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A comparison of ammonia borane dehydrogenation methods for proton-exchange-membrane fuel cell vehicles / Ahmad Al-Kukhun in Industrial & engineering chemistry research, Vol. 50 N° 15 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 8824-8835 Titre : A comparison of ammonia borane dehydrogenation methods for proton-exchange-membrane fuel cell vehicles : hydrogen yield and ammonia formation and Its removal Type de document : texte imprimé Auteurs : Ahmad Al-Kukhun, Auteur ; Hyun Tae Hwang, Auteur ; Arvind Varma, Auteur Année de publication : 2011 Article en page(s) : pp. 8824-8835 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Proton  exchange  membrane  fuel  cells  Dehydrogenation Résumé : Current promising methods to release hydrogen from ammonia borane (NH3BH3, AB; 19.6 wt % H2) including neat thermolysis, thermolysis in ionic liquid bmimCl with or without proton sponge, thermolysis with nano-BN and hydrothermolysis, were investigated for hydrogen yield and ammonia formation. It was found that even trace moisture influences AB dehydrogenation significantly. The hydrothermolysis at 85 °C (13.5 wt % H2, 1 mol % NH3) and thermolysis in bmimCl with 3 wt % moisture at 110 °C (13 wt % H2, 0.2 mol % NH3) methods were found to be the most promising. Since the target for a proton exchange membrane (PEM) fuel cell is an ammonia concentration less than 0.1 ppm, different purification methods were evaluated. Using experiments and simulations, the proposed ammonia removal method, involving absorption in water followed by adsorption on carbon, was optimized and tested. This study demonstrates that, with high hydrogen yield and an effective method to remove ammonia and borazine, AB dehydrogenation is an attractive approach to generate hydrogen for PEM fuel cell vehicle applications. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395828 [article] A comparison of ammonia borane dehydrogenation methods for proton-exchange-membrane fuel cell vehicles : hydrogen yield and ammonia formation and Its removal [texte imprimé] / Ahmad Al-Kukhun, Auteur ; Hyun Tae Hwang, Auteur ; Arvind Varma, Auteur . - 2011 . - pp. 8824-8835. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 8824-8835 Mots-clés : Proton  exchange  membrane  fuel  cells  Dehydrogenation Résumé : Current promising methods to release hydrogen from ammonia borane (NH3BH3, AB; 19.6 wt % H2) including neat thermolysis, thermolysis in ionic liquid bmimCl with or without proton sponge, thermolysis with nano-BN and hydrothermolysis, were investigated for hydrogen yield and ammonia formation. It was found that even trace moisture influences AB dehydrogenation significantly. The hydrothermolysis at 85 °C (13.5 wt % H2, 1 mol % NH3) and thermolysis in bmimCl with 3 wt % moisture at 110 °C (13 wt % H2, 0.2 mol % NH3) methods were found to be the most promising. Since the target for a proton exchange membrane (PEM) fuel cell is an ammonia concentration less than 0.1 ppm, different purification methods were evaluated. Using experiments and simulations, the proposed ammonia removal method, involving absorption in water followed by adsorption on carbon, was optimized and tested. This study demonstrates that, with high hydrogen yield and an effective method to remove ammonia and borazine, AB dehydrogenation is an attractive approach to generate hydrogen for PEM fuel cell vehicle applications. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395828

Hydrogen for vehicle applications from hydrothermolysis of ammonia borane / Hyun Tae Hwang in Industrial & engineering chemistry research, Vol. 49 N° 21 (Novembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 10994–11000 Titre : Hydrogen for vehicle applications from hydrothermolysis of ammonia borane : Hydrogen yield, thermal characteristics, and ammonia formation Type de document : texte imprimé Auteurs : Hyun Tae Hwang, Auteur ; Ahmad Al-Kukhun, Auteur ; Varma, Arvid, Auteur Année de publication : 2011 Article en page(s) : pp. 10994–11000 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrogen  Hydrothermolysis Résumé : Among chemical hydrides, ammonia borane (AB) is of interest as a hydrogen storage material due to its high hydrogen capacity (19.6 wt %). In this paper, our recently developed hydrothermolysis process was investigated over a wide range of AB weight percentages (wt %) in water, pressures, and heating rates. It was found that hydrogen yield and thermal characteristics were influenced by these operating conditions. Ammonia generation was also observed during AB hydrothermolysis, where 14−53% of AB was converted to NH3 depending on the reaction conditions. It is remarkable that some AB (2−4%) was converted to NH3, which must be removed for use in proton exchange membrane (PEM) fuel cells, even by neat thermolysis. It was also found that during the hydrothermolysis reaction at Treactor of 85 °C, the Tsample can exceed 500 °C, where AB can be completely decomposed to boron nitride (BN). The 11B NMR characterization of hydrothermolysis products showed compounds with B−O and B−N bonds. This paper suggests directions for future research to identify optimal conditions, where the hydrothermolysis process provides the best balance between H2 yield and undesirable products, for PEM fuel cell vehicle applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100520r [article] Hydrogen for vehicle applications from hydrothermolysis of ammonia borane : Hydrogen yield, thermal characteristics, and ammonia formation [texte imprimé] / Hyun Tae Hwang, Auteur ; Ahmad Al-Kukhun, Auteur ; Varma, Arvid, Auteur . - 2011 . - pp. 10994–11000. