Solubility of solids in supercritical fluids from the measurements of the dielectric constant: Application to CO2–naphthalene

A new method for the measurement of solid solubilities in supercritical fluids is described in detail. The method is based on the measurement of the dielectric constant of the saturated supercritical solution solvent–solute and that of the supercritical solvent as a function of pressure along different isotherms. Our method is simple, absolute, easy to use, and permits precise measurement of the solubility of solids in supercritical fluids. Solubilities of naphthalene in supercritical CO2 in the pressure range 12–30 MPa are reported along the isotherms 313.15, 318.15, and 323.15 K.