Multiphase equilibria for mixtures containing water, acetic acid, propionic acid, methyl acetate and methyl propionate

Isobaric vapor–liquid equilibrium (VLE) data were measured for the binary mixtures of acetic acid + methyl propionate, propionic acid + methyl acetate, propionic acid + methyl propionate, and methyl propionate + methyl acetate in a temperature range of 330.05–413.15 K at 101.3 kPa. Isothermal vapor–liquid–liquid equilibrium (VLLE) data were also measured for water + methyl acetate + methyl propionate over a pressure range of 43.7–157.0 kPa at 323.24 and 343.15 K. The NRTL-HOC and the UNIQUAC-HOC models with the model parameters determined from the phase equilibrium data of the constituent binaries were applied to predict the VLLE properties for water + methyl acetate + methyl propionate. The validity of the prediction from the UNIFAC-HOC and the UNIFAC-Lyngby-HOC was also tested with the ternary VLLE data. Additionally, the best-fitted values of the six binary parameters of the UNIQUAC-HOC were determined, simultaneously, from the isothermal VLLE ternary data as well.