A thermodynamic model for strong aqueous electrolytes based on the eSAFT-VR Mie equation of state

The latest formulation of the SAFT-VR Mie equation of state (EoS) is extended to solutions of salts which are assumed to be strongly dissociating in water through the addition of a Born term for accurate representation of the Gibbs energy of solvation, and a Debye-Htickel term for long-range, electrostatic interactions. Two adjustable parameters are assigned to each ionic species, the ion-solvent (here water) cross dispersion energy parameter and the ion segment diameter, which are optimized against experimental data for electrolyte solution densities and mean ionic activity coefficients. Model correlations for the activity coefficients and liquid densities, as well as predictions for vapor pressure and osmotic coefficients, show that the developed model performs accurately and, in many cases, is more accurate than other recent formulations for electrolyte solutions. Finally, a methodology for equation of state parameterization is presented to capture the non-monotonic temperature dependence of activity coefficient isotherms at low temperatures. (C) 2018 Elsevier B.V. All rights reserved.