New data of gas-liquid mass transfer for cocurrent downflow through packed beds of non-porous particles are presented. Mass transfer parameters for air/carbon dioxide/water and air/carbon dioxide/sodium hydroxide systems were evaluated by least squares fit of the calculated CO2 concentration profiles in the gas phase to the experimental values. The dependence of k(G)a on gas and liquid flow rates is caused by the dependence of gas-liquid interfacial area, not by the gas-side mass transfer coefficient k(G). In the case of the absorption of dilute carbon dioxide the gas-side resistance is considerably smaller than the liquid-side resistance. In the pulse flow regime, gas-liquid interfacial area calculated from k(L)a and k(L) values obtained by physical, respectively, chemical absorption are lower than the gas-liquid interfacial area evaluated from the measurements under reaction conditions.