An electrolyte CPA equation of state for mixed solvent electrolytes

Bjørn Maribo-Mogensen, Kaj Thomsen, Georgios M. Kontogeorgis

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Despite great efforts over the past decades, thermodynamic modeling of electrolytes in mixed solvents is still a challenge today. The existing modeling frameworks based on activity coefficient models are data-driven and require expert knowledge to be parameterized. It has been suggested that the predictive capabilities could be improved through the development of an electrolyte equation of state. In this work, the Cubic Plus Association (CPA) Equation of State is extended to handle mixtures containing electrolytes by including the electrostatic contributions from the Debye-Hückel and Born terms using a self-consistent model for the static permittivity. A simple scheme for parameterization of salts with a limited number of parameters is proposed and model parameters for a range of salts are determined from experimental data of activity and osmotic coefficients as well as freezing point depression. Finally, the model is applied to predict VLE, LLE, and SLE in aqueous salt mixtures as well as in mixed solvents.
Original languageEnglish
JournalAIChE Journal
Volume61
Issue number9
Pages (from-to)2933-2950
Number of pages18
ISSN0001-1541
DOIs
Publication statusPublished - 2015

Keywords

  • Aqueous solutions
  • Electrochemistry
  • Thermodynamics/classical

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