Visualization and Quantitative Analysis of Consecutive Reactions in Taylor Bubble Flows

Taylor bubbles are bubbles that are filling a capillary fixed or rising in a liquid flow. Due to their well-defined size, shape and velocity the flow field around Taylor bubbles is well controllable. Furthermore, only a small amount of gas and liquid is required for experiments, making the study of Taylor bubbles simple and safe. In this chapter, Taylor bubbles are used to study mass transfer with chemical reaction in dependency of various fluid dynamic conditions. Experimental setups are presented to study chemical reactions at Taylor bubbles and in Taylor flows. Furthermore, a Taylor bubble benchmark experiment is presented and used for the validation of numerical simulations that are performed with a front tracking technique in a FEM framework to enable a high resolution of interfaces and boundary layers. It is shown that the interplay of mass transfer, hydrodynamics and chemical reactions can be successfully determined using experimental and numerical methods presented. It is shown further how the selectivity of competitive-consecutive reactions can be influenced by the local fluid dynamics, especially in the wake of a Taylor bubble or within the liquid slug in a Taylor flow.