Measurement and correlation of liquid–liquid equilibrium data for water + methanol + methyl acetate + potassium acetate

•LLE data for water + MeOH + MA were measured at 303.15 K.•LLE data for water + MeOH + MA + KAc were measured at 283.15 K and 303.15 K.•The two phase region and separation factors increased with the increasing of KAc.•The consistency of the results was tested with the Othmer–Tobias and Bachman equations.•The experimental data could be correlated well with the modified NRTL model.

In this paper, liquid–liquid equilibrium (LLE) data for a ternary system of water + methanol (MeOH) + methyl acetate (MA) at 303.15 K and a quaternary system of water (1) + MeOH (2) + MA (3) + potassium acetate (KOAc) at 283.15 K and 303.15 K have been measured at atmospheric pressure. Liquid-phase splitting of the ternary system water + MeOH + MA can be enhanced by adding KOAc salt. Distribution coefficients and separation factors corresponding to different concentrations of KOAc are obtained and the salt-out effects of calcium chloride and KAc have been compared. A modified non-random two-liquid (NRTL) model was used to correlate the experimental data, which considers the salt-effect on LLE. The model shows good performance for this correlation.