Why does this project matter?

Crude glycerol (CG) is produced in large quantities as a co-product of biodiesel and fatty ester manufacturing. Its catalytic dehydration to acrolein, which is a key industrial intermediate, offers an attractive valorization route for this renewable waste stream. However, CG composition varies significantly by origin: water content, salt load, methanol residues, and organic impurities all alter reaction kinetics and catalyst behavior in ways that are poorly understood. Existing kinetic studies cover only fixed, idealized compositions and cannot guide reactor design for variable real-world feedstocks. P4 develops the first comprehensive kinetic model and model-based tolerant reactor design for CG valorization.

What are we aiming to achieve?

The central objective is to establish a reaction kinetic model for CG dehydration valid across a wide range of compositions and operating conditions, and to use it within the Multi-Level Reactor Design (MLRD) methodology to derive an optimal tolerant reactor design and operation strategy. Key objectives are: (1) design and commission a dedicated kinetic setup with operando Raman spectroscopy and GC analytics; (2) perform systematic catalyst and feedstock screening; (3) develop and validate a high-fidelity kinetic model; and (4) identify optimal tolerant reactor design specifications via the MLRD methodology, transferable to other bio-based conversions in TALENT.

What will you work on as a PhD researcher?

As doctoral researcher in P4, you design and commission a Berty-type reactor setup for intrinsic kinetic measurements of gas-phase CG dehydration, equipped with analytics such as an online GC for acrolein, glycerol and side product quantification and an operando Raman spectroscopy probe for real-time in-situ monitoring. You then run a systematic screening campaign: varying individual and combined feed impurities (methanol, salts, water content, fatty acids) to map their effect on conversion and selectivity, and testing literature-reported heterogeneous acid catalysts to identify the most suitable one for tolerant operation.

With catalyst and benchmark composition selected, you perform detailed kinetic measurements across a broad range of temperatures, space velocities, and feed compositions under differential reactor conditions. These data are used to develop and parameterize a mechanistic kinetic model by non-linear regression. The validated model is integrated into the MLRD methodology to identify optimal reaction conditions for a tolerant reactor, and shared with P5 for integration into scale-resolved multiphase simulations.

Skills and methods you will develop during your doctorate:

• Laboratory reactor design and commissioning (Berty-type reactor, gas-phase heterogeneous catalysis)

• Operando analytics: Raman spectroscopy, online GC, calibration, and data interpretation

• Heterogeneous catalyst characterization and screening

• Reaction kinetic modelling: network analysis, microkinetic formulations, ODE systems

• Non-linear parameter estimation and statistical model validation

• Model-based reactor design using the MLRD methodology

• Scientific programming (Python or MATLAB) for modelling and data analysis

Who will you work with and where?

The Freund group is one of the pioneers of tolerant process design in chemical engineering and has an outstanding track record in reaction kinetic modeling and model-based design of chemical reactors for both gas-phase and multiphase reaction systems. The laboratory is equipped with customized reactor setups including Berty-type and trickle-bed reactors for intrinsic kinetic studies, state-of-the-art operando analytics (in-situ Raman spectroscopy, online GC, IR, UV-Vis, NMR), and high-pressure equipment. The group is directly affiliated with the Center for Advanced Liquid Phase Engineering (CALEDO) at TU Dortmund University, providing additional infrastructure and equipment access. Embedded in RTG TALENT, you gain access to a structured qualification program that combines advanced scientific training with transferable skills development, active exchange with academic and industrial collaboration partners, and tailored career support including the opportunity for a three-month placement in research, industry, or a start-up aligned with your career goals.