Effects of Operating Conditions on the Catalytic Performance of HZSM-5 Zeolites in n-Pentane Cracking

• 来源期刊: 中国炼油与石油化工（英文版）
• 年，卷（期）: 2021,（1）
• 所属期刊栏目: Catalyst Research
• 页码范围: 67-75
• 页数: 9页
• 语种: 英文

摘要

In this work, n-pentane catalytic cracking over HZSM-5 zeolites was studied at 650 °C under atmosphere pressure. A particular attention was paid to the measurement of n-pentane conversion, light olefins production, product distribution, coke deposit, etc. Several indexes were defined to evaluate the effects of operating conditions on the catalytic performance of HZSM-5 zeolites. It was found that decreasing the weight hourly space velocity, increasing the reactant partial pressure, and increasing the carrier gas flow rate could inhibit C-H bond breaking and enhance the C-C bond breaking and hydride transfer reactions, leading to reduced alkenes selectivity, which suppressed the formation of external coke and alleviated the deactivation of HZSM-5 zeolites. It was deduced that the catalytic stability of HZSM-5 zeolites was improved at the cost of alkenes selectivity. Compared with decreasing the weight hourly space velocity and increasing the reactant partial pressure, increasing the carrier gas flow rate could enhance the diffusion process and protect alkenes from being consumed in coke formation in order to improve the catalytic stability of HZSM-5 zeolites with less reduction of alkenes selectivity.