Molecular Dynamics Simulation of Diffusion Coefficients of Oxygen, Nitrogen and Sodium Chloride in Supercritical Water

Molecular dynamics simulation has been performed to determine the infinite-dilution diffusion coefficients of oxygen and nitrogen, and the diffusion coefficients of NaCl in supercritical water from 703.2-763.2 K and 30-45 MPa. The results obtained show that the diffusion coefficients in supercritical water increase with temperature, while decrease with pressure. Nevertheless, the diffusion coefficients in supercritical water are much larger than those in normal water.