Fast and efficient CO2 absorption in non-aqueous tertiary amines promoted by ethylene glycol

With the catalytic induction of EG, anhydrous DMEA shows CO2 absorption performance via chemical binding and physical storage under normal pressure. Among the absorbents, pure DMEA can hardly absorb CO2 directly but when the zwitterionic alkylcarbonates are formed between CO2 and DMEA-EG which can be characterized by 13C NMR and FTIR, the absorption rate of CO2 will be improved at this time. An increasing the CO2 loading as the mass fraction of EG in DMEA-EG, 90wt.% EG captures up to 0.72 mol/mol. The amount of chemically bound and physically stored is directly dependent on temperature, within the range of 293 to 323K, an absorption-regeneration cycle can be formed in a closed vessel because of the zwitterion DMEA-EG-CO2 is unstable at the higher temperature. In other words, DMEA-EG-CO2 can be easily regenerated upon appropriate depressurization or heating, corresponding thermodynamic calculations prove that the regenerative energy of DMEA-EG-CO2 is 25.49kJ/mol.