Salting-out precipitation of NaCl, KCl and NH4Cl in mixtures of water and methanol described by the modified Pitzer model

Abstract

Experimental data and modelling of electrolyte solutions are important in different fields. Separation and purification of such materials depend on knowledge of solid-liquid equilibrium as well as the mathematical models allow the development of solution theories and process simulators. Therefore, the current work presents the study of NaCl, KCl and NH4Cl solubility in binary liquid solutions formed by water and methanol at temperatures ranging from 288.15 K to 328.15 K. Solubility decreases with increasing methanol concentration and increases with increasing temperature, with the exception of the NaCl, where the temperature has a minimum effect on its solubility. The modified Pitzer model was applied to describe the solid-liquid equilibrium and its successful implementation also described the salting-out precipitation by the addition of an anti-solvent.