Data analysis, modeling and thermodynamic consistency of CO₂ + β-carotene high pressure mixtures

All experimental solubility data available in the open literature for the mixture β-carotene and high pressure carbon dioxide at several temperatures (15 isotherms, 31 data sets, 204 data points), have been modeled and tested for thermodynamic consistency. The experimental data has been modeled using the Peng-Robinson equation of state with the mixing rules of Wong and Sandler and thermodynamic consistency has been performed by extending a method developed by one the authors. The system β-carotene + carbon dioxide is highly asymmetric and presents inherent difficulties of analysis. Despite this, for most of the cases studied the model employed allows correlating the solubility of solid β-carotene in the high pressure gas phase within acceptable deviations. Therefore, the thermodynamic test could be applied with confidence and consistency or inconsistency of the data presented in the literature could be accurately determined.