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

Characterization of LiFePO4 / C cathode for lithium Ion batteries / Nathalie Lyczko in Industrial & engineering chemistry research, Vol. 51 N° 1 (Janvier 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 1 (Janvier 2012) . - pp. 292–300 Titre : Characterization of LiFePO4 / C cathode for lithium Ion batteries Type de document : texte imprimé Auteurs : Nathalie Lyczko, Auteur ; Ange Nzihou, Auteur ; Patrick Sharrock, Auteur Année de publication : 2012 Article en page(s) : pp. 292–300 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Lithium  Ion  Batteries Résumé : LiFePO4/C was synthesized from a mixture of different precursors of Li, Fe, and C by solid-state reaction. The initial mixture obtained was heated in different calcination conditions under inert atmosphere. The precursor of LiFePO4 doped with carbon was studied using different techniques such as thermal analysis, chemical and physical characterizations, and Mösbauer spectroscopy. A calculation of the crystallinity of the final product with two different methods is also presented. The chemical analysis techniques used were IRTF, XRD, and SEM. This characterization confirmed that we obtained a well-crystallized LiFePO4/C in all the operating conditions tested. The SEM showed aggregation and sintering during the calcination process, which were confirmed by the particle-size distribution measurements and by the physical characterizations. Mösbauer spectroscopy was used to determine the quantity of Fe(II) and Fe(III) contained in the final product. Our calcination conditions did not significantly modify the quantity of the two oxidation states. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201799x [article] Characterization of LiFePO4 / C cathode for lithium Ion batteries [texte imprimé] / Nathalie Lyczko, Auteur ; Ange Nzihou, Auteur ; Patrick Sharrock, Auteur . - 2012 . - pp. 292–300. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 1 (Janvier 2012) . - pp. 292–300 Mots-clés : Lithium  Ion  Batteries Résumé : LiFePO4/C was synthesized from a mixture of different precursors of Li, Fe, and C by solid-state reaction. The initial mixture obtained was heated in different calcination conditions under inert atmosphere. The precursor of LiFePO4 doped with carbon was studied using different techniques such as thermal analysis, chemical and physical characterizations, and Mösbauer spectroscopy. A calculation of the crystallinity of the final product with two different methods is also presented. The chemical analysis techniques used were IRTF, XRD, and SEM. This characterization confirmed that we obtained a well-crystallized LiFePO4/C in all the operating conditions tested. The SEM showed aggregation and sintering during the calcination process, which were confirmed by the particle-size distribution measurements and by the physical characterizations. Mösbauer spectroscopy was used to determine the quantity of Fe(II) and Fe(III) contained in the final product. Our calcination conditions did not significantly modify the quantity of the two oxidation states. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201799x

One - step synthesis of sodium trimetaphosphate (Na3P3O9) from sodium chloride and orthophosphoric acid / Doan Pham Minh in Industrial & engineering chemistry research, Vol. 51 N° 10 (Mars 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 10 (Mars 2012) . - pp. 3851–3854 Titre : One - step synthesis of sodium trimetaphosphate (Na3P3O9) from sodium chloride and orthophosphoric acid Type de document : texte imprimé Auteurs : Doan Pham Minh, Auteur ; Jocelyn Ramaroson, Auteur ; Ange Nzihou, Auteur Année de publication : 2012 Article en page(s) : pp. 3851–3854 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Trimetaphosphate  Sodium Résumé : One-step thermal synthesis of sodium trimetaphosphate (STM) from sodium chloride and 85 wt % orthophosphoric acid as starting materials was investigated. The reaction temperature and volume-mean diameter of sodium chloride influenced strongly the elimination of chloride and the selectivity in STM. STM of high quality (99%) was obtained at 600 °C from fine powder of sodium chloride. Hydrochloric acid was the only byproduct of the reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201085b [article] One - step synthesis of sodium trimetaphosphate (Na3P3O9) from sodium chloride and orthophosphoric acid [texte imprimé] / Doan Pham Minh, Auteur ; Jocelyn Ramaroson, Auteur ; Ange Nzihou, Auteur . - 2012 . - pp. 3851–3854. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 10 (Mars 2012) . - pp. 3851–3854 Mots-clés : Trimetaphosphate  Sodium Résumé : One-step thermal synthesis of sodium trimetaphosphate (STM) from sodium chloride and 85 wt % orthophosphoric acid as starting materials was investigated. The reaction temperature and volume-mean diameter of sodium chloride influenced strongly the elimination of chloride and the selectivity in STM. STM of high quality (99%) was obtained at 600 °C from fine powder of sodium chloride. Hydrochloric acid was the only byproduct of the reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201085b

Rheological behavior of gypsum, plaster, and hydroxyapatite gel blends / Mohamed Raii in Industrial & engineering chemistry research, Vol. 51 N° 34 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11163-11169 Titre : Rheological behavior of gypsum, plaster, and hydroxyapatite gel blends Type de document : texte imprimé Auteurs : Mohamed Raii, Auteur ; Francisco Javier Escudero Sanz, Auteur ; Ange Nzihou, Auteur Année de publication : 2012 Article en page(s) : pp. 11163-11169 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydroxyapatite  Plaster Résumé : The rheological behavior of water―calcium sulfates and hydroxyapatite―calcium sulfates binary blends was considered in this study. These blends are to be used as permeable reactive barriers for groundwater remediation. The influence of gypsum and plaster on the rheological behavior of Ca-HAGel has been studied. The results show that all blends and formulations exhibit a shear-thinning effect and thixotropic behavior. The viscosity also depends on the level of concentration of the solid and the reactivity of the blends. The hydration of plaster causes cohesion and agglomeration between particles due to electrostatic forces, while the hydration of gypsum leads to dispersion due to repulsive forces between particles. The ζ potential was used in this study to understand the interaction between particles and its effect on the global behavior of the blends. The dissolution in water of sulfate ions containing calcium sulfate leads to a change in the surface charge of the blend. This allowed the dispersion or agglomeration of the mixtures to be predicted. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26299442 [article] Rheological behavior of gypsum, plaster, and hydroxyapatite gel blends [texte imprimé] / Mohamed Raii, Auteur ; Francisco Javier Escudero Sanz, Auteur ; Ange Nzihou, Auteur . - 2012 . - pp. 11163-11169. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11163-11169 Mots-clés : Hydroxyapatite  Plaster Résumé : The rheological behavior of water―calcium sulfates and hydroxyapatite―calcium sulfates binary blends was considered in this study. These blends are to be used as permeable reactive barriers for groundwater remediation. The influence of gypsum and plaster on the rheological behavior of Ca-HAGel has been studied. The results show that all blends and formulations exhibit a shear-thinning effect and thixotropic behavior. The viscosity also depends on the level of concentration of the solid and the reactivity of the blends. The hydration of plaster causes cohesion and agglomeration between particles due to electrostatic forces, while the hydration of gypsum leads to dispersion due to repulsive forces between particles. The ζ potential was used in this study to understand the interaction between particles and its effect on the global behavior of the blends. The dissolution in water of sulfate ions containing calcium sulfate leads to a change in the surface charge of the blend. This allowed the dispersion or agglomeration of the mixtures to be predicted. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26299442