On the Influence of Wake Structures on Competitive Chemical Reactions at Taylor Bubbles (Band 11)

Vorschau

Leseprobe, PDF (430 KB)
Inhaltsverzeichnis, PDF (30 KB)

Reactive bubbly flows are an indispensable process for the production of various chemicals. To optimize these processes in terms of yield and selectivity, an in-depth understanding of the complex interplay of fluid dynamics, mass transfer, and chemical reaction is essential. To gain the necessary insights, Taylor bubbles are used. In this work three experiments at low Eötvös numbers 4 ≤ Eo ≤ 10 are carried out. Firstly, the fluid dynamics of buoyancy driven Taylor bubbles in different organic solvents are investigated and compared to aqueous systems. Secondly, the local flow fields in the wake of fixed Taylor bubbles in methanol are analyzed by means of PIV. Lastly, the transient concentration and selectivity fields resulting from a consecutive competitive gas-liquid model reaction are determined and analyzed using a novel measurement technique, the highspeed imaging UV- VIS spectroscopy. The findings of the first two experiments indicate that it is not possible to directly transfer knowledge from aqueous systems to organic ones, as the local flow fields and thus the mixing behavior is differing significantly. Furthermore, a clear dependency of the fluid dynamics on the progression of the model reaction is proven, indicating potential for further process optimization.