Experimental study and modeling of the salting-out effect of KCl on the liquid-liquid equilibria of the ternary system (water plus propionic acid plus dichloromethane) at 296.65 K

The effect of potassium chloride on the liquid-liquid phase equilibria of the ternary system water-propionic acid-dichloromethane was considered experimentally at 296.65 K, at different salt mass fractions of 5%, 10% and 15%, in the quaternary mixture. The binodal and tie line data were determined by cloud point measurements method and the results showed that the addition of the salt has effectively affected LLE of water-propionic acid-dichloromethane, with a salting out of the propionic acid from the aqueous solution to the dichloromethane phase, particularly at high salt concentrations. The experimental data were correlated considering a modified version of the NRTL model and the deviations between experimental and calculated compositions in both phases for the ternary system using this model were less than 1%. The obtained results confirmed the ability of the NRTL model for the correlation of liquid-liquid equilibrium data for the considered quaternary system water (1)-propionic acid (2)-dichloromethane (3)-potassium chloride (4).