Documents disponibles écrits par cet auteur

Catalyst properties and catalytic performance of char from biomass gasification / Naomi B. Klinghoffer in Industrial & engineering chemistry research, Vol. 51 N° 40 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13113–13122 Titre : Catalyst properties and catalytic performance of char from biomass gasification Type de document : texte imprimé Auteurs : Naomi B. Klinghoffer, Auteur ; Marco J. Castaldi, Auteur ; Ange Nzihou, Auteur Année de publication : 2012 Article en page(s) : pp. 13113–13122 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biomass  Gasification Résumé : Gasification provides a mechanism to convert solids, such as biomass, coal, or waste, into fuels that can be easily integrated into current infrastructure. This paper discusses the use of residual char from a biomass gasifier as a catalyst for tar decomposition and presents an investigation of the catalytic properties of the char. Poplar wood was gasified in a fluidized bed reactor at temperatures ranging from 550 to 920 °C in reaction environments of 90% steam/10% N2 and 90% N2/10% CO2. The properties of the char recovered from the process were analyzed, and the catalytic performance for hydrocarbon cracking reactions was tested. Brunauer–Emmett–Teller (BET) measurements showed that the surface area of the char was higher than conventional catalyst carriers. The surface area, which ranged from 429 to 687 m2 g–1, increased with temperature and reaction time. The catalytic activity of the char was demonstrated through testing the catalytic decomposition of methane and propane to produce H2 and solid carbon. Higher char surface area resulted in increased performance, but pore size distribution also affected the activity of the catalyst, and evidence of diffusion limitations in microporous char was observed. Clusters of iron were present on the surface of the char. After being used for catalytic applications, carbon deposition was observed on the iron cluster and on the pores of the char, indicating that these sites may influence the reaction. When the char was heated to 800 °C in an inert (N2), atmosphere mass loss was observed, which varied based on the type of char and the time. ESEM/EDX showed that when char was heated to 1000 °C under N2, oxygen and metals migrated to the surface of the char, which may impact its catalytic activity. Through investigating the properties and performance of biomass gasification char, this paper demonstrates its potential to replace expensive tar decomposition catalysts with char catalysts, which are continuously produced on-site in the gasification process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3014082 [article] Catalyst properties and catalytic performance of char from biomass gasification [texte imprimé] / Naomi B. Klinghoffer, Auteur ; Marco J. Castaldi, Auteur ; Ange Nzihou, Auteur . - 2012 . - pp. 13113–13122. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13113–13122 Mots-clés : Biomass  Gasification Résumé : Gasification provides a mechanism to convert solids, such as biomass, coal, or waste, into fuels that can be easily integrated into current infrastructure. This paper discusses the use of residual char from a biomass gasifier as a catalyst for tar decomposition and presents an investigation of the catalytic properties of the char. Poplar wood was gasified in a fluidized bed reactor at temperatures ranging from 550 to 920 °C in reaction environments of 90% steam/10% N2 and 90% N2/10% CO2. The properties of the char recovered from the process were analyzed, and the catalytic performance for hydrocarbon cracking reactions was tested. Brunauer–Emmett–Teller (BET) measurements showed that the surface area of the char was higher than conventional catalyst carriers. The surface area, which ranged from 429 to 687 m2 g–1, increased with temperature and reaction time. The catalytic activity of the char was demonstrated through testing the catalytic decomposition of methane and propane to produce H2 and solid carbon. Higher char surface area resulted in increased performance, but pore size distribution also affected the activity of the catalyst, and evidence of diffusion limitations in microporous char was observed. Clusters of iron were present on the surface of the char. After being used for catalytic applications, carbon deposition was observed on the iron cluster and on the pores of the char, indicating that these sites may influence the reaction. When the char was heated to 800 °C in an inert (N2), atmosphere mass loss was observed, which varied based on the type of char and the time. ESEM/EDX showed that when char was heated to 1000 °C under N2, oxygen and metals migrated to the surface of the char, which may impact its catalytic activity. Through investigating the properties and performance of biomass gasification char, this paper demonstrates its potential to replace expensive tar decomposition catalysts with char catalysts, which are continuously produced on-site in the gasification process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3014082

