Surfactant effect on mass transfer characteristics in the generation and flow stages of gas–liquid Taylor flow in a microchannel

Abstract

The understanding of surfactant effect on mass transfer behaviors in microchannel devices remains insufficient even though it has been frequently added into gas–liquid systems to promote process stability. Accordingly, this work concentrates on the surfactant effect on mass transfer performances by decoupling the whole process as bubble generation and flow stage. The results show that the role of gas absorption during bubble generation process always exceeds 30 % of the total amount in the microdevice. The surfactant concentration remarkably influences the mass transfer in the bubble generation stage but slightly affects the flow stage. Importantly, the mass transfer coefficient in the generation stage is dozens of times that in the flow stage, and the inherent mechanism is revealed. Finally, the semi-empirical correlations containing the surfactant content are developed for mass transfer coefficients in two stages. This work provides some indispensable information about the selection of surfactants in microfluidic technology.