Ika Monika, Miftahul Huda, Axl Mevia, Retno Damayanti, Retno Wijayanti, Evi Dwi Yanti, Asnan Rinovian, Yudha Gusti Wibowo
Surface characteristics and performance of adsorbent materials are vital for understanding CO2 sorption. This study utilizes unexploited coal from a power plant, demonstrating its potential as an effective CO2 adsorbent through proximate, ultimate analyses and iodine number evaluations. BET analysis showed that mesopores consistently exhibited higher volumes than micropores in all samples, with the ‘CMC’ sample showing the greatest mesopore volume at over 0.3 cm³/g. Surface chemical functional groups and pore structure significantly influence the performance of activated carbon in adsorption processes. In this research, coal-based activated carbon served as a precursor, highlighting the effects of oxygen incorporation into the precursor structure to create new oxygen-containing sites on the surface. These groups were further examined by calcination in a nitrogen atmosphere. The oxygenation process was conducted at varying temperatures-100, 200, 300, 400, and 500 °C-with subsequent calcination at 900 °C. The highest functional group activity occurred at 500 °C, transitioning from hydroxyl to carboxyl groups. High-temperature calcination at 900 °C facilitated the formation of nitrogen-carboxyl bonds, enhancing the micropore volume and CO2 adsorption capacity. The calcined samples demonstrated extended breakthrough times, indicating improved adsorption efficacy. Overall, this study confirms that targeted oxygenation and calcination enhance the functional group composition and pore structure of coal-based activated carbon, albeit with a modest increase in adsorption capacity due to low volatile content. © 2026, Penerbit Universiti Kebangsaan Malaysia. All rights reserved.
Research Center for Mineral Technology, National Research and Innovation Agency (BRIN), South Lampung, 35361, Indonesia; Metallurgical Faculty, Bandung Institute of Technology, Jl. Ganesha 10, Bandung, 40132, Indonesia; Research Center for Geological Resources, National Research and Innovation Agency (BRIN), West Java, 40135, Indonesia; Department of Mining Engineering, Faculty of Technology Industry, Institut Teknologi Sumatera, South Lampung, Lampung, Indonesia; Center for Green and Sustainable Materials, Institut Teknologi Sumatera, South Lampung, Lampung, Indonesia