Abstract Ethanol is an alternative for producing petrochemicals, especially propylene and aromatics (benzene, toluene, and xylenes). To understand ethanol processing routes into olefins and aromatics, it is interesting to use ethylene that is the major primary product of ethanol reaction into hydrocarbons and the intermediate for the formation of olefins and aromatics. In this work, the influence of the operating conditions (ethylene partial pressure, reaction temperature and contact time) in the ethylene conversion into propylene and aromatics, and in the product yield was investigated using HZSM-5 zeolite as catalyst. Lower contact time and ethylene partial pressure, and higher reaction temperature favored propylene yield. Olefin production was based on the formation of carbene species from ethylene that reacts with ethylene to produce propylene and on ethylene dimerization to form butenes. On the other hand, intermediate reaction temperatures and contact times, and higher ethylene partial pressure promote the formation of aromatics, where the dehydrocyclization reaction is favored over hydrogen transfer. The presence of water vapor in long-term reactions deactivated the catalyst. For propylene production, the decrease of ethylene conversion was due to zeolite framework dealumination, while for aromatic formation the reaction mechanism was changed. Graphic Abstract

中文翻译：

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在 HZSM-5 上将乙烯转化为丙烯和芳烃：对反应路线和水影响的见解

摘要 乙醇是生产石油化工产品的替代品，尤其是丙烯和芳烃（苯、甲苯和二甲苯）。要了解乙醇加工成烯烃和芳烃的路线，使用乙烯是有趣的，它是乙醇反应成烃的主要主要产品，也是形成烯烃和芳烃的中间体。在这项工作中，使用HZSM-5沸石作为催化剂，研究了操作条件（乙烯分压、反应温度和接触时间）对乙烯转化为丙烯和芳烃以及产品收率的影响。较低的接触时间和乙烯分压以及较高的反应温度有利于丙烯收率。烯烃生产基于由乙烯形成的卡宾物种，该物种与乙烯反应生成丙烯，以及乙烯二聚生成丁烯。另一方面，中间反应温度和接触时间以及较高的乙烯分压促进芳烃的形成，其中脱氢环化反应比氢转移更有利。长期反应中水蒸气的存在使催化剂失活。对于丙烯生产，乙烯转化率的下降是由于沸石骨架脱铝，而对于芳烃的形成，反应机理发生了变化。图形摘要 其中脱氢环化反应优于氢转移。长期反应中水蒸气的存在使催化剂失活。对于丙烯生产，乙烯转化率的下降是由于沸石骨架脱铝，而对于芳烃的形成，反应机理发生了变化。图形摘要 其中脱氢环化反应优于氢转移。长期反应中水蒸气的存在使催化剂失活。对于丙烯生产，乙烯转化率的下降是由于沸石骨架脱铝，而对于芳烃的形成，反应机理发生了变化。图形摘要