Study of Vapor–Liquid Equilibria for Acetic Acid + n-Propyl Acetate + Isopropyl Acetate Systems

A mixture of acetic acid, n-propyl acetate, and isopropyl acetate, which needs to be separated, is obtained when isopropyl acetate is produced from acetic acid and propene. The vapor–liquid equilibria (VLE) for the acetic acid + n-propyl acetate + isopropyl acetate ternary system and three subsystems were studied with ebulliometry at (20, 40, 60, 80, and 101.3) kPa. The vapor-phase nonideality was described by the Hayden–O'Connell (HOC) equation, and the liquid-phase nonideality was represented by the NRTL model and the UNIQUAC model, respectively. The model parameters for acetic acid–n-propyl acetate, acetic acid–isopropyl acetate, and n-propyl acetate–isopropyl acetate were acquired from the experimental data with the aid of Aspen Plus. The maximum overall average deviation of temperature between the experiment and model predictions is 0.46 K for the NRTL-HOC model and 0.47 K for the UNIQUAC-HOC model. The VLE data and the model parameters acquired may provide basic information for the separation of isopropyl acetate by distillation.