Solubility Prediction of Supercritical Fluids Extraction By Equations of State

The main puropose of this work is to study the influence of the equations of state on the prediction of the performance of supercritical fluid extraction of herbal essential oils. The applied equations are van der Waals, Redlich-Kwong and the Peng-Robinson equations of state with their related mixing rules. To study of the performance of these equations on the solubility prediction, Mint (Spearmint) essential oil was choosen as the solute and supercritical carbon dioxide as the solvent. An experimental apparatus was used for extraction of Mint essence and the best operating conditions were reached after many experiments. Thermodynamic properties of Carvone, as the specific compound of Mint essential oil, including critical pressure; critical temperature and eccentric factor have been estimated. According to the experimental results, Peng-Robinson equation of state with its mixing rules was the best selected equation of state to assess the solubility of essential oils