PVT PROPERTIES, VAPOR-PRESSURES AND CRITICAL PARAMETERS OF HFC-32

One hundred twenty three PVT data points for HFC-32 in the gaseous phase have been measured using Burnett method along fourteen isotherms for temperatures from 243 to 373 K, pressures from 0.07 to 5.7 MPa and densities from 1.8 to 240 kg m(-3). The present experimental PVT data, compared with the EOS developed by Piao et al., has an RMS deviation of 0.17%. Sixty vapor pressure data points for HFC-32 have also been measured for the temperature range from 233 to 351 K. The RMS deviation of the pressures in the present data from the vapor pressure equation developed by Piao et al. is 0.063%. Based on the present data and selected data from other investigators, a new vapor pressure equation for HFC-32 has been developed. By means of visual observation of the disappearance of the meniscus in an optical cell, the critical temperature, density and pressure for HFC-32 have been determined to be 351.295 +/- 0.010 K, 425 +/- 3 kg m(-3) and 5.785 +/- 0.002 MPa, respectively. The purity of the HFC-32 was 99.95 wt.%.