Application of SAFT–VRX to binary phase behaviour: alkanes

Abstract

In previous work, we developed the crossover SAFT–VR equation of state (SAFT–VRX) for pure fluids by following the crossover approach proposed by Kiselev. The SAFT–VRX equation was shown to be very accurate in the prediction of PVT and phase behaviour for both non-associating and associating fluids. In particular, simple expressions for the potential model parameters for the n-alkane homologous series were developed, allowing the prediction of the thermodynamic properties without fitting to experimental data. In this work, we have applied the SAFT–VRX equation to binary mixtures of short-chain n-alkanes, using the prescriptions for the model parameters developed previously to determine the pure fluid parameters. The SAFT–VRX equation is found to accurately predict the gas–liquid critical locus and vapor–liquid equilibrium data for the systems studied without fitting to binary experimental mixture data.