Measurement and Correlation of α-Bisabolol Solubility in Near-Critical Carbon Dioxide

The solubility of (-)-alpha-bisabolol, ((-)-6-methyl-2-(4-methyl-3-cyclohexen-1-yl)-5-hepten-2-ol), a monocyclic sesquiterpene alcohol, in sub- and supercritical CO2 was measured at the temperatures (313.2, 323.2, and 333.2) K and pressures ranging from (7 to 12.5) MPa by a dynamic method. To the best of our knowledge, there are no previous measurements of alpha-bisabolol solubility in near critical CO, reported in the literature. The solubility isotherms were in the crossover region; the maximum mole fraction of alpha-bisabolol in CO2. 9.10(-3), was therefore at 313.2 K and 11.5 MPa, the maximum pressure applied at this temperature. The Soave-Redlich-Kwong equation of state (SRK-EoS) was employed to correlate the experimental data and an acceptable agreement was obtained. Furthermore, the thermophysical properties of the solute required by the modeling were estimated and reported.