Documents disponibles écrits par cet auteur

Adsorption equilibrium and kinetics of water vapor on different adsorbents / Ana M. Ribeiro in Industrial & engineering chemistry research, Vol. 47 N°18 (Septembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°18 (Septembre 2008) . - p. 7019–7026 Titre : Adsorption equilibrium and kinetics of water vapor on different adsorbents Type de document : texte imprimé Auteurs : Ana M. Ribeiro, Auteur ; Ticiane P. Sauer, Auteur ; Carlos A. Grande, Auteur Année de publication : 2008 Article en page(s) : p. 7019–7026 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Water  vapor  Kinetic  data  Adsorption  equilibrium  Zeolite  Activated  carbon Résumé : Water vapor needs to be removed from many industrial streams using, for example, adsorption processes. Equilibrium and kinetic data are essential for the design of these adsorption processes. In this work, the adsorption equilibrium isotherms of water vapor were measured at 303 K by a gravimetric system on three commercial adsorbents, an activated carbon, an activated alumina, and a zeolite. The zeolite sample presented the highest capacity at low relative pressures, while at pressures near saturation the higher amount adsorbed was obtained on the alumina sample. The experimental points obtained for the activated carbon and the zeolite were fitted with the Virial isotherm while the n-layer BET equation was used in the fitting of the alumina data. The adsorption kinetics was evaluated through the analysis of breakthrough curves obtained at the same temperature for different feed humidity values. The fixed bed behavior was described using an isothermal model that includes axial dispersion and external (film model) and internal (homogeneous LDF model) mass transfer resistances. The homogeneous diffusivity values were determined by adjusting the model to the experimental data. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701732x [article] Adsorption equilibrium and kinetics of water vapor on different adsorbents [texte imprimé] / Ana M. Ribeiro, Auteur ; Ticiane P. Sauer, Auteur ; Carlos A. Grande, Auteur . - 2008 . - p. 7019–7026. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°18 (Septembre 2008) . - p. 7019–7026 Mots-clés : Water  vapor  Kinetic  data  Adsorption  equilibrium  Zeolite  Activated  carbon Résumé : Water vapor needs to be removed from many industrial streams using, for example, adsorption processes. Equilibrium and kinetic data are essential for the design of these adsorption processes. In this work, the adsorption equilibrium isotherms of water vapor were measured at 303 K by a gravimetric system on three commercial adsorbents, an activated carbon, an activated alumina, and a zeolite. The zeolite sample presented the highest capacity at low relative pressures, while at pressures near saturation the higher amount adsorbed was obtained on the alumina sample. The experimental points obtained for the activated carbon and the zeolite were fitted with the Virial isotherm while the n-layer BET equation was used in the fitting of the alumina data. The adsorption kinetics was evaluated through the analysis of breakthrough curves obtained at the same temperature for different feed humidity values. The fixed bed behavior was described using an isothermal model that includes axial dispersion and external (film model) and internal (homogeneous LDF model) mass transfer resistances. The homogeneous diffusivity values were determined by adjusting the model to the experimental data. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701732x

Enhancing capacity of activated carbons for hydrogen purification / Filipe V. S. Lopes in Industrial & engineering chemistry research, Vol. 48 N° 8 (Avril 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 8 (Avril 2009) . - pp. 3978–3990 Titre : Enhancing capacity of activated carbons for hydrogen purification Type de document : texte imprimé Auteurs : Filipe V. S. Lopes, Auteur ; Carlos A. Grande, Auteur ; Ana M. Ribeiro, Auteur Année de publication : 2009 Article en page(s) : pp. 3978–3990 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Steam  methane  reforming  Pressure  swing  adsorption  Activated  carbon Résumé : The commercial technology for the separation of off-gases from steam methane reforming is pressure swing adsorption (PSA). To improve the performance of the PSA units, materials with enhanced capacity toward contaminants are required. In this work, a commercial activated carbon (AC) was used for the preparation of a new material with enhanced capacity toward contaminants (CO2, CH4, CO, and N2). Different samples were prepared by physical activation with CO2 under different operating conditions. The conditions where the sample with the highest microporosity was obtained were reproduced to prepare a scale-up of 400 g. Carbon dioxide, hydrogen, methane, carbon monoxide, and nitrogen adsorption equilibrium and kinetics were studied on the modified AC and compared to the original AC results. An improvement of CO2 adsorption capacity of 17.5% was observed at 303 K and 7 bar. Carbon dioxide micropore diffusivity of same order of magnitude (Dc/rc2 = ∼4 × 10−2 s−1 at 303 K) was observed for both adsorbents. Finally, ternary breakthrough curves (CO2−H2−CH4) were performed for the validation of the multicomponent adsorption equilibrium. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801132t [article] Enhancing capacity of activated carbons for hydrogen purification [texte imprimé] / Filipe V. S. Lopes, Auteur ; Carlos A. Grande, Auteur ; Ana M. Ribeiro, Auteur . - 2009 . - pp. 3978–3990. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 8 (Avril 2009) . - pp. 3978–3990 Mots-clés : Steam  methane  reforming  Pressure  swing  adsorption  Activated  carbon Résumé : The commercial technology for the separation of off-gases from steam methane reforming is pressure swing adsorption (PSA). To improve the performance of the PSA units, materials with enhanced capacity toward contaminants are required. In this work, a commercial activated carbon (AC) was used for the preparation of a new material with enhanced capacity toward contaminants (CO2, CH4, CO, and N2). Different samples were prepared by physical activation with CO2 under different operating conditions. The conditions where the sample with the highest microporosity was obtained were reproduced to prepare a scale-up of 400 g. Carbon dioxide, hydrogen, methane, carbon monoxide, and nitrogen adsorption equilibrium and kinetics were studied on the modified AC and compared to the original AC results. An improvement of CO2 adsorption capacity of 17.5% was observed at 303 K and 7 bar. Carbon dioxide micropore diffusivity of same order of magnitude (Dc/rc2 = ∼4 × 10−2 s−1 at 303 K) was observed for both adsorbents. Finally, ternary breakthrough curves (CO2−H2−CH4) were performed for the validation of the multicomponent adsorption equilibrium. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801132t

