A static VLE apparatus has been used for the measurement of the (vapour + liquid + liquid) equilibrium of the (propylene + isopropanol + water) system at
T = 313.15 K and pressures between (1.381 and 1.690) MPa. Using an isothermal flow calorimeter,
HE values have been obtained for the binary system (isopropanol + water) over the temperature range from (313.15 to 353.15) K and pressures from (3.8 to 4.19) MPa. For the pseudo-binary mixture (propylene + (isopropanol + water)),
HE values have been measured in the temperature range from (313.15 to 353.15) K and pressures from (1.997 to 5.89) MPa. This last mixture was studied starting from (isopropanol + water) at 0.25, 0.50, and 0.75 molar compositions in isopropanol. The new data, together with the available phase equilibrium and
HE data from the literature, have been regressed by a conventional
GE–EoS model reaching satisfactory results, except for the VLLE representation.