Effect of deashing rice straws on their derived activated carbons produced by phosphoric acid activation

• Published in: Biomass & bioenergy 2011-05, Vol.35 (5), p.1954-1959
• Main Authors: Basta, A.H., Fierro, V., Saied, H., Celzard, A.
• Format: Article
• Language: English
• Subjects: Activated carbon; Adsorption; Applied sciences; Chemical activation; Energy; Exact sciences and technology; Fuel processing. Carbochemistry and petrochemistry; Fuels; methylene blue; Oryza sativa; Phosphoric acid; rice; Rice straw; Solid fuel processing (coal, coke, brown coal, peat, wood, etc.); sorption isotherms; surface area
• ISSN: 0961-9534; 1873-2909
• DOI: 10.1016/j.biombioe.2011.01.043

We studied the effect of physically and/or chemically deashing rice straw (RS) on the adsorption capacity of their derived activated carbons (ACs) produced by chemical activation with H 3PO 4. Surface area and pore volumes were determined by nitrogen adsorption at 77 K. Methylene blue adsorption isotherms onto ACs were carried out, and we applied Langmuir and Freundlich models to fit the adsorption data. We showed that preliminary deashing does not bring significant improvement to the resultant ACs’ properties. ACs prepared by H 3PO 4 activation of raw and deashed RS have intermediate performances between those of ACs prepared by 1- and 2-step KOH activation, but are much cheaper to produce. ► In Egypt, RS is mainly considered as a waste and most of the times RS is burnt without any profit and caused atmospheric pollution. ► This article presents an overview of research studies carried out on biomass valorization. ► The production of activated carbon from deashed RS and phosphoric acid was evaluated.