BUBBLE PRESSURES AND SATURATED LIQUID MOLAR VOLUMES OF THE PROPANE (1)-DICHLOROTETRAFLUOROETHANE(2)-TRICHLOROTRIFLUOROETHANE(3) TERNARY-SYSTEM AND OF THE 3 CORRESPONDING BINARIES

An apparatus described previously has been used for the present measurements. It is based on a synthetic static method with a variable-volume cell. Results are given at different temperatures between 343 and 423 K for three binary mixtures: propane-dichlorotetrafluoroethane (C3H8-R114), propane-trichlorotrifluoroethane (C3H8-R113), dichlorotetrafluoroethane-trichlorotrifluoroethane (R114-R113), and the corresponding ternary propane-dichlorotetrafluoroethane-trichlorotrifluoroethane (C3H8-R114-R113). The two binaries with propane are well represented by a one-parameter delta(ij) Peng-Robinson equation of state to within less than 1% for pressures and 6%, without volume translation, for saturated liquid molar volumes. By using a volume translation, an improved volume representation, 2%, for the propane-dichlorotetrafluoroethane system is achieved. For the third binary system, delta(ij) = 0 is the best choice (representation is within 0.6% for pressure and 2% for molar volumes through a volume translation). Use of values of the binary interaction parameters delta(ij) established for binary systems enables good prediction of ternary data (representation to within 1% for pressures and 3.8% for saturated molar volumes). Volume translation does not improve the representation of the ternary saturated liquid molar volumes because it does not do it for the propane-trichlorotrifluoroethane system.