Representation of CO2 Absorption in Sterically Hindered Amines

Post-combustion capture technology implemented at carbon-rich power plants offers an alternative for mitigating CO2 emissions. Aqueous alkanolamines such as monoethanolamine and N-methyldiethanolamine are utilized to chemically absorb CO2. However, current laboratory practice for evaluating new absorbents is laborious and time consuming. In this paper, we presented a possible relationship between acid dissociation constant, Ka and the CO2 absorption affinity of sterically hindered amines. We demonstrated that addition of hydroxyl and methyl groups to AMP decreases the absorption affinity of sterically hindered amines towards CO2. This finding adds to our understanding in trying to find a new and better CO2 absorbent.