Hydrogen production via sorption enhanced steam methane reforming process using Ni / CaO multifunctional catalyst / Naruewan Chanburanasiri in Industrial & engineering chemistry research, Vol. 50 N° 24 (Décembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13662-13671 Titre : Hydrogen production via sorption enhanced steam methane reforming process using Ni / CaO multifunctional catalyst Type de document : texte imprimé Auteurs : Naruewan Chanburanasiri, Auteur ; Ana M. Ribeiro, Auteur ; Alirio E. Rodrigues, Auteur Année de publication : 2012 Article en page(s) : pp. 13662-13671 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalyst  Reforming  Water  vapor  Sorption  Hydrogen  production Résumé : Sorption enhanced steam methane reforming (SESMR) is a promising concept for hydrogen production. The in situ removal of CO2 shifts the reaction equilibrium toward increased H2 production as well as H2 concentration. Generally, most of the previous studies operated the SESMR system using separate materials of a CO2 adsorbent and a reforming catalyst. In this study, a combined catalyst-adsorbent material (considered as multifunctional catalyst), whose functions are not only to catalyze the reaction but also to adsorb CO2 simultaneously, was developed and utilized for the SESMR process. CaO and hydrotalcite (MK30-K), well-known adsorbents for CO2 capture, were selected as supports to replace a conventional Al2O3 support for Ni catalyst. The material was prepared in the form of powder by incipient wetness technique, and the tests were carried out in the fixed bed reactor system. Experimental results indicated that the activity of Ni/CaO was less than Ni/Al2O3 but high hydrogen concentration in the product stream can be achieved. The effect of Ni loading was investigated, and it was found that at atmospheric pressure, steam to methane ratio of 3 and T = 873 K, 12.5 wt % Ni/CaO was the appropriate ratio, offering high hydrogen concentration (80%). The study also suggested that the use of the multifunctional catalyst eliminates the use of Al2O3 and thus requires a reactor with a smaller size. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25299828 [article] Hydrogen production via sorption enhanced steam methane reforming process using Ni / CaO multifunctional catalyst [texte imprimé] / Naruewan Chanburanasiri, Auteur ; Ana M. Ribeiro, Auteur ; Alirio E. Rodrigues, Auteur . - 2012 . - pp. 13662-13671. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13662-13671 Mots-clés : Catalyst  Reforming  Water  vapor  Sorption  Hydrogen  production Résumé : Sorption enhanced steam methane reforming (SESMR) is a promising concept for hydrogen production. The in situ removal of CO2 shifts the reaction equilibrium toward increased H2 production as well as H2 concentration. Generally, most of the previous studies operated the SESMR system using separate materials of a CO2 adsorbent and a reforming catalyst. In this study, a combined catalyst-adsorbent material (considered as multifunctional catalyst), whose functions are not only to catalyze the reaction but also to adsorb CO2 simultaneously, was developed and utilized for the SESMR process. CaO and hydrotalcite (MK30-K), well-known adsorbents for CO2 capture, were selected as supports to replace a conventional Al2O3 support for Ni catalyst. The material was prepared in the form of powder by incipient wetness technique, and the tests were carried out in the fixed bed reactor system. Experimental results indicated that the activity of Ni/CaO was less than Ni/Al2O3 but high hydrogen concentration in the product stream can be achieved. The effect of Ni loading was investigated, and it was found that at atmospheric pressure, steam to methane ratio of 3 and T = 873 K, 12.5 wt % Ni/CaO was the appropriate ratio, offering high hydrogen concentration (80%). The study also suggested that the use of the multifunctional catalyst eliminates the use of Al2O3 and thus requires a reactor with a smaller size. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25299828