Chemical Reactions at Freely Ascending Single Bubbles
Sprache des Titels:
Reactive Bubbly Flows
A joint approach of chemists, mathematicians and engineers in the field of chemical reaction enhanced gas-liquid mass transfer on single bubbles is presented. New chemical systems are developed for homogenous chemical reactions in the liquid. By applying different metal-complex based reaction systems with diverse ligands in different reaction media (water and organic solvents) a broad range of reaction kinetics is available. As one measure, the bubble size change over time is investigated. The shrinking of the bubble allows the determination of overall mass transfer rates under diverse conditions. Numerous groups investigated the wake region of the bubble. The influence of the mixing behavior in this region on the mass transfer in general but also, e.g., on competitive consecutive chemical reactions is visualized. For a deeper understanding of the effect of surfactants on mass transfer, simulations are performed providing a high temporal and spatial resolution of the flow and concentration field near the bubbles surface. Furthermore, a compartment model for the description of the mass transfer near a single bubble is developed which allows the calculation of competitive consecutive chemical reactions with reasonable numerical effort.