CFD modeling on the chemical absorption of CO2 in a microporous tube-in-tube microchannel reactor

In this paper, combining recently developed mesoscale mass transfer model with reaction kinetics, the chemical absorption process of CO2 by MEA solution in a microporous tube-in-tube microchannel reactor (MTMCR) was numerically simulated for the first time. The predicted values by CFD simulations were in agreement with the public experimental data (Na-Na Gao et al., Ind. Eng. Chem. Res., 2011). The distributions of CO2 removal ef-ficiency and volumetric mass transfer coefficient under different gas flow rate, solvent flow rate, solvent tem-perature, and MEA concentration were analyzed. Among these factors, MEA concentration had a more significant influence on the CO2 chemical absorption. The K(G)a in the MTMCR was more than 200 times of that in the randomly packed bed under the similar operating conditions. The local mass transfer rate of chemical absorption was one order of magnitude higher than that of physical absorption. This research work could lay a theoretical foundation for the simulation of the complex gas-liquid systems including the chemical absorption by CFD method.

Automated summary

This study combines mesoscale mass transfer model with reaction kinetics to numerically simulate the chemical absorption process of CO2 by MEA solution in a microporous tube-in-tube microchannel reactor. The research found that MEA concentration has the most significant impact on CO2 chemical absorption, with K(G)a in the MTMCR being over 200 times higher than in a randomly packed bed, and the local mass transfer rate being one order of magnitude higher.