Thermal Properties and Phase Behavior of Water - n-pentane and Water -n-hexane Systems

The pvTx properties of H2O-n-C5H12 and H2O-n-C6H14 mixture have been measured in the temperature interval 303-680 K and pressure up to 60 MPa. Measurements were made along 265 liquid and vapor isochors in the density range 63-713 kg/m3. Measurements were made for 15 concentrations between 0.110 and 0.987 mole fraction of H2O for mixtures with C5H12 and 11 concentrations between 0.166 and 0.977 for mixtures with C6H14. The temperatures and pressures at the three-phase and two-phase boundary curves for the mixtures were obtained using the isochoric (p-T) break point technique. The critical properties data of the upper and lower branches of the critical curves were extracted from the derived phase boundary data. The measured three-phase data were used to estimate the value of the upper critical end point.