seriously hindered the effective separation of components from lignocellulose biomass.Moreover,the complex structure of hemicellulose and its diverse properties also limit its large-scale industrial application.Hemicellulose could be hydrolyzed into xylose,which could be further converted into many valuable chemicals such as xylitol,furfural and xylulose.High selective dissolution and hydrolysis of hemicellulose from lignocellulosic biomass is the key technology to the preparation of high valuable chemicals.Furthermore,the controlled conversion of xylose is also an important step in the chemicals production.Due to the complexity of xylose degradation,there are still many hot issues in the catalyst design,solvent effect and reaction mechanism,especially,in structure-performance relationship of catalysts,solvent effect and reaction pathway.In this work,we proposed new ways for high selectivity in-situ separation of hemicellulose and its directed catalytic conversion.Many new catalysts were designed for hemicellulose catalysis,and the in-situ separation mechanism of hemicellulose and the corresponding theoretical system were established based on the regulation of selective C-O bond breaking.The reaction pathway of hemicellulose and xylose conversion was analyzed by carbon labeling and other advanced testing methods.In addition,the formation conditions and reaction paths of the carbon deposition products as by-products were revealed,and accordingly,the effective solvent system for inhibiting the by-products was proposed.And the highest yield of furfural was 98%,the highest yield of xylulose was 28%.Also the mechanism of solvent effect on the reaction was further confirmed by using the molecular dynamics software.更多还原