Experimental Study of Mass Transfer in a Plug Regime of Immiscible Liquid–Liquid Flow in a T-Shaped Microchannel

Abstract

In the presented work, the influence of parameters such as the total flow rate of phases, the ratio of flow rates, and residence time on mass transfer during the two-phase flow of immiscible liquids in a T-shaped microchannel was investigated using the micro-LIF technique. The study focused on the plug flow regime, where a 70% water–glycerol solution was used as the dispersed phase, and tri-n-butyl phosphate (TBP) was used as the carrier phase. We determined the transition boundary between the dispersed and parallel flow patterns and calculated the plug length and velocities to develop a mass transfer model. Furthermore, we measured the partition coefficient for the set of liquids used in the experiments and analyzed the concentration fields inside the slugs of the continuous phase at various distances downstream of the T-junction. Using the obtained data, we determined the extraction efficiency and overall volumetric mass transfer coefficient and established dependencies demonstrating the effect of the flow-rate ratio, total flow rate, and the residence time on mass transfer rate and extraction efficiency. Finally, we developed a model for the overall volumetric mass transfer coefficient corresponding to the set of liquids used with an R-squared value of 0.966.