Carbon Dioxide Capture by Chemical Solvents based on Amino Acids: Absorption and Regeneration

The use of sodium salts of aqueous solutions of different amino acids (glycinate and prolinate) for carbon dioxide (CO2) separation by chemical absorption is analyzed in a bubble-column reactor under different experimental conditions of solvent concentration and gas flow rate. The differences in absorption rate and reaction mechanism caused by the presence of carboxylic groups in comparison to the case without (monoethanolamine and pirrolidine) are evaluated. Glycinate solvent reaches a similar behavior than monoethanolamine aqueous solutions but with a higher destabilization of carbamate that allows to increase CO2 loading. Prolinate exhibits a similar behavior than pirrolidine at low CO2 loadings. Both solvents show a significant reduction in absorption capacity when stripping regeneration is carried out.