Fabrication of waste biomass-derived KOH activated carbon for enhanced CO2 capture

Abstract

This study investigated the production of biomass-derived activated carbons (ACs) Borassus flabellifer flower (BF), sugarcane bagasse (SB), and coconut shells (CS), which were subsequently utilized for carbon dioxide (CO₂) capture. The raw materials were subjected to carbonization followed by chemical activation using potassium hydroxide (KOH) to enhance the porosity and surface area of the ACs. Various characterization techniques such as Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and nitrogen adsorption–desorption isotherms were employed to assess the textural and structural properties of the prepared charcoals and ACs. The results indicated that the CO₂ adsorption capacity of BFC, CCC, and SBC were 1.91, 1.28, and 1.07 mmol g⁻¹, respectively. After activation using KOH, AC-BFC exhibited the highest CO₂ adsorption capacity of 4.8 mmol g⁻¹ compared to AC-SBC of 3.26 mmol g⁻¹ and AC-CCC of 1.76 mmol g⁻¹. The findings demonstrate that KOH activation significantly increased the surface area and microporosity, leading to an enhanced CO₂ adsorption capacity of the ACs. Overall, this research underscores the dual benefit of using agricultural waste for producing ACs, addressing both waste management and environmental sustainability in terms of CO₂ mitigation.