Documents disponibles écrits par cet auteur

Dispersed calcium oxide as a reversible and efficient CO2−sorbent at intermediate temperatures / Philipp Gruene in Industrial & engineering chemistry research, Vol. 50 N° 7 (Avril 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 7 (Avril 2011) . - pp. 4042–4049 Titre : Dispersed calcium oxide as a reversible and efficient CO2−sorbent at intermediate temperatures Type de document : texte imprimé Auteurs : Philipp Gruene, Auteur ; Anuta G. Belova, Auteur ; Tuncel M. Yegulalp, Auteur Année de publication : 2011 Article en page(s) : pp. 4042–4049 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Dispersion  calcium  oxide Résumé : Dispersion of calcium oxide on high surface area γ-Al2O3 creates a stable and reversible CO2−sorbent that overcomes the problems associated with bulk CaO, such as limited long-term stability, slow uptake kinetics, and energy-intensive regeneration. This sorbent is a candidate for the sorption-enhanced hydrogen production via steam reforming and/or water-gas shift reactions. CO2 uptake tests were performed in a 15% CO2/N2 atmosphere to evaluate the efficacy at typical hydrocarbon reformer gas partial pressure. CO2 uptake kinetics and capacities are investigated in TGA studies, while the long-term stability is shown in multicycle experiments. The dispersed CaO is an active sorbent at low temperatures and binds CO2 at 300 °C up to 1.7 times as efficiently as compared to bulk CaO powder. Furthermore, the sorbent can be regenerated in a CO2-free atmosphere at intermediate temperatures between 300 and 650 °C. Multicycle CO2 uptake and release has been tested for 84 cycles at a constant temperature of 650 °C and shows the superior long-term stability of dispersed CaO as compared to bulk CaO. The attempt to increase the uptake capacity from 0.16 to 0.22 mmol CO2 per gram of sorbent occurred with a commensurate loss in BET area from 115 to 41 m2, leading to a decline in overall uptake efficiency from 15% to 6%. Infrared spectroscopy is used to characterize the CO2−sorbent binding interaction on a molecular level and to distinguish between CO2 adsorbing on the bare support, on bulk CaO, and on dispersed CaO/Al2O3. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102475d [article] Dispersed calcium oxide as a reversible and efficient CO2−sorbent at intermediate temperatures [texte imprimé] / Philipp Gruene, Auteur ; Anuta G. Belova, Auteur ; Tuncel M. Yegulalp, Auteur . - 2011 . - pp. 4042–4049. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 7 (Avril 2011) . - pp. 4042–4049 Mots-clés : Dispersion  calcium  oxide Résumé : Dispersion of calcium oxide on high surface area γ-Al2O3 creates a stable and reversible CO2−sorbent that overcomes the problems associated with bulk CaO, such as limited long-term stability, slow uptake kinetics, and energy-intensive regeneration. This sorbent is a candidate for the sorption-enhanced hydrogen production via steam reforming and/or water-gas shift reactions. CO2 uptake tests were performed in a 15% CO2/N2 atmosphere to evaluate the efficacy at typical hydrocarbon reformer gas partial pressure. CO2 uptake kinetics and capacities are investigated in TGA studies, while the long-term stability is shown in multicycle experiments. The dispersed CaO is an active sorbent at low temperatures and binds CO2 at 300 °C up to 1.7 times as efficiently as compared to bulk CaO powder. Furthermore, the sorbent can be regenerated in a CO2-free atmosphere at intermediate temperatures between 300 and 650 °C. Multicycle CO2 uptake and release has been tested for 84 cycles at a constant temperature of 650 °C and shows the superior long-term stability of dispersed CaO as compared to bulk CaO. The attempt to increase the uptake capacity from 0.16 to 0.22 mmol CO2 per gram of sorbent occurred with a commensurate loss in BET area from 115 to 41 m2, leading to a decline in overall uptake efficiency from 15% to 6%. Infrared spectroscopy is used to characterize the CO2−sorbent binding interaction on a molecular level and to distinguish between CO2 adsorbing on the bare support, on bulk CaO, and on dispersed CaO/Al2O3. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102475d

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