Fluorinated Liquids: High-Pressure Phase Equilibrium with Carbon Dioxide

Fluorinated alkyl segments exhibit a heightened affinity for the dissolution of light gases, as evident by the increased solubility of carbon dioxide in compounds containing a fluorinated alkyl segment compared to their nonfluorinated counterparts. Despite this, published experimental phase equilibrium data related to the solubility of carbon dioxide in fluorinated compounds remain limited, with the available data comprising mostly fluorinated hydrocarbons. This work measured high-pressure phase equilibrium data at three temperatures over 273.15–313.15 K and pressures up to approximately 7.5 MPa. The data include binary carbon dioxide systems with perfluoroheptane, perfluorooctane, perfluorononane, or 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether. The data were modeled using the Peng–Robinson equation of state with either the van der Waals or Wong–Sandler mixing rules.