Reaction behaviors and mechanisms of catalytic pyrolysis of C4 hydrocarbons
Reaction behaviors and mechanisms of catalytic pyrolysis of C4 hydrocarbons
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DOI：
10.1016/j.cej.2005.11.002
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发表时间：
2006-03
影响因子：
15.1
通讯作者：
Li Li-Li;Jinsen Gao;Chunming Xu;X. Meng
中科院分区：
文献类型：
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作者：
Li Li-Li;Jinsen Gao;Chunming Xu;X. Meng
在固定床反应器中研究了C4烃在改性ZSM-5分子筛上的催化裂解反应。研究了反应温度和稀释比对产物产率和分布的影响，乙烯产率随反应温度的升高而单调上升，丙烯产率在580°C左右出现最大值。随着稀释比的增加，丙烯的产率增加，直到稀释比达到2.0，然后略有变化，乙烯的产率在约2.0处达到最大值。对于正丁烯的催化裂解，有两种反应途径，即单分子反应机理和双分子反应机理。通过对这两种反应途径的分析和实验数据的分析，得出了正丁烯催化裂解遵循双分子反应机理的结论。根据这一机理，正丁烯催化裂解包括两个连续的反应步骤：正丁烯的二聚和二聚物的裂解。
Catalytic pyrolysis of C4 hydrocarbons over a modified ZSM-5 zeolite was investigated in a fixed bed reactor. The effects of reaction temperature and dilution ratio on product yields and distribution were studied, ethylene yield goes up monotonously with the enhancement of reaction temperature; meanwhile, propylene yield shows a maximum at about 580°C. As dilution ratio increases, the yield of propylene increases until a dilution ratio of 2.0 is reached, and then changes slightly, and that of ethylene passes through a maximum at about 2.0. For catalytic pyrolysis of n-butylene, two reaction pathways have been proposed, the monomolecular reaction mechanism and the bimolecular reaction mechanism. With the analysis of these two reaction pathways and the experimental data, a conclusion is drawn that catalytic pyrolysis of n-butylene follows the bimolecular reaction mechanism. According to this mechanism, n-butylene catalytic pyrolysis involves two successive reaction steps: the dimerization of n-butylene and the cracking of the dimers.