Hydrodynamics and mass transfer performance in packed microbubble column reactor

Microbubbles, characterized by small size, slow rising velocity, and long existence time compared to large bubbles, have been introduced into traditional packed bubble column reactors to achieve process intensification in gas–liquid–solid multiphase systems. In this work, the bubble flow behaviors within packed microbubble column reactor are visualized and analyzed by varying reactor length, packing size, gas/liquid superficial velocity, and liquid viscosity. The results show that larger packing size promotes the stable existence of microbubble swarms, thereby increasing the gas–liquid interfacial area and enhancing mass transfer efficiency. Moreover, a comparative analysis of porous and non‐porous packing materials reveals that, although porous packings provide higher liquid holdup, they hinder microbubble stability and result in lower volumetric mass transfer coefficients ( k L a ). Ultimately, the empirical correlations for k L a were developed, exhibiting excellent agreement with the experimental data.