An implicit type EOS-GE(VP) model employing vapor pressure standard state I. Prediction of high-pressure vapor-liquid equilibria based on low temperature data

The implicit type EOS-GE0 model at zero pressure has been successfully used for prediction of thermodynamic properties with available excess free energy model parameters. It has been pointed out however that this model needs an extrapolation procedure at reduced temperatures above about 0.85 and the extrapolation procedure is rather cumbersome. s paper, an implicit type EOS-GE model which requires no extrapolation method is proposed. This proposed model (EOS-GE(VP)) employs a standard state for the mixing process which is the vapor pressure of the most volatile component at the temperature of the mixture. Using this EOS-GE(VP) model with the Soave-Redlich-Kwong equation of state and the Wilson and NRTL equations, vapor-liquid equilibria including near-critical and super-critical components have been predicted for 8 binary systems consisting of 50 data sets.