| 초록 |
Substantial efforts have been made to increase the CO2 working capacity of amine adsorbents for efficient CO2 capture. However, the ultimate metric for assessing adsorbents is not the CO2 capacity but the regeneration heat required for capturing a fixed amount of CO2. In this work, we synthesized PEI/SiO2 adsorbents functionalized with various epoxides. This provided adsorbents with different amine structures showing various CO2/H2O adsorption properties. Our studies revealed that, contrary to what we would normally expect, the CO2 working capacity was not a decisive factor in determining the regeneration heat required for CO2 capture. This is because the benefit of large CO2 working capacity was cancelled out by the difficulty of CO2 desorption. Instead, the suppression of H2O co-adsorption was critical for reducing regeneration heat, because substantial latent heat is required for H2O desorption. Consequently, the PEI/SiO2 functionalized with 1,2-epoxybutane required much lower regeneration heat (2.66 GJ tCO2-1) than the conventional PEI/SiO2 (4.03 GJ tCO2-1), because of suppressed H2O co-adsorption as well as moderately high CO2 working capacity. |
