(591e) Phase, Interfacial, Derivative and Transport Properties of Aqueous Systems with the Soft-SAFT EoS

Water is a fascinating
molecule that exhibits a high complex non-ideal behaviour both as a pure fluid
and in mixtures from a thermophysical point of view. The modelling of water and
their mixtures is still an issue for scientists, as there is still not any
single model able to accurately reproduce all its thermophysical properties.
However, aqueous systems are present everywhere, and reliable tools are needed.

The goal of this contribution
is to present a simple but quite efficient model, within the framework of the
soft-SAFT molecular-based equation of state, for representing an important
amount of thermophysical properties of water and several aqueous systems,
including  water + CO₂, water + 1-alkanols and water + ionic
liquids. The vapour-liquid and liquid-liquid equilibria of these systems are
described in a wide range of temperatures and pressures in good agreement with
the experimental data. The calculation of the interfacial tension of some of these
mixtures is adressed using the Density Gradient Theory approach into soft-SAFT,
while the viscosity of these mixtures is also evaluated using the
Free-Volume-Theory (FVT). A further discussion about the ability of the model
to calculate some derivative and excess properties of interest is  included.

Acknowledgements: F. Llovell acknowledges a TALENT fellowship from the Generalitat
de Catalunya. This work was partially financed by the Spanish Government under
projects CTQ2008-05370/PPQ and CEN-2008-1027. Additional support from Carburos
Metálicos and the Catalan Government was also provided (2009SGR-666).