Phase equilibria modeling in aqueous systems containing 2-propanol and calcium chloride or/and magnesium chloride

Phase equilibria data (solid-liquid equilibria (SLE), vapor-liquid equilibria (VLE), liquid-liquid equilibria (LLE)) for CaCl2-2-PrOH-H2O, MgCl2-2-PrOH-H-O-2, and MgCl2-CaCl2-2-PrOH-H2O mixtures and results of modeling are considered. VLE measurements performed at 313.15, 333.15 and 353.15 K, and at pressure 1 bar have shown that the both salts exhibit salting-out effect in the range of high and middle water concentration. In the quaternary system the salting-out effect is higher than that estimated in approximation of additive contributions of two salts. The developed model takes into account hydration and solvation of ions. The mixture of various species (water, organic compound, "free", hydrated and solvated ions) is described as non-ideal using the UNIQUAC model and the extended form of the Pitzer-Debye-Htickel equation. The model gives a satisfactory description of VLE data in the studied systems. (C) 2002 Elsevier Science B.V. All rights reserved.