Phase behavior of lemon and bergamot peel oils in supercritical CO2

The main objective of this work was to investigate the high-pressure phase behavior of the binary systems CO2–lemon (Citrus latifolia Tanaka) and CO2–bergamot (Citrus bergamia Risso et Poit.) peel oils. The static synthetic method using a variable-volume view cell was employed for obtaining the experimental data in the CO2 overall composition range of 5–98 wt.%, from 313 to 343 K and pressures up to 19 MPa. For both systems, the experimental data revealed the occurrence of vapor–liquid, liquid–liquid and vapor–liquid–liquid phase transitions. Additionally, vapor–liquid equilibrium data were measured for CO2–linalyl acetate, one of the major compounds of the bergamot oil. The thermodynamic modeling was performed using the Peng–Robinson equation of state with the classical quadratic mixing rules, with a satisfactory agreement between experimental and calculated values.