Effect Of Addition Of LiBr Salt In Iso-Propanol - Water Binary Azeotropic Mixture

Abstract

Isopropanol is a very useful solvent for many industries and it requires in pure form for specific applications. It makes an azeotrope with water at 80.3 0C having composition of 87.4 % by weight. It is seen that conventionally methods used are not much effective or large energy consuming. Another alternative is to add salt which is helpful in changing the relative volatility of the mixture and separation gets is much more easier. In this paper the effect of addition of Lithium Bromide salt in isopropanol -water binary azeotropic mixture using extractive distillation is discussed. As LiBr is a high boiling point salt, it will not appear in the distillate and moreover LiBr is hygroscopic and has a characteristic to give higher boiling point elevation with water which is main cause of its use in this application. Addition of salt (40% of water) eliminates azeotrope formation and purity of 99.74% (by wt.) is achieved.