Post-combustion CO2 capture using polyethyleneimine impregnated mesoporous cellular foams

Abstract

Abstract In this work, mesoporous cellular foams (MCFs) were synthesized and impregnated with different weight percentage of polyethylenimine (PEI) for post-combustion CO 2 capture. The synthesized adsorbents were characterized using various techniques such as nitrogen adsorption/desorption SEM, TEM, and FTIR analysis. The CO 2 adsorption capacity of PEI-impregnated MCFs was measured using thermogravimetric analyzer (TGA). The effects of PEI loadings, adsorption temperatures, and CO 2 partial pressures on CO 2 adsorption performance were studied. 70 wt.% PEI was found to be the optimum PEI loading in MCFs for post-combustion CO 2 capture with higher CO 2 adsorption capacity, higher amine efficiency and fast kinetics. The adsorbent with optimal PEI loading was tested for CO 2 adsorption capacity, multi-cycle stability and adsorption/desorption kinetics. The CO 2 adsorption capacity of about 5.16 mmol/g in 95% CO 2 /5% N 2 gas mixture and 3.95 mmol/g in 10% CO 2 /90% N 2 gas mixture at 75 °C was observed. The CO 2 adsorption performance of PEI-impregnated MCFs improved in the presence of moisture, only at low adsorption temperatures. The adsorbent with optimum PEI loading was also tested for multi-cycle stability and adsorption/desorption kinetics in both humid and dry conditions. A good thermal stability of adsorbent and no degradation in CO 2 adsorption capacity was observed in multi-cycle tests. Fractional-order kinetic model was found to be the best fitted to describe the adsorption behavior of PEI-impregnated MCFs for CO 2 capture.