APPLICATIONS OF NEAR-CRITICAL DILUTE-SOLUTION THERMODYNAMICS

Much of the thermodynamics of dilute solutions near the solvent's crit ical point is governed by a single thermodynamic derivative known as t he Krichevskii parameter. This parameter manifests itself in some line ar asymptotic relationships that describe the behavior of solute Henry 's constants and Infinite-dilution K-factors in the vicinity of the so lvent's critical point. This paper reviews the application of these as ymptotic relationships to practical thermodynamic calculations. Succes sful correlations have been produced for Henry's constants and K-facto rs. Application to apparent molar properties is discussed, and an expl anation is given for its quantitative inadequacy. The Henry's constant relationship has been extended to describe the solubility of solids i n supercritical fluids; current limitations and future prospects are d iscussed for this application. Finally, a new linear relationship is d erived for the capacity factor in supercritical fluid chromatography a nd applied to some data from the literature.