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

Related People

Related Covers

Related Publications

Reaction Network of the Chloromethane Conversion into Light Olefins using a HZSM-5 Zeolite Catalyst

by Gamero, Valle, Castaño, Aguayo, Bilbao
J. Ind. Eng. Chem. Year: 2018

Abstract

The second step of chlorine-mediated methane valorization into hydrocarbons has been investigated using a HZSM-5 zeolite catalyst. A parametric study has enabled to set the reaction network, which is dominated by the dual cycle mechanism and secondary reactions of light olefins. This network explains the formation of methane, light olefins, C5+ aliphatics, paraffins, aromatics and coke. Under the optimal conditions, the light olefin selectivity is >70%, of which >40% corresponds to propylene. Coke is originated in the zeolite micropores and then grows within the matrix meso- and macropores.

Keywords

O2H MKM