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 Publications

Water and methanol cofeeding modulates kinetics in crude-to-chemical cracking

by Al Aslani, Colom, Lezcano, Alahmadi, Shoinkhorova, Dikhtiarenko, Cui, Alfilfil, Alsalman, Morales-Osorio, Almajnouni, Castaño, Gascon
React. Chem. Eng. Year: 2026 DOI: https://doi.org/10.1039/d5re00525f

Abstract

The co-processing of crude oil with green methanol offers a promising pathway for integrating renewable carbon into conventional refining, yet the presence of water or any hydrophilic components such as methanol can significantly influence catalyst performance, reaction selectivity, and overall process efficiency. We discuss experimental and kinetic modeling aspects of cofeeding water and methanol during crude oil catalytic cracking over a wide range of temperatures (525–650 °C) and catalyst-to-oil ratios (0–4.14) using a microactivity testing unit (MAT). During cofeeding, yields of gas and coke, and propylene-to-ethylene ratios fluctuated at low and high catalyst-to-oil ratios, respectively. Interestingly, cofeeding water and methanol lowered coke formation, while higher selectivity to light olefins over paraffins was observed in the presence of only water. Reparameterization of the kinetic model for Arabian light crude using water cofeeding data revealed changes in the intrinsic kinetic parameters of the cracking reactions. Specifically, the rate constant for the monomolecular cracking pathway leading to propylene increased across the entire temperature range, while the rate constants associated with condensation reactions, responsible for generating coke precursors, were reduced.

Keywords

C2C MKM