Correlation of Infinite-Dilution Diffusion Coefficients in Supercritical Fluids

Abstract

A correlation based on an extensive literature database was proposed to estimate the infinite-dilution diffusion coefficients in supercritical fluids. The input parameters required for the correlation are temperature, the solute molar mass, the solute density near ambient temperature, the solvent critical temperature, the solvent critical density, and the solvent reduced density. The total average absolute deviation (AAD%) of the prediction is 6.55% for 153 binary systems and 1968 data points over the solvent reduced temperature range of 1.00−1.78, the solvent reduced density range of 0.21−2.34, the solute molar mass range of 58.08−885.40 g/mol, and the solute ambient-temperature density range of 0.63−2.04 g/cm3. Introduction of solute density into this new correlation makes it possible to predict with reasonable accuracy the diffusivities in supercritical fluids over a wide solute density range