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Activated carbons obtained from rice husk / Cristina Deiana in Industrial & engineering chemistry research, Vol. 47 n°14 (Juillet 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°14 (Juillet 2008) . - p. 4754–4757 Titre : Activated carbons obtained from rice husk : influence of leaching on textural parameters Type de document : texte imprimé Auteurs : Cristina Deiana, Auteur ; Dolly Granados, Auteur ; Rosa Venturini, Auteur ; Alejandro Amaya, Auteur Année de publication : 2008 Article en page(s) : p. 4754–4757 Note générale : Bibliogr. p. 4757 Langues : Anglais (eng) Mots-clés : Activated  carbons;  Rice  husk;  Textural  parameters Résumé : Activated carbons obtained from rice husk exhibit low specific surface areas when physical activation is applied due to its high silica content. The purpose of this work was to improve textural parameters of powdered activated carbons obtained from rice husk. To avoid the negative influence of the raw material ash content, a leaching step was included in the preparation process. Hydrofluoric acid, in two concentrations (25 and 50 wt %), was used as leaching agent and applied in different stages of the process. Physical activation using water vapor as activating agent was applied. Specific surface area and porosity were evaluated from nitrogen adsorption data. When a leaching step was included, specific surface area values between 700 and 1200 m2/g were obtained. These values are higher than that corresponding to the activated carbon prepared from rice husk not treated with acid (290 m2/g). Pore size distribution depends on the step sequence of the preparation process and on the HF concentration. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071657x [article] Activated carbons obtained from rice husk : influence of leaching on textural parameters [texte imprimé] / Cristina Deiana, Auteur ; Dolly Granados, Auteur ; Rosa Venturini, Auteur ; Alejandro Amaya, Auteur . - 2008 . - p. 4754–4757. Bibliogr. p. 4757 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°14 (Juillet 2008) . - p. 4754–4757 Mots-clés : Activated  carbons;  Rice  husk;  Textural  parameters Résumé : Activated carbons obtained from rice husk exhibit low specific surface areas when physical activation is applied due to its high silica content. The purpose of this work was to improve textural parameters of powdered activated carbons obtained from rice husk. To avoid the negative influence of the raw material ash content, a leaching step was included in the preparation process. Hydrofluoric acid, in two concentrations (25 and 50 wt %), was used as leaching agent and applied in different stages of the process. Physical activation using water vapor as activating agent was applied. Specific surface area and porosity were evaluated from nitrogen adsorption data. When a leaching step was included, specific surface area values between 700 and 1200 m2/g were obtained. These values are higher than that corresponding to the activated carbon prepared from rice husk not treated with acid (290 m2/g). Pore size distribution depends on the step sequence of the preparation process and on the HF concentration. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071657x