Deactivation mechanism of beta-zeolite catalyst for synthesis of cumene by benzene alkylation with isopropanol  

作　　者：Yefei Liu Yang Zou Hong Jiang Huanxin Gao Rizhi Chen 

机构地区：[1]State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University [2]SINOPEC Shanghai Research Institute of Petrochemical Technology

出　　处：《Chinese Journal of Chemical Engineering》2017年第9期1195-1201,共7页中国化学工程学报（英文版）

基　　金：Supports by the National Key Research and Development Plan(2016YFB0301503);the Jiangsu Natural Science Foundation for Distinguished Young Scholars(BK20150044);the National Natural Science Foundation of China(91534110,21606124);the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province(14KJB530004);the Foundation from State Key Laboratory of Materials-Oriented Chemical Engineering(ZK201402,ZK201407);the Technology Innovation Foundation for Science and Technology Enterprises in Jiangsu Province(BC2015008)

摘　　要：The alkylation of benzene with isopropanol over beta-zeolite is a more cost-effective solution to cumene production. During the benzene alkylation cycles, the cumene selectivity slowly increased, while the benzene conversion presented the sharp decrease due to catalyst deactivation. The deactivation mechanism of betazeolite catalyst was investigated by characterizing the fresh and used catalysts. The XRD, SEM and TEM results show that the crystalline and particle size of the beta-zeolite catalyst almost remained stable during the alkylation cycles. The drop in catalytic activity and benzene conversion could be explained by the TG, BET,NH_3-TPD and GC–MS results. The organic matters mainly consisted of ethylbenzene, p-xylene and 1-ethyl-3-(1-methyl) benzene produced in the benzene alkylation deposited in the catalyst, which strongly reduced the specific surface area of beta-zeolite catalyst. Moreover, during the reaction cycles, the amount of acidity also significantly decreased. As a result, the catalyst deactivation occurred. To maintain the catalytic performance,the catalyst regeneration was carried out by using ethanol rinse and calcination. The deactivated catalyst could be effectively regenerated by the calcination method and the good catalytic performance was obtained.The alkylation of benzene with isopropanol over beta-zeolite is a more cost-effective solution to cumene production. During the benzene alkylation cycles, the cumene selectivity slowly increased, while the benzene conversion presented the sharp decrease due to catalyst deactivation. The deactivation mechanism of betazeolite catalyst was investigated by characterizing the fresh and used catalysts. The XRD, SEM and TEM results show that the crystalline and particle size of the beta-zeolite catalyst almost remained stable during the alkylation cycles. The drop in catalytic activity and benzene conversion could be explained by the TG, BET,NH_3-TPD and GC–MS results. The organic matters mainly consisted of ethylbenzene, p-xylene and 1-ethyl-3-（1-methyl） benzene produced in the benzene alkylation deposited in the catalyst, which strongly reduced the specific surface area of beta-zeolite catalyst. Moreover, during the reaction cycles, the amount of acidity also significantly decreased. As a result, the catalyst deactivation occurred. To maintain the catalytic performance,the catalyst regeneration was carried out by using ethanol rinse and calcination. The deactivated catalyst could be effectively regenerated by the calcination method and the good catalytic performance was obtained.

关 键 词：CUMENE BENZENE ISOPROPANOL ALKYLATION BETA-ZEOLITE Catalyst deactivation 

分 类 号：O643.36[理学—物理化学] TQ241.14[理学—化学]