Dehydration of Isopropyl Alcohol Using Hybrid Separation Technique

Abstract

Isopropyl alcohol (IPA) – water mixture exhibits a homogeneous minimum-boiling azeotrope (at 80.3–80.4 0C, 87.4–87.7 wt. %). Some methods of enhanced distillation of this mixture have been developed, such as azeotropic distillation, reactive and extractive distillation, and membrane separation either in the form of membrane distillation or pervaporation. This paper is a basic study of a state of the art of technology, called fixed adsorptive distillation, in which distillation and adsorption are applied simultaneously. Fixed adsorptive distillation consists of two raschig ring-packing distillation columns, which are equipped with an inter-bed of adsorbent filled of silica gel. First column (I) distils the mixture to produce distillate at slightly below the azeotropic composition. Silica then adsorbs selectively one of the components (water), so that IPA rises in purity passing the azeotropic point. Finally, the second column (II) distils it to achieve higher composition or pure. This paper aims to investigate the possibility of fixed adsorptive distillation in application of enhancement of azeotropic IPA–water solution.