Hydrodynamics and mass transfer in metal‐foam micro‐packed beds: Implications for continuous aerobic oxidation

Metal‐foam micro packed bed reactors (M‐μPBRs) exhibit great potential in gas–liquid–solid reactions due to their superior transport characteristics. However, fundamental understanding of hydrodynamics and mass transfer under continuous liquid‐phase aerobic oxidation conditions remains limited, especially under high‐pressure and low‐flow regimes relevant to actual operating conditions. In this study, nickel foam M‐μPBRs were employed to investigate gas–liquid flow patterns, pressure drop, residence time distribution, and liquid holdup using air and representative organic solvents. Gas–liquid mass transfer performance was further evaluated with CO 2 /N 2 mixtures and aqueous N‐methyldiethanolamine or NaOH. To simulate catalytic operation, Ni–Co mixed oxides were electrodeposited on the foam to assess the effect of surface modification. Empirical correlations for pressure drop, liquid holdup, and mass transfer coefficients were established with good agreement to experimental data. Based on these results, key design guidelines for applying M‐μPBRs in continuous liquid‐phase aerobic oxidation processes were proposed, providing insight into reactor intensification and scale‐up.