In this study, the absorption of carbon dioxide (CO2) in a microchannel reactor by use of the three solvents monoethanolamine (MEA), diethanolamine (DEA) and activated methyldiethanolamine (a-MDEA) was investigated under different operating conditions, including temperature, solvent and gas flow rates, and amine concentration. The results show that increasing solvent flow rate or amine concentration has effect of increasing the mass transfer flux. Raising the gas flow rate increased the mass transfer flux for MEA and DEA, while for a-MDEA it initially increased and then reduced the flux. The temperature was found to be a less effective parameter. Additionally, the performance of the microreactor in the enhancement of the absorption rate was demonstrated. The optimum molar flux of volumetric mass transfer was determined to be 12,826, 11,374 and 8241 kmol per cubic meter-hour for MEA, DEA and aMDEA respectively. © 2019 Published by Elsevier Lt