PHASE-EQUILIBRIA IN BINARY-MIXTURES OF PROPANE AND HEXACONTANE

This paper reports on the phase behaviour of binary mixtures of propane with hexacontane (n-C60H122). The measurements cover a temperature range from about 310 K up to 430 K. Pressures up to 15 MPa were applied. In the binary propane + hexacontane, a three-phase equilibrium liquid + liquid + vapour (l1 l2g) occurs in the near-critical region of propane. However, in this system the lower critical end point (LCEP) was hidden by solidification of hexacontane. The pressure temperature coordinates of the upper critical end point were determined at 369.95 K and 4.275 MPa. Because the three-phase equilibrium l1 l2 g is interrupted by the three-phase equilibrium, solid hexacontane + liquid + vapour (s(B)l(g)), a Q-point solid hexacontane + liquid + liquid + vapour (s(B)l1 l(2)g) is present in this binary. Its pressure and temperature coordinates were located at 352.0 K and 3.05 MPa.