Journal of Chemical and Engineering Data, Vol.48, No.2, 317-323, 2003
Vapor-liquid equilibrium data for the azeotropic difluoromethane plus propane system at temperatures from 294.83 to 343.26 K and pressures up to 5.4 MPa
Isothermal vapor-liquid equilibrium data for the difluoromethane (R32) + propane binary system are presented at (278.10, 294.83, 303.23, 313.26, and 343.26) K and pressures up to 5.4 MPa. The experimental method is the static-analytic type. It takes advantage of mobile pneumatic capillary samplers (Rolsi, Armines' patent) developed in this laboratory. At a fixed temperature, the azeotrope vapor pressure is larger than those of the pure component. The R32 + propane azeotropic binary system presents two critical points in a specific temperature range. This behavior was verified and visually observed in two supplementary experiments with equipment based on the static-synthetic method involving a variable volume cell. Data along the five isotherms have been represented with the Soave-Redlich-Kwong (SRK) equation of state and MHV1 mixing rules involving the NRTL model. We have calculated the location of the azeotrope by using an equality of equation of state attractive parameters of the two phases.