Catalytic Performance and Coking Behavior of a Submicron HZSM‐5 Zeolite in Ethanol Dehydration
Catalytic Performance and Coking Behavior of a Submicron HZSM‐5 Zeolite in Ethanol Dehydration
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亚微米HZSM-5沸石在乙醇脱水中的催化性能和结焦行为
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
Wende Xiao
中科院分区：
文献类型：
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作者：
Fei Wang;Man Luo;Wende Xiao
采用低温氮吸附、热重分析和核磁共振等手段研究了亚微米ZSM-5沸石在乙醇脱水制乙烯过程中的催化性能和焦化行为。亚微米催化剂由于具有更多的介孔和更强的酸位，表现出比微米催化剂更高的活性。随着反应温度的升高，亚微米催化剂上乙醇转化率增加，乙烯选择性达到最大值。丙烯和丁烯的选择性随反应温度的升高而升高，随反应时间的延长而降低。焦炭沉积可分为焦炭前驱体和硬焦，其成因分别为多烷基苯和多环芳烃；提高反应温度可以加速焦炭前驱体向硬焦的转变。结果表明，预焦化预处理方法对提高催化剂的稳定性非常有效。
The catalytic performance and coking behavior of a submicron ZSM-5 zeolite in dehydration of ethanol to ethylene were investigated by means of low temperature nitrogen adsorption, thermal gravimetric analysis, and nuclear magnetic resonance. The submicron catalyst showed higher activity than the micron one due to more mesopores and more strong acid sites. As the reaction temperature increased, ethanol conversion increased over the submicron catalyst, while ethylene selectivity went through a maximum. The selectivities of propylene and butylene increased with increasing reaction temperature, and they decreased with time on stream at constant temperature. The coke deposits can be divided into coke precursor and hard coke, which were attributed to polyalkylbenzene and polycyclic aromatic hydrocarbons, respectively; and increasing reaction temperature can accelerate the transformation of coke precursor into hard coke. A precoking pretreatment method was verified very effective for improving the catalyst stability.