Bachelor theses / Master theses

Water electrolyzer is one of the promising technologies to produce green hydrogen as an energy source to reach carbon neutrality. Hitherto three types of water electrolyzer cells have been established, alkaline electrolytic cells, polymer electrolytic cells, and solid oxide electrolytic cells. To improve their performances and energy efficiency, a wide range of catalysts containing critical raw materials are developed. For instance, Ir-based or Pt-based catalysts are considered state-of-the-art materials in polymer electrolyte membrane electrolyzers (PEMELs). As the demand for hydrogen production increases, the consumption of materials used in water electrolysis is also expected to increase. Therefore, an investigation into the recycling of these materials is necessary for a circular economy. However, a very limited number of studies have investigated on recycling processes of water electrolyzers, especially mechanical separation processes for fine particle mixtures after comminution or delamination processes (below 100 µm).
According to previous study results, the representative materials (Carbon black and TiO2) used for the two electrodes of PEMEL showed a clear difference in their hydrophobicity, so the particles can be separated using these characteristics. (Recovery rate: 97% TiO2, 99% carbon black) However, the catalyst ink coated on the cell electrodes is a mixture of particles and ionomers (Nafion) that act as a binder. The presence of the ionomer might affect their hydrophobicity and play an important role in the separation processes. In order to approximate the composition of actual particles, ionomer-containing particles will be prepared as the material for this study. The influence of the ratio of ionomer on the particle wettability has been studied in the previous student thesis. The purpose of this work is to investigate the influence of ionomer on the separation processes by exploiting methods such as particle liquid-liquid extraction and flotation. Furthermore, for effective separation in the binary particle systems, diverse reactants and organic liquids can be considered.

• Student (f/m/d) of e.g. Process Engineering, Chemical Engineering, Mechanical Engineering, …
• Independent and structured way of working
• Good written and oral communication skills in English

• Place of work: Freiberg
• Start possible at any time by arrangement