Microbubble swarm in a HiGee-aided bubble column reactor: Size, gas holdup, and effective interfacial area

Abstract

Microbubble technology is promising for intensifying gas–liquid mass transfer in the bubble column reactor (BCR). The HiGee microbubble generator (HMG), flexibly controlling the microbubble size by adjusting the rotational speed, was developed for the BCR with obvious advantages. However, the hydrodynamics and mass transfer performance of the microbubble swarm generated by HMG in the bubble column were not clear, which hinders its industrial application process. In this work, a HiGee-aided bubble column reactor (HBCR), including an HMG and a bubble column, was proposed and designed. The effects of operating conditions on flow behavior, Sauter mean diameter (d₃₂), and gas holdup (φ_G) were studied. A prediction model for gas holdup was established, and the deviation between the predicted and experimental values was within ±15%. Based on d₃₂ and φ_G, the effective interfacial area in HBCR was calculated as 500–3800 m²/m³. This study provided fundamental data for the design and scale-up of HBCR.