New Correlation of the binary interaction factor for polar solutes in supercritical carbon dioxide

摘要

Recently a number of investigators have emphasized the need of obtaining reliable measurements of the solubility of a solute in a supercritical fluid. It is the most important thermophysical property that needs to be determined and modelled as a first step to develop any supercritical fluid applications. The contribution is focalised on very dilute solutions of many polar solutes in carbon dioxide (nonpolar solvent) when the molar polarization of the solute at infinite dilution is accurately known. A database containing experimental solubility data for many solutes was used in this study where isotherms were comprised between 308 and 343 K. This research was undertaken to develop a mathematical model to compute the solubility of solids in supercritical fluids, particularly in the carbon dioxide. As a result, a new correlation of binary interaction (k_(ij)) is proposed. The new relationship considers the binary interaction term k_(ij) as a function of the dipole moment, the solute carbon number and the reduced temperature.