Documents disponibles écrits par cet auteur

Ammonia decomposition on tungsten-based catalysts in the absence and presence of syngas / Sourabh S. Pansare in Industrial & engineering chemistry research, Vol. 47 n°12 (Juin 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4063–4070 Titre : Ammonia decomposition on tungsten-based catalysts in the absence and presence of syngas Type de document : texte imprimé Auteurs : Sourabh S. Pansare, Auteur ; James G. GoodwinJr., Auteur Année de publication : 2008 Article en page(s) : p. 4063–4070 Note générale : Bibliogr. p. 4069-4070 Langues : Anglais (eng) Mots-clés : Ammonia  decomposition;  Tungsten  carbide;  Tungstated  zirconia Résumé : Synthesis gas produced from biomass gasification can serve as a starting point for producing electricity, low-to-medium energy fuels, and even hydrogen for fuel cells. The major barrier in commercialization of biomass gasification is the presence of impurities such as NH3, tars, and H2S in the gas products that are detrimental to downstream processes. This paper reports the results of a study of NH3 decomposition to N2 and H2 on tungsten-based catalysts, tungsten carbide (WC) and tungstated zirconia (WZ), for a gasification gas cleanup strategy that involves removal of tars first followed by NH3 decomposition. The effects of the presence of H2 and CO on the behavior of these catalysts are also reported. At the NH3 decomposition reaction conditions used in the present study (1 atm, 465−650 °C, 4000 ppm), both WC and WZ showed an induction period. The main reason for this induction period is hypothesized to be a restructuring of the catalyst surface by NH3 so that the surface is more favorable for reaction. Both WC and WZ displayed superior activity compared to a commercial Fe-based NH3 synthesis catalyst (Amomax-10). At 600 °C and in the presence of syngas, no conversion was observed on WC while ca. 20% and 10% conversions were observed on WZ and Amomax-10, respectively, at steady state for the reaction conditions used. This corresponds to intrinsic rates of 1.2 μmol/g cat./s and 0.53 μmol/g cat./s (0.021 μmol/m2 cat./s and 3.1 μmol/m2 cat./s), respectively, for WZ and Amomax-10. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800077p [article] Ammonia decomposition on tungsten-based catalysts in the absence and presence of syngas [texte imprimé] / Sourabh S. Pansare, Auteur ; James G. GoodwinJr., Auteur . - 2008 . - p. 4063–4070. Bibliogr. p. 4069-4070 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4063–4070 Mots-clés : Ammonia  decomposition;  Tungsten  carbide;  Tungstated  zirconia Résumé : Synthesis gas produced from biomass gasification can serve as a starting point for producing electricity, low-to-medium energy fuels, and even hydrogen for fuel cells. The major barrier in commercialization of biomass gasification is the presence of impurities such as NH3, tars, and H2S in the gas products that are detrimental to downstream processes. This paper reports the results of a study of NH3 decomposition to N2 and H2 on tungsten-based catalysts, tungsten carbide (WC) and tungstated zirconia (WZ), for a gasification gas cleanup strategy that involves removal of tars first followed by NH3 decomposition. The effects of the presence of H2 and CO on the behavior of these catalysts are also reported. At the NH3 decomposition reaction conditions used in the present study (1 atm, 465−650 °C, 4000 ppm), both WC and WZ showed an induction period. The main reason for this induction period is hypothesized to be a restructuring of the catalyst surface by NH3 so that the surface is more favorable for reaction. Both WC and WZ displayed superior activity compared to a commercial Fe-based NH3 synthesis catalyst (Amomax-10). At 600 °C and in the presence of syngas, no conversion was observed on WC while ca. 20% and 10% conversions were observed on WZ and Amomax-10, respectively, at steady state for the reaction conditions used. This corresponds to intrinsic rates of 1.2 μmol/g cat./s and 0.53 μmol/g cat./s (0.021 μmol/m2 cat./s and 3.1 μmol/m2 cat./s), respectively, for WZ and Amomax-10. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800077p

Toluene decomposition in the presence of hydrogen on tungsten-based catalysts / Sourabh S. Pansare in Industrial & engineering chemistry research, Vol. 47 n°12 (Juin 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4077–4085 Titre : Toluene decomposition in the presence of hydrogen on tungsten-based catalysts Type de document : texte imprimé Auteurs : Sourabh S. Pansare, Auteur ; James G. GoodwinJr., Auteur ; Santosh Gangwal, Auteur Année de publication : 2008 Article en page(s) : p. 4077–4085 Note générale : Bibliogr. p. 4084-4085 Langues : Anglais (eng) Mots-clés : Toluene;  Tungstated  zirconia;  Tungsten  carbide Résumé : Removal of NH3, tars, and H2S from biomass gasification gas represents a significant step in the commercial use of biomass gasification as a source of hydrogen, syngas, and electricity. This paper reports the results of an investigation into the use of W-based catalysts [tungsten carbide (WC), tungstated zirconia (WZ), and platinum supported on tungstated zirconia (PtWZ)] for catalytic tar removal. In this study, toluene was used as a model compound for tars. In the case of WZ, the effect of calcination temperature on the activity of toluene decomposition was also investigated. The toluene decomposition reaction was conducted at 1 atm, in the temperature range of 300−800 °C, and in the presence of 10% H2. CH4 and benzene were the only detectable products of toluene decomposition on all the catalysts. Incorporation of 5 wt % Pt with WZ was found to give the most effective catalyst considering initial rates of product formation. WC, WZ, and PtWZ each showed an initial partial deactivation for both CH4 and benzene formation due to coke deposition on active sites. Pt incorporation had a significant effect on the steady-state activity of WZ for toluene decomposition at temperatures below 600 °C; however, at temperatures above 700 °C, the effect was nullified. All W-based catalysts showed comparable performance to that of a commercial cracking catalyst (ultra-stable Y zeolite) above 700 °C. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8002864 [article] Toluene decomposition in the presence of hydrogen on tungsten-based catalysts [texte imprimé] / Sourabh S. Pansare, Auteur ; James G. GoodwinJr., Auteur ; Santosh Gangwal, Auteur . - 2008 . - p. 4077–4085. Bibliogr. p. 4084-4085 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4077–4085 Mots-clés : Toluene;  Tungstated  zirconia;  Tungsten  carbide Résumé : Removal of NH3, tars, and H2S from biomass gasification gas represents a significant step in the commercial use of biomass gasification as a source of hydrogen, syngas, and electricity. This paper reports the results of an investigation into the use of W-based catalysts [tungsten carbide (WC), tungstated zirconia (WZ), and platinum supported on tungstated zirconia (PtWZ)] for catalytic tar removal. In this study, toluene was used as a model compound for tars. In the case of WZ, the effect of calcination temperature on the activity of toluene decomposition was also investigated. The toluene decomposition reaction was conducted at 1 atm, in the temperature range of 300−800 °C, and in the presence of 10% H2. CH4 and benzene were the only detectable products of toluene decomposition on all the catalysts. Incorporation of 5 wt % Pt with WZ was found to give the most effective catalyst considering initial rates of product formation. WC, WZ, and PtWZ each showed an initial partial deactivation for both CH4 and benzene formation due to coke deposition on active sites. Pt incorporation had a significant effect on the steady-state activity of WZ for toluene decomposition at temperatures below 600 °C; however, at temperatures above 700 °C, the effect was nullified. All W-based catalysts showed comparable performance to that of a commercial cracking catalyst (ultra-stable Y zeolite) above 700 °C. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8002864