Showing papers in "Industrial & Engineering Chemistry Fundamentals in 1986"
TL;DR: In this article, a synthese sur les catalyseurs CoMo/Al 2 O 3 and Ni-Mo/Ni-O 3 d'hydrodesulfuration is presented, using techniques d'investigation, identification des structures actives et sites actifs, influence du support (alumine, silice, carbone), comprehension du comportement catalytique.
Abstract: Article de synthese sur les catalyseurs Co-Mo/Al 2 O 3 et Ni-Mo/Al 2 O 3 d'hydrodesulfuration: techniques d'investigation, identification des structures actives et sites actifs, influence du support (alumine, silice, carbone), comprehension du comportement catalytique
177Â citations
TL;DR: In this paper, the contribution of single-crystal studies to the understanding of structure sensitivity in catalytic reaction is discussed, and reactions are classified in three types: structure sensitive reactions, structure insensitive reactions and reactions that show both behaviors, depending on the experimental conditions.
Abstract: The rate and product distribution of chemical reactions catalyzed by metals can depend on the particle size of supported catalysts. This can be explained by the interaction between chemisorbed species and surface sites of different configuration in the metal associated with atoms in terrace, steps and kinks. Single-crystal catalysts are excellent models for studying these interactions. In this review, the contribution of single-crystal studies to the understanding of structure sensitivity in catalytic reaction is discussed. Reactions are classified in three types. Structure sensitive reactions, structure insensitive reactions and reactions that show both behaviors, depending on the experimental conditions. Several examples are discussed in each of the three categories. 72 refs., 13 figs.
148Â citations
143Â citations
TL;DR: In this article, the discovery and development of the Thermal DeNO/sub X/ are described, and the continuation of the basic research in order to develop the computer model of the NO reduction chemistry is described.
Abstract: The discovery and development of the Thermal DeNO/sub X/ are described. One important aspect of that development was the continuation of the basic research in order to develop the computer model of the NO reduction chemistry. This model proved useful in optimizing the application of the Thermal DeNO/sub X/ process to boilers and furnaces, in understanding other potential applications, e.g., gas turbines, automobiles, fluid bed combustors, and low-Btu gas, and in understanding problems in the chemistry such as the self-inhibition effect and the lack of an effect from addition of sulfur oxides.
110Â citations
97Â citations
TL;DR: In this paper, a nouvelle formulation de programmation non lineaire permet la conception optimale de ce reseau de reacteurs, including diagrammes de melange complexes.
Abstract: Etant donne un mecanisme cinetique et des expressions de la vitesse de reaction, on doit frequemment choisir de facon appropriee les diagrammes de melange et l'addition/elimination de la chaleur au cours de la conception du reacteur. Une nouvelle formulation de programmation non lineaire permet la conception optimale de ce reseau de reacteurs. On inclut les reseaux composes de reacteurs ideaux et non ideaux et les diagrammes de melange complexes. Le modele et les equations adjointes forment un probleme de valeur limite en deux points qui cree une interface avec une strategie d'optimisation efficace
82Â citations
81Â citations
TL;DR: Mise en evidence de la formation d'alcanes a chaine droite de C 1 a C 14 and D'alcenes de C 2 a c 14 ; il se forme egalement de grandes quantites d' alcanes de C 18 a C 30 a chaines droites and reticulees.
Abstract: Mise en evidence de la formation d'alcanes a chaine droite de C 1 a C 14 et d'alcenes de C 2 a C 14 ; il se forme egalement de grandes quantites d'alcanes de C 18 a C 30 a chaines droites et reticulees. Mecanisme de formation de ces nouveaux produits
79Â citations
TL;DR: Modelisation du comportement hydrodynamique d'un ecoulement piston turbulent ascendant gaz-liquide, basee sur une analyse detaillee de la structure de l'ecoulement.
