(636h) An Investigation on the Utility of Association Electrolyte Nonrandom Two-Liquid Activity Coefficient Model for Aqueous Electrolyte Systems

Capturing the ion hydration and ion pairing phenomena due to association, the association electrolyte nonrandom two-liquid (association eNRTL) model accurately correlates mean ionic activity coefficient data of 46 aqueous single electrolyte systems from 10 cations and 5 anions commonly encountered in brines up to their solubility limits at 298.15 K. Moreover, with the ion-specific association parameters identified, the model reliably predicts activity and osmotic coefficients for aqueous mixed-electrolyte systems at 298.15 K (Y.-J. Lin, C.-J. Hsieh, and C.-C. Chen, AIChE Journal, 68 (2022) e17422). To further validate the utility of the association eNRTL model for practical applications, we report a comprehensive investigation in-progress of the model performance for various thermodynamic properties (mean ionic activity coefficient, osmotic coefficient, vapor pressure, and excess enthalpy) and for wide varieties of aqueous single and mixed-electrolyte systems with univalent, divalent, and trivalent ions. The association parameters are ion-specific and point out the association strength of individual ions. By quantifying the ion-specific association parameters, we explore the relationship between the association strength of ions with ionic radii and valence.