Thermodynamic equilibrium distribution of light olefins in catalytic pyrolysis

作     者：Zhang, Rui Wang, Zhixi Liu, Haiyan Liu, Zhichang Liu, Guili Meng, Xianghai 

作者机构：China Univ Petr State Key Lab Heavy Oil Proc Beijing 1022495 Peoples R China SINOPEC Aromat Plant Yangzi Petrochem Co Ltd Nanjing 210048 Jiangsu Peoples R China 

出 版 物：《APPLIED CATALYSIS A-GENERAL》 (应用催化，A辑：总论)

年 卷 期：2016年第522卷

页      面：165-171页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 081704[工学-应用化学] 07[理学] 070304[理学-物理化学(含∶化学物理)] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 

基　　金：National Basic Research Program of China (973 Program) [2012CB215001] Program for New Century Excellent Talents in the University of China [NCET-12-0970] 

主　　题：Catalytic pyrolysis Thermodynamic equilibrium Gibbs free energy Ethene Propene 

摘      要：Catalytic pyrolysis is a promising technology to produce light olefins. Gibbs free-energy minimization method was used to study the thermodynamic equilibrium distribution of olefins in catalytic pyrolysis with Aspen Plus software. The result showed that olefin systems with different carbon numbers demonstrated a similar thermodynamic equilibrium distribution. The ethene equilibrium composition increased with increasing reaction temperature and decreased with increasing total hydrocarbon pressure. By contrast, the propene equilibrium composition reached a maximum of 40 wt% at 850-950 K under 0.1 MPa. Ethene yield and propene yield of thermodynamic equilibrium, catalytic pyrolysis and thermal pyrolysis were compared. The use of catalyst greatly increased the yields of ethene and propene, but the yields were still lower than the equilibrium data. Catalytic pyrolysis was carried out in the interaction zone where both catalytic conversion and thermal conversion were important. Propene yield was close to ethene yield at about 950 K from the thermodynamic view. Given the shape-selective effect of the catalyst on branched olefins with large carbon number, the equilibrium carbon number distribution of olefins possibly shifted from large carbon numbers to low carbon numbers, resulting in enhanced ethene and propene yields. (C) 2016 Elsevier B.V. All rights reserved.