Hydrogenation of alkenes and alkynes and related reactions catalysed by metals and metal complexes

Kemball, C.; Dowden, D. A.; Webb, G.

doi:10.1039/9781847553157-00145

Cited by 18 publications

(11 citation statements)

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“…Bond and Wells and Webb previously discussed product distribution patterns, possible mechanisms, and other relevant kinetic trends concerning the reactions of n -butenes over Pd catalysts. Boitiaux et al proposed a kinetic model for the hydrogenation and irreversible isomerization of 1-butene.…”

Section: Introductionmentioning

confidence: 99%

Kinetic Study of the Hydrogenation and Hydroisomerization of the n-Butenes on a Commercial Palladium/Alumina Catalyst

Bressa

Martı́nez

Barreto

2003

Ind. Eng. Chem. Res.

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A kinetic investigation of the vapor-phase hydrogenation and hydroisomerization of 1-butene and cis-and trans-2-butene is presented. This investigation is aimed at validating a practical set of rate equations. The experiments were performed at approximately atmospheric pressure using a commercial Pd/Al 2 O 3 catalyst of the eggshell type in an integral fixed-bed isothermal reactor. The outlet composition was measured under 120 sets of operating conditions at six levels of temperature between -8 and 30 °C. The mole fractions of 1-butene and hydrogen in the feed were varied between 0.5 and 3% and between 0.5 and 50%, respectively. Space-time covered the range of (5-55) × 10 -3 s. Internal diffusion limitations affected the effective reaction rates and product distribution. Hence, the mass conservation equations inside the catalyst had to be solved to estimate the intrinsic values of the kinetic parameters. Two rival kinetic models of the Langmuir-Hinshelwood-Hougen-Watson type were proposed, one of which could be confidently discriminated as the better of the two models considered. An essential feature of the chosen model is that hydrogen concentration exhibits distinct effects on the hydrogenation and hydroisomerization reactions of n-butenes. The selected model predicts the experimental results with an average deviation of 8.8%. The estimates of the kinetic parameters show inference intervals in the range of (10-30%.

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Section: Introductionmentioning

confidence: 99%

Kinetic Study of the Hydrogenation and Hydroisomerization of the n-Butenes on a Commercial Palladium/Alumina Catalyst

Bressa

Martı́nez

Barreto

2003

Ind. Eng. Chem. Res.

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“…A 1 sites are highly active and selective in the hydrogenation of acetylene to ethylene and are not active in the hydrogenation of ethylene. We assume that acetylene is adsorbed on A 1 sites in the form of vinylidene 8,25 which requires only one palladium atom for adsorption, whereas ethylene cannot be strongly adsorbed in the form of vinylidyne, which requires three Pd atoms for adsorption. ,,− Additionally we assume that adsorption of ethylene in the forms requiring only one atom for adsorption (e.g., π-complexed or in the form of vinyl) is too weak to compete with adsorption of acetylene. Thereby A 1 sites do not adsorb ethylene, even at very low partial pressures of acetylene and at high partial pressures of ethylene.…”

Section: Discussionmentioning

confidence: 99%

Surface Heterogeneity of Supported Palladium Catalyst for the Hydrogenation of Acetylene−Ethylene Mixtures

Borodziński

Gołębiowski²

1997

Langmuir

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The hydrogenation of acetylene−ethylene mixtures over a Pd/α-Al2O3 catalyst was studied. Kinetic investigations were carried out in a flow system equipped with a gradientless microreactor over a wide range of acetylene and ethylene partial pressures. Three types of active sites were thus identified: A 1 and A 2 sites which are highly selective in the hydrogenation of acetylene to ethylene via a mechanism involving the competitive (A 1 ) and noncompetitive (A 2 ) adsorption of acetylene and hydrogen, and E sites which are active only for the hydrogenation of ethylene. E sites are able to adsorb acetylene, an effect which strongly inhibits ethane formation. The above three types of active sites are very likely created on the palladium surface by carbonaceous deposits formed during the stabilization process. The identified sites determine the selectivity of the catalyst and manifest themselves in kinetic investigations depending on the process conditions.

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“…Para representar el estado adsorbido que los n-butenos adoptan durante su hidrogenación e hidroisomerización se han postulado dos formas básicas: una adsorción tipo " σ " y una adsorción tipo " π ". No obstante, los mecanismos de reacción han sido generalmente interpretados en términos de la adsorción tipo " π " ( Bond & Wells, 1963;Kripylo et al, 1975;Webb, 1980;Goetz et al, 1997 ).…”

Section: Vii111 Estados De Adsorción Intermediarios Y Reacciones unclassified

“…Las reacciones de hidro-isomerización entre los n-butenos pueden explicarse de manera sencilla partiendo del precursor π-butílico para cada uno de los n-butenos y mediante la participación de un único intermediario adsorbido: el radical 2-butílico, ver Figura VII.2. Este mecanismo, denominado de " adiciónsustracción " de hidrógeno, ha recibido amplia aceptación en la literatura ( Webb, 1980 ).…”

Section: Vii111 Estados De Adsorción Intermediarios Y Reacciones unclassified

Purificación catalítica de 1-buteno: estudio cinético y simulación de un reactor industrial de hidrogenación selectiva

Bressa¹

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El tema de investigación de esta tesis son los procesos catalíticos de hidrotratamiento selectivo de cortes de hidrocarburos insaturados, de cadena de cuatro carbonos, ricos en n-butenos. El presente trabajo se inició en el marco de un Proyecto de Investigación referente a la simulación matemática de reactores industriales de lecho fijo con flujo bifásico de vapor y líquido, aplicados al hidrotratamiento de cortes de C4's. A partir de la revisión de la bibliografía se concluyó que sería necesario desarrollar dos herramientas sobre las cuales la información disponible es insuficiente para llevar a cabo la simulación propuesta. Las dos tareas centrales requeridas son: la formulación de un modelo plausible del reactor industrial de hidrotratamiento y la realización de un estudio cinético experimental destinado a dotar al simulador de información cinética confiable.

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Hydrogenation of alkenes and alkynes and related reactions catalysed by metals and metal complexes

Cited by 18 publications

References 0 publications

Kinetic Study of the Hydrogenation and Hydroisomerization of the n-Butenes on a Commercial Palladium/Alumina Catalyst

Kinetic Study of the Hydrogenation and Hydroisomerization of the n-Butenes on a Commercial Palladium/Alumina Catalyst

Surface Heterogeneity of Supported Palladium Catalyst for the Hydrogenation of Acetylene−Ethylene Mixtures

Purificación catalítica de 1-buteno: estudio cinético y simulación de un reactor industrial de hidrogenación selectiva

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