Unifac prediction of vapor—liquid equilibria in mixed solvent—salt systems

✍ Scribed by Ireneo Kikic; Maurizio Fermeglia; Peter Rasmussen

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 491 KB
• Volume: 46
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(91)85146-o

✦ Synopsis

Sander model for correlation and prediction of salt effects on vapor-liquid equilibria (VLE) of mixed solvents combines a term of the Debye-Hiickel type with a modified UNIQUAC equation with concentration dependent parameters. In this work the UNIQUAC equation has been substituted by the original UNIFAC group-cuntribulion model with concentration independent group interaction parameters. Group interaction parameters have been estimated between 1011s (Li+, Naf, K', Cazf, Ba'+, Sr*+, Cu2+, Ni 2+ HgZf, F-, Cl-, Br-, J-, NO; and CH,COO-), and solvent groups (CH,, OH, CH,OH, , H,O, CH,CO). while previously published group interaction parameters between solvent groups have been maintained. It is shown that the proposed model represents VLE for solvent-water-salt mixtures with an expected average accuracy of the total pressure around 9% and of the vapor-phase mole fractions around 4%. Since it is a predictive group-contribution m&hod it has a-much broader range of applicability than the Sander model.