Non-Thermal CO2 Capture and Amine Regeneration from Flue Gas Using Electrodialysis
W. M. Uvin G. De Alwis, Aayush Bendre, Omar A. Carrasco-Jaim, Hana Soriano, Alyssa Beekman, Daniel King, Upali P. Weerasooriya, Manish Kumar, Ryosuke OkunoAbstract
Post-combustion CO2 capture is central to carbon management. However, conventional thermal regeneration is energy-intensive, prone to solvent degradation, and requires additional processing of captured CO2. This study explored the technical viability of an integrated ambient-condition process that combines CO2 capture using a surface-active tertiary amine, N-4PO, with electrodialysis (ED) for simultaneous solvent regeneration and bicarbonate separation. Using a model flue gas containing CO2 and O2, the process achieved 78% bicarbonate formation during capture, complete regeneration of N-4PO, and approximately 50% bicarbonate separation, with no performance reduction due to the presence of O2. ED required nearly 94% less estimated regeneration energy than the laboratory-scale low-temperature batch thermal regeneration setup evaluated in this study. Across N-4PO concentrations of 0.05, 0.10, and 0.20 M, only modest performance variations were observed, demonstrating operational flexibility. This process supports future modular integration with renewable electricity and potential extensions to direct air capture.