Enhancement of CO2 capture in post combustion process using actived carbon modified by amino acids

In this study, surface modification of a general purpose activated carbon is achieved through impregnation of three common amino acids namely, glycine, serine and lysine for CO2 adsorption in post-combustion processes at temperature range 298–358 K. Glycine, due to its smaller molecular size, higher nitrogen content, and enhanced pore accessibility caused the adsorption to increase by 25% compared to original activated carbon uptake. N2 adsorption isotherms were measured to comparatively evaluate adsorption preference and infer potential CO2/N2 selectivity. The modified adsorbents with glycine exhibited similar N2 uptake to initial activated carbon at 358 K. All adsorbents exhibited physisorption behavior, with isosteric heat of adsorption values ranging from − 11 to − 33.9 kJ/mol for CO2 and − 15.6 to − 17.8 kJ/mol for N2. Overall, the results demonstrate that functionalizing by glycine, significantly enhances CO2 adsorption capacity of activated carbon. These findings provide valuable insights for designing tailored adsorbents for post combustion CO2 capture.