CFD analysis on the intensified mechanism of gas-liquid mass transfer in a microporous tube-in-tube microchannel reactor

A three-dimensional CFD model coupled with a mesoscale mass transfer model was developed to simulate the absorption of CO2 in the microporous tube-in-tube microchannel reactor (MTMCR). The simulation results were validated by experimental data and empirical correlations, with the discrepancies within +/- 20%. The local breakage and coalescence of the gas-liquid interfaces enhanced mass transfer in the annular microchannel. The higher Re-G and Re-L means lower ratio between energy for mass transfer and surface, and also, larger contribution of interfacial area to the mass transfer. Additionally, an entrance-effect zone was revealed, and the entrance-effect zone enlarged with the increase in Re-G and Re-L. The overall mass transfer coefficient and entrance-effect zone enlarged significantly with appropriate decrease in the length of the gas-liquid collision zone. Results of this work could provide a theoretical basis for the further optimization of MTMCR. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

A three-dimensional CFD model coupled with a mesoscale mass transfer model was developed to simulate CO2 absorption in a microporous tube-in-tube microchannel reactor. The simulation results were validated by experimental data, showing enhanced mass transfer due to local breakage and coalescence of gas-liquid interfaces. An entrance-effect zone was revealed, and the overall mass transfer coefficient enlarged significantly with a decrease in the length of the gas-liquid collision zone, providing a theoretical basis for further optimization of the reactor.