Implementing and testing different models of the static permittivity in e-CPA (electrolyte CPA equation of state)

Abstract

Electrolytes are a part of many industrially relevant applications and systems and good understanding of electrolyte thermodynamics is important to be able to describe these systems well.

When investigating thermodynamics of electrolyte solutions it has been found necessary to analyze the fundamental aspects because there are several unanswered questions.

One such question is how the relative static permittivity should be considered within an electrolyte equation of state type model.

Especially, it is uncertain if the salt concentration dependency of the static permittivity should be considered or if the value of the pure solvent should be used. Both methods have been applied in different published models.

In this seminar, several different models of the relative static permittivity will be discussed.

To attempt to determine the best approach, the different models of the relative static permittivity has been implemented within the electrolyte cubic plus association (e-CPA) equation of state.

The parameters of e-CPA are optimized with each of the models of the relative static permittivity. The results are compared for their ability to describe other thermodynamic properties.