Abstract: Pressure swing distillation process with heat integration was proposed for separation of the ethanol-toluene mixture because of its pressure sensitivity. Vapor-liquid equilibria（VLE）data for the toluene-ethanol mixture were measured using a VLE recirculating still. The experimental data verified that NRTL model can be successfully applied to VLE prediction of this system. The optimum simulation was performed using the RadFrac pattern of Aspen Plus and NRTL equation，aiming at minimizing the energy consumption at fixed purities of ethanol and toluene. Due to relatively low boiling point of ethanol-toluene mixture，high-low pressure columns were selected. The optimal process parameters such as the total number of theoretical plate，reflux ratio，feeding position，operating pressure and circulating ratio were specified by using optimizing analysis. The obtained purities and the yields of the products were more than 99.9%. The results showed that pressure swing distillation process with heat integration can save 49% of energy compared with traditional pressure swing distillation.

Key words: ethanol-toluene, heat integration, pressure swing distillation, simulation and optimization, energy-saving

摘要： 由于乙醇-甲苯体系为压力敏感体系，本文提出了热集成变压精馏分离乙醇-甲苯共沸体系的工艺方法，并通过实验数据验证了NRTL模型对模拟分离该体系的适用性。利用Aspen模拟软件，以NRTL方程为物性计算模拟，以乙醇和甲苯的纯度为约束变量，分离过程能耗最低为目标函数，采用优化分析，得到了模拟的优化参数，并通过模拟计算，制取了纯度不低于99.9%的甲苯和乙醇产品，收率达到99.9%以上。用高压塔的塔顶气相潜热作为常压塔再沸器热源的热集成变压精馏，与两塔均采用外界蒸汽供热的传统变压精馏方式相比，节能高达49%。

关键词: 乙醇-甲苯, 热集成, 变压精馏, 模拟优化, 节能