The rate of CO2 absorption in aqueous morpholine (MOR), and aqueous mixtures of MOR and diglycolamine (R) (DGA) was measured in a wetted wall contactor. 23.5 wt% MOR and 11 wt% MOR/53 wt% DGA were studied at 298-333 K. The second order rate constant for MOR at 25 degrees C, 22000 L/mol s, is four times greater than DGA. The MOR reaction with CO2 was found to be catalyzed by DGA, consistent with the zwitterion mechanism. Predictions made with a rigorous eddy diffusivity theory suggest that 11 wt% MOR/53 wt% DGA absorbs CO2 50% faster than 65 wt% DGA of the same CO2 loading. (c) 2006 Elsevier Ltd. All rights reserved.