变压精馏分离乙腈-异丙醇模拟计算及中试应用

Simulation Calculation of Acetonitrile and Isopropanol Separating by Pressure Swing Distillation and the Pilot Application

利用乙腈-异丙醇物系在不同压力下共沸组成有较大变化的特点,提出变压精馏分离该共沸物系的工艺流程。对该分离过程进行了模拟计算,分析了减压塔和常压塔的理论板数、进料位置和回流比对分离效果的影响,得到了优化后的工艺参数。以模拟计算结果为指导设计并建立了中试装置。结果表明,优化后的工艺参数为:减压塔理论板数20,进料位置为第16块板,回流质量比2.66;常压塔理论板数22,进料位置为第13块板,回流质量比1.79。减压塔底异丙醇产品质量分数可达99.50%,常压塔底乙腈产品质量分数可达99.90%。中试结果表明关键数据与模拟值基本相符。

Since the azeotropic composition of acetonitrile and isopropanol system varied with the pressure obviously, the pressure swing distillation was used for the separation. By simulating the separation processes, the effects of theory stage, feed location and reflux ratio of vacuum tower and atmospheric tower on separation effect were analyzed, and the optimal parameters were obtained. The vacuum tower optimal parameters were as follows: stage number 20, feed location 16 and reflux ratio 2.66. The atmospheric tower optimal parameters were as follows: stage number 22, feed location 13 and reflux ratio 1.79. The mass froction of isopropanol in bottom of vacuum tower could reach 99.5% and acetonitrile in bottom of atmospheric tower could reach 99.9%. A pilot plant was established and the results showed that the simulation results agreed with the experiment results.