Mass transfer performance and two-phase flow characteristic in membrane dispersion mini-extractor

In this experiment, a new membrane dispersion mini-extractor with a microfiltration membrane as the dispersion media was developed for liquid-liquid extraction processes. The performance of the new extractor was tested in six experimental systems with different dispersed phase media to measure the effects of flow rates on mixing and mass transfer characteristics, as well as the relationship between transmembrane pressure and dispersed phase flow rate. For all systems, the results showed droplet diameter decreasing with an increase of volume flow rate, and higher extraction efficiency due to the increase in specific interfacial area and decrease in diffusion distance. At higher flow rates, the droplet diameter reached a minimum value and the mass transfer efficiency could be as high as 100% with residence time less than 0.2 s. The mini-extractor's capacity reached around 500m(3)/(m(2) h) under the mass transfer efficiency of almost one theory stage. Because of its simple design, low cost production and increased efficiency, the membrane dispersion mini-extractor has potential for widespread industrial extraction process application. (C) 2004 Published by Elsevier B.V.