Direct air capture (DAC) of CO2 using polyethylenimine (PEI) “snow”: a scalable strategy

Abstract

We have developed a cross-linked polyethyleneimine non-porous material (PEI “snow”) for direct air capture (DAC) of CO₂. This new hydrogel is green, inexpensive, readily scalable and can be fabricated through simple crosslinking of PEI with triglycidyl trimethylolpropane ether (TTE) in 10 minutes. It demonstrates outstanding DAC performance (overall CO₂ uptake efficiency of approximately 50 mg g⁻¹ of sorbent) at lab scale (sorbent weight roughly 60 g, air flow rate 2000 ml min⁻¹) and the CO₂ can be desorbed using low-grade waste steam.