Numerical simulation of flow characteristics in microbubble column reactors with two different tubular gas spargers

Bubble column reactors (BCRs) are intensively used in industries for different purposes. However, the overall reaction rate in traditional BCRs is constrained by the non-uniform gas distribution and slow gas-liquid mass transfer. Microbubble technology is seen as a potential method to enhance the performance of BCRs. In this work, computational fluid dynamics (CFD) simulations were performed to study the flow characteristics of the gas-liquid phase in microbubble column reactors (MBCRs) with different tubular gas spargers. The CFD model was validated against experimental results from the literature. The findings indicate that the overall gas holdup and the interfacial area in the MBCRs with tree-type sparger increase by 26.67 %∼45.45 % and 19.55∼23.68 times. In the MBCRs with multiple ring sparger, the above parameters increase by 22.22 %∼48.00 % and 18.00∼ 23.27 times. Compared to the MBCRs with multiple ring spargers, MBCRs with tree-type spargers demonstrate notable enhancement even at a low inlet flow rate, facilitating considerable energy conservation. It is believed that this work will provide viable suggestions for the application and optimization of large MBCRs with tubular gas spargers.