153d A Statistical Associating Fluid Theory for Electrolyte Solutions

Honggang Zhao and Clare McCabe. Department of Chemical Engineering, Vanderbilt University, Nashville, TN 37235-1604

The statistical associating fluid theory (SAFT) [1, 2] has proven to be a powerful equation of state for modeling complex fluids and their mixtures. In the present work, we extended a version of the SAFT-VR [3] equation, which models non-conformal fluids with potentials of variable attractive range, to describe several aqueous strong electrolytes. Good agreement is obtained between the theoretical calculations and the experimental data for the density and vapor pressure of several aqueous strong electrolytes. Additionally the approach describes the salting-out effect of aqueous strong electrolytes well, using SAFT-VR parameters for gases obtained in earlier work [4].

References

1. Chapman, W. G., K. E. Gubbins, G. Jackson, and M. Radosz, "SAFT - Equation-of-State Solution Model for Associating Fluids," Fluid Phase Equilibria, 52, 31-38 (1989). 2. Chapman, W. G., K. E. Gubbins, G. Jackson, and M. Radosz, "New reference equation of state for associating liquids," Industrial & Engineering Chemistry Research, 29, 1709-1721 (1990). 3. Gil-Villegas, A., A. Galindo, P. J. Whitehead, S. J. Mills, G. Jackson, and A. N. Burgess, "Statistical associating fluid theory for chain molecules with attractive potentials of variable range," Journal of Chemical Physics, 106, 4168-4186 (1997). 4. McCabe, C. and G. Jackson, "SAFT-VR modelling of the phase equilibrium of long-chain n-alkanes," Physical Chemistry Chemical Physics, 1, 2057-2064 (1999).