Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

In this study, we report phase behavior data for propylene + toluene and ethylene + toluene mixtures at temperatures to 580 K and pressures to 8.5 MPa. We also report high-pressure, mixture density data for the two mixtures at temperatures to 555 K and pressures to 70 MPa. Both the phase behavior and density data are simultaneously determined using a windowed variable-volume, high-pressure view cell coupled with a linear variable differential transformer. The phase behavior and mixture density data are modeled with the Soave-Redlich-Kwong (SRK), Peng-Robinson (PR), Modified Sanchez-Lacombe (MSL), and Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) equations of state (EoS). The PC-SAFT and MSL EoS provide very good fits of the phase behavior for both the propylene + toluene and ethylene + toluene systems with each binary interaction parameter, kij, set to zero. The PC-SAFT equation also provides the best fit of the high-pressure, mixture density data for the ethylene + toluene system. However, the SRK EoS provides the best fit of the high-pressure, mixture density data for the propylene + toluene system. Although both equations slightly over predict the solution density for the two studied systems, the fit of the densities are insensitive to small variations in kij.