LIQUID-LIQUID-VAPOR EQUILIBRIA IN BINARY FAMILIES OF SF6, CCLF3, C2H3F3, AND C2H4 WITH N-ALKANES

Liquid-liquid-vapor equilibria were determined experimentally for bina ry and quasi-binary systems which consisted of a low-volatile n-alkane or mixture of n-alkanes with a more volatile component, chlorotrifluo romethane, sulfur hexafluoride, 1,1,1-trifluoroethane, and ethene. Fro m the location of the critical endpoints L-2 = L-1 + T/ and L-2 + L-1 = V of the three-phase curves, the coordinates of the tricritical poin t and the double critical endpoint of these families were estimated by extrapolation. For the families studied it was found that increasing the carbon number of the n-alkane leads to a transition from type II t o type IV to type III fluid phase behavior.