木质纤维生物质制备乙酰丙酸及其应用综述

Production of levulinic acid from lignocellulosic biomass and application

随着资源的枯竭以及环境问题的日益严峻,可再生绿色资源的高值化利用日益受到重视。乙酰丙酸作为一种新一代生物质基绿色平台化合物,可用来制备燃料和高附加值的化学品。笔者详细介绍了木质纤维生物质制备乙酰丙酸的最新研究进展,重点介绍了乙酰丙酸的两条重要制备路径和各种催化体系的制备方法以及乙酰丙酸的应用。生产乙酰丙酸最原始的方法是在水溶液中进行。虽然液体酸制备乙酰丙酸具有反应效率高、反应时间短等优点,但也存在一些缺点,比如酸回收成本高、乙酰丙酸分离困难、对设备的要求高等,而固体酸的应用很好地克服了以上问题。固体酸催化剂制备过程需要考虑的是强酸位点的数量和酸位点的类型,这是生成目标化学品乙酰丙酸的关键因素。离子液体和γ-戊内酯作为绿色溶剂,也应用于乙酰丙酸的生产。此外,还对乙酰丙酸的衍生物5-氨基乙酰丙酸、γ-戊内酯和2-甲基四氢呋喃作了详细描述。最后分析了乙酰丙酸制备面临的可能挑战,提出了未来的研究方向,以期为广大研究者提供有益参考。

With the rising of the oil price and the pollution of petrochemical industry to the environment,all countries in the world are looking for green intermediate chemicals to replace petroleum and break through the bottleneck of petroleum-dependent chemical production.The use of biomass renewable resources to produce fuels and chemicals has become an irresistible trend and a hot topic of research and concern.Levulinic acid(LA)is a new generation of biomass resource green platform compound,which can be used to prepare fuel and high value-added chemicals.The special molecular structure of LA contributes to its good reactivity:weak acidity,esterification,halogenation,hydrogenation,oxidation and condensation.These chemical properties make LA a basis for chemical platform compounds.As a new type of green platform compound,LA is a widely used fine chemical product,which has important applications in the production of pharmaceutical fuels,pesticides,food inks,fragrances,plasticizers,cosmetics,electronic products and fabric processing.Biomass resources can be used as a good resource for the preparation of LA,but the current conversion process limits the economic benefits of biomass conversion to LA.In order to promote the development of biomass LA,it is necessary to further improve the technology.How to improve the raw material conversion rate,reduce the by-products of the reaction process,develop new conversion technology and high-selectivity catalyst,and expand the application of LA are important directions for future development and research.In this paper,the latest research progresses in preparation of LA from lignocellulosic biomass was reviewed,and the pretreatment methods,preparation principles and methods of LA and its application were mainly introduced.The traditional preparation of LA is catalyzed by inorga-nic acid in aqueous solution.In recent years,more and more attention has been paid to organic solvents as the reaction medium.The development trend of preparing LA with homogeneous or heterogeneous catalysts in organic solvents was summarized in detail,and the advantages and disadvantages of different reaction systems were compared.Finally,the upgrading of LA is also discussed.As an important intermediate compound,LA has not achieved large-scale industrial production,which hindered extensive application in various fields.Therefore,researchers should make breakthroughs in the LA preparation and open up new ways for further development and utilization of LA.