Post‐combustion carbon dioxide adsorption of concurrent activated and surface modified palm kernel shell‐derived activated carbon

Abstract

AbstractThis research applied a concurrent activation and surface modification (CAM) process to synthesize palm kernel shell‐derived activated carbon (PKSdAC) to obtain CO2 affinity surface functionalization. The CAM process is a simplified activated carbon activation process that is cost‐effective. The CAM process used in this study integrates sulphuric acid activation and barium chloride functionalization. The formation of barium sulphate is targeted to incorporate barium through a reduction process with carbon‐containing material at elevated temperatures into PKSdAC to obtain basic metal surfaces functional group for chemical adsorption. The optimal temperature for CAM‐PKSdAC CO2 adsorption performance was at 40–60 °C, established through temperature‐programmed desorption of CO2 (TPD‐CO2) analysis. The CAM‐PKSdAC adsorption performance was tested using a lab‐scale adsorption system. The bed CO2 content was determined using gas chromatography coupled with a thermal conductivity detector (GC‐TCD) by manual syringe injection. CAM‐PKSdAC exhibited a high CO2 adsorption capacity of 0.89 mmol g−1 from TPD‐CO2, and 1.91 mmol g−1 from GC‐TCD at 40 °C and 1 bar. It showed comparable CO2 adsorption capacity to conventional surface modified‐activated PKSdAC (1.96 mmol g−1) while higher than commercial and modified ACs (1.14–1.60 mmol g−1), but lower than potassium hydroxide modified ACs (1.81–2.10 mmol g−1) at 40 °C and 1 bar. Barium promoted chemisorption of CO2 as supplementary reaction, which increases adsorption capacity. The non‐linear Dubinin Radushkevich model strongly correlates with the experimental adsorption data for CAM‐PKSdAC adsorption, indicating the physisorption process via micropore filling on CAM‐PKSdAC. CAM‐PKSdAC showed moderate reusability with negligible variation in adsorption capacity after 10 adsorption–desorption cycles. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.