催化学报

催化学报 ›› 2010, Vol. 31 ›› Issue (10): 1209-1216.

• 研究论文 • 上一篇    下一篇

铂和 HF 掺杂的 H-ZSM-5 分子筛催化甲苯与甲醇烷基化反应

Ahmed K. ABOUL-GHEIT1,*, Ateyya A. ABOUL-ENEIN1, Ahmed E. AWADALLAH1, Salwa A. GHONEIM1, Eman A. EMAM2   

  1. 1Process Development Division, Egyptian Petroleum Research Institute, Nasr City, PO Box 9540, Cairo 11787, Egypt; 2Department of Petroleum Refining and Chemical Engineering, College of Petroleum and Mining Engineering, Suez Canal University, Suez, Egypt
  • 收稿日期:2010-10-25 出版日期:2010-10-25 发布日期:2014-03-04

Para-Xylene Maximization Part VIII: Promotion of H-ZSM-5 Zeolite by Pt and HF Doping for Use as Catalysts in Toluene Alkylation with Methanol

Ahmed K. ABOUL-GHEIT1,*, Ateyya A. ABOUL-ENEIN1, Ahmed E. AWADALLAH1, Salwa A. GHONEIM1, Eman A. EMAM2   

  1. 1Process Development Division, Egyptian Petroleum Research Institute, Nasr City, PO Box 9540, Cairo 11787, Egypt; 2Department of Petroleum Refining and Chemical Engineering, College of Petroleum and Mining Engineering, Suez Canal University, Suez, Egypt
  • Received:2010-10-25 Online:2010-10-25 Published:2014-03-04

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摘要： Toluene was alkylated with methanol in a flow type reactor at temperatures between 300 and 500 °C using H-ZSM-5 zeolite, 0.2%Pt/H-ZSM-5 and hydrofluorinated 0.2%Pt/H-ZSM-5 with HF concentrations of 1.0%, 2.0%, 3.0%, or 4.0%. Pt primarily enhances toluene conversion, total xylenes production, and p-xylene relative to its thermodynamic equilibrium. As the concentration of HF increases from 1.0% to 3.0%, the catalyst activity increases because of the increase in the number of acid sites and their strength. Additionally, the surface area and Pt dispersion also increases. An advantage of increased HF doping is that the formation of voluminous trimethylbenzene (TMB) byproducts is inhibited. However, at a HF concentration of 4.0%, Al and Si are partially leached and then deposited mostly in the wider catalytic pores. This was determined by evaluating the pore volume distribution and we determined that reactivity inhibition was ob-viously present and was due to diffusion restriction.

关键词: methanol, toluene, alkylation, platinum, hydrofluorination, shape-selectivity, ZSM-5

Abstract: Toluene was alkylated with methanol in a flow type reactor at temperatures between 300 and 500 °C using H-ZSM-5 zeolite, 0.2%Pt/H-ZSM-5 and hydrofluorinated 0.2%Pt/H-ZSM-5 with HF concentrations of 1.0%, 2.0%, 3.0%, or 4.0%. Pt primarily enhances toluene conversion, total xylenes production, and p-xylene relative to its thermodynamic equilibrium. As the concentration of HF increases from 1.0% to 3.0%, the catalyst activity increases because of the increase in the number of acid sites and their strength. Additionally, the surface area and Pt dispersion also increases. An advantage of increased HF doping is that the formation of voluminous trimethylbenzene (TMB) byproducts is inhibited. However, at a HF concentration of 4.0%, Al and Si are partially leached and then deposited mostly in the wider catalytic pores. This was determined by evaluating the pore volume distribution and we determined that reactivity inhibition was ob-viously present and was due to diffusion restriction.

Key words: methanol, toluene, alkylation, platinum, hydrofluorination, shape-selectivity, ZSM-5