Carbon dioxide absorption into promoted carbonate solutions

Abstract

Abstract CO 2 absorption rates into diethanolamine (DEA)‐promoted carbonate solutions were measured over a wide range of carbonate conversions and temperatures. Analysis of the data showed that the CO 2 ‐DEA reaction rate was controlled by the rate of formation of zwitterion intermediate for carbonate conversions below 30%, and was controlled by the rate of abstraction of proton from the zwitterion intermediate for carbonate conversions greater than 30%. Hydroxyl ion, free amine, and carbonate ion were identified to act as bases to abstract the proton from the zwitterion. The modeling of the CO 2 absorption rates and the effects of carbonate conversion and amine concentration on the CO 2 ‐DEA reaction kinetics were investigated.