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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