High-pressure gas–liquid equilibrium of the system carbon dioxide–citral at 50 and 70 °C

Measurements of high-pressure gas–liquid equilibria of the binary system carbon dioxide–citral were carried out in the present work. The knowledge of the phase equilibrium behaviour of this system is relevant with regard to the design and optimization of the supercritical deterpenation process. The measurements were carried out at 50 and 70 °C, in the pressure range 7.8–15.6 MPa, by means of a two-chamber gas-phase recirculation apparatus of 340 cm3. Both the liquid and the gas phase composition were measured. The data at 50 °C measured in this work were compared with literature data, whereas no comparison was possible at 70 °C because of their lack. The experimental data measured in this work were successfully correlated by means of a thermodynamic model based on the Peng–Robinson equation of state.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► New phase equilibrium data of the system CO2–citral are provided at 50 and 70 ̊C. ► The measurements were carried out by means of a double-chamber apparatus of 340 cm3. ► The measurements are in the range 7.8–15.6 MPa. ► Both the liquid and the gas phase composition were determined. ► A satisfactory data correlation is obtained by means of the Peng–Robinson equation of state.