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 bina ry mixtures containing fluorinated hydrocarbons have been taken into a ccount to develop an extension to the UNIFAC group assignment for comm on refrigerants. It is shown that ten new main groups are necessary to describe all the various forms of halogenated refrigerants. The accur acy of this extension is within the range usually obtained with the UN IFAC 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 pr essures up to 2 MPa. The consistency of the data has been shown by a m aximum-likelihood method.