AN EXTENSION TO THE UNIFAC GROUP ASSIGNMENT FOR PREDICTION OF VAPOR-LIQUID-EQUILIBRIA OF MIXTURES CONTAINING REFRIGERANTS

All previously published vapor-liquid equilibrium data points for binary mixtures containing fluorinated hydrocarbons have been taken into account to develop an extension to the UNIFAC group assignment for common refrigerants. It is shown that ten new main groups are necessary to describe all the various forms of halogenated refrigerants. The accuracy of this extension is within the range usually obtained with the UNIFAC method. Furthermore, experimental data for the systems R134a-R23, R134a-R13, R134a-R114, R13B1-R23, R134a-dimethyl ether, R13B1-R13 and R142b-dimethyl ether have been obtained between 251 and 298 K, and pressures up to 2 MPa. The consistency of the data has been shown by a maximum-likelihood method.