Adsorption and separation behaviors of CO₂ and CH₄ gases on nanoporous carbon fabricated from rice husk

抄録

The adsorption and separation behaviors of CO₂ and CH₄ gases on nanoporous carbon (NPC) fabricated from rice husk were investigated for possible applications in industrial carbon dioxide capture and storage (CCS). The NPC was fabricated from carbonized rice husks by alkaline activation with potassium hydrate (KOH), and it had pore sizes of 1.0, 1.2, and 1.7 nm and a specific surface area of 1520–3379 m²/g. The adsorption and separation behaviors of CO₂ and CH₄ on it were measured by gas chromatography (GC). The adsorption and separation behaviors on NPCs was depended on it’s pore structures. The single-gas storage capacities were 3.7–19.3 mmol/g for CO₂ and 3.8–9.5 mmol/g for CH₄ at temperatures of 278–333 K. Furthermore, the separation coefficient for selective adsorption of CH₄ from a mixture of CO₂ and CH₄ gases was measured to range from 1.36–2.38. These results indicate that this NPC produced using agricultural sustainable material is a good candidate for industrial CCS techniques.