Bubble size, mass transfer, and hydrodynamics in a self-priming aeration draft tube reactor

The advancement of airlift reactors holds significant importance in the fields of fermentation, chemical processes, and environmental remediation. However, there are few reports on the novel reactor derived from the airlift reactors. This study reported a self-priming aeration draft tube reactor (SPADT-Reactor), aimed to investigate the impact of speed, superficial gas velocity, and draft tube diameter on the bubble size, mass transfer, and hydrodynamics of the SPADT-Reactor for intensifying gas-liquid mass transfer. A 200-mm draft tube achieved optimal performance with a 0.96 downcomer-to-riser area ratio, this configuration enhanced the overall reactor's volumetric oxygen mass transfer coefficient (k_La) and gas holdup by 55 % and 50 %, respectively. Furthermore, a 10 mm impeller channel width proved most effective, notably reducing the dead zone and enhancing the mass transfer and mixing capabilities of the reactor. This study offers valuable insights into the future scale-up and application of the original SPADT-Reactor.