Sustainable ionic liquid organic solution with efficient recyclability and low regeneration energy consumption for CO2 capture

A novel sustainable amino functionalized ionic liquid (AFIL) organic solution of tetraethylene pentamine 5-amino-4-imidazolecarboxamide/n-propanol/ethylene glycol ([TEPAH][AICA]/NPA/EG) was proposed for CO 2 capture to reduce the regeneration energy consumption. The solution had an efficient absorption loading of 1.78 mol·mol −1 , and it still maintained a good recyclability after 10 cycles (regeneration efficiency > 88%). Under this condition, the regeneration energy consumption was 2.30 GJ·t −1 CO 2 , which was 39.5% lower than that of MEA/water. The absorption and desorption mechanisms were investigated by 13 C NMR. For CO 2 absorption reaction, N atom of [AICA] − combined with CO 2 to form the carbamate directly, while other amino groups followed the zwitterion formation and deprotonation. Then some carbamates combined with alcohol to form the alkyl carbonates. For CO 2 desorption reaction, both the alkyl carbonates and carbamates combined with AFILH + to decompose, but the alkyl carbonates decomposed completely and a small amount of carbamates remained, indicating that carbonate was easier to decompose than carbamate. The novel [TEPAH][AICA]/NPA/EG solution with low energy consumption and good recyclability, which provides a sustainable strategy for advancing carbon capture technologies.