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Adsorption behavior of a mixture of C13 isomers onto a fixed-bed of H-ZSM-5 / M. A. Uguina in Industrial & engineering chemistry research, Vol. 48 N° 15 (Août 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7301–7307 Titre : Adsorption behavior of a mixture of C13 isomers onto a fixed-bed of H-ZSM-5 Type de document : texte imprimé Auteurs : M. A. Uguina, Auteur ; Sotelo, J. L., Auteur ; J. A. Delgado, Auteur Année de publication : 2009 Article en page(s) : pp. 7301–7307 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Liquid-phase  adsorption  C13  Isomers  Fixed  bed  H-ZSM-5  (Si/Al  =  200)  Breakthrough  curves Résumé : Multicomponent liquid-phase adsorption of C13 paraffins (mainly monomethyldodecanes and tridecane) onto a fixed bed of H-ZSM-5 (Si/Al = 200) has been studied (428 K and 21 barg), obtaining complete breakthrough curves for all the solutes, in order to ensure that equilibrium between the liquid feed and the adsorbent was achieved. The concentration of adsorbates in the feed mixture has been varied by diluting a concentrated mixture of C13 paraffins with a nonadsorbing solvent (2,2,4-trimethylpentane) in different proportions. The relationship between the branching position of the isomer and its adsorption affinity has been studied. The following affinity order is obtained (estimated as adsorbed concentration/liquid concentration): 2-MC12 ≈ 3-MC12 < 4-MC12 < n-C13 < 5-MC12 < 6-MC12. This order can be attributed to the difference in length of the lateral chains of each isomer, considering that a CH3−CH−CH2 group is placed the pore intersections of H-ZSM-5 for the branched isomers, and a CH2−CH2 group for n-C13. For the more symmetric isomers (n-C13, 5-MC12, 6-MC12), the affinity decreases continuously as the concentration of the feed mixture is increased, whereas it passes through a maximum for the asymmetric ones (2- MC12, 3- MC12, 4-MC12), because the asymmetric isomers adsorb weakly if the concentration of the symmetric ones is not very high, but they are displaced from the adsorbed phase as the concentration of the feed mixture is increased. The practical implication of this result is that, if the recovery of both symmetric and asymmetric C13 isomers from kerosene with H-ZSM-5 is desired for the production of tensoactives, it is convenient to use a feed concentration where the displacement of asymmetric isomers is minimal. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900419k [article] Adsorption behavior of a mixture of C13 isomers onto a fixed-bed of H-ZSM-5 [texte imprimé] / M. A. Uguina, Auteur ; Sotelo, J. L., Auteur ; J. A. Delgado, Auteur . - 2009 . - pp. 7301–7307. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7301–7307 Mots-clés : Liquid-phase  adsorption  C13  Isomers  Fixed  bed  H-ZSM-5  (Si/Al  =  200)  Breakthrough  curves Résumé : Multicomponent liquid-phase adsorption of C13 paraffins (mainly monomethyldodecanes and tridecane) onto a fixed bed of H-ZSM-5 (Si/Al = 200) has been studied (428 K and 21 barg), obtaining complete breakthrough curves for all the solutes, in order to ensure that equilibrium between the liquid feed and the adsorbent was achieved. The concentration of adsorbates in the feed mixture has been varied by diluting a concentrated mixture of C13 paraffins with a nonadsorbing solvent (2,2,4-trimethylpentane) in different proportions. The relationship between the branching position of the isomer and its adsorption affinity has been studied. The following affinity order is obtained (estimated as adsorbed concentration/liquid concentration): 2-MC12 ≈ 3-MC12 < 4-MC12 < n-C13 < 5-MC12 < 6-MC12. This order can be attributed to the difference in length of the lateral chains of each isomer, considering that a CH3−CH−CH2 group is placed the pore intersections of H-ZSM-5 for the branched isomers, and a CH2−CH2 group for n-C13. For the more symmetric isomers (n-C13, 5-MC12, 6-MC12), the affinity decreases continuously as the concentration of the feed mixture is increased, whereas it passes through a maximum for the asymmetric ones (2- MC12, 3- MC12, 4-MC12), because the asymmetric isomers adsorb weakly if the concentration of the symmetric ones is not very high, but they are displaced from the adsorbed phase as the concentration of the feed mixture is increased. The practical implication of this result is that, if the recovery of both symmetric and asymmetric C13 isomers from kerosene with H-ZSM-5 is desired for the production of tensoactives, it is convenient to use a feed concentration where the displacement of asymmetric isomers is minimal. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900419k

Heterogeneous fenton catalyst supports screening for mono azo dye degradation in contaminated wastewaters / Rodrguez, A. in Industrial & engineering chemistry research, Vol. 49 N° 2 (Janvier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 2 (Janvier 2010) . - pp 498–505 Titre : Heterogeneous fenton catalyst supports screening for mono azo dye degradation in contaminated wastewaters Type de document : texte imprimé Auteurs : Rodrguez, A., Auteur ; Ovejero, G., Auteur ; Sotelo, J. L., Auteur Année de publication : 2010 Article en page(s) : pp 498–505 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Heterogeneous  Catalyst  Wastewater. Résumé : Degradation of acid orange II (AOII), a dye present in textile industry wastewater, by the heterogeneous Fenton process (HFP) was performed. In order to select an adequate support, heterogeneous Fenton catalysts were prepared using several materials such as carbon nanotubes, carbon nanofibers, activated carbon, hydrotalcite-like materials, mesoporous silica (MCM41), silica, silica xerogel, sepiolite, and zeolite USY, that were tested in the degradation of AOII as the model compound. Color, total organic carbon, chemical oxygen demand removal, and toxicity were studied in the process. The best catalyst was iron supported on sepiolite. The best performing catalytic material was used to investigate the influence of the presence of carbonate ions, pH, and reuse of catalyst. Also, a real textile wastewater was successfully treated with this catalyst. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901212m [article] Heterogeneous fenton catalyst supports screening for mono azo dye degradation in contaminated wastewaters [texte imprimé] / Rodrguez, A., Auteur ; Ovejero, G., Auteur ; Sotelo, J. L., Auteur . - 2010 . - pp 498–505. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 2 (Janvier 2010) . - pp 498–505 Mots-clés : Heterogeneous  Catalyst  Wastewater. Résumé : Degradation of acid orange II (AOII), a dye present in textile industry wastewater, by the heterogeneous Fenton process (HFP) was performed. In order to select an adequate support, heterogeneous Fenton catalysts were prepared using several materials such as carbon nanotubes, carbon nanofibers, activated carbon, hydrotalcite-like materials, mesoporous silica (MCM41), silica, silica xerogel, sepiolite, and zeolite USY, that were tested in the degradation of AOII as the model compound. Color, total organic carbon, chemical oxygen demand removal, and toxicity were studied in the process. The best catalyst was iron supported on sepiolite. The best performing catalytic material was used to investigate the influence of the presence of carbonate ions, pH, and reuse of catalyst. Also, a real textile wastewater was successfully treated with this catalyst. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901212m