Vapor-liquid equilibria for binary systems carbon dioxide 1,1,1,2,3,3-hexafluoro-3-(2,2,2-trifluoroethoxy)propane or 1-ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane at 303.15-323.15 K

The phase behavior of binary mixtures of carbon dioxide (CO2) and hydrofluoroethers (HFEs) has been studied. In particular, experimental vapor-liquid equilibrium (VLE) data for CO2 + 1,1,1,2,3,3-hexafluoro-3-(2,2,2-trifluoroethoxy)propane (HFE-449mec-f) and 1-ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane (HFE-7200) at temperatures of 303.15, 313.15, and 323.15 K are reported. The VLE data were measured using a static-type apparatus and then correlated using the Peng-Robinson equation of state with the van der Waals one fluid and Wong-Sandler-NRTL mixing rules. Reasonable correlation results were obtained from the Peng-Robinson equation of state with both the van der Waals one fluid and the Wong-Sandler-NRTL mixing rules. The GC-SAFT-VR equation also gave good predictions of the phase behavior. Additionally, the group contribution SAFT-VR (GC-SAFT-VR) equation was used to predict the experimental VLE in good agreement with the experimental data, as well as the full p,T phase diagram for both systems