The Effect of Physicochemical Properties and Surface Chemistry on CO2 Adsorption Capacity of Potassium Acetate-Treated Carbon Pellets

Abstract

The aim of this study is to prepare a carbon pellet using low-cost material and a green process with excellent surface properties for carbon dioxide (CO2) capture application. To enhance the surface properties of the carbon pellet, a chemical activation method was introduced by modifying the pellet with potassium acetate. Then, the carbon pellet was tested in a packed-bed adsorption column to evaluate their performance for breakthrough time and CO2 adsorption. The effect of the physicochemical and surface chemistry of the carbon pellet on CO2 adsorption was also studied. The SEM image showed remarkable changes in the surface morphology of the carbon pellet after modification with potassium acetate. In addition, the presence of oxygen-containing functional groups such as hydroxyl and carbonyl groups in the modified carbon pellet could effectively enhance the CO2 adsorption capacity. Thus, it is proven that the carbon pellet modified with potassium acetate is suitable for CO2 adsorption. The results revealed that the CAC-PA 2M obtained the longest breakthrough time (19.4 min), higher adsorption capacity (0.685 mmol/g), and good recyclability (the regenerated sample can be reused for more than five cycles). The comprehensive characterization study and CO2 adsorption experimental data on new carbon pellets can provide a direction for new researchers that are venturing into the CO2 capture field.