Effect Of Addition Of Calcium Chloride On Separation Of Acetic Acid-Water Mixture By Extractive Distillation

The study of influence of salt on vapour liquid equilibrium of solvent mixture is of interest, because addition of salt to a mixed solvent will enhance the relative volatility and break azeotrope of the mixture.Salt-Effect distillation is a method of Extractive distillation in which salt is dissolved in the mixture of liquids to be distilled. The salt acts as a separating agent by raising the relative volatility of the mixture and by breaking any azeotropes that may otherwise form.Vapour-liquid equilibrium (VLE), is a condition where a liquid and its vapour (gas phase) are in equilibrium with each other or more precisely a state where the rate of evaporation equals the rate of condensation on a molecular level such that there is no overall vapor-liquid inter-conversion. The addition of calcium chloride to this solvent mixture increases the water concentration in vapour phase at equilibrium. This indicates a preferential association of salt with less volatile component, acetic acid in the acetic acid-water mixture, water is more volatile component in acetic acid-water mixture. Most of the Salt effect studies were carried out at saturated level of salt. The objective is to study the effect of addition of CaCl2 on separation of Acetic acid ? water mixture and to find out the possibility of the use of concentrated solution of CaCl2 as a solvent for separating dilute solution of acetic acid in water by extractive distillation process.