HIGH PRESSURE PHASE EQUILIBRIUM: PREDICTION OF ESSENTIAL OIL SOLUBILITY

This work describes a method to predict the solubility of essential oils in supercritical carbon dioxide. The method is based on the formulation proposed in 1979 by Asselineau, Bogdanic and Vidal. The Peng-Robinson and Soave-Redlich-Kwong cubic equations of state were used with the van der Waals mixing rules with two interaction parameters. Method validation was accomplished calculating orange essential oil solubility in pressurized carbon dioxide. The solubility of orange essential oil in carbon dioxide calculated at 308.15 K for pressures of 50 to 70 bar varied from 1.7<FONT FACE="Symbol">±</font> 0.1 to 3.6<FONT FACE="Symbol">±</font> 0.1 mg/g. For same the range of conditions, experimental solubility varied from 1.7<FONT FACE="Symbol">±</font> 0.1 to 3.6<FONT FACE="Symbol">±</font> 0.1 mg/g. Predicted values were not very sensitive to initial oil composition.