Calculation of Thermodynamic Equilibria with the Predictive Electrolyte Model COSMO-RS-ES: Improvements for Low Permittivity Systems

Abstract

The predictive electrolyte model COSMO-RS-ES is refined to improve the description of systems at 25°C in which strong ion pairing is expected due to a low static permittivity of the liquid phase. Furthermore, the short-range ion energy interaction equations have been modified to better describe the misfit and energy interaction terms between ions and solvent molecules. In addition, the salt solubility database is extended with additional non-aqueous systems containing solvents that have a low (ε_s<15) dielectric constant and promote near to full ion association. Throughout this work it is demonstrated that liquid-liquid equilibrium calculations and solid-liquid equilibrium predictions for electrolyte systems can be markedly improved with the inclusion of Bjerrum treatment based phenomenological considerations while introducing only one general additional parameter. Our modified approach reinforces the capabilities of COSMO-RS ES as a powerful predictive tool for the calculation of phase equilibria in systems with scarce experimental data.

References in corpus (4)

• The Electrostatic Screening Length in Concentrated Electrolytes Increases with Concentration
• Underscreening in concentrated electrolytes
• Are Room Temperature Ionic Liquids Dilute Electrolytes?
• Evaluation and Refinement of the novel predictive electrolyte model COSMO-RS-ES based on solid-liquid equilibria of salts and Gibbs free Energies of Transfer of Ions

Cited by in corpus (4)

• On the analogy between the restricted primitive model and capacitor circuits: Semi-empirical alternatives for over- and underscreening in the calculation of mean ionic activity coefficients
• On the analogy between the restricted primitive model and capacitor circuits. Part II: A generalized Gibbs-Duhem consistent extension of the Pitzer-Debye-Hückel term with corrections for low and variable relative permittivity
• Impact of extended long-range electrostatics on the correlation of liquid-liquid equilibria in aqueous ionic liquid systems
• Thermodynamic modeling using Extended UNIQUAC and COSMO-RS-ES models: Case study of the cesium nitrate - water system over a large range of temperatures