A simplified local composition mixing rule on the basis of the UNIFAC equation

In this work,a simplified UNIFAC-based local compositi on mixing rule containing one or two adjustable parameters was proposed for the PRSV equation of state.The energy parameters λ_ji in the local composition expression were estimated by UNIFAC group contribution method and the local mole fraction was directly introduced into the EOS parameters a_m and b_m of mixture. High pressure vapor-liquid equilibria for 8 strongly non-ideal systems including polar-polar and nohpolar-polar binary systems were, arbitrarily selected for testing calculations. The results calculated by the proposed mixing rule are much better than those obtained by the conventional and HV mixing rules.