无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2024, Vol. 56 ›› Issue (5): 135-140.doi: 10.19964/j.issn.1006-4990.2023-0545

• 催化材料 • 上一篇    下一篇

全结晶纳米ZSM-5分子筛团聚体的合成及在甲苯甲基化中的应用

李永恒(), 米晓彤, 张培培()   

  1. 中海油化工与新材料科学研究院,北京 102209
  • 收稿日期:2023-11-15 出版日期:2024-05-10 发布日期:2024-05-15
  • 通讯作者: 张培培(1989— ),博士,高工,从事C1催化技术的开发研究;E-mail:Zhangpp15@cnooc.com.cn
  • 作者简介:李永恒(1989— ),博士,工程师,从事石油化工催化剂的开发研究;E-mail:liyh90@cnooc.com.cn
  • 基金资助:
    中国海洋石油集团有限公司科研项目(KJGG-2022-12-CCUS-030401)

Synthesis of holycrystalline nano-ZSM-5 aggregate and its application in methylation of toluene

LI Yongheng(), MI Xiaotong, ZHANG Peipei()   

  1. CNOOC Institute of Chemical & Advanced Materials,Beijing 102209,China
  • Received:2023-11-15 Published:2024-05-10 Online:2024-05-15

摘要:

高效催化剂的开发是甲苯甲醇烷基化制对二甲苯工业化应用的主要挑战之一。以纳米ZSM-5分子筛团聚体为前体,以硅溶胶为黏合剂,采用液相转晶的方式合成了全结晶纳米ZSM-5团聚体。结果表明:硅溶胶挤条后的成型分子筛SolZ150的表面无定型SiO2物种在重结晶过程中转变为晶相结构;成型后的分子筛HCZ150形成了丰富且均一的二元孔道结构,孔径分布分别集中在1.3 nm和10 nm左右,总比表面积和外比表面积分别为260 m2/g和72 m2/g。甲苯甲醇烷基化评价结果表明:全结晶ZSM-5分子筛HCZ150对二甲苯选择性达到70%,远高于以拟薄水铝石作为黏结剂挤条的SBZ150;经P2O5改性制备的催化剂P/HCZ150对二甲苯选择性达90%,且反应24 h后催化剂活性未下降,表明丰富的孔道结构及活性中心的易接近性使得催化剂具有良好的稳定性。该研究为甲苯甲基化催化剂的制备提供了一条新的途径,对该技术的工业化应用具有一定的指导意义。

关键词: 全结晶分子筛, 纳米ZSM-5团聚体, 甲苯甲醇烷基化, 对二甲苯

Abstract:

It is a great challenge to develop an efficient catalysts for the industrial application of toluene methanol alkylation technology to produce p-xylene.The holocrystalline nano-ZSM-5 aggregates were synthesized using ZSM-5 zeolites shaped by silica sol as the precursor by means of liquid phase crystallization.The characterization results showed that the amorphous SiO2 species on the surface of shaped-ZSM-5 by silica sol were transformed into crystalline phase structure during recrystallization process.In addition to its inherent microporous pores,the formed HCZ150 zeolite possessed abundant and uniform binary pore structure,concentrated at around 1.3 nm and 10 nm,with a total specific surface area of 260 m2/g and an external specific surface area of 72 m2/g,respectively.The evaluation results of toluenealkylation with methanol showed that the holocrystalline HCZ150 zeolite had a p-xylene selectivity of 70%,which was significantly higher than that of SBZ150 extruded with pseudo boehmite as binder.The P/HCZ150 catalyst prepared by P2O5 modification exhibited a p-xylene selectivity of 90%,and there was no decrease in catalyst activity ever after 24 hours of reaction.The good stability was attributed to the rich pore structure and easy accessibility of active centers.A new approach for the preparation of toluene methylation catalysts was provided,which had certain guiding significance for the industrial application of this technology.

Key words: holycrystalline zeolte, nano-ZSM-5 aggregate, toluene alkylation with methanol, p-xylene

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