萃取和热集成变压精馏分离异丙醇与异丙醚的模拟

Simulation of the Separation for Isopropanol and Diisopropyl ether by Extractive Distillation and Heat Integration Pressure Swing Distillation

异丙醇-异丙醚形成二元共沸物,一般精馏方法很难分离。利用化工过程软件Aspen Plus,在异丙醇和异丙醚产物的摩尔分数达到0.999的条件下,以乙二醇为溶剂的萃取精馏流程和热集成变压精馏流程对异丙醇-异丙醚混合物分离进行模拟。以全年总费用最低为目标,确定萃取精馏流程两塔的理论板数、进料位置和溶剂进料位置以及热集成变压精馏流程的高压塔操作压力,两塔的理论板数,进料位置,得到两种流程的最优操作条件。从模拟结果可知,对于异丙醇-异丙醚混合物的分离,热集成变压精馏所需的全年总费用更低,比萃取精馏的全年总费用降低了10.86%。对于该混合物,热集成变压精馏流程要优于萃取精馏流程。

Diisopropyl ether and isopropanol can form a binary azeotrope which can not be separated by con- ventional distillation method. In this paper, comparison of extractive distillation and heat integration pres- sure swing distillation for isopropanol-diisopropyl ether separation is investigated by Aspen Plus, based on isopropanol and diisopropyl ether purities setting at 0. 999mol%. In order to get the lowest total annual cost, the optimization of trays, the feed position and the extractant feed position on the extractive distil- lation, and the operating pressure of the high pressure column, trays and the feed position on the pressure swing distillation is investigated. From the simulation results, it is found that heat integration pressure swing distillation is better than extractive distillation for the system of diisopropyl ether and isopropanol. It can save the cost by 10.86% compared with extractive distillation.