文献类型：期刊文献

中文题名：Effect of Steam Treatment on the Catalytic Performance of ZSM-5 in the Co-conversion of Methanol and n-Hexane to Aromatics

英文题名：Effect of Steam Treatment on the Catalytic Performance of ZSM-5 in the Co-conversion of Methanol and n-Hexane to Aromatics

作者：Wei, Shumei[1,2];Xu, Yarong[2];Fan, Yang[1];Zhu, Kake[1];Zhu, Xuedong[1]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Petrochina, Res Inst Urumqi Petrochem Co, Urumqi 830019, Peoples R China

年份：2024

卷号：26

期号：3

起止页码：73

中文期刊名：China Petroleum Processing & Petrochemical Technology

外文期刊名：CHINA PETROLEUM PROCESSING & PETROCHEMICAL TECHNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:001340200800008)】；CSCD:【CSCD2023_2024】；

基金：We gratefully acknowledge financial support from the National Nature Science Foundation of China (2177606) and PetroChina (Development of methanol coupled light hydrocarbon aromatization catalyst and process technology, 2016A-24308) .

语种：英文

中文关键词：steam;ZSM-5 zeolites;co-conversion;aromatization;methanol;n-hexane

外文关键词：steam; ZSM-5 zeolites; co-conversion; aromatization; methanol; n -hexane

摘要：Steam pretreatment is a widely used method for modifying the acidity and structure of zeolites,thereby enhancing their catalytic properties.This study systematically investigated the effects of steam treatment on ZSM-5 zeolites at varying treatment temperatures and durations.The structural evolution of the catalysts was monitored using N2 adsorptiondesorption,X-ray diffraction,inductively coupled plasma optical emission spectroscopy,scanning electron microscopy,NH3 temperature-programmed desorption,in situ pyridine infrared spectroscopy,and thermogravimetric analysis.The characterization results revealed that mesopores were introduced into the ZSM-5 zeolite catalysts through dealumination induced using steam treatment at moderate temperatures(400 and 500℃).Moreover,compared with the parent catalyst,the steam-treated catalysts exhibited a lower amount of acid sites and relative crystallinity,while the n(Si)/n(Al)ratio increased.In the co-conversion of methanol and n-hexane in a fixed bed reactor at 400℃and 0.5 MPa(N2 atmosphere),with a weight hourly space velocity of 1 h?1 and a stoichiometric ratio of 1:1(CH3OH to n-hexane),the steam-treated catalysts displayed a prolonged catalyst lifetime.Particularly,the parent zeolite had a lifetime of 96 h,while the catalyst treated at 500℃for 12 h had a lifetime of up to 240 h.Additionally,the steam-treated catalysts maintained stable n-hexane conversion and improved aromatic selectivity.Notably,these treated catalysts exhibited a lower deactivation rate than the parent catalyst,and would be conducive to industrial scale-up production.
Steam pretreatment is a widely used method for modifying the acidity and structure of zeolites, thereby enhancing their catalytic properties. This study systematically investigated the effects of steam treatment on ZSM-5 zeolites at varying treatment temperatures and durations. The structural evolution of the catalysts was monitored using N-2 adsorption-desorption, X-ray diffraction, inductively coupled plasma optical emission spectroscopy, scanning electron microscopy, NH3 temperature-programmed desorption, in situ pyridine infrared spectroscopy, and thermogravimetric analysis. The characterization results revealed that mesopores were introduced into the ZSM-5 zeolite catalysts through dealumination induced using steam treatment at moderate temperatures (400 and 500 degrees C). Moreover, compared with the parent catalyst, the steam-treated catalysts exhibited a lower amount of acid sites and relative crystallinity, while the n(Si)/n(Al) ratio increased. In the co-conversion of methanol and n-hexane in a fixed bed reactor at 400 degrees C and 0.5 MPa (N-2 atmosphere), with a weight hourly space velocity of 1 h(-1) and a stoichiometric ratio of 1:1 (CH3OH to n-hexane), the steam-treated catalysts displayed a prolonged catalyst lifetime. Particularly, the parent zeolite had a lifetime of 96 h, while the catalyst treated at 500 degrees C for 12 h had a lifetime of up to 240 h. Additionally, the steam-treated catalysts maintained stable n-hexane conversion and improved aromatic selectivity. Notably, these treated catalysts exhibited a lower deactivation rate than the parent catalyst, and would be conducive to industrial scale-up production.