title: Predicting mixture phase equilibria and critical behavior using the SAFT-VRX approach.
abstract: The SAFT-VRX equation of state combines the SAFT-VR equation with a crossover function that smoothly transforms the classical equation into a nonanalytical form close to the critical point. By a combinination of the accuracy of the SAFT-VR approach away from the critical region with the asymptotic scaling behavior seen at the critical point of real fluids, the SAFT-VRX equation can accurately describe the global fluid phase diagram. In previous work, we demonstrated that the SAFT-VRX equation very accurately describes the pvT and phase behavior of both nonassociating and associating pure fluids, with a minimum of fitting to experimental data. Here, we present a generalized SAFT-VRX equation of state for binary mixtures that is found to accurately predict the vapor-liquid equilibrium and pvT behavior of the systems studied. In particular, we examine binary mixtures of n-alkanes and carbon dioxide + n-alkanes. The SAFT-VRX equation accurately describes not only the gas-liquid critical locus for these systems but also the vapor-liquid equilibrium phase diagrams and thermal properties in single-phase regions.
authors.affiliation: Department of Chemical Engineering, Vanderbilt University, Nashville, Tennessee 37235-1604, USA.
authors.forename: Lixin
authors.initials: L
authors.lastname: Sun
authors.forename: Honggang
authors.initials: H
authors.lastname: Zhao
authors.forename: Sergei B
authors.initials: SB
authors.lastname: Kiselev
authors.forename: Clare
authors.initials: C
authors.lastname: McCabe