Enhancing Adsorbent Characteristics from Activated Carbon-Palm Kernel Shells (AC-PKS) with Impregnated Tetraethylenepenthanamine (TEPA) and Imidazoles (IMS) for Carbon Capture Applications

The combustion of fossil fuels significantly contributes to greenhouse gas emissions, particularly carbon dioxide (CO₂), a primary driver of global warming. Carbon capture and storage (CCS) has been recognized as a promising solution to mitigate these emissions, with adsorption being one of the most effective methods. Activated carbon (AC), especially derived from palm kernel shells (PKS), is widely utilized for CO₂ capture due to its large surface area, high adsorption capacity, well-defined porous structure, and robust mechanical properties. However, further enhancing its adsorption performance is necessary to improve efficiency and practicality. This study investigates the chemical modification of activated carbon-palm kernel shell (AC-PKS) using tetraethylenepentamine (TEPA) and imidazole (IMS) through amine impregnation. The objective is to optimize critical factors, including impregnation ratios and operational temperatures, to maximize CO₂ adsorption efficiency. Experimental evaluations were conducted by varying the impregnation ratio between 4:3, 3:4, 5:2, and 7:0 and the temperature ranged from 60°C to 90°C. The findings revealed that an optimal TEPA-to-IMS impregnation ratio of 4:3 yielded the best performance. This modification enhanced the CO₂ adsorption capacity to approximately 79.41 wt% while maintaining N₂ content around 23.32 wt%. Furthermore, the modified AC-PKS exhibited a uniform pore structure and an acceptable iodine number within the range of 800-950 mg/g, indicating improved surface chemistry and adsorption efficiency. These findings highlight the importance of characterizing TEPA-IMS-modified AC-PKS to ensure its suitability for adsorption studies. The enhanced adsorbent properties demonstrated in this work underscore its potential as an efficient and sustainable material for CO₂ capture, contributing to the advancement of adsorption-based CCS technologies and environmental sustainability.