ABSTRACT
D. E. Woessner et al. developed an approximate dense gas molecular theory by calculating the Enskog correction factor from the Redlich-Kwong equation of state. Most theories for predicting dense gas diffusion coefficients result from Enskog, who accounted for the departure from the dilute gas kinetic theory, in terms of a factor Y which may be defined by the relationship. The chapter considers methods of estimating the binary diffusion coefficients the multicom-ponent diffusion coefficients, or the effective diffusion coefficients in either gases or liquids. Normally, the binary diffusion coefficients are estimated in two steps. First, the two diffusion coefficients at infinite dilution are calculated with one of the predictive methods. Next, the value of the binary diffusion coefficient at a desired concentration is estimated using the two limiting diffusion coefficients with one of the proposed expressions for correlating the effect of concentration on diffusion coefficient.
