CO₂ capture on an optimally prepared highly microporous KOH-activated carbon from rice husk

In this study, rice husk was used as a low-cost agro-waste to produce optimally a high microporous KOH-chemically activated carbon for efficient CO₂capture. In order to find the optimum conditions to prepare this carbon-based adsorbent, the rice husk was subject to different carbonization temperatures, followed by various KOH impregnation ratios, activation temperatures, and activation times, in absence of an inert atmosphere. All developed carbons were characterized by using different analytical methods. Results showed that the rice husk carbonization at 600 oC by 1 hour followed by KOH-chemical activation using a mass impregnation ratio of 1:3 at 600 oC during 1 h, produced an activated carbon of microporous structure, with a high surface area of 1384.4 m²/g and a high total pore volume of 1.0854 cm³/g, these obtained morphological and textural properties were correlated with their exhibited CO₂ adsorption capacity of 110.78 mg/g under atmospheric conditions, measured by the thermogravimetric method. The results indicate that KOH chemical activation under no inert gas conditions as an optimized synthesis route does seem to be a suitable modification technique that offered to prepare with economic feasibility a valuable activated carbon to be potentially used in CO₂ capture technologies.

Keywords: rice-husk, KOH-chemically activated carbon, CO₂ capture, adsorption, microporous.