Master thesis

Simulation-based optimization of a magnetically

supported vortex bed electrode for in-situ generation of

of H2O2 for electroenzymatic syntheses

Background:

Conventional processes for chemical synthesis mostly use fossil raw materials and thus cause climate-damaging emissions. An innovative alternative for green chemical production is electrobiosynthesis, which combines electrochemistry with biotechnology. Through electricity from renewable sources, the use of green catalysts (e.g. enzymes) and the use of renewable raw materials, chemicals can be synthesized in a "CO2-neutral" way. To achieve electrobiosyntheses that are as competitive as possible, high space-time yields are targeted and reactors with high volume-specific electrode surfaces are required. In the research project in which the master thesis is embedded, a magnetically assisted fluidized bed reactor for electroenzymatic syntheses is to be developed and used. In this reactor concept, the electrode is formed by electrically conductive magnetic particles, which enable controlled fluidization through magnetic linkage. Due to the advantageous magnetic support, improved electrical contacting is to be achieved and the high surface area of the particle electrode is to be utilized for electrochemical reactions.In combination with the good mass transfer properties of the fluidized bed, a scalable reactor prototype for high electrochemical turnovers is to be developed. The efficiency of the reactor for electro-enzymatic syntheses will be demonstrated by the reduction of oxygen to hydrogen peroxide, which is required as a co-factor for oxyfunctionalization reactions of peroxygenases. Since the solubility of oxygen in aqueous solutions is low, it is a challenge to maximize the electrode surface area and optimize the contacting of the particle electrode.

Task:

As part of the master thesis, the in-situ generation of hydrogen peroxide in a magnetically assisted fluidized bed will be optimized experimentally and simulatively.

The work packages include:

- Design of contacting elements for optimized electrical contacting of the particle electrode.

- Experimental investigation of influencing parameters such as flow rate, voltage, magnetic field and pH on the electrochemical generation of hydrogen peroxide in the optimized electrochemical fluidized bed reactor

- Modeling of core phenomena for the electrochemical generation of hydrogen peroxide using COMSOL Multiphysics simulation software.

- Comparison of the simulation model with the experimental results

Supervision:

In addition to the scientific supervision by Prof. Dr.-Ing. Matthias Franzreb, Mr./Mrs. XXX is supported in the practical execution of the work by Mr. M. Sc. Michael Abt, PhD student at the chair.