Dry hydrated potassium carbonate for effective CO2 capture

Abstract

Dry hydrated potassium carbonate (DHPC) is a free-flowing powder prepared by uniformly mixing hydrated K₂CO₃ and hydrophobic nanosilica. We demonstrated that DHPCs can absorb CO₂ rapidly because of their high surface-to-volume ratio. Their CO₂ capture performance is superior to that of 30 wt% monoethanolamine (MEA), an industry standard. DHPC-75 (containing 75 wt% K₂CO₃) has a CO₂ uptake capacity of 233 mg g⁻¹ (90% saturation uptake within 13 min), higher than the widely used 30 wt% MEA aqueous solution (111 mg g⁻¹, 90% saturation uptake within 25 min). DHPC-75 also exhibits an excellent cycling performance, thus becoming a promising candidate for practical application.