Presentation by:

1. Fred Meunier (Institut de Recherche sur la Catalyse et l’Environnement de Lyon, Villeurbanne, France),

The combination of kinetic and thermodynamic analyses can provide an in-depth knowledge of into crucial steps of the reaction mechanisms taking place over catalysts. A few examples dealing with alkane hydroisomerization, methanol steam reforming, NO oxidation to NO2, and ethanol condensation to butanol show how mechanism(s) can be supported or rejected based on trivial reactant and product concentration analyses.The conclusion is that the comparison of the reaction quotient (Q) or similar ratios to the corresponding thermodynamic equilibrium ratios (e.g. K) can be very useful in supporting or rejecting a reaction mechanism.

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  Unraveling the mechanism of catalytic reactions through kinetics and thermodynamics - Downloaded 2284 times

Presentation by:

1. Martijn F. De Lange, Thijs J.H. Vlugt, Jorge Gascon, Freek Kapteijn (Catalysis Engineering – Dept. Chemical Engineering, Delft University of Technology, The Netherlands),

Based on the paper published in Microporous and Mesoporous Materials (200 (2014) 199–215) the widely used technique of nitrogen adsorption @77 K on porous materials is analyzed and discussed.Based on a thorough error analysis using data from six representative porous materials, recommendations are made how to perform the optimal measurements, to determine pore volume, an easy to use method to determine the relative pressure window for the BET analysis, and to use nonlinear parameter estimation for higher accuracy.
A pore size distribution technique like the BJH method is contaminated with such a large error that statistically hardy conclusions can be drawn. Application of the outline approach reduces enormously the scatter in literature data for a metal organic framework MIL-101 (Cr).

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  Analysis of the nitrogen adsorption technique to characterize porous materials - partA - Downloaded 1817 times
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  Analysis of the nitrogen adsorption technique to characterize porous materials - partB - Downloaded 1947 times

Presentation by:

1. Ruud van Ommen (Product & Process Engineering, ChemE, Delft University of Technology, the Netherlands),

Gas-phase coating using atomic layer deposition (ALD, a variant of chemical vapour deposition) can be used to provide the full surface of particles – non-porous or porous – with either an ultrathin continuous coating or a decoration of nanoclusters. When carried out in a fluidized bed or a pneumatic reactor, ALD is an attractive way of producing such nanostructured particles with excellent scale-up potential. We demonstrate the fabrication of catalysts using ALD: a very good dispersion of the catalytic material can be achieved. Moreover, we show by modelling and experiments that the gaseous precursors can be used with high efficiency.

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  Gas-phase deposition (ALD) for highly efficient preparation of catalysts - Downloaded 2302 times

Presentation by:

1. Mark Saeys (Laboratory for Chemical Technology, Ghent University, Belgium),

Catalyst design and kinetic modeling often start from molecular-scale hypotheses about the reaction mechanism, the structure of the active sites and the nature of the rate and selectivity determining steps. Computational catalysis has become a crucial tool to analyze molecular-scale concepts. In combination with characterization and kinetic validation, insights from computational catalysis can be quickly translated to the industrial scale. This pas-de-deux between experiment and theory is rapidly becoming the new paradigm in catalyst design and kinetic modeling. It also allows testing hypotheses about the catalyst structure under reaction conditions and possible reaction mechanisms. This presentation illustrates the success of this approach with the discovery of a boron promotor that enhances the stability of cobalt FT catalysts by an order of magnitude.

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  Operando computational catalysis: structure, mechanism and design of cobalt Fischer-Tropsch catalysts - Downloaded 1977 times

Presentation by:

1. Luis Pereira de Oliveira (IFP Energies nouvelles, France),

The new composition modelling methodology models the kinetic modelling of oil refining processes for both the feedstock composition and the process reactions at a molecular level. It consists of generating a synthetic set of molecules, whose properties are close to those obtained from the process feedstock analyses, by a two-step molecular reconstruction algorithm.

The refining process is simulated using Gillespie’s Stochastic Simulation Algorithm, in which the evolution of the composition is followed by applying, step by step, the refining reactions to the created set of molecules by means of a Monte Carlo method. This methodology was applied to hydrotreating of Light Cycle Oil gas oils. Overall properties of the effluent are well predicted. The methodology is also able to predict molecular properties of the effluent not accessible with traditional kinetic models..

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  Molecule-based kinetic modelling of complex mixtures - Application to gas oil hydrotreating - Downloaded 1774 times

Presentation by:

1. Chetan Raghuveer (Ghent University, Belgium, and BP plc, Sunbury – UK),

The presentation concerns a case study on extension of models constructed with the help of gas phase data to three phase reactions. Pyridine hydrodenitrogenation has been considered as the model reaction. A comparison of gas and three phase reaction for the same model compound is included. The methodology of extension of the gas phase model to three phase reaction is performed by taking into account the non-ideality in the liquid phase and the aggregation state effect.

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  Extension of gas-phase models to liquid-phase reactions - Hydrodenitrogenation of pyridine - Downloaded 1841 times

Presentation by: David Vervloet, Ruud van Ommen, Freek Kapteijn (TU Delft, Catalysis Engineering)

Diffusion limitation in the liquid-filled pores of Fischer-Tropsch catalysts causes a increase of the H2/CO ratio inside the catalyst pellets, which negatively affects the chain-growth parameter alpha. A modelling study was performed to investigate whether a lower bulk H2/CO ration can improve the reactor performance. Using literature reaction kinetics and a chain growth probabilty function taken from De Deugd (TU Delft) a bulk H2/CO of 0.8 preserves the productivity also at CO Thiele modulus > 1, i.e. at higher temperature. The catalyst requires a water-gas shift functionality and should be as active as possible and not deactivate at low H2/CO ratio.

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  Fischer-Tropsch Synthesis revisited: Considerations on Reaction Diffusion and Selectivity in a cobalt catalyst particle - Downloaded 1909 times

Presentation by:

1. Christophe T’joen, Martin Rohde (TU Delft, Radiation Radionuclides & Reactors, The Netherlands),
2. Ruud van Ommen (TU Delft, Chemical Engineering, The Netherlands

Short overview of current activities at TU Delft related to packed bed thermo-hydraulics; experimental as well as computational (random packed beds of spherical particles).
Applications: multi-tubular catalytic reactors and nuclear pebble bed reactor. The higher voidage near the wall causes potential problems: bypass, reduced heat transfer, hot spots. This is not easy to model with e.g CFD. The packages Fluidity and OpenFoam are used. A structured tubes for gas-liquid reactions such as a Sulzer packings offer a superior pressure drop, superior heat transfer, flatter temperature profiles and a comparable mass transfer.

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  Enhanced heat transfer in small diameter packed beds - Downloaded 2528 times

Presentation by: Tapan Bera, Joris W. Thybaut, Guy B. Marin (Ghent University)

The experimental results on naphtalene hydrogenation on a sulphided NiMo/gamma-Al2O3 catalyst were fitted well using a micro-kinetic model by accounting for competitive solvent chemisorption and also for the liquid phase non-ideality using fugacity coefficients obtained with the Peng-Robinson method. This methodology allows collecting experimental data at conditions corresponding to a gas phase, construct a kinetic model and then apply this model to conditions corresponding to the presence of both gas and liquid aggregation states. It is also applicable for different reaction systems.

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  A Single-Event MicroKinetic Model for the Hydrogenation of Aromatic Components on a Pt Catalyst - Downloaded 1838 times