A packed tower was used to investigate the removal of CO2 from polluted air using aqueous alkaline solutions. Experiments were conducted with NaOH concentration 0.30—0.97 kmol·m-3

MEA concentration 0.02—0.50 kmol·m-3 and DEA concentration 0.10-0.50 kmol·m-3 at 25 ℃. A mathematical model based on chemical absorption was proposed. The effective gas-liquid interfacial area (av) was calculated from the results of CO2 absorption into aqueous solutions of sodium hydroxide. For the solutions of MEA and DEA

the overall reaction rate constant (kov)expwas obtained from the results of the experiments and av calculated from NaOH-CO2 system. The overall reaction rate of MEA is much higher than that of DEA. The predictions of the theoretical model were compared with the experimental data and results from literature. Both the experimental data and the results from literatures were in good agreement with the model predictions.