A note on the composition-dependency of the density within the mass transfer layer

摘要

In the conventional mass transfer analysis in binary mixtures, a constant total mass concentration (or density) in the mass transfer layer has been assumed. This assumption is valid only once the concentration of diffusing component in the mixture is very low. Here, an explicit composition-dependency is introduced for the density within the mass transfer layer in order to see what happens when the conventional composition-independency assumption for the density within the mass transfer layer is relaxed. The governing equations are derived analytically and solved numerically. It was found that the conventional approach is a special case of our newly proposed composition-dependent density profile. While application of conventional approach is limited to very dilute binary mixtures, newly approach is applicable to general binary mixtures.