Perturbation theory of dipolar hard spheres: The vapour-liquid equilibrium of strongly polar mixtures

Abstract

Winkelmann, J., 1983. Perturbation theory of dipolar hard spheres: the vapour-liquid equilibrium of strongly polar mixtures. Fluid Phase Equilibria 11: 207-224.Thermodynamic perturbation theory has been applied to calculate vapour-liquid equilibria (VLE) for binary mixtures of polarizable, dipolar hard-sphere fluids. Effective potential parameters determined previously from the vapour pressures of pure compounds are used to represent the intermolecular interactions in strongly polar and associating fluids. The one-fluid conformal-solution approach is adopted.With a binary correction factor k12 the theory is found able to predict VLE over wide ranges of temperature and pressure. A similar procedure yields a calculated azeotropic line. In the case of hydrogen-bond formation, a temperature-dependent k12 reproduces both GE and HE at various temperatures and results in a rather exact azeotropic line.