Photo-swing CO2 capture using aminopolymers as sorbents and TiN light absorber

Using aminopolymers as the sorbent material for dilute CO2 capture, a photo-swing method is demonstrated in an industrially relevant contactor architecture using titanium nitride (TiN) nanosized light absorbers coupled with low-power LEDs with irradiances up to 420 mW/cm². The photo-driven desorption process is applied to dry and humid CO2 streams. Consistent with known sorption mechanisms for aminopolymers, humid CO2 streams increased the CO2 uptake, in our case by ~30%. The photo-swing CO2 capture desorbed ~83% and ~100% CO2 compared to thermally-driven desorption over the same period for a dry and humid CO2 stream, respectively. The photo-swing CO2 capture exhibits robust performance over > 90 cycles without significant signs of photo(thermal) induced sorbent degradation. This work lays the groundwork for photo-swing DAC technology as a scalable, energy-efficient solution for CO2 capture, well-suited for modular systems in remote locations utilizing intermittent renewable energy sources.