甲醇制芳烃催化剂及相关工艺研究进展

Research progress of catalysts and related technologies for methanol to aromatics

当前我国芳烃生产面临石油资源短缺等困难,而我国丰富的煤炭资源和当前过剩的甲醇产能为煤基甲醇制芳烃提供了价格低廉的原料,对于我国的能源安全具有重要意义。本文综述了近年来国内外甲醇制芳烃(MTA)技术的相关研究进展,分别介绍了MTA固定床、流化床技术;针对传统MTA过程产物复杂,分离能耗大,经济效益差等不足,归纳总结了更具经济性的甲醇一步法制对二甲苯(MTPX)以及甲醇一步法制对二甲苯联产低碳烯烃(MTO&PX)技术;针对传统MTA催化剂稳定性差等不足,对比介绍了甲醇直接制芳烃以及低碳烯烃制芳烃路线,结果表明甲醇经低碳烯烃制芳烃工艺路线具有催化剂寿命长、产品组成易调节等优势。最后,本文认为分子筛限域效应、分子筛表面修饰新技术、金属-酸双活性中心协同效应是未来MTA研究的重要方向。

Aromatics production in China is now facing the difficulty of shortage of oil resources,while the abundant coal resources and the current excess methanol capacity can provide low-cost raw materials for the production of aromatics from coal-based methanol,which is of great significance for the energy security of China.This article summarizes the recent research progress of methanol to aromatic hydrocarbon(MTA)technologies at home and abroad,and then introduces the MTA fixed bed and fluidized bed technologies respectively.In view of the disadvantages of traditional MTA process,such as complex products,large energy consumption in separation and poor economic benefits,the more economical one-step methanol to p-xylene(MTPX)and one-step methanol to p-xylene and low carbon olefins(MTO&PX)technologies are summarized.In view of the insufficient stability of traditional MTA catalysts and other deficiencies,the comparison introduces two novel routes of methanol directly to aromatics and methanol to aromatics through dimethyl ether or low-carbon olefins.The results show that the route of methanol to aromatics through low-carbon olefins has the advantages of long catalyst life and easy adjustment of product composition.Finally,this paper points out that zeolite confinement effect,new technology for molecular sieve surface modification,and metal-acid dual active center synergistic effect are important directions for future MTA research.