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 10994–11000 Mots-clés : Hydrogen  Hydrothermolysis Résumé : Among chemical hydrides, ammonia borane (AB) is of interest as a hydrogen storage material due to its high hydrogen capacity (19.6 wt %). In this paper, our recently developed hydrothermolysis process was investigated over a wide range of AB weight percentages (wt %) in water, pressures, and heating rates. It was found that hydrogen yield and thermal characteristics were influenced by these operating conditions. Ammonia generation was also observed during AB hydrothermolysis, where 14−53% of AB was converted to NH3 depending on the reaction conditions. It is remarkable that some AB (2−4%) was converted to NH3, which must be removed for use in proton exchange membrane (PEM) fuel cells, even by neat thermolysis. It was also found that during the hydrothermolysis reaction at Treactor of 85 °C, the Tsample can exceed 500 °C, where AB can be completely decomposed to boron nitride (BN). The 11B NMR characterization of hydrothermolysis products showed compounds with B−O and B−N bonds. This paper suggests directions for future research to identify optimal conditions, where the hydrothermolysis process provides the best balance between H2 yield and undesirable products, for PEM fuel cell vehicle applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100520r

Process Intensification in Hydrogen Production from Biomass-Derived Syngas / Mitra Abdollahi in Industrial & engineering chemistry research, Vol. 49 N° 21 (Novembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp 10986–10993 Titre : Process Intensification in Hydrogen Production from Biomass-Derived Syngas Type de document : texte imprimé Auteurs : Mitra Abdollahi, Auteur ; Jiang Yu, Auteur ; Hyun Tae Hwang, Auteur Année de publication : 2011 Article en page(s) : pp 10986–10993 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Biomass  Hydrogen Résumé : Biomass is a renewable and worldwide-abundant energy resource that shows great potential for environmentally benign power generation by minimizing greenhouse gas emissions. A “one-box” process has been proposed and studied in order to economically produce pure hydrogen from biomass-derived syngas in the presence of its common impurities through the use of the water gas shift (WGS) reaction. The heart of the process is a catalytic membrane reactor making use of carbon molecular sieve (CMS) membranes and an impurity-tolerant commercial Co/Mo/Al2O3 catalyst. CMS membrane stability was investigated in the presence of model tar and organic vapor compounds at experimental conditions similar to the WGS reaction environment. Experimental studies were carried out utilizing simulated biomass-derived syngas containing H2S and NH3 as key impurities, which was fed into the catalytic membrane reactor to produce a contaminant-free hydrogen product using the WGS reaction. The reactor performance has been investigated for various experimental conditions, and has been compared with simulation results from a mathematical model. The model was also used to study the effect of various parameters on system performance. A key observation is that both the membranes and the catalyst show satisfactory stability in the presence of impurities typically encountered in biomass-derived syngas, and that the system shows good performance, delivering higher CO conversion and hydrogen purity than when using a traditional reactor system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100620e [article] Process Intensification in Hydrogen Production from Biomass-Derived Syngas [texte imprimé] / Mitra Abdollahi, Auteur ; Jiang Yu, Auteur ; Hyun Tae Hwang, Auteur . - 2011 . - pp 10986–10993. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp 10986–10993 Mots-clés : Biomass  Hydrogen Résumé : Biomass is a renewable and worldwide-abundant energy resource that shows great potential for environmentally benign power generation by minimizing greenhouse gas emissions. A “one-box” process has been proposed and studied in order to economically produce pure hydrogen from biomass-derived syngas in the presence of its common impurities through the use of the water gas shift (WGS) reaction. The heart of the process is a catalytic membrane reactor making use of carbon molecular sieve (CMS) membranes and an impurity-tolerant commercial Co/Mo/Al2O3 catalyst. CMS membrane stability was investigated in the presence of model tar and organic vapor compounds at experimental conditions similar to the WGS reaction environment. Experimental studies were carried out utilizing simulated biomass-derived syngas containing H2S and NH3 as key impurities, which was fed into the catalytic membrane reactor to produce a contaminant-free hydrogen product using the WGS reaction. The reactor performance has been investigated for various experimental conditions, and has been compared with simulation results from a mathematical model. The model was also used to study the effect of various parameters on system performance. A key observation is that both the membranes and the catalyst show satisfactory stability in the presence of impurities typically encountered in biomass-derived syngas, and that the system shows good performance, delivering higher CO conversion and hydrogen purity than when using a traditional reactor system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100620e