Solubility, liquid–liquid equilibrium and critical states for the system acetic acid + n-propanol + n-propyl acetate + water at 293.15 K and 303.15 K

• Solubility data for acetic acid–n-propanol–n-propyl acetate–water system at 293.15 K and 303.15 K.
• LLE tie-lines and critical states of LLE for quaternary system have been determined.
• The data for two ternary sub-systems with miscibility gap are presented.
• The LLE data have been calculated by using UNIFAC and NRTL models.

Solubility and liquid–liquid equilibrium (LLE) for the quaternary system acetic acid–n-propanol–n-propyl acetate–water and for the ternary sub-systems acetic acid–n-propyl acetate–water and n-propanol–n-propyl acetate–water were studied at 293.15 K and 303.15 K and atmospheric pressure. Binodal surfaces and curves, tie-lines, and compositions of critical LLE points were determined. Experimental LLE data were correlated by UNIFAC and NRTL models.