Chemical Engineering Communications, Vol.166, 35-56, 1998
Prediction of phase equilibria in binary mixtures using an improved equation of state and a theoretically consistent mixing rule
Prediction of thermodynamic properties and phase equilibria in fluid mixtures using a simple cubic equation of state is still a challenging problem. In this paper, we have predicted vapor/liquid phase equilibria of several binary fluid mixtures using our previously developed improved Peng-Robinson equation of state and a theoretically consistent mixing rule. Our mixing rule combines the mixing rule of Wong-Sandler with a physically based combination rule. Mixtures are composed of nonpolar, nonassociating polar and associating polar fluids. Comparisons of theoretical predictions with experimental data show a very good performance of our approach in describing vapor/liquid phase equilibria of several mixtures, namely, carbon dioxide/propane, ethane/hexane, butane/methanol, benzene/methanol, acetone/methanol, methanol/ethanol, methanol/1-butanol, methanol/water and ethanol/water.
Keywords:VAPOR-LIQUID-EQUILIBRIA;PENG-ROBINSON EQUATION;CUBIC EQUATIONS;HYDROCARBON SYSTEMS;ENERGY MODELS;PRESSURE;UNIFAC;PARAMETERS;POLAR