Coalescence‐inhibited dense bubble swarm with millimeter‐sized bubbles for interfacial mass transfer intensification

Abstract The efficiency of industrial multiphase reactors is fundamentally constrained by millimeter‐sized bubbles easily coalescing into centimeter‐sized bubbles. In this study, we observe a coalescence‐inhibited dense bubble swarm (CIDS) (the local gas volume fraction ε exceeds 30%) with millimeter‐sized bubbles (ca. 5 mm) in ultrapure water. The flow regime of CIDS remains homogeneous even under high ε , while under common conditions it is heterogeneous. Compared with common bubble swarms, CIDS achieves at most an 185% increase in overall ε , a 723% increase in local ε in the downcomer, a 216% increase in mass transfer area, and a 252% increase in volumetric mass transfer coefficient. For CIDS, friction generated by the gas through the ultra‐microporous (