Nanosilica-supported polyethoxyamines as low-cost, reversible carbon dioxide sorbents

Novel hybrid quasi-solid-state sorbents pairing inexpensive CO(2)-reactive polyethoxyamine (Jeffamine®) fluids with an abundantly available silica support have been investigated for carbon capture. The highest performance sorbent was capable of reversibly capturing close to 70 mg of CO(2) per gram of sorbent at 45°C, could be almost fully (~90%) regenerated by simple vacuum swing, and was stable over many sequential capture-release cycles. The new supports can be handled as solventless, free-flowing powders even post-CO(2) capture, obviating the mass flow problems arising from viscous liquid (or solid, gel, or wax) formation frequently attending carbamate formation. Our results have important ramifications for reducing the high costs of thermal regeneration in conventional carbon capture schemes, particularly in comparison with the aqueous monoethanolamine-based system currently favoured industrially. The strategy of uniformly dispersing a functional fluid onto a solid nanosupport in a manner that allows intimate contact with and diffusion of external gaseous species is additionally projected to find value in a range of gas separation and sensing endeavours.