Effect of mesopore spatial distribution of HZSM-5 catalyst on zinc state and product distribution in 1-hexene aromatization  

作　　者：Chenhao Wei Di Gao Guohao Zhang Liang Zhao Jinsen Gao Chunming Xu 

机构地区：[1]The State Key Lab of Heavy Oil Processing,China University of Petroleum(Beijing),Beijing 102249,China [2]SINOPEC Research Institute of Petroleum Processing Co.,Ltd.,Beijing 100083,China

出　　处：《Chinese Journal of Chemical Engineering》2024年第3期16-26,共11页中国化学工程学报（英文版）

基　　金：supported by National Natural Science Foundation of China(22021004).

摘　　要：1-hexene aromatization is a promising technology to convert excess olefin in fluid catalytic cracking(FCC)gasoline to high-value benzene(B),toluene(T),and xylene.Besides,the increasing market demand of xylene has put forward higher requirements for new generation of catalyst.For increasing xylene yield in 1-hexene aromatization,the effect of mesopore structure and spatial distribution on product distribution and Zn loading was studied.Catalysts with different mesopore spatial distribution were prepared by post-treatment of parent HZSM-5 zeolite,including NaOH treatment,tetra-propylammonium hydroxide(TPAOH)treatment,and recrystallization.It was found the evenly distributed mesopore mainly prolongs the catalyst lifetime by enhancing diffusion properties but reduces the aromatics selectivity,as a result of damage of micropores close to the catalyst surface.While the selectivity of high-value xylene can be highly promoted when the mesopore is mainly distributed interior the catalyst.Besides,the state of loaded Zn was also affected by mesopores spatial distribution.On the optimized catalyst,the xylene selectivity was enhanced by 12.4%compared with conventional Zn-loaded parent HZSM-5 catalyst at conversion over 99%.It was attributed to the synergy effect of mesopores spatial distribution and optimized acid properties.This work reveals the role of mesopores in different spatial positions of 1-hexene aromatization catalysts in the reaction process and the influence on metal distribution,as well as their synergistic effect two on the improvement of xylene selectivity,which can improve our understanding of catalyst pore structure and be helpful for the rational design of high-efficient catalyst.

关 键 词：1-Hexene aromatization Alkali treatment Xylene selectivity MESOPORES Zinc state 

分 类 号：TQ426[化学工程]