Mass Transfer Enhancement in Liquid–Liquid Extraction with Discrete Liquid Film Flow

This paper presents a method to enhance the mass transfer rate in the liquid–liquid extraction process. In this method, discrete liquid films were realized by controlling the flow of the dispersed phase along a wire immersed in the continuous phase. An experimental setup was built to quantify the mass transfer of the liquid film. The results showed that liquid films increased the mass transfer efficiency by 40–65% compared to liquid droplets, enlarged the specific surface area by 53.3%–69.7%, and extended the residence time by 27.6%–51.9%. Additionally, the effects of the wire height were examined under two different wire diameters to confirm the feasibility of the new extraction method. Finally, based on the experimental data of liquid films, correlations were formulated to predict the overall mass transfer coefficient. This study opens a new direction for the development of liquid–liquid extraction technologies.