M Yazdizadeh - School of Chemical and Petroleum Engineering, Shiraz University, ۷۱۳۴۸-۵۱۱۵۴ Shiraz, Iran
H Nourbakhsh - School of Chemical and Petroleum Engineering, Shiraz University, ۷۱۳۴۸-۵۱۱۵۴ Shiraz, Iran
V Zabihi - School of Chemical and Petroleum Engineering, Islamic Azad University, Dezful Branch, Dezful, Iran.
A Tofighi - School of Chemical and Petroleum Engineering, Islamic Azad University, Dezful Branch, Dezful, Iran.

Application of supercritical CO2 for separation of ionic liquids from their organic solvents or extraction of various solutes from ionic liquid solvents have found great interest during the recent years. Therefore, knowledge of phase behaviors of the mixtures of supercritical CO2 + ionic liquids is drastic in order to efficiently design such separation processes. In this work, the most famous two-parameter Soave- Redlich- Kwong (SRK), and the Peng-Robinson (PR) cubic equations of state (CEoS) accompanied with three mixing rules including the Wong-Sandler (WS), the van der Waals one (vdW1), and the van der Waals two (vdW2) have been applied to study the phase behaviors of mixtures of supercritical CO2 in 4 mostly-used ionic liquid compounds. The results show that the set of the PR EoS along with the WS mixing rule lead to the least absolute deviations of the calculated/predicted equilibrium pressures from existed experimental values from the literature.

Cubic equation of state, Ionic liquid, Supercritical CO2, Phase behavior, Separation