Thermodynamic Consistency of High Pressure Phase Equilibrium Data of Ternary Gas-Solid-Solid Mixtures

摘要

A thermodynamic consistency test developed by the authors is applied to high pressure phase equilibrium data of ternary mixtures containing a compressed gas and two solid solutes. The experimental data have been modeled using the Peng-Robinson equation of state with classical van der Waals mixing rules. These type of mixtures are ussualy highly asymmetric and present inherent difficulties of analysis, in particular because of the dispersion of the data and the very low concentration of the solutes in the compressed gas phase. Despite this, the model employed allows correlating the solubility of the solids in the high pressure gas with deviations much lower than other models. The complex Mixture carbon Flioxide+capsaicin+b-carotene is used as a study case. It is shown that the thermodynamic test can be applied with confidence and consistency or inconsistency of the data can be accurately determined.