A MODEL FOR CORRELATING THE SOLUBILITY OF SOLIDS IN SUPERCRITICAL CO2

A model for correlating the phase equilibria of solid-supercritical fl uid (SCF) systems has been developed. The model is based on the fact t hat the free solute molecules, the solvent molecules, and the solute-s olvent clusters in such a solid-SCF system are in chemical equilibrium . The local density of the solvent surrounding a solute is used as one of the parameters in the model. The validity of the model is verified by correlation of the phase equilibrium data of supercritical CO2-sol id systems reported in the literature. Using the solubility data, the model can be used to estimate the local density and the average number of the solvent molecules in the clusters. (C) 1998 Elsevier Science B .V. All rights reserved.