Separation of a water/MIBK mixture by batch heteroazeotropic distillation: A self-entrained case

Abstract

In this work, we present a study on the dehydration of methyl isobutyl ketone (MIBK) by batch distillation, using the dynamic module for batch distillation (BatchSep) provided by the commercial chemical process simulator Aspen Plus V11®. A 98 wt.% MIBK/water mixture was initially fed to the column. The scope of the separation was set at 99.8 wt.%, as a standard purity for solvent reuse. Taking advantage of the heteroazeotropic behaviour of the mixture water/MIBK (self-entrained), an alternative configuration with a decanter, which allowed selective reflux of the organic phase, was studied and compared with the conventional batch distillation configuration at 1 atm. This alternative configuration presented clear operating advantages compared to the conventional case, i.e. reduction of both operational time and energy demand by 50% and increase in specific production by 100%. Finally, the distillation-decanter configuration was studied at reduced pressures (50–400 mbar), registering further operating improvements.