Directly Spun Epoxy-Crosslinked Polyethylenimine Fiber Sorbents for Direct Air Capture and Postcombustion Capture of CO2

A novel, directly-injected solid fiber sorbent is synthesized from a solvent-stable, epoxy-crosslinked basic immobilized amine sorbent (BIAS) for CO2 capture. Leach resistance of the BIAS organics toward 1-methyl-2-pyrrolidone/H2O (90/10, fiber solvent) reaches near 100% at the expense of CO2 capture and is achieved by increasing the extent of crosslinking. The optimized fiber sorbent, prepared with an N,N-diglycidyl-4-glycidyloxyaniline/polyethylenimine (PEI)-0.35/1 wt. ratio, retains 79.2% of PEI and captures 0.37 (direct air capture [DAC]) and 0.67 (postcombustion) mmol CO(2)g-fiber(-1). A nonoptimized prototype hollow fiber exhibits a stable 0.2 mmol CO(2)g-fiber(-1) during DAC cycling and is assembled into a ten-fiber module. These results demonstrate a large step toward practical application of this material.