Predicting the thermodynamic properties and dielectric behavior of electrolyte solutions using the SAFT-VR+DE equation of state

Gaurav Das, Stepan Hlushak, M. Carolina dos Ramos, Clare McCabe*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)

Abstract

We extend the SAFT-VR+DE equation of state to describe 19 aqueous electrolyte solutions with both a fully dissociated and a partially dissociated model. The approach is found to predict thermodynamic properties such as the osmotic coefficient, water activity coefficient, and solution density, across different salt concentrations at room temperature and pressure in good agreement with experiment using only one or two fitted parameters. At higher temperatures and pressures, without any additional fitting, the theory is found to be in qualitative agreement with experimental mean ionic activities and osmotic coefficients. The behavior of the dielectric constant as a function of salt concentration is also reported for the first time using a statistical associating fluid theory (SAFT)-based equation of state. At high salt concentrations, the stronger electrostatic interactions between the ionic species due to the dielectric decrement, is captured through the inclusion of ion association.

Original languageEnglish
Pages (from-to)3053-3072
Number of pages20
JournalAIChE Journal
Volume61
Issue number9
DOIs
Publication statusPublished - Sep 2015

Keywords

  • Aqueous solutions
  • Liquids
  • Mechanics
  • Salt
  • Thermodynamics/statistical
  • Water activity

ASJC Scopus subject areas

  • Biotechnology
  • Environmental Engineering
  • Chemical Engineering(all)

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