Vapor-liquid equilibria and critical points of the CO₂ + 1-hexanol and CO₂ + 1-heptanol systems

Vapor-liquid equilibria (VLE), vapor-liquid-liquid equilibria (VLLE) and critical point (CP) data for the carbon dioxide+1-hexanol (at 324.56, 353.93, 397.78, 403.39, 431.82 and 432.45K up to 20MPa) and carbon dioxide+1-heptanol (at 313.14, 333.16, 373.32, 411.99 and 431.54K up to 21MPa) systems are reported. Phase behavior measurements were made in a new equilibrium cell based on the static-analytic method and capable of measurements up to 60MPa and 673K. The Peng-Robinson equation of state (EoS) with the Wong-Sandler mixing rules and temperature independent parameters was able to correlate and extrapolate the VLE for the carbon dioxide+1-hexanol system. However, in order to obtain good agreement with experimental data for the carbon dioxide+1-heptanol system, the mixture EoS parameters were adjusted to the experimental VLE data at each temperature.