Investigation of CO₂ Absorption Rate in Gas/Liquid Membrane Contactors with Inserting 3D Printing Mini-Channel...

The CO₂ absorption by Monoethanolamine (MEA) solutions as chemical absorption was conducted in the membrane gas absorption module with inserting 3D mini-channel turbulence promoters of the present work. A mathematical modeling of CO₂ absorption flux was analyzed by using the chemical absorption theory based on mass-transfer resistances in series. The membrane absorption module with embedding 3D mini-channel turbulence promoters in the current study indicated that the CO₂ absorption rate improvement is achieved due to the diminishing concentration polarization effect nearby the membrane surfaces. A simplified regression equation of the average Sherwood number was correlated to express the enhanced mass-transfer coefficient of the CO₂ absorption. The experimental results and theoretical predictions showed that the absorption flux improvement was significantly improved with implementing 3D mini-channel turbulence promoters. The experimental results of CO₂ absorption fluxes were performed in good agreement with the theoretical predictions in aqueous MEA solutions. A further absorption flux enhancement up to 30.56% was accomplished as compared to the results in the previous work, which the module was inserted the promoter without mini channels. The influences of the MEA absorbent flow rates and inlet CO₂ concentrations on the absorption flux and absorption flux improvement are also illustrated under both concurrent- and countercurrent-flow operations.