Multiscale kinetic modeling in catalysis ⇒ from microkinetics to computational fluid dynamics and process simulations

Problem statement

We envision multiscale modeling as critical enablers of reaction understanding, catalyst and reactor design, scale-up, and process optimization. The framework includes predicting the molecular reaction mechanism at the molecular level to the process optimization stage. As catalytic processes occur at the multiscale, we address these issues individually and collectively.

At the microkinetic level, our models resolve the rates of the individual elementary steps, rate-determining step (RDS), adsorption, and desorption mechanisms. We use quantum chemical calculations (density functional theory, DFT) to support our assumed kinetic pathways, original parameter estimations, and adsorption-desorption energies.

We incorporate thermodynamic constraints into our models. Once developed, the microkinetic model could guide the catalyst and reactor design. We also have experience developing Langmuir-Hinshelwood and Eley-Rideal types of kinetic models.

At the macrokineitc level, we develop lump-based and empirical models which, in some cases, are very robust and, together with other models, can be used to extract information such as mechanism change, optimize conditions, or for reactor pre-design.

We couple hydrodynamics, heat transfer, and reaction kinetics at the reactor level in computational fluid dynamic (CFD) simulations. Together with optimization algorithms, we aim to improve operating scenarios, develop innovative reactor prototypes, and predict process behaviors at the industrial scale.

Goals

  • Microkinetics I ⇒ key thermodynamic relationships
  • Microkinetics II ⇒ fitting, training, and optimization
  • Microkinetics III ⇒ ab initio kinetic modeling
  • Macrokinetics ⇒ complex reaction networks and population balances
  • CPFD ⇒ reactor modeling and scale-up
  • CFD ⇒ reactor modeling and optimization
  • CFD II ⇒ modeling operando reactors
  • Process system engineering ⇒ gPROMS

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Related Covers

Related Publications

Kinetic and Deactivation Modelling of Biphenyl Liquid-Phase Hydrogenation over Bimetallic Pt-Pd Catalyst

by Castaño, Van Herk, Kreutzer, Moulijn, Makkee
Appl. Catal. B: Environ. Year: 2009

Abstract

The hydrogenation of biphenyl was modelled kinetically on a Pt–Pd supported catalyst, comprising the influence of the sulphur poisoning. Aromatic deep hydrogenation is one of the challenges for meeting the environmental requirements of fuels. Noble bimetallic catalysts are promising systems for such purpose due to their (i) improved activity compared to standard hydrotreating catalysts and their (ii) enhanced resistance toward sulphur poisoning in contrast to their monometallic counterparts. The experiments used for the modelling have been obtained in the intrinsic kinetic regime, excluding internal and external mass transfer limitations. A robust model for both kinetic and deactivation performance is derived, taking as initial estimations the values derived from the pseudo-first-order kinetics. This model clarifies the mechanisms of adsorption, reaction, and deactivation during polycyclic-aromatic-hydrocarbon (PAH) hydrogenation on intrinsic kinetic conditions.

Keywords

HPC MKM