Enhanced CO2 Capture-Desorption by Surface-Active Amine

Developing an efficient solvent for carbon dioxide (CO2) capture stands as a pivotal step in mitigating greenhouse gas emissions and long-term climate change. In this study, we evaluated the CO2 capture-desorption performance of 3-(dimethylamino)propylamine-6-propylene oxide (DMAPA-6PO), as a surface-active tertiary amine for cyclic CO2 capture as bicarbonate. Results delineate a distinct CO2 capture pathway utilizing DMAPA-6PO, which not only promotes bicarbonate generation, but also enhances CO2 solubilization. This enhancement is attributed to the surface activity, based on C-13 nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) analyses. Furthermore, DMAPA-6PO demonstrated a stable cyclic capacity, maintaining the CO2 capture performance and bicarbonate concentration profiles over 900 min of testing cycles. We also examined the CO2 capture capacity regeneration efficiency and desorption heat requirement in comparison with those of common commercial solvents. DMAPA-6PO showed a capture capacity regeneration efficiency that was 30% higher than that of monoethanolamine (MEA). Additionally, it exhibited a superior desorption rate, resulting in a substantial reduction of 88% in the heat duty requirements compared to MEA. The results demonstrate that DMAPA-6PO is a promising surface-active tertiary amine for capturing CO2, offering significant advantages in both the CO2-capture-as-bicarbonate pathway and traditional amine-based thermal desorption process.