CALCULATION OF PHASE-EQUILIBRIA FOR SOLUTIONS OF STRONG ELECTROLYTES IN SOLVENT WATER MIXTURES

The Sander model for correlation and prediction of salt effects on vapor-liquid equilibria (VLE) combines a Debye-Hückel-type term with a modified UNIQUAC equation with concentration-dependent-parameters. The Debye-Hückel term has in this work been modified to ensure a more correct representation of the long-range forces. The modification has required a reestimation of previously published interaction parameters. It is shown that the modified model represents VLE for alcohol-water-salt mixtures with the same accuracy as the Sander model. The modified model has a broader range of applicability than the Sander model since the solvents acetone and 1-butanol have been added to water methanol ethanol, 1- and 2-propanol, and the ions Cu2+, Ba2+, Ni2+ Hg2+ Sr2+, F-, and I- have been included besides Li+, Na+, K+, Ca2+, Cl-, Br-, NO-3 and CH3COO-. © 1990.