Correlation and prediction of solid-supercritical fluid phase equilibriums

Abstract

A semiempirical correlation has been developed to describe quantitatively the solubility of heavy nonpolar solids in slightly subcritical and supercritical solvents using only one temperature-independent pure component parameter for each component. The method, based partly on regular solution theory and the van der Waals equation of state, correlates available solubility data for 24 binary solid-fluid systems within an average standard deviation of 25% with ethylene, ethane, and carbon dioxide as solvents. The range of solubility correlated was 10/sup -6/ to 10/sup -2/ mole fraction, 20-80 /sup 0/C, and 80-500 bar. Pure-component parameters for solutes are presented for naphthalene, anthracene, triphenylmethane, phenanthrene, fluorene, pyrene, 2,3- and 2,6-dimethylnaphthalene, biphenyl, hexamethylbenzene, and hexachloroethane along with solvent parameters for ethylene, ethane, and carbon dioxide.