64 research outputs found
Total catalytic oxidation of a side-product for an autothermal restoring hydrogen process
International audienceThe catalytic total oxidation of toluene is used to bring the required calories to restore hydrogen from methylcyclohexane (MCH). Two coupled reactions, both catalyzed by Pt/alumina, are thus considered in one autothermal heat-exchanger reactor (HER): endothermic dehydrogenation of methylcyclohexane and catalytic combustion of less than 10% of produced toluene (6% for the chemical reaction, about 4% for heat losses). Both reactions are carried out at 350 °C. Methylcyclohexane and toluene light-off curves have been performed in one elementary module. Methylcyclohexane combustion has been eliminated due to its safety drawbacks, although the MCH combustion provides best stability to autothermal HER
CFD for the Study of the Multiphase Flow and Mass Transfer in a Stirred Tank Reactor for the Screening of Shaped Catalysts
International audienc
CFD for the Study of the Multiphase Flow and Mass Transfer in a Stirred Tank Reactor for the Screening of Shaped Catalysts
International audienc
Stockage d’hydrogène - comparaison de méthodes
SSCI-VIDE+CARE+VMLNational audienceLe stockage d’hydrogène, sous forme moléculaire, ou lié à un solide ou un liquide, permet d’envisager diverses applications stationnaires ou mobiles utilisant l’hydrogène, soit dans une pile à combustible, soit dans un moteur à combustion interne. Les avantages et inconvénients des différentes méthodes de stockage dépendent des usages de l’hydrogène. Une petite revue de ces différents moyens de stockage sera présentée, et une analyse sera proposée à partir des éléments publiés par de nombreux groupes de recherche.Le tableau inclus donne un aperçu des points qui seront discutés, d’autres voies de stockage (méthanol, acide formique, ammoniac...) seront ajoutés
Stockage d’hydrogène - comparaison de méthodes
SSCI-VIDE+CARE+VMLNational audienceLe stockage d’hydrogène, sous forme moléculaire, ou lié à un solide ou un liquide, permet d’envisager diverses applications stationnaires ou mobiles utilisant l’hydrogène, soit dans une pile à combustible, soit dans un moteur à combustion interne. Les avantages et inconvénients des différentes méthodes de stockage dépendent des usages de l’hydrogène. Une petite revue de ces différents moyens de stockage sera présentée, et une analyse sera proposée à partir des éléments publiés par de nombreux groupes de recherche.Le tableau inclus donne un aperçu des points qui seront discutés, d’autres voies de stockage (méthanol, acide formique, ammoniac...) seront ajoutés
Networking Axelera "hydrogène décarboné" (en virtuel)
SSCI-VIDE+CARE+VMLInternational audienceNon
Nouveaux systèmes de stockage et transfert d'hydrogène sans hydrogène moléculaire
SSCI-VIDE+CARE+XJI:VML:ELMNational audienceNon
Nouveaux systèmes de stockage et transfert d'hydrogène sans hydrogène moléculaire
SSCI-VIDE+CARE+XJI:VML:ELMNational audienceNon
Experimental and Kinetic Modeling Study on the Catalytic Hydroconversion of Lignin
SSCI-VIDE+ECI2D+JPU:DLA:CGENational audienceIn order to find a catalytic way to valorize lignin coming either from pulp industry or biorefineries, we propose here the catalytic hydroconversion as a mean to depolymerize lignin and produce aromatic compounds. The reaction takes place in tetralin, a H-donor solvent, which allows to avoid condensation reactions between the radical fragments and also improve hydrogen diffusion into the liquid phase where the catalytic process occurs. A new upgraded batch reactor is used, opened for gas phase with a continuous feeding of H2, a condensing system followed by cooled traps to remove continuously light products, and water from the reacting mixture and recycle the solvent. The advanced reaction system has been demonstrated to be powerful compared to a traditional batch system previously used3,4, as the hydrogen is fed during the whole process and water and light products are separated avoiding long contact of catalyst with water and over-conversion of lights to gas. We presents the evolution of the conversion and selectivities for a CoMoS/Al2O3 catalysts versus residence time and a reaction scheme
Catalytic hydroconversion of lignin to monomers
SSCI-VIDE+ECI2D+DLA:CGEInternational audienceLignin which represents almost 30 wt% of lignocellulosic biomass is the most relevant and abundant bio-resource to produce aromatic compounds thanks to its original polymeric structure composed by methoxy- and hydroxy-phenylpropane units with ether inter-unit linkages. The full valorization of lignin co-produced in pulp industry or ethanol biorefinery would be highly beneficial for carbon economy as well as for environmental reasons. However the conversion of lignin is not an easy step due to the complex analysis of the starting material and the numerous products formed. Among the various thermochemical processes already proposed in literature, catalytic hydroconversion appeared very attractive to lead to high liquid yield. We propose here the catalytic hydroconversion, with a supported CoMo sulfide catalyst, as a mean to depolymerize lignin and produce aromatic compounds. The originality of this work is the use of a batch reactor opened on the gas-phase, with a continuous feeding of H2 and a reflux system to remove continuously light products and water from the reacting mixture and recycle the solvent. This advanced reaction system has been demonstrated to be powerful compared to a traditional batch system previously used. In addition, the lignin chemical transformations were followed thanks to various well-chosen analytical tools (m-GC, NMR, GPC, CHONS, GCxGC) performed on the liquid and solid products
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