Background

Achieving climate neutrality, particularly for the aviation sector, poses a significant challenge due to the need for high-energy-density fuels. While electric propulsion systems remain impractical for this sector, and the potential of biofuels is limited, synthetic liquid fuels produced from renewable electricity, water, and CO2 from regenerative sources offer a promising sustainable alternative. The Fischer-Tropsch Synthesis (FTS) represents a key process step within the Power-to-X value chain. In conventional cobalt-based Low-Temperature FTS (LTFTS), long-chain hydrocarbons are generated from syngas (CO/H2), which can be processed into Sustainable Aviation Fuel (SAF). However, this setup requires an additional upstream step for syngas production before the FTS can take place. In contrast, iron-based High-Temperature CO2-FTS (HTFTS) enables the direct conversion of CO2 and hydrogen, thereby eliminating the need for syngas generation. However, compared to LTFTS, the HTFTS process tends to produce more methane, unsaturated hydrocarbons, and shorter-chain hydrocarbons. To enable the scale-up of HTFTS, it is essential to develop a reaction kinetic model that accurately predicts the behavior and selectivity of the process under varying operating conditions.

Objectives

The aim of this work is to accurately describe the catalytic system under different operating conditions, with a particular focus on the recycling of unreacted product gas. The thesis is structured as follows:

• - Experimental characterization of the catalytic reaction behavior under varying conditions
• - Selection of an appropriate model for describing reaction kinetics
• - Parameterization of the model
• - Experimental validation of the developed model

Prerequisites

• - Field of study: Chemical Engineering, Process Engineering, or related disciplines
• - Careful and independent working style
• - Knowledge of MATLAB is beneficial (not mandatory)

The content and focus of the thesis can be tailored to individual interests.

The thesis can either be in German or in English.