PREDICTIVE METHOD FOR CALCULATING THE SOLUBILITY OF SOLIDS IN SUPERCRITICAL GASES APPLICATION TO APOLAR MIXTURES

A thermodynamic method is proposed for calculating the solublities of apolar solids compounds in apolar supercritical gases. The method, analogous to the Hildebrand theory of solids' solubilities in liquid solvents, is mainly based on the application of Scatchard-Hildebrand equation to supercritical fluid mixtures. The derived method is applied to the determination of the ethylene/naphthalene equfiibria at 5 temperatures between 12 and 50°C and over pressure ranges of 50-270 ata. Calculated data are compared with the experimental data by Diepen and Scheffer. Methods for determining the solubility parameters of supercritical gases are discussed. The possibility of extending the proposed theory to polar mixtures of condensed phases in supercritical gases is also indicated. © 1979.