分隔壁萃取精馏塔分离C_4烯烃与烷烃的模拟

采用AspenPlus化工流程模拟软件中的MultiFrac模块,对分隔壁萃取精馏塔分离正丁烷和反-2-丁烯混合物的过程进行模拟,分析了溶剂比、回流比、汽相分配比对分离效果及能耗的影响。模拟结果表明,当分离要求为正丁烷纯度大于99.0%(w),反-2-丁烯纯度大于99.9%(w)时,分隔壁萃取精馏塔主塔理论板数40,副塔理论板数10;最佳工艺条件为溶剂比2.5,主塔回流比3.5,汽相分配比2.5;分隔壁萃取精馏塔能有效避免常规萃取精馏塔内的返混效应,因此节能效果显著。与常规萃取精馏塔相比,分隔壁萃取精馏塔再沸器和冷凝器可分别节能17.31%,25.81%。

Simulation of Separation of C40lefins and Alkanes Through Dividing Wall Extractive Distillation Column

A novel single column extractive distillation process for the separation of n-butane and trans-2-butene was proposed and simulated by means of the MultiFrac module of Aspen Plus software.The influences of solvent ratio,reflux ratio and distribution ratio of vapor phase on the separation efficiency and energy consumption were investigated.The simulation results show that under the conditions of the number of theoretical plates of main column and side column 40 and 10 respectively,solvent ratio 2.5,reflux ratio 3.5,and distribution ratio of vapor phase 2.5,the purities of the products n-butane and trans-2-butene can reach 99.0%(w),99.9%(w),respeetively which can meet the requirement of the separation.It was found that the novel process had higher energy efficiency than conventional extractive distillation process,the reboiler and condenser can save energy up to 17.31% and 25.81%,respectively.The reason for the energy saving was discussed based on the analysis of the component concentration distributions in the dividing wall extractive distillation column.