石油炼制与化工 ›› 2012, Vol. 43 ›› Issue (7): 27-32.

• 催化剂 • 上一篇    下一篇

Zn改性ZRP沸石催化剂对催化裂化汽油芳构化性能的影响

王永军   

  1. 万华实业集团有限公司
  • 收稿日期:2012-02-07 修回日期:2012-03-08 出版日期:2012-07-12 发布日期:2012-07-05
  • 通讯作者: 王永军 E-mail:jnrwang@163.com

EFFECT OF Zn MODIFIED ZRP ZEOLITE CATALYST ON THE AROMATIZATION OF CATALYTIC CRACKING NAPHTHA

  • Received:2012-02-07 Revised:2012-03-08 Online:2012-07-12 Published:2012-07-05

摘要: 以催化裂化汽油为原料,在固定床微反装置上考察Zn改性ZRP沸石催化剂对催化裂化汽油芳构化反应性能的影响,通过实验考察改性金属Zn在芳构化反应中的作用,并结合吡啶吸附红外吸收光谱分析改性前后催化剂的酸性变化,提出催化裂化汽油在Zn改性ZRP沸石催化剂上的反应机理。结果表明,Zn改性能够显著提高ZRP沸石催化剂的芳构化性能。分析认为催化裂化汽油芳构化反应在ZRP沸石催化剂上主要通过氢转移反应实现,在Zn改性的ZRP沸石催化剂上以环化、脱氢为主,氢转移反应为辅,并涉及到裂化、齐聚、异构化等反应。Zn改性的ZRP沸石孔道中可能存在[Zn(OH)]+活性位,它具有B酸和L酸的双重属性,芳构化反应在不同的反应步骤需要不同性质的活性位,因此Zn改性可提高ZRP沸石的芳构化性能。

关键词: 催化裂化汽油 , Zn 改性, 芳构化, 机理

Abstract: The effect of zinc modified ZRP zeolite catalyst on the aromatization of FCC naphtha was studied using a fixed bed micro-reactor, and the function of zinc on the aromatization reaction was investigated. Through analyzing the surface acidity of catalyst prior and post to Zn modification from pyridine adsorption FT-IR spectra, the aromatization reaction mechanism of FCC naphtha over Zn/ZRP zeolite catalyst was proposed. Test results showed that the aromatization performance of ZRP zeolite catalyst was improved significantly by Zn modification. By discussing the reaction mechanism, it was found that the aromatization of FCC naphtha over ZRP zeolite catalyst was mainly through hydrogen transfer reactions, yet over Zn/ZRP zeolite catalyst was mainly through cyclization and dehydrogenation reactions assisted by hydrogen transfer reactions, besides, cracking, oligomerization and isomerization reactions were implicated as well. [Zn(OH)]+ active sites having both B/L acid functions might exist in the channels of Zn/ZRP zeolite to meet the requirements of aromatization reaction in various stages, thus the aromatization performance of ZRP zeolite catalyst was enhanced by Zn modification.

Key words: FCC naphtha, Zn modification, aromatization, mechanism