Following our study on the Hydrogen-bonding of HFCs with dimethyl ether, the VLE (P-T-x-y) data for the pentafluoroethane (R125) + dimethyl ether (RE170) and R125 + propane (R290) systems are measured at 258.15 K, 273.15 K, 288.15 K and 303.15 K by means of an apparatus based on the vapour recirculation. The estimated accuracies of measured data are ±0.02 K for temperature, ±1 kPa for pressure, ±0.002 in mole fraction for both liquid and vapour phase by gas-chromatographic analysis. The R125+RE170 system shows strong negative deviations from the Raoult's law. The deviations are attributed to H-bonding between oxygen of RE170 as proton acceptor and hydrogen of R125 as proton donor. The H-bonding for the R125+RE170 system is estimated through the homomorphic concept, evaluating the physical interaction through excess Gibbs energy of the homomorphic R125+propane system. The data for R125+propane system were reduced by means of a RKS EoS with classical mixing rules. To improve the reduction for the system R125+RE170, the Huron-Vidal mixing rule and NRTL model for the excess energy were used, while the virial equation of state was applied to calculate the fugacity of the vapour phase.
Hydrogen-bonding of hfcs with Dimethyl Ether: evaluation by isothermal VLE measurements
Bobbo S;Fedele L;Camporese R;
2002
Abstract
Following our study on the Hydrogen-bonding of HFCs with dimethyl ether, the VLE (P-T-x-y) data for the pentafluoroethane (R125) + dimethyl ether (RE170) and R125 + propane (R290) systems are measured at 258.15 K, 273.15 K, 288.15 K and 303.15 K by means of an apparatus based on the vapour recirculation. The estimated accuracies of measured data are ±0.02 K for temperature, ±1 kPa for pressure, ±0.002 in mole fraction for both liquid and vapour phase by gas-chromatographic analysis. The R125+RE170 system shows strong negative deviations from the Raoult's law. The deviations are attributed to H-bonding between oxygen of RE170 as proton acceptor and hydrogen of R125 as proton donor. The H-bonding for the R125+RE170 system is estimated through the homomorphic concept, evaluating the physical interaction through excess Gibbs energy of the homomorphic R125+propane system. The data for R125+propane system were reduced by means of a RKS EoS with classical mixing rules. To improve the reduction for the system R125+RE170, the Huron-Vidal mixing rule and NRTL model for the excess energy were used, while the virial equation of state was applied to calculate the fugacity of the vapour phase.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.