Remarkable improvement of gas–liquid mass transfer by modifying the structure of conventional T‐junction microchannel

Abstract Enhancing the mass transfer performance just by modifying the channel structure without external energy input is one of the most important topics for microchemical technology development. This work reports the high‐performance gas–liquid mass transfer in a novel step T‐junction microchannel. The liquid‐side mass transfer coefficient in the step T‐junction has been significantly improved by one order of magnitude when compared with the conventional T‐junction, which is higher up to 60 × 10 −4 m/s. To our knowledge, it might be the highest value obtained in the microchannel without external energy input. The parameters of bubble generation frequency and gas–liquid interface movement velocity in different microdevices are explored to reveal the mechanism behind the ultra‐high mass transfer coefficient in the step T‐junction. Finally, two models considering the gas absorption are developed for the bubble generation frequency and volume, and two models are proposed for the gas–liquid mass transfer coefficient.