May 14, 2025
Successful diploma defense by Shin Hyeok Kang
Diploma student Shin Hyeok Kang (left) and Prof. Dr.-Ing. Michael Beckmann, Chair of Energy Process Engineering, after the successful defense.
Shin Hyeok Kang's diploma defense took place on 12.05.2025 at the Chair of Energy Process Engineering. The title of the thesis supervised by Dipl.-Ing. Pascal Otto (Institute of Waste Management and Circular Economy, TU Dresden) was: "Development and validation of an in-situ methanation system for the efficient conversion of hydrogen in anaerobic digestion systems".
As part of this work, an experimental test rig for in-situ methanation was developed and analysed in which hydrogen was injected directly into an anaerobic digester with a meandering reactor structure. The aim was to evaluate the efficiency of the biological conversion ofH₂ andCO₂ toCH₄ under real conditions and to investigate the process stability and conversion rates using biological and chemical parameters.
The test setup included a complex MSR system for controlling the hydrogen and substrate supply as well as continuous temperature control using external heating cables. The evaluation of the gas concentrations showed a partially efficient conversion of the supplied hydrogen, with maximum conversion rates of over 80 % being achieved. However, in critical phases, especially with low CO₂ availability and accumulation of volatile fatty acids, the H₂ conversion rates fell below 10 %, indicating microbial inhibition and imbalances in the system. The increase in acetic acid, propionic acid and the FOS/TAC ratio clearly demonstrated this destabilization.
The reactor performance could be stabilized by dosing H₂ in a targeted manner and regulating the temperature. The validation of the balancing model showed a high prediction quality with regard to H₂conversion.
These results prove that in-situ methanation is a promising approach for the production of methane, but can only be operated efficiently with synchronized substrate availability and coordinated reactor design.
Mr. Kang was successful in his defense and received a very good grade. We congratulate him on this great result and wish him all the best for the future!