The concentrations of naphthalene in CO2-rich phase for the ternary system CO2 + ［bmim］［PF6］+ naphthalene were determined by a static method with online high-pressure ultraviolet detection

under the conditions of naphthalene molality in the liquid phase ranging from 0.0169 to 0.378 mol·kg-1

and temperature 313—333 K

pressure 8—20 MPa.It was found that the naphthalene mole fraction in the CO2-rich phase decreased with increasing temperature

increased with increasing pressure

and decreased with decreasing naphthalene concentration in the liquid phase.The logarithm of naphthalene mole fraction in the CO2-rich phase was shown to be approximately linear

at the same temperature and pressure

with the logarithm of naphthalene concentration in the liquid phase.All the solubility data were correlated to the Chrastil’s association model and the mean relative deviation was found to be 14.9%.Moreover

operation modes of supercritical CO2 extraction were discussed base on the solubility data.It was found that batch operation was better than continuous operation for organics extraction from ionic liquids using supercritical CO2.