Salt Effects on Vapor Liquid Equilibrium of Acetic Acid-Water System

Abstract

The vapor-liquid equilibrium of several acetic acid-water-salt systems under atmospheric pressure was determined by employing lithium nitrate, magnesium nitrate, potassium nitrate, and potassium acetate as salts. In the vapor-liquid equilibrium of an acetic acid-water-salt system, lithium nitrate, magnesium nitrate, and potassium nitrate showed a salting-out effect, while potassium acetate showed a salting-in effect. The vapor-liquid equilibria with the nitrate, chloride, bromide, and acetate salts at a salt concentration of 1.0 mol/kg were also determined, and it was shown that by keeping the anion the same and changing the cations of salts with those having a smaller hydration enthalpy showed an increased salting-out effect. Alternatively, when the cation was kept the same, the salts showed the salting-out effect in the following order: chloride > bromide > nitrate > acetate salts; the acetate salt showed a salting-in effect.