甲醇制烃类反应机理研究进展

Research progress on the reaction mechanism of methanol to hydrocarbons

甲醇制烃类(MTH)反应是从非石油路线出发制取各种烃类的重要途径,有着重要的基础研究和工业应用价值,已成为煤基替代能源的研究热点之一。然而,目前对甲醇制烃类反应机理的认知、反应步骤的确认仍存在很多争论,复杂的反应网络限制了对反应机理的分析和证实,因而减缓了反应过程的反应器设计和工艺开发进程。本文从直接机理和间接机理两个方面,阐述了近年来MTH反应机理研究的主要进展,着重介绍了已被广泛接受的烃池双循环催化机理。MTH烃池机理涉及6个主要的化学过程——烯烃甲基化、烯烃裂解、氢转移、环化、芳烃甲基化和芳烃脱烷基化。系统了解该反应机理为精准设计催化剂的晶体形貌、尺寸和孔道结构、调控酸性位点的分布等提供理论依据,为这种复杂反应催化剂构效关系的建立奠定基础,这对煤化工发展的产业化进程具有重要意义。

Methanol to hydrocarbons(MTH)reaction is an important way to prepare various hydrocarbons from non-petroleum route,which has important basic research and industrial application value,and has become one of the research hotspots of coal-based alternative energy sources.However,there are still many debates about the understanding of reaction mechanism and confirmation of reaction steps for methanol to produce hydrocarbons.Complex reaction networks limite the analysis and verification of reaction mechanism,which slow down the reactor design and process development of technology in these reactions.In this paper,the main progress of MTH reaction mechanism in recent years is summarized from two aspects of direct mechanism and indirect mechanism.The widely accepted double-cycle catalytic mechanism of hydrocarbon pool is introduced emphatically.The MTH hydrocarbon pool mechanism involves six major chemical processes:olefin methylation,olefin cracking,hydrogen transfer,cyclization,aromatic methylation and aromatic dealkylation.The systematic understanding of the reaction mechanism provides theoretical basis for the accurate design of crystal shape,size and pore structure of catalysts,and the regulation of the distribution of acidic sites.It also lays a foundation for the establishment of structure-activity relationship of catalysts,which is of great significance to the industrialization process of the development of coal chemical industry.