Steady State Simulation of Extractive Distillation System Using Aspen Plus

Abstract

In this project work, we report Aspen-plus simulation results of an azeotropic system viz. isopropanol-water which forms a minimum boiling azeotrope. Because of its large scale industrial application, separation of isopropanol-water mixture using the distillation process gained prominence. In this work, two routes were followed leading to the simulation. The first involved more conventional extractive distillation mechanism where Dimethyl sulfoxide (DMSO) was used as an entrainer. A percentage purity of 99.9% was achieved w.r.t isopropanol in the distillate or top product. However, a significant percentage of DMSO remained in the bottom product. Since the recovery of DMSO was critical, another auxiliary column was configured with the main scheme and a recovery of more than 99% was achieved as the bottom product from the second column. Since this process involved two distillation columns, a relatively more contemporary and modern distillation mechanism was resorted to viz. divided wall distillation process. Improvisations were made in the flow sheet to mimic divided wall distillation mechanism as Aspen-plus don’t have such specific simulator. The results were comparable to what was achieved in extractive distillation process.