Experimental investigation of a JP8 fuel processor / Barrai, Federico in Industrial & engineering chemistry research, Vol. 49 N° 4 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1577–1587 Titre : Experimental investigation of a JP8 fuel processor : autothermal reformer and CO-cleanup train Type de document : texte imprimé Auteurs : Barrai, Federico, Auteur ; Marco J. Castaldi, Auteur Année de publication : 2010 Article en page(s) : pp 1577–1587 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fuel  processor  Autothermal  CO-cleanup  train. Résumé : This paper presents an experimental investigation of a fuel processor consisting of a JP-8 autothermal reforming (ATR) reactor and a surrogate-fed CO-cleanup train. The CO-cleanup train, comprising a water−gas shift (WGS) and two preferential oxidation (PROX) reactors, was tested as an integrated reactor train. A finned-wall ATR reactor was examined for light-off behavior and for steady-state product distribution, upon which the CO-cleanup train was designed. The thermal and chemical transient analysis during catalyst ignition indicated that the fuel undergoes deep oxidation to CO2 and H2O until 80% of the catalyst bed is ignited, followed by a significant rise in synthesis gas production. The WGS and PROX reactors were tested individually with the objective of identifying operating regimes for maximum CO removal. The PROX reactor train, consisting of two identical reactors connected in series, reduced the CO concentration from 1% to less than 6 ppm. The PROX-1 and PROX-2 reactors were compared in order to elucidate the CO conversion and selectivity loss observed for PROX-1 at T > 250 °C and for PROX-2 at temperatures between 120 and 145 °C, suggesting that the CO conversion decrease follows different controlling mechanisms for the two reactors. Finally the CO-cleanup train was tested as three reactors in series, illustrating the critical effect that the CO conversion in the water−gas shift reactor has on the downstream PROX reactors. The CO-cleanup train was operated at the maximum conversion, demonstrating the capability to decrease the CO concentration from 8% to single-digit ppm level. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901735x [article] Experimental investigation of a JP8 fuel processor : autothermal reformer and CO-cleanup train [texte imprimé] / Barrai, Federico, Auteur ; Marco J. Castaldi, Auteur . - 2010 . - pp 1577–1587. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1577–1587 Mots-clés : Fuel  processor  Autothermal  CO-cleanup  train. Résumé : This paper presents an experimental investigation of a fuel processor consisting of a JP-8 autothermal reforming (ATR) reactor and a surrogate-fed CO-cleanup train. The CO-cleanup train, comprising a water−gas shift (WGS) and two preferential oxidation (PROX) reactors, was tested as an integrated reactor train. A finned-wall ATR reactor was examined for light-off behavior and for steady-state product distribution, upon which the CO-cleanup train was designed. The thermal and chemical transient analysis during catalyst ignition indicated that the fuel undergoes deep oxidation to CO2 and H2O until 80% of the catalyst bed is ignited, followed by a significant rise in synthesis gas production. The WGS and PROX reactors were tested individually with the objective of identifying operating regimes for maximum CO removal. The PROX reactor train, consisting of two identical reactors connected in series, reduced the CO concentration from 1% to less than 6 ppm. The PROX-1 and PROX-2 reactors were compared in order to elucidate the CO conversion and selectivity loss observed for PROX-1 at T > 250 °C and for PROX-2 at temperatures between 120 and 145 °C, suggesting that the CO conversion decrease follows different controlling mechanisms for the two reactors. Finally the CO-cleanup train was tested as three reactors in series, illustrating the critical effect that the CO conversion in the water−gas shift reactor has on the downstream PROX reactors. The CO-cleanup train was operated at the maximum conversion, demonstrating the capability to decrease the CO concentration from 8% to single-digit ppm level. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901735x

Experimental investigation of methane gas production from methane hydrate / Yue Zhou in Industrial & engineering chemistry research, Vol. 48 N° 6 (Mars 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3142–3149 Titre : Experimental investigation of methane gas production from methane hydrate Type de document : texte imprimé Auteurs : Yue Zhou, Auteur ; Marco J. Castaldi, Auteur ; Tuncel M. Yegulalp, Auteur Année de publication : 2009 Article en page(s) : pp. 3142–3149 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Large-scale  reactor  vessel  Methane  gas  hydrates  Pure  methane  gas  Deionized  water Résumé : A 72 L large-scale reactor vessel was designed, manufactured, and built to investigate the gas production from methane gas hydrates. Methane hydrates were successfully formed within the reactor using pure methane gas and deionized water in a sand matrix with grain sizes between 100 and 500 μm. Hydrate formation tests resulted in formation at 2.2 °C around 600 psi. Mass balance calculations show that 11% of the pore space volume was occupied by hydrate. Measurements and simulations suggest that hydrate was initially formed at the top section of the reactor followed by formation within the lower part of the sediment. A cooling effect was observed during the dissociation via depressurization experiments, caused by the endothermic dissociation reaction. The observed temperature decrease of the system was between 4.0 and 0.8 °C. During the hydrate dissociation tests, a transition regime showing an increased gas production from 9.5 to 13 L/min within a very narrow range of temperature between −1.6 and −1.2 °C and pressure between 310 and 360 psi was recorded. In addition, the temperature was observed to jump to 0 °C in an extremely short time period. The interpretation of this phenomenon is ice formation in the transition regime where hydrate decomposes to gas and ice instead of gas and liquid. This is the first experimental observation of this phenomenon. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801004z [article] Experimental investigation of methane gas production from methane hydrate [texte imprimé] / Yue Zhou, Auteur ; Marco J. Castaldi, Auteur ; Tuncel M. Yegulalp, Auteur . - 2009 . - pp. 3142–3149. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3142–3149 Mots-clés : Large-scale  reactor  vessel  Methane  gas  hydrates  Pure  methane  gas  Deionized  water Résumé : A 72 L large-scale reactor vessel was designed, manufactured, and built to investigate the gas production from methane gas hydrates. Methane hydrates were successfully formed within the reactor using pure methane gas and deionized water in a sand matrix with grain sizes between 100 and 500 μm. Hydrate formation tests resulted in formation at 2.2 °C around 600 psi. Mass balance calculations show that 11% of the pore space volume was occupied by hydrate. Measurements and simulations suggest that hydrate was initially formed at the top section of the reactor followed by formation within the lower part of the sediment. A cooling effect was observed during the dissociation via depressurization experiments, caused by the endothermic dissociation reaction. The observed temperature decrease of the system was between 4.0 and 0.8 °C. During the hydrate dissociation tests, a transition regime showing an increased gas production from 9.5 to 13 L/min within a very narrow range of temperature between −1.6 and −1.2 °C and pressure between 310 and 360 psi was recorded. In addition, the temperature was observed to jump to 0 °C in an extremely short time period. The interpretation of this phenomenon is ice formation in the transition regime where hydrate decomposes to gas and ice instead of gas and liquid. This is the first experimental observation of this phenomenon. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801004z