C_(9)^(+)重芳烃催化加氢脱烷基技术研究进展

Research progress in the catalytic hydrodealkylation of C_(9)^(+) heavy aromatics

随着我国芳烃联合装置、乙烯裂解装置的扩能或新建,国内C_(9)^(+)重芳烃产量也大幅增加;利用催化加氢脱烷基技术将C_(9)^(+)重芳烃转化为BTX等轻质芳烃,对炼化企业具有良好的经济效益。本文以C_(9)^(+)重芳烃生产BTX为出发点,阐述了催化加氢脱烷基反应体系中的碳正离子机理和自由基机理,概述了国内外催化加氢脱烷基反应工艺和催化剂的研究进展,并分析了各工艺、催化剂的优缺点,最后对反应机理、工艺及催化剂的发展方向进行了展望。增产BTX的同时联产三甲苯、四甲苯等高附加值单体芳烃是未来催化加氢脱烷基工艺的发展方向。新型催化剂的研发方向则应结合具体的生产目标和反应机理,定向制备出高活性、高选择性、高稳定性的催化加氢脱烷基催化剂。

The capacity expansion or new construction of aromatic complex and ethylene cracking plant in China led to a drastic increase in the yield of C_(9)^(+)heavy aromatics.The conversion of C_(9)^(+)heavy aromatics to BTX by catalytic hydrodealkylation technology would be conducive to improving economic benefits for refinery.Based on the production of BTX from C_(9)^(+)heavy aromatics,firstly,the mechanism of carbeniumion and free radical in the reaction system of catalytic hydrodealkylation was emphasized.Secondly,the progress of the research on the hydrodealkylation process and catalysts in the domestic and foreign was summarized.Thirdly,the advantages and disadvantages of those process and catalysts was analyzed.Finally,the development direction of reaction mechanism,process and catalyst were forecasted.The future development direction of catalytic hydrodealkylation was to increase the production of BTX and simultaneously produce high value-added monomers such as tritoluene and tetratoluene.The research and development of novel catalysts should be combined with specific production objectives and reaction mechanisms,and the catalytic hydrodealkylation catalysts with high reaction activity,high selectivity and high stability should be prepared directionally.