THE SOLUBILITY OF 2 MONOTERPENES IN SUPERCRITICAL CARBON-DIOXIDE

The solubilities in supercritical CO2 of two terpenes, alpha-pinene as a representative of the monoterpene hydrocarbons and cis-verbenol as one of the oxygenated terpenes, have been measured at temperatures from 40 to 55-degrees-C and pressures from 5 to 12 MPa using a dynamic flow apparatus, which was tested by measuring the solubilities of naphthalene in compressed carbon dioxide. The experimental solubility data were correlated using a compressed gas model with the Peng Robinson equation of state and empirical equations based on the dependence of the concentration of solute on the density of pure solvent. The unknown critical properties of both monoterpenes were estimated using the Joback contribution method. The vapour pressure of cis-verbenol was determined by the modified Watson method. The optimum conditions for the supercritical fluid extraction of both monoterpenes were determined.