A simulation case study on separation of IPA-Methanol-Water mixture by distillation

The present work focuses on the simulation and analysis of the separation of an Isopropyl Alcohol (IPA)–Methanol–Water mixture using distillation with Dimethyl Sulfoxide (DMSO) as an entrainer. Due to the close boiling points and non-ideal vapor–liquid equilibrium behavior of IPA and methanol, conventional distillation becomes inefficient for achieving high-purity separation. In this study, a three-column extractive distillation process was simulated for efficient methanol separation, IPA recovery, and DMSO solvent recycling. The feed mixture consisted of 40 wt.% IPA, 40 wt.% methanol, and 20 wt.% water, while DMSO was introduced as the extractive solvent. The simulation results demonstrated that methanol purity of 99.25 wt.% and IPA purity of 99.65 wt.% were achieved. Additionally, DMSO recovery of approximately 99.99 wt.% was obtained with negligible solvent losses. The results confirm that extractive distillation using DMSO is an effective and industrially viable technique for the separation of IPA–Methanol–Water systems. Keywords: IPA, Methanol, Water, DMSO, Simulation