采用双效变压精馏工艺分离甲苯-正丁醇的模拟

采用双效变压精馏工艺流程分离甲苯-正丁醇物系。利用Aspen Plus化工模拟软件,以分离过程能耗最低为目标函数、甲苯和正丁醇纯度为约束变量,对双效变压精馏工艺流程进行了优化计算。模拟结果表明,采用负压和常压双效变压精馏工艺可以实现甲苯-正丁醇物系的高纯度分离,即负压塔的优化操作参数为:塔压20.0 kPa、理论塔板数26块、进料板为第12块塔板、回流比1.1;常压塔的优化操作参数为:塔压102.0 kPa、理论塔板数32块、进料板为第14块塔板、回流比3.2。计算结果表明,与两塔采用外界蒸汽供热的方式相比,采用常压塔塔顶汽相潜热为负压塔塔底再沸器供热可节能约42.3%。

Simulation of Separating Toluene-Butanol by Double Effect Pressure Swing Distillation

Double effect pressure swing distillation (PSD) for separating toluene-butanol was proposed based on the feature that system pressure difference influenced azeotropic composition of the system. Optimization simulation of double effect pressure swing distillation was performed by Aspen Plus software aiming at minimal energy consumption and bounded purities of toluene and butanol. The research results showed that high-purity separation of toluene-butanol could be realized and purity of each product could reach 99.5 %. The vacuum tower operation parameters were: operating pressure 20.0 kPa, number of theoretical plates 26, feeding plate the 12th and reflux ratio 1. 1. The atmospheric tower operation parameters were: operating pressure 102.0 kPa, number of theoretical plates 32,feeding plate the 14th and reflux ratio 3.2. The results showed that the double effect PSD can save energy by 42.3 % in comparing with conventional distillation.