Highly optimized CO₂ capture by inexpensive nanoporous covalent organic polymers and their amine composites

다국어 초록 (Multilingual Abstract)

<P>Carbon dioxide (CO<SUB>2</SUB>) storage and utilization requires effective capture strategies that limit energy penalties. Polyethylenimine (PEI)-impregnated covalent organic polymers (COPs) with a high CO<SUB>2</SUB> adsorption capacity are successfully prepared in this study. A low cost COP with a high specific surface area is suitable for PEI loading to achieve high CO<SUB>2</SUB> adsorption, and the optimal PEI loading is 36 wt%. Though the adsorbed amount of CO<SUB>2</SUB> on amine impregnated COPs slightly decreased with increasing adsorption temperature, CO<SUB>2</SUB>/N<SUB>2</SUB> selectivity is significantly improved at higher temperatures. The adsorption of CO<SUB>2</SUB> on the sorbent is very fast, and a sorption equilibrium (10% wt) was achieved within 5 min at 313 K under the flow of simulated flue gas streams. The CO<SUB>2</SUB> capture efficiency of this sorbent is not affected under repetitive adsorption–desorption cycles. The highest CO<SUB>2</SUB> capture capacity of 75 mg g<SUP>−1</SUP> at 0.15 bar is achieved under dry CO<SUB>2</SUB> capture however it is enhanced to 100 mg g<SUP>−1</SUP> in the mixed gas flow containing humid 15% CO<SUB>2</SUB>. Sorbents were found to be thermally stable up to at least 200 °C. TGA and FTIR studies confirmed the loading of PEIs on COPs. This sorbent with high and fast CO<SUB>2</SUB> sorption exhibits a very promising application in direct CO<SUB>2</SUB> capture from flue gas.</P>