MOLECULAR SIMULATION OF SUPERCRITICAL AQUEOUS SOLUTIONS

We review our molecular-based study of infinitely dilute supercritical aqueous electrolyte (isolated Na⁺ and Cl^- as well as the ion pair Na⁺/Cl^-) and non-electrolyte (Ar, Xe, methanol, benzene, toluene, benzonitrile) solutions, and report new simulation· results on the potential of mean-force for Na⁺/Cl^- at two thermodynamic states: one at the critical density and at 5% above the critical temperature, the other at 50% above the critical density and along the critical isotherm. The main thrust of this work is the determination of the solute-induced effect on the system's structure and thermodynamics aimed at developing a molecular understanding of the solubility of nonpolar noble gases, ionic fluids and organics in supercritical water. Such an understanding can provide important insight into fundamental thermodynamic and kinetics aspects of supercritical water oxidation of organic wastes.