Solubility of K2SO4, Li2SO4, and (NH4)2SO4 in mixtures of water and methanol at different temperatures: Experimental and application of the modified Pitzer model

The study of electrolyte solutions is crucial for various industrial sectors. A thorough understanding of the solid-liquid equilibrium associated with mathematical models is necessary for the separation and purification of these materials, as well as for developing solution theories and process simulators. This study focuses on the solubility of K2SO4, Li2SO4, and (NH4)2SO4 in binary liquid solutions of water and methanol, at temperatures ranging from 283.2 K to 323.2 K. The results show that as the concentration of methanol increases, solubility decreases drastically while increasing temperature leads to an increase in solubility (except for Li2SO4). The modified Pitzer model was successfully applied to describe the solid-liquid equilibrium, and it also explained the salting-out precipitation by the addition of an antisolvent.