Mass transfer model for the film countercurrent flow of two liquid phases in a packed bed column

Previously, the film flow of two liquids in a packed bed column was not very often encountered in industrial practice and was therefore not intensively investigated. Now however, the significance of this kind of flow has increased because of the rapid-development of column supercritical extraction, where the film flow is frequently observed. In this study, a mass transfer model for the film flow of two liquid phases in a packed bed is proposed. Based on the hydrodynamic considerations under fully developed laminar flow conditions, the mass transfer correlations have been derived. Hydrodynamic predictions have been compared with experimental data on holdup in the literature. Also, correlations proposed for the mass transfer coefficients in both the film and the core phases respectively, have been successfully verified by comparing them with experimental data from the literature.