Modification of the Furter equation and correlation of the vapor-liquid equilibrium for mixed-solvent electrolyte systems

Isobaric vapor-liquid equilibrium values at 1 atm pressure were measured for the systems 1-propanol-water-potassium acetate and 2-propanol-water-potassium acetate under fixed salt mole fractions using a modified Othmer recirculation still. A modified Furter equation, In(alpha(s)/alpha) = k(1)z + k(2)z(2), was proposed for correlating the effect of dissolved salts on vapor-liquid equilibrium (VLE). The modified equation contains two parameters that are applicable to the entire salt/solvent composition range. Correlation of VLE for 15 mixed-solvent electrolyte systems was made by means of the proposed modified equation with better results than those obtained from the original equation. (C) 1999 Elsevier Science B.V. All rights reserved.