Inter-phase mass transfer in turbulent liquid-liquid dispersions: A comparative analysis of models

A comparative evaluation of eight models used to predict the dispersed phase mass transfer coefficient was undertaken using recent drop size and mass transfer data obtained under well known and controlled hydrodynamic conditions encountered in screen-type static mixers. A wide range of experimental conditions were covered (ɛ = 1.5–117 W/kg, ϕ = 0.1–0.47) thereby allowing for proper assessment of the strength and weaknesses of each model.All models failed to properly predict the experimental results over a wide range of design and operating conditions with the exception of those that contain a system-specific adjustable fitting parameter. Although these models yielded reasonably acceptable order-of-magnitude predictions, they could not accurately account for the variations in the different parameters investigated. This shows that proper understanding of the various factors affecting the dispersed phase mass transfer coefficient is still incomplete and highlights the need for phenomenological models that can account for the various physicochemical and hydrodynamic conditions on the dispersed-phase mass transfer coefficient.

► Eight models describing dispersed phase mass transfer coefficient were compared.
► The models were incorporated in a population balance algorithm.
► The models were tested under varying turbulent conditions.
► Only the models containing a fitting parameter predicted the experimental results.
► New models that account for physicochemical and hydrodynamic conditions are needed.