Presentation by: Adrie Straathof (TU Delft, Department of Biotechnology)

This presentation reviews the state-of-the art concerning biokinetics. Enzymes concerns only catalysis and transport, but microbial cultures also concern growth, regulation, and evolution. Steady-state enzyme kinetics are mature and are used in biochemistry just like in bioprocess development and are used for advanced enzymology. Michaelis-Menten type of equations are often applicable with specific assumptions. Measurement of the initial rate is sufficient for basic kinetic studies; the whole progression curve should be measured for the full kinetics. Parallel and consecutive reactions have to be investigated as well. High-throughput assays are bottlenecks in development of biocatalytic processes.
The last 8 slides concern the much more complex kinetics of microbial cells for which new methods are being developed (i.e. the field of Systems Biology).

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  Introduction to biokinetics - Downloaded 2048 times

Presentation by: Anton Nagy (Integrated Lab Solutions)

Presentation demonstrating parallel/high throughput custom-made lab solutions for use at any set of conditions defined by the user: (i) Fixed bed reactors from lab to pilot scale for gas, liquid, and multiphase flow systems; (ii) Autoclave test reactors (ranging from 2ml – 100 L); (iii) Continuous reactors (internal recycle CSTR, very suitable for kinetic experiments); and (iv) High throughput and parallel units.

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  Integrated Lab Solutions: Designing the system for your chemistry - Downloaded 2828 times

Presentation by:

1. Niels Hansen, Till Brüggemann, Frerich J. Keil (Hamburg University of Technology, Germany),
2. Alexis T. Bell (Dep. Chem. Eng. Univ. of California at Berkeley, USA),
3. R. Krishna, and J. M. van Baten (Van ‘t Hoff Institute for Molecular Sciences, Univ. of Amsterdam, The Netherlands

The methods based on statistical and quantum mechanics have reached a level of sophistication that they can now be used to describe elementary processes involved in heterogeneous catalysis almost quantitatively. These methods can therefore be used to predict the effects of catalyst composition/structure on reaction rates and product distribution and to decide which zeolite structure in the best for a given reaction. It is worked out using the alkylation of benzene with ethene over H-ZSM-5. The investigation includes diffusion, adsorption and reaction.

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  Analysis of diffusion limitation in the alkylation of benzene over H-ZSM-5 by combining quantum chemical calculations, molecular simulations and a continuum approach - Downloaded 1862 times

Presentation by: Eric Gaigneaux (CATA, Université catholique de Louvain)

The presentation starts with an overview of the broad expertise of the catalysis and chemical materials group at UCL (CATA = Unité de catalyse et chimie des matériaux divisés). The case study on the catalytic abatement of dioxine shows that the choice of the model molecule to study biases the results. Chlorobenzene is often used as the model molecule but it lacks the O-containing ring which seems to enhance the adsorption significantly. Catalyst modifications for enhancing the adsorption are therefore probably of little use.

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  Expertise of the Unité de catalyse et chimie des matériaux divisés - Downloaded 2006 times

Presentation by: Joris Thybaut, (Ghent University, Laboratory for Chemical Technology)

In this presentation Thybaut uses the single-events approach to show that the protonation enthalpy, the number of sites, the physisorption properties, and the atomic adsoption enthalpies are the major catalyst descriptors in the isomerisation and cracking over USY and ZSM-22 zeolites. The reaction kinetics in the Fischer-Tropsch synthesis was estimated successfully using the UNI-QEB approach.

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  Single-event microkinetic assisted design of new and improved catalytic materials - Downloaded 1844 times

Presentation by:

Linda Broadbelt, Shumaila S. Khan, and Jim Pfaendtner (Northwestern University, Evanston, IL 60208, USA)

In this presentation Linda Broadbelt shows that lubricant degradation, tropospheric ozone formation and the production of biofuels from biomass need to be described with complex reaction networks. In these reaction networks the individual components and reaction families can be represented by specific matrices. The Evans-Polanyí relationship is used to estimate activation energies causing a reduction of the number of parameters. Kinetic parameters are estimated from the transition-state theory. The results are illustrated for decane and octane autoxidation, and for tropospheric ozone formation.

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  Creating and harnessing complex reaction networks: application to oxidation chemistry - Downloaded 1979 times

Presentation by: Marie-Françoise Reyniers (Ghent University, Laboratory for Chemical Technology)

In this presentation Reyniers showed how QM methods and experiment (steady-state, transient, in-situ, XANES/EXAFS) can be used to develop ab-initio based fundamental kinetic models. Options in and results of DFT; different routes, possible steps, and adsorption. The TiO2 support influences the propylene adsorption on on the V2O5 catalyst. The periodic slab models worked the best.

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  First principles kinetics of heterogeneously catalyzed reactions: oxidation of hydrocarbons over V2O5 catalysts - Downloaded 2043 times

Presentation by: Rhona Van Borm, M.-F. Reyniers, G.B. Marin (Ghent University, Laboratory for Chemical Technology)

This poster shows the four major catalyst descriptors are the number of sites, the change of the protonation enthalpy, the change of the activation energy, and the physisorption properties of the catalyst. The acid properties control the cracking but not the selectivity; the framework topology controls the selectivity.

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  Influence of acid properties and framework topology of FAU and MFI zeolites on their catalytic cracking behavior - Downloaded 2159 times

Presentation by: Veronique van Speybroeck (Ghent University, Center for Molecular Modeling))

In this presentation Veronique showed the application of first-principle kinetics and the transition state theory. Isolated molecules are modelled using the molecular energy difference (DFT, Hartree-Fock; estimation of pre-exp. factor using translational, rotational, electronic and vibrational energy). Ab-initio kinetic modelling was applied to the network of coke formation.
Finally, supramolecular systems were treated in an onion-like approach in which part of the system has be treated in partly semi-empirical way.

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  First-principle chemical kinetics: from isolated molecules to supramolecular systems (18MB) - Downloaded 1165 times

Presentation by: Freek Kapteijn (TU Delft, Catalysis Engineering)

In this presentation Kapteijn showed the results of a modelling study of the influence of the inhibition by the H2S in catalytic hydrotreating (HDS) when operating in co-current and when operating in countercurrent mode. If H2S inhibition is strong countercurrent operation is particularly advantageous at high conversion. If the H2S inhibition is small, co-current operation is preferred when mass transfer is slow and counter-current when the mass transfer is fast. Additionally, Kapteijn explained in the introduction of this presentation the differences between stripping and reactive distillation.

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  Countercurrent operation in catalytic hydrotreating - the impact of kinetics - Downloaded 2192 times