叔丁醇气相脱水生产异丁烯反应热力学分析

Thermodynamic analysis on the dehydration of vapor phase TBA into isobutene

研究了叔丁醇(TBA)气相脱水生成异丁烯过程所涉及主、副反应的热力学,采用平衡常数计算法得出主、副反应在不同温度下的标准摩尔焓变、标准摩尔生成吉布斯自由能变和标准平衡常数等热力学数据。采用吉布斯自由能最小化法,从热力学角度讨论了反应温度、压力、惰性稀释和水蒸气稀释对TBA脱水反应的影响规律,可为工业化TBA脱水工艺开发提供借鉴。热力学分析结果说明了TBA脱水反应易在高温低压下进行,异丁烯平衡产率对温度和压力的变化更为敏感,TBA原料含水量对异丁烯平衡产率几乎无影响,以热力学角度而言,无需对TBA原料进行干燥处理。

Thermodynamic analysis on the dehydration of vapor phase tert butyl alcohol （TBA） into isobutene and its relevant side reactions were carried out in detail. Thermodynamic data on each reaction, i.e. standard molar enthalpy change, standard change of molar Gibbs function and standard equilibrium constant, were calculated. Using the Gibbs energy minimization method, effects of temperature, pressure and introduction of inert material and steam were obtained from the thermodynamic point of view, which can be used for improving industrial TBA cracking process. Thermodynamic analysis indicates that TBA dehydration reaction favors high temperature and low pressure, the yield of isobutene is more sensitive towards the change of temperature and pressure, while water content in feedstock TBA has little influence on isobutene yield. Therefore, it is not necessary to dry the feed from the thermodynamic point of view.