Prediction of vapor-liquid equilibria in symmetric polar systems with G(E)-EOS mixing rules based on UNIFAC

A G(E)-EOS mixing rule based on UNIFAC '93, is shown to be useful for makin g vapor-liquid equilibrium predictions for symmetric polar mixtures at high temperatures and pressures. We compare the performances of this mixing rul e (called HVID model), coupled with the SRK equation of state and a reduced UNIQUAC model, with those of Dahl and Michelsen (MHV2). Six binary systems are used in this study, and we find that the errors in the predicted press ure with the clew mixing rule are, on the average, less than those obtained when using the MHV2 model.