High-pressure gas-liquid equilibrium measurements by means of a double-chamber recirculation apparatus. Data on the system carbon dioxide-limonene at 50 and 70°C

Measurements of the phase equilibria for the system carbon dioxide-limonene were performed at 50 and 70 degrees C in the pressure range 8.54-13.34 MPa. Both the liquid and the gas phase composition were measured. The experiments were carried out by means of a two-chamber recirculation apparatus. According to the procedure, in one of the chambers the gas-liquid equilibrium is established, whereas the second one contains only the gas phase which is continuously recirculated through the chambers to reduce time for equilibration. Before sampling, the chambers are separated to avoid disturbances of the equilibrium when reducing pressure during the withdrawal of the gas phase. Experimental data at 50 degrees C were used for the validation of the experimental method, through comparison with literature data, whereas those at 70 degrees C are mostly original. The experimental data were successfully correlated by means of a thermodynamic model based on the Peng-Robinson equation of state. (C) 2010 Elsevier B.V. All rights reserved.