Dynamic performance of TEPA-impregnated carbon nanofibers composites for direct air carbon capture in fixed bed columns

Carbon nanofibers (CNFs), renowned for their high specific surface area and porosity, exhibit significant potential in applications such as energy storage, catalysis, and gas adsorption. However, the affinity of typical CNFs for CO 2 in direct air capture scenarios is compromised by less partial pressure of CO 2 in the atmosphere. In contrast, amine-functionalized materials, especially those incorporating tetraethylenepentamine (TEPA), which possesses a strong propensity for CO 2 , are recognized for their efficacy in CO 2 capture. This study aimed to develop amine-functionalized adsorbents by integrating TEPA into electrospun CNFs. The synthesized material's structural properties were examined using BET, TGA, and FTIR. The effects of amine content, temperatures, and relative humidity on the CO 2 adsorption/desorption dynamics of CNF-TEPA50 within a fixed-bed system were evaluated. The results showed that, at 35 ℃, 1 bar pressure, and 40 % RH, the material achieved its highest adsorption capacity of 3.75 mmol/g for a 0.04 vol% CO 2 mixture. The adsorption/desorption kinetics align with various models, indicating suitability for complex processes. This study underscores the potential of TEPA-modified CNFs for capturing CO 2 at ultralow concentrations, thereby contributing to the advancement of CO 2 mitigation technologies.