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.