Isothermal vapor-liquid equilibria (VLE) for the binary systems difluoromethane (R32) + 1,1,1,3,3,3-hexafluoropropane (R236fa) and pentafluoroethane (R125) f 1,1,1,3,3,3-hexafluoropropane (R236fa) were measured at 303.2 and 323.3 K using a recirculation apparatus in which the vapor phase was forced through the liquid. The phase composition at equilibrium was measured by gas chromatography, calibrating its response using gravimetrically prepared mixtures. Both systems show a slight deviation from Raoult's law. The data were reduced by the Carnahan-Starling-De Santis EOS. The deviations observed in vapor composition, averaging below 0.003 in mole fraction, confirm the consistency of the experimental findings and the model used for their reduction. Calculated excess Gibbs energy functions reveal values to be within +/-40 J mol(-1) at T = 303 K. The margins of error in pressure, temperature, and composition of vapor and liquid-phase measurements were estimated to be less than +/-0.15%, +/-0.005 K, and +/-0.0015 of mole fraction, respectively
Vapor-liquid equilibria for difluoromethane (R32) plus and pentafluoroethane (R125) plus 1,1,1,3,3,3-hexafluoropropane (R236fa) at 303.2 and 323.3 K
Bobbo S;Camporese R;
1999
Abstract
Isothermal vapor-liquid equilibria (VLE) for the binary systems difluoromethane (R32) + 1,1,1,3,3,3-hexafluoropropane (R236fa) and pentafluoroethane (R125) f 1,1,1,3,3,3-hexafluoropropane (R236fa) were measured at 303.2 and 323.3 K using a recirculation apparatus in which the vapor phase was forced through the liquid. The phase composition at equilibrium was measured by gas chromatography, calibrating its response using gravimetrically prepared mixtures. Both systems show a slight deviation from Raoult's law. The data were reduced by the Carnahan-Starling-De Santis EOS. The deviations observed in vapor composition, averaging below 0.003 in mole fraction, confirm the consistency of the experimental findings and the model used for their reduction. Calculated excess Gibbs energy functions reveal values to be within +/-40 J mol(-1) at T = 303 K. The margins of error in pressure, temperature, and composition of vapor and liquid-phase measurements were estimated to be less than +/-0.15%, +/-0.005 K, and +/-0.0015 of mole fraction, respectivelyI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.