Solubility Measurement in Crossover Region of Supercritical CO₂-Naphthalene-Phenanthrene System

Abstract

Solubilities of pure naphthalene, pure phenanthrene, and a mixture of naphthalene and phenanthrene in supercritical CO₂ were measured in the temperature range from 308 to 338K to obtain fundamental data for purification of polycyclic aromatic compounds using the retrograde crystallization technique. As a result, it was found that (1) the crossover region of supercritical CO₂-naphthalene-phenanthrene system was wide enough to isolate either solid component from the mixture, (2) the Peng-Robinson and Soave-Redlich-Kwong equations of state well represented the solubilities of pure solids in supercritical CO₂, and (3) the equations of state gave a fairly good estimated solubility of the more soluble component but poor estimated solubility of the less soluble component for the solid mixture.