Why does this project matter?

The selective partial hydrogenation of polyunsaturated fatty acids (PUFAs) to monounsaturated fatty acids (MUFAs) is a key step in valorizing bio-based vegetable oils, generating versatile platform molecules for polymers, surfactants, and specialty chemicals. However, bio-based feedstocks are inherently variable in PUFA composition, degree of unsaturation, and minor component profiles, and current hydrogenation processes are designed for steady-state operation with well-defined inputs. No continuous process reliably delivers consistent product quality under changing feed conditions. P3 develops the first tolerant continuous flow hydrogenation process for variable PUFA-rich feedstocks.

What are we aiming to achieve?

The objective of P3 is to develop a tolerant, continuous flow hydrogenation process combining a highly active colloidal palladium catalyst (stabilized in polar liquid phase) with a segmented capillary flow reactor in which hydrogen is supplied through permeable tubing. Key goals are: (1) establish stable gas-liquid segmented (Taylor) flow with precise residence time control; (2) maintain consistent hydrogen supply under varying substrate composition and load; (3) develop and validate a combined reaction kinetic and mass transport model; and (4) demonstrate stable operation with realistic PUFA-rich substrates of variable composition provided by P1 and P2.

What will you work on as a PhD researcher?

As doctoral researcher in P3, you develop a continuous gas-liquid capillary flow process for selective PUFA hydrogenation. You adapt an existing microreactor setup for segmented (Taylor) flow: selecting capillary materials, designing pump and pressure control systems, and integrating in-line or at-line analytics. You then quantitatively characterize hydrogen permeation through the permeable capillary wall as a function of pressure, temperature, and substrate concentration, establishing the conditions that ensure consistent H₂ availability across the expected range of PUFA feed compositions.

Systematic reaction condition optimization follows (H₂ pressure, temperature, flow rate, catalyst loading) using model PUFA substrates characterized by different degrees of unsaturation You build a one-dimensional unit-cell reactor model in Python or MATLAB capturing hydrogen mass transfer, plug-flow reaction kinetics, and gas-segment shrinkage, and validate it against experimental data. The model guides process adaptation in collaboration with P8, and realistic PUFA substrates from P1/P2 are implemented in the final project phase.

Skills and methods you will develop during your doctorate:

• Continuous flow chemistry: capillary reactor design, pump/pressure systems, segmented flow hydrodynamics

• Colloidal catalyst handling and characterization (Pd nanoparticles in biphasic systems)

• Gas-liquid mass transfer characterization and permeation measurements

• Product analytics: Gas Chromatography, NMR, (online) Raman- and/or IR-spectroscopy

• Reaction kinetics: mechanistic network analysis, parameter estimation

• Mathematical modelling: ODEs for unit-cell reactor models, Python/MATLAB programming

• Design of experiments (DoE), response surface methodology

Who will you work with and where?

The Seidensticker group is recognized for homogeneous catalysis with renewable feedstocks, with pioneering contributions to colloidal Pd catalysis, biphasic reaction systems, and the catalytic valorization of bio-based oleochemicals via hydroformylation, metathesis, and methoxycarbonylation. The laboratory is equipped with capillary microreactor setups for continuous flow gas-liquid reactions, high-pressure autoclaves for batch kinetic studies, GC-FID and GC-MS for comprehensive fatty acid characterization, and NMR infrastructure for detailed product analysis, as well as online spectroscopy. The group has a strong technology transfer orientation, exemplified by the spin-off Simplyfined GmbH. which is founded on research developed within the group. 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.