Abstract: Modelisation du comportement hydrodynamique d'un ecoulement piston turbulent ascendant gaz-liquide, basee sur une analyse detaillee de la structure de l'ecoulement. Mecanisme de l'ecoulement du liquide dans le bouchon contenant des bulles de gaz dispersees, en vue d'evaluer la fraction de vide du bouchon de liquide
67Â citations
63Â citations
TL;DR: In this paper, a methode de continuation for resoudre les grands systemes d'equations rigoureuses non lineaires de modelisation is proposed. But this methode is not suitable for the case of multiples.
Abstract: Determination des regimes stables multiples de trois differents types de systemes de separation relies entre eux, en utilisant un programme de simulation qui applique une methode de continuation pour resoudre les grands systemes d'equations rigoureuses non lineaires de modelisation. Les solutions multiples ont ete trouvees a partir de points de depart multiples
TL;DR: In this paper, it is shown that the early Cr(VI) breakthrough is not due to poor column kinetics but is predictable from an equilibrium model by using the appropriate exchange reaction involving both HCrO/sub 4//sup -/ and Cr/sub 2/O/Sub 7//sup 2 -/.
Abstract: The chromate ion exchange recovery process for cooling tower blowdown is unique due to the early, gradual breakthrough of highly preferred Cr(VI) from fixed-bed columns for all types of anion-exchange resins. It is shown that the early Cr(VI) breakthrough is not due to poor column kinetics but is predictable from an equilibrium model by using the appropriate exchange reaction involving both HCrO/sub 4//sup -/ and Cr/sub 2/O/sub 7//sup 2 -/. At acidic pH, HCrO/sub 4//sup -/ is practically the only Cr(VI) species in the aqueous phase, while in the exchanger phase both HCrO/sub 4//sup -/ and Cr/sub 2/O/sub 7//sup 2 -/ exist. The presence of Cr/sub 2/O/sub 7//sup 2 -/ in the exchanger's solid phase causes a positively cured (concave upward) isotherm at relatively low Cr(VI) loading of the resin, and this equilibrium property is primarily responsible for the unusual, gradual breakthrough of Cr(VI). The presence of Cr/sub 2/O/sub 7//sup -/ in the solid phase may be viewed as the dimerization of HCrO/sub 4//sup -/, according to the Donnan equilibrium principle.
TL;DR: In this paper, a relation modifiee concernant l'influence des macropores sur la porosite d'un lit de spheres is modified, and the theory is applied to melanges de distribution granulometrique de Gaudin-Schuhmann.
Abstract: Relation modifiee concernant l'influence des macropores sur la porosite d'un lit de spheres. Cette theorie s'applique aux melanges de distribution granulometrique de Gaudin-Schuhmann
TL;DR: In this paper, the separation of a melange H 2 /CO, 50/50 sur charbon actif, and a motrice lineaire is studied in a comparison between two models: a model d'equilibre and a model de force motrices lineaire.
Abstract: Etude theorique et experimentale de la separation d'un melange H 2 /CO, 50/50 sur charbon actif, en deux produits. Comparaison d'un modele d'equilibre et d'un modele de force motrice lineaire. Dans ces deux modeles on tient compte de l'adsorption a partir des deux composants du melange et du bilan energie
TL;DR: Etude de l'influence de la structure des pores du catalyseur sur le craquage des asphaltenes presents dans les residus lourds.
Abstract: Etude de l'influence de la structure des pores du catalyseur sur le craquage des asphaltenes presents dans les residus lourds. Determination des cinetiques de craquage des asphaltenes et de recuperation du vanadium
TL;DR: In this article, an expression analytique du facteur de facilitation, au cours du transport facilite dans un film liquide, is derived, which tient compte des resistances externes au transfert de matiere et de la diffusion and de la reaction a l'interieur du film liquidide.
Abstract: On derive une expression analytique du facteur de facilitation, au cours du transport facilite dans un film liquide. Cette expression tient compte des resistances externes au transfert de matiere et de la diffusion et de la reaction a l'interieur du film liquide
TL;DR: Etude experimentale de la pyrolyse de petits echantillons de quatre charbons sur une grille a differentes temperatures and a different conditions.
Abstract: Etude experimentale de la pyrolyse de petits echantillons de quatre charbons sur une grille a differentes temperatures et a differentes pressions