Application of a Wire‐Mesh Sensor for the Study of Chemical Species Conversion in a Bubble Column

Abstract

The utilization of a wire-mesh sensor for the measurement of chemical species conversion during the chemical adsorption of carbon dioxide in sodium hydroxide solution is reported for the first time. The wire-mesh sensor obtains cross-sectional images of the liquid-phase conductivity, which changes with the consumption of hydroxide during the reaction. A theoretical model was applied to verify the use of conductivity as an indicator for the reaction progress. Experiments were carried out using a lab-scale bubble column reactor with two wiremesh sensors at different reactor heights. The results obtained from the reactor model and experiments showed very good agreement and demonstrate the potential of this imaging instrument to follow the course of a chemical reaction via ionic species concentration even in a dense bubbly flow. This way, a better understanding of the coupling of hydrodynamics, mass transfer, and reaction in bubble columns and other reaction devices can be achieved.

Comparative Hydrodynamic Analysis of Narrow and Pilot‐Scale Bubble Columns with Internals

“…This way, gas can be distinguished from the liquid to study the gas‐liquid flow morphology. Moreover, conductivity tracers can be added to study liquid mixing , . The spatial resolution of WMSs depends on the application and is usually in the range of 3 – 5 · 10 −3 m for pipe flows and 5 – 10 · 10 −3 m for larger bubble columns.…”

“…Subsequently, bubble detection algorithms are applied to extract single bubbles for the calculation of a bubble size distribution. More details on WMS applications and data post‐processing can be found elsewhere , . It was further shown that both measurement techniques provide consistent results .…”

Reaction Systems for Bubbly Flows

“…For further progress in evaluating the chemical differences when varying the solvent or the system, which is activated or changed by the gas, the basic environment of the actual multiphase system should be investigated first. Interesting factors like the bubble velocities, sizes and rising behaviour is usually measured in a water/CO 2 system …”

“…Rising bubbles in a bubble column can also be measured by a wire‐mesh sensor as shown by Kipping et al A setup was built to analyse changes in conductivity at different heights of the column with CO 2 bubbles rising in the column through the wire‐mesh measurement planes (Figure ). This conductivity changes occur through the reaction shown in Scheme .…”

Genauigkeit der Bestimmung von Blasengrößen aus Messdaten eines Leitfähigkeits‐Gittersensors

“…In der Vergangenheit wurden Gittersensoren bereits häufig zur Untersuchung von Strömungsphänomenen in Blasensäulen eingesetzt, bspw. zur Messung von lokalen und integralen Gasgehalten im Querschnitt sowie radialen Gasgehaltsprofilen , zur Aufklärung der Flüssigkeitsrückvermischung oder zur Messung der Stoffumwandlung bei der chemischen Absorption von CO 2 .…”