化工进展 ›› 2022, Vol. 41 ›› Issue (S1): 247-259.DOI: 10.16085/j.issn.1000-6613.2021-2635

• 工业催化 • 上一篇    下一篇

苯与合成气在ZnAlCrO x &HZSM-5双功能催化剂上一步法制甲苯/二甲苯

石轩1(), 杨东元2, 胡浩斌3, 王焦飞4, 张壮壮5, 贺建勋1, 代成义1(), 马晓迅1,3()   

  1. 1.西北大学化工学院,陕西 西安 710069
    2.陕西延长石油(集团)有限责任公司,陕西 西安 710065
    3.陇东 学院化学化工学院,甘肃 庆阳 745000
    4.宁夏大学化学化工学院,省部共建煤炭高效利用与绿色化工国家 重点实验室,宁夏 银川 750021
    5.延安大学化学与化工学院,陕西 延安 716000
  • 收稿日期:2021-12-27 修回日期:2022-03-30 出版日期:2022-10-20 发布日期:2022-11-10
  • 通讯作者: 代成义,马晓迅
  • 作者简介:石轩(1995—),男,硕士研究生,研究方向为合成气催化转化。E-mail:1043790750@qq.com
  • 基金资助:
    陕西省重点研发计划(2020ZDLGY11-06);陕西省技术创新引导专项(2022QFY07-02);国家自然科学基金(22168042);甘肃省高等学校产业支撑引导项目(2019C-08);省部共建煤炭高效利用与绿色化工国家重点实验室开放课题(2021-K52)

One-step preparation of toluene/xylene from benzene and syngas over ZnAlCrO x &HZSM-5 bifunctional catalyst

SHI Xuan1(), YANG Dongyuan2, HU Haobin3, WANG Jiaofei4, ZHANG Zhuangzhuang5, HE Jianxun1, DAI Chengyi1(), MA Xiaoxun1,3()   

  1. 1.School of Chemical Engineering, Northwest University, Xi'an 710069, Shaanxi, China
    2.Shaanxi Yanchang Petroleum (Group) Co. , Ltd. , Xi'an 710065, Shaanxi, China
    3.College of Chemistry and Chemical Engineering, Longdong University, Qingyang 745000, Gansu, China
    4.State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, Ningxia, China
    5.School of Chemistry & Chemical Engineering, Yan'an University, Yan'an 716000, Shaanxi, China
  • Received:2021-12-27 Revised:2022-03-30 Online:2022-10-20 Published:2022-11-10
  • Contact: DAI Chengyi, MA Xiaoxun

摘要:

与传统的甲醇和苯烷基化反应相比,合成气和苯一步法制甲苯/二甲苯具有苯转化率高,催化剂稳定性好,经济性高等优点。本研究将系列Zn基的金属氧化物与H-ZSM-5分子筛组成双功能催化剂,实现了合成气与苯高效转化为甲苯/二甲苯,并筛选出最优的双功能催化剂为ZnAlCrO x &H-ZSM-5。原位红外实验发现,单独的合成气在催化剂上的转化较弱,但加入苯之后,苯与甲氧基等中间体的烷基化反应可以有效拉动合成气的转化。这表明,双功能催化剂中金属组分和分子筛组分间的协同作用拉动了该反应的高效进行。通过Zn、Mg、Ga等元素改性H-ZSM-5分子筛,使得分子筛B酸酸量与L酸酸量的比值降低,发现比值的降低有助于苯的转化。其中Zn改性后B酸与L酸的比值降低最为显著,苯转化率增加的也最多。调变反应温度、原料空速、合成气氢碳比可以控制苯的烷基化程度,调节苯烷基化各产物的选择性。ZnAlCrO x &H-ZSM-5双功能催化剂在压力3MPa、温度400℃的反应条件下,兼具高的苯转化率(90.6%)和甲苯/二甲苯选择性(74.3%),同时CO有效利用率为33.7%。

关键词: 苯, 合成气, 烷基化, 双功能催化剂, 固定床

Abstract:

Compared with the traditional alkylation reaction of methanol and benzene, the one-step process of syngas and benzene to toluene/xylene has the advantages of high benzene conversion, good catalyst stability, and high economic efficiency. In this study, a series of Zn-based metal oxides were coupled with H-ZSM-5 zeolite to form bifunctional catalysts for the efficient conversion of syngas and benzene into toluene and xylene, and the optimal bifunctional catalyst was ZnAlCrO x &H-ZSM-5. In-situ FT-IR analysis showed that the conversion of syngas alone on the catalyst was weak, but after the addition of benzene, the alkylation reaction of benzene with methoxy species can effectively prompt the conversion of syngas, indicating the synergy between the metal components and zeolite components in bifunctional catalyst. The modifying of H-ZSM-5 zeolite with Zn, Mg, Ga elements to reduce the ratio of B acid to L acid in zeolite was found to contribute to the conversion of benzene. Among them, the ratio of B acid to L acid was the lowest after Zn modification, and the conversion of benzene was also the highest. The degree of benzene alkylation can be controlled by adjusting the reaction temperature, the space velocity of raw materials, and the H2/CO ratio of in syngas, and the product selectivity can be adjusted. Under the reaction conditions of pressure 3MPa and temperature 400℃, ZnAlCrO x &H-ZSM-5 bifunctional catalyst gives both high benzene conversion (90.6%) and toluene/xylene selectivity (74.3%), and the effective utilization rate of CO is 33.7%.

Key words: benzene, syngas, alkylation, bifunctional catalysts, fixed bed

中图分类号: 

京ICP备12046843号-2;京公网安备 11010102001994号
版权所有 © 《化工进展》编辑部
地址:北京市东城区青年湖南街13号 邮编:100011
电子信箱:hgjz@cip.com.cn
本系统由北京玛格泰克科技发展有限公司设计开发 技术支持:support@magtech.com.cn