Dynamic Modeling & Transport Phenomena in Fixed-Bed Catalytic Reactors¶
Double Bachelor of Science Thesis in Applied Physics & Applied Mathematics
Delft University of Technology
Author: Lucas van Dekken
Departments: Catalysis Engineering (ChemE / TNW) & Delft Institute of Applied Mathematics (DIAM / EEMCS)
Executive Project Overview¶
This thesis investigates the non-linear dynamics, transport phenomena, and numerical modeling of fixed-bed catalytic reactors under forced periodic operation. Combining continuum physics with numerical mathematics, the primary focus centers on the selective semi-hydrogenation of acetylene () over heterogeneous bimetallic palladium catalysts.
🔬 Applied Physics Core (TNW / ChemE)¶
Multi-Scale Transport Balances: Derivation of the one-dimensional Axial Dispersion Model (ADM) coupling plug flow convective transport, effective axial dispersion (), and intra-pellet diffusional resistance.
Gas-Solid Surface Kinetics: Formulation of dynamic Langmuir-Hinshelwood-Hougen-Watson (LHHW) rate expressions tracking unmeasurable, transient surface coverage states .
Dynamic Forcing: Analyzing how periodic inlet concentration pulsing breaks static equilibrium constraints to enhance intermediate ethylene selectivity.
📐 Applied Mathematics Core (DIAM / EEMCS)¶
Spatial Semi-Discretization: Method of Lines (MOL) implementation using first-order Upwind schemes, enforcing strict downstream causality and eliminating stiff spatial matrix inversions.
Stiff Time Integration: Evaluating implicit multi-step and Runge-Kutta solvers (BDF / Radau) to resolve the disparate timescales between fast catalytic surface chemistry and slow convective gas transport.
Periodic Limit Cycles: Establishing an open-loop forward propagation framework to evaluate the impact of modulation frequency and wave parameters on cumulative yield.
📚 Thesis Structure & Quick Navigation¶
| Chapter | Focus Area | Key Content |
|---|---|---|
| 1. Introduction | Industrial Context & Scope | Ethylene purification, limitations of steady-state PBRs, and dynamic excitation rationale. |
| 2. Theory | Physical & Chemical Formulation | Continuum conservation PDEs, Danckwerts boundary conditions, and dimensionless scaling (). |
| 3. Methods | Numerical Discretization | Method of Lines (MOL), Upwind scheme stability, and ODE system staging in Python. |
| 4. Results & Simulation | Interactive Analysis & Verification | Executable Jupyter Notebook demonstrating transient state propagation, parameter fitting, and response curves. |
| 5. Conclusion | Synthesis & Outlook | Key findings, model validity domain, and experimental verification roadmap in the Urakawa Lab. |
👥 Graduation Committee & Research Supervision¶
| Position on Form TWN3002-24 | Staff Member | Department & Affiliation |
|---|---|---|
| First Supervisor & 1st Examiner (TN) | Dr. Bijoy Bera | Assistant Professor, Transport Phenomena (ChemE / TNW) |
| First Supervisor & 1st Examiner (TW) | Dr.ir. Zoë Gromotka | Assistant Professor, Mathematical Physics (DIAM / EEMCS) |
| Daily Supervisor & Catalysis Lead | Damian Vico van Berkel | PhD Candidate, Catalysis Engineering (ChemE / TNW) |
| Second Examiner (TW) | Dr. N.V. (Neil) Budko | Associate Professor, Numerical Analysis (DIAM / EEMCS) |
| Second Examiner (TN) | Dr. C.S. (Carlas) Smith | Associate Professor, Systems & Control (DCSC / 3mE-TNW) |
| Laboratory Head / Advisor | Prof. dr. Atsushi Urakawa | Full Professor, Catalysis Engineering Group (ChemE / TNW) |