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Comparison of methods to obtain micropore size distributions of carbonaceous materials from CO2 adsorption based on the dubinin − radushkevich isotherm / Moisés L. Pinto in Industrial & engineering chemistry research, Vol. 49 N° 10 (Mai 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4726-4730 Titre : Comparison of methods to obtain micropore size distributions of carbonaceous materials from CO2 adsorption based on the dubinin − radushkevich isotherm Type de document : texte imprimé Auteurs : Moisés L. Pinto, Auteur ; Ana S. Mestre, Auteur ; Ana P. Carvalho, Auteur Année de publication : 2010 Article en page(s) : pp. 4726-4730 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption  Carbon  dioxide  Particle  size  distribution  Microporosity Résumé : Micropore size distributions of various carbonaceous materials were obtained using two methods based on the Dubinin-Radushkevich equation and the relationship between the characteristic parameter of this equation and the pore width. One method was the well-known Dubinin-Radushkevich-Stoeckli (DRS) equation, and the other method used the integral adsorption equation without assuming a mathematical distribution for dw0/dE0. These methods were applied to carbon dioxide adsorption data on four activated carbons and eight chars to obtain micropore size distributions. Significant differences were found between the results obtained by the two methods. The DRS method gives an average of the distribution obtained by the method using the integral adsorption equation, because the latter is not constrained to a particular preassumed shape. The results reveal that the differences are more significant for the analysis of adsorption data on chars than on activated carbons. This was attributed to the fact that a less-homogeneous pore structure is expected to exist on chars than on activated carbons that cannot be described by the DRS method and can be described by the method based on the integral adsorption equation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797466 [article] Comparison of methods to obtain micropore size distributions of carbonaceous materials from CO2 adsorption based on the dubinin − radushkevich isotherm [texte imprimé] / Moisés L. Pinto, Auteur ; Ana S. Mestre, Auteur ; Ana P. Carvalho, Auteur . - 2010 . - pp. 4726-4730. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4726-4730 Mots-clés : Adsorption  Carbon  dioxide  Particle  size  distribution  Microporosity Résumé : Micropore size distributions of various carbonaceous materials were obtained using two methods based on the Dubinin-Radushkevich equation and the relationship between the characteristic parameter of this equation and the pore width. One method was the well-known Dubinin-Radushkevich-Stoeckli (DRS) equation, and the other method used the integral adsorption equation without assuming a mathematical distribution for dw0/dE0. These methods were applied to carbon dioxide adsorption data on four activated carbons and eight chars to obtain micropore size distributions. Significant differences were found between the results obtained by the two methods. The DRS method gives an average of the distribution obtained by the method using the integral adsorption equation, because the latter is not constrained to a particular preassumed shape. The results reveal that the differences are more significant for the analysis of adsorption data on chars than on activated carbons. This was attributed to the fact that a less-homogeneous pore structure is expected to exist on chars than on activated carbons that cannot be described by the DRS method and can be described by the method based on the integral adsorption equation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797466

Effect of the alcohol cosolvent in the removal of caffeine by activated carbons / Ana S. Mestre in Industrial & engineering chemistry research, Vol. 51 N° 29 (Juillet 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9850-9857 Titre : Effect of the alcohol cosolvent in the removal of caffeine by activated carbons Type de document : texte imprimé Auteurs : Ana S. Mestre, Auteur ; Susana C. R. Marques, Auteur ; Ana P. Carvalho, Auteur Année de publication : 2012 Article en page(s) : pp. 9850-9857 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Activated  carbon  Cosolvent Résumé : The effect of the addition of methanol and 2-propanol as cosolvents on the caffeine adsorption onto activated carbons was evaluated by both kinetic and equilibrium studies. The kinetic results presented a good adjustment to the pseudo-second-order kinetic model and reveal that the alcohol cosolvent has a double negative effect on caffeine adsorption: it enhances caffeine's solubility lowering its affinity toward the adsorbent and it seems to compete with caffeine for the adsorption active sites. The change in the isotherm shape from L to F type, when the mixture 2-propanol/water was used, was justified in terms of the higher interaction between the caffeine and 2-propanol molecules. This solvent presents the most similar Hansen three-dimensional solubility parameters when compared to the ones of caffeine. The overall adsorption results point out that when the sample with acidic surface chemistry is used, the water adsorption is favored and consequently the effect of the cosolvent is less marked and is mainly explained by the solubility. For the carbons with basic surfaces the addition of the alcohol cosolvent reflects in the adsorption mechanism due to the competitive adsorption of the alcohol, especially when the cosolvent is 2-propanol. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26184963 [article] Effect of the alcohol cosolvent in the removal of caffeine by activated carbons [texte imprimé] / Ana S. Mestre, Auteur ; Susana C. R. Marques, Auteur ; Ana P. Carvalho, Auteur . - 2012 . - pp. 9850-9857. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9850-9857 Mots-clés : Activated  carbon  Cosolvent Résumé : The effect of the addition of methanol and 2-propanol as cosolvents on the caffeine adsorption onto activated carbons was evaluated by both kinetic and equilibrium studies. The kinetic results presented a good adjustment to the pseudo-second-order kinetic model and reveal that the alcohol cosolvent has a double negative effect on caffeine adsorption: it enhances caffeine's solubility lowering its affinity toward the adsorbent and it seems to compete with caffeine for the adsorption active sites. The change in the isotherm shape from L to F type, when the mixture 2-propanol/water was used, was justified in terms of the higher interaction between the caffeine and 2-propanol molecules. This solvent presents the most similar Hansen three-dimensional solubility parameters when compared to the ones of caffeine. The overall adsorption results point out that when the sample with acidic surface chemistry is used, the water adsorption is favored and consequently the effect of the cosolvent is less marked and is mainly explained by the solubility. For the carbons with basic surfaces the addition of the alcohol cosolvent reflects in the adsorption mechanism due to the competitive adsorption of the alcohol, especially when the cosolvent is 2-propanol. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26184963