Pt–Pd bimetallic catalysts for methane emissions abatement

International audienceBimetallic Pd–Pt catalysts with constant 2 wt% metal loading and varying Pt/Pd ratios were prepared, characterized and studied in the catalytic combustion of methane at low temperature under lean conditions in view of their use for CH4 abatement from lean-burn NGV heavy duty vehicles exhausts. The influence of mild steam ageing featuring long-term use of the catalysts was also addressed together with their tolerance to H2S. Catalysts were characterised by Transmission Electron Microscopy and Temperature Programmed Oxidation experiments. Experimental data agreed to suggest an interaction between Pd and Pt in Pdrich catalysts, thus explaining their improved catalytic activity, even after mild ageing, compared to reference Pd/Al2O3. This interaction has no effect on the sulfur tolerance

Vacuum gas oil hydrocracking performance of bifunctional Mo/ Y Zeolite catalysts in a semi-batch reactor

International @ RAFFINAGE+RHE:MTF:PAF:CLOInternational audienceA new approach has been developed to characterize bifunctional catalysts in a complex matrix of hydrotreated vacuum gas oil, 370°C+ using a batch reactor test. Triphasic reactions were carried out in a reactor equipped with a stationary basket, hydrogen injection and products sampling systems. Bifunctional catalysts containing different relative amounts of alumina-supported NiMo sulfide and zeolite were tested at 400°C under 120 bars over different reaction times. The repeatability of the test conditions was validated and the lack of mass transfer limitations at phase interfaces was confirmed. Gas and liquid samples were analyzed by one and two-dimensional gas chromatography (2D-GCGCxGC) respectively to obtain quantitative distributions of linear and branched paraffins, olefins, naphthenes and aromatics. The details of the products distribution provided by the chromatography were analyzed using model kinetic mechanisms of bifunctional catalysis. It has been established that the limiting step defining the total conversion is scission of the hydrocarbon chains on zeolite sites. The increase of the molybdenum to zeolite ratio provided an improvement of selectivity to middle distillate (150-370°C

Vapor-Liquid Equilibrium of Hydrogen, Vacuum Gas Oil, and Middle Distillate Fractions

RAFFINAGE+BBR:RHE:PAF:#30:MTFVapor-liquid equilibrium (VLE) data for hydrogen/hydrocarbon mixtures based on real feedstocks at high temperature and pressure is scarce and is needed to model hydrocracking systems accurately. Experiments with a vacuum gas oil have been used to generate VLE data for real hydrogen/hydrocarbon mixtures under hydrocracking conditions in a semibatch reactor with a range of compositions. Flash calculations were performed using a process simulation program and compared to the experimental results. The data was used to verify the existence of equilibrium conditions in the reactor and to show that the Grayson Streed activity coefficient model, combined with Peng-Robinson equation of state, provides a good estimate of liquid phase and vapor phase compositions and individual component volatility

Vacuum gas oil hydrocracking performance of bifunctional Mo/Y zeolite catalysts in a semi-batch reactor

RAFFINAGE+RHE:MTF:PAF:CLO:#30A new approach has been developed to characterize bifunctional catalysts in a complex matrix of hydrotreated vacuum gas oil using a batch reactor test. Triphasic reactions were carried out in a reactor equipped with a stationary basket, hydrogen injection and products sampling systems. Bifunctional catalysts containing different relative amounts of alumina-supported NiMo sulfide and zeolite were tested at 400 degrees C under 120 bars over different reaction times. The repeatability of the test conditions was validated and the lack of mass transfer limitations at phase interfaces was confirmed. Gas and liquid samples were analyzed by one and two-dimensional gas chromatography (GC x GC) respectively to obtain quantitative distributions of linear and branched paraffins, naphthenes and aromatics. The details of the products distribution provided by chromatography were explained using mechanisms of bifunctional catalysis. It has been established that the limiting step defining the total conversion is the scission of the hydrocarbon chains on acid sites of the zeolite. The increase of the molybdenum to zeolite ratio provided an improvement of middle distillate selectivity. (C) 2013 Elsevier B.V. All rights reserved

Methodology for the study of vacuum gas oil hydrocracking catalysts Coupling of GC-2D data with vapour-liquid equilibrium

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Methodology and modeling for correlating structure and performance of vacuum gas oil hydrocracking catalysts in a batch reactor

International @ ECI2D+BBR:MTF:PAFInternational audienceA new approach for studying and modeling complex reaction kinetics with a batch reactor test has been developed. A kinetic model is proposed to represent the hydroconversion of Vacuum Gas Oil (VGO) with a bifunctional catalyst, taking into account the vapor-liquid equilibrium (VLE). A batch reactor apparatus was therefore developed [1]. Liquid samples were analyzed by two-dimensional gas chromatography (GC-2D). The vapor-liquid equilibrium model have been determined and compared with experimental data. The kinetic model has been validated with several catalysts containing different ratios of metal-zeolite

Methodology and modeling for correlating structure and performance of vacuum gas oil hydrocracking catalysts in a batch reactor

International @ ECI2D+BBR:MTF:PAFInternational audienceA new approach for studying and modeling complex reaction kinetics with a batch reactor test has been developed. A kinetic model is proposed to represent the hydroconversion of Vacuum Gas Oil (VGO) with a bifunctional catalyst, taking into account the vapor-liquid equilibrium (VLE). A batch reactor apparatus was therefore developed [1]. Liquid samples were analyzed by two-dimensional gas chromatography (GC-2D). The vapor-liquid equilibrium model have been determined and compared with experimental data. The kinetic model has been validated with several catalysts containing different ratios of metal-zeolite