On the Treatment of Electrostatic Interactions of Non-spherical Molecules in Equation of State Models

Abstract

For predictive applications, equation of state (EOS) models have to describe all relevant physical interactions accurately. In this contribution, the vapor–liquid equilibria of various dipolar two-center Lennard-Jones model molecules are determined by molecular simulation, as function of molecular elongation and deflection angle of the dipole. It is shown that present PC-SAFT-based EOS models require additional adjustable parameters in order to describe the orientational effects of the dipole-moment. We present extensions of the model to avoid the additional parameters and apply the extended equations to model systems and real molecules.

Keywords:

• Chemical thermodynamics
• Continuum solvation model
• COSMO
• Molecular properties
• Perturbation theory
• Phase equilibria
• Prediction
• SAFT
• Vapor-liquid

ACKNOWLEDGMENTS

We gratefully acknowledge financial support from the German Research Council (Deutsche Forschungs Gemeinschaft, DFG) within the priority programme SPP 1155 by grant LE2221/2 and through the cluster of excellence “Tailormade Fuels From Biomass” (EXC236) as well as from the GRANT program of the Delft University of Technology.