Absorption of CO2CO2 in aqueous blends of diglycolamine®® and morpholine

The rate of CO2CO2 absorption in aqueous morpholine (MOR), and aqueous mixtures of MOR and diglycolamine®® (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 °C, 22000 L/mol s, is four times greater than DGA. The MOR reaction with CO2CO2 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 CO2CO2 50% faster than 65 wt% DGA of the same CO2CO2 loading.