Crossover PC-SAFT equations of state based on White's method for the thermodynamic properties of CO₂, n-alkanes and n-alkanols

In order to improve the prediction accuracy of the thermophysical properties of fluid in near critical region, in this work, White's renormalization group (RG) corrections were applied to construct the crossover PC-SAFT EoS (simplified as PC-SAFT-RG). We first fit the three parameters introduced by the crossover process to the experimental data, then the phase behavior as well as derivative properties in the critical region and outside the critical region for several fluids such as CO₂, n-alkanes and n-alkanols were investigated using the PC-SAFT EoS and the PC-SAFT-RG. Our results show that the PC-SAFT-RG is able to modify the behavior of the PC-SAFT EoS in the critical region and revert to classic behavior outside the critical region. The PC-SAFT-RG improves the PC-SAFT EoS's performances on the second derivative thermodynamic properties, with the average absolute relative deviations (AADs) of 9.96%, 6.99% and 3.91% for isobaric heat capacity, isochoric heat capacity and speed of sound respectively.