Experimental and theoretical investigation of amine-modified biomass-derived activated carbon for CO2 capture: The effects of carbon chain length and types of amine

Sustainable feedstocks and low-cost precursors are crucial for the development of adsorbents for CO 2 capture. In this study, three different amine-modified adsorbents were synthesized using sustainable green feedstock, coconut shells, and physical impregnation of DETA, TETA, and TEPA at different loadings (30%, 30%, and 10%, respectively). Their potential as alternative adsorbents for CO 2 capture was investigated. Compared to the original activated carbon, all three amine-modified adsorbents showed improved CO 2 uptake, with the DETA-modified adsorbent showing the highest CO 2 adsorption capacity. The influence of carbon chain length and amine types on CO 2 capture was studied in detail. Density functional theory (DFT) calculations were performed to study the CO 2 adsorption on the bare activated carbon and the amine-modified adsorbents. The results showed that shorter carbon chains and primary amines could improve the CO 2 adsorption performance of the adsorbents regardless of whether the organic amines were dehydrogenated.