Acta Phys. -Chim. Sin. ›› 2009, Vol. 25 ›› Issue (10): 2055-2060.doi: 10.3866/PKU.WHXB20091032

• ARTICLE • Previous Articles     Next Articles

Catalytic Conversion of Mixed C4 Hydrocarbons over ZSM-5/ZSM-57 Composite Zeolite Catalyst

LIU Bai-Jun, ZENG Xian-Jun   

  1. Key Laboratory of Catalysis, China National Petroleum Corporation, China University of Petroleum, Beijing 102249, P. R. China|State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, P. R. China
  • Received:2009-05-14 Revised:2009-07-14 Published:2009-09-29
  • Contact: LIU Bai-Jun E-mail:bjliu@cup.edu.cn

Abstract:

The catalytic performance of a ZSM-5/ZSM-57 composite zeolite catalyst for the conversion of mixed C4 hydrocarbons was investigated. The acidic properties of the ZSM-5/ZSM-57 composite zeolite catalyst were characterized by means of ammonia temperature-programmed desorption (NH3-TPD) and pyridine adsorption Fourier transform infrared (FT-IR) spectroscopy. Results indicated that compared with ZSM-5 zeolite, the ZSM-5/ZSM-57 composite zeolite with lower ZSM-5 content showed higher catalytic activity and higher selectivity for ethylene and propylene because of its enhanced acidic strength and increased acid amount. ZSM-57 has small pores in the composite zeolite and this is beneficial in the shape-selective reaction of ethylene and propylene. On the contrary, the ZSM-5/ZSM-57 composite zeolite with higher ZSM-5 content exhibited higher selectivity for benzene and toluene. This probably results from the pore structure and the structure matching property of the ZSM-5/ZSM-57 composite zeolite, which favors the aromatization of mixed C4 hydrocarbons.

Key words: ZSM-5/ZSM-57 composite zeolite, Mixed C4 hydrocarbons, Ethylene, Propylene, Benzene, Toluene, Shape-selective catalysis