Modeling dilute supercritical mixtures utilizing solvent-cluster interactions

✍ Scribed by S.V.G. Krishna Sastry; M. Mukhopadhyay

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 797 KB
• Volume: 6
• Category: Article
• ISSN: 0896-8446
• DOI: 10.1016/0896-8446(93)90006-j

✦ Synopsis

Supercritical fluids are, in general, known to dissolve solids and to result in dilute mixtures representing a class by themselves. The asymmetry between the large solute and small solvent molecules, and the strong solute-solvent interactions render a nonuniform, nonrandom distribution of solvent molecules. The present study proposes a model for the binary interactions in the dilute SC mixtures and demonstrates how an adequate representation of the attraction energy and size -parameters of the cluster accounts for both short-range and long-range interactions. The EOS parameters for the cluster are obtained by incorporating covolume dependency of the short-range interactions between the solvent and solute molecules constituting the cluster. This facilitates reduction in the difference in the energy and size parameters of the interacting species for long-range interactions. The behavior of the solvent population in the cluster conforms to the spectroscopically observed behavior of the clustering phenomena reported in the literature. The validity of the model is successfully verified by the predictions of partial molar volume data and the solubilities of binary mixtures of solids in SCF.