Conversion

In addition to the production of hydrogen by water electrolysis and steam reforming of biogas, the Institute of Plant and Process Technology is focusing on the conversion of hydrogen to various hydrogen derivatives. In particular, the ammonia and methanol processes are investigated through process simulations. One of the primary objectives of this research is to develop design and operational strategies for the flexible operation of ammonia plants. Moreover, material and heat integration potentials within the overall process chain of e-methanol production are identified and assessed. To investigate different operation strategies and the flexibility of an e-methanol process, a digital twin is developed for a methanol plant at a container scale.

Website: Research at APT 
Contact: Sebastian Rehfeldt

Series production and industrialization of integrated & sector-coupled electrolysis systems for water

The market scale-up of the production of green hydrogen and its derivatives, as well as hydrogen application technologies, is intended to be further accelerated according to the continuation of the German National Hydrogen Strategy. In Germany, at least 10 gigawatts of electrolysis capacity for green hydrogen production should be installed by 2030. This ambitious goal necessitates a significant upscaling of electrolysis technology, a challenge addressed in the flagship project H₂Giga. Through mass production of electrolysis stacks and increased electrolysis plant capacities, investment costs can be reduced, which enhances the economic viability compared to conventional processes and later, in particular, impacts the hydrogen production costs in dynamic operation with reduced operating hours. Lower investment costs are also expected to open up new markets and facilitate the utilization of hydrogen in additional sectors.

The Institute of Plant and Process Technology is investigating the material and thermal process integration of green hydrogen produced through electrolysis into chemical production processes such as ammonia or methanol. At present, the focus is on the flexibilization of ammonia plants to enable an increasingly dynamic operation. Ultimately, integration possibilities and design parameters for electrolyzers are being identified to develop a requirement catalogue for the optimal integration of various downstream processes with water electrolysis. Additionally, additive manufacturing possibilities in the periphery of electrolysis plants are being explored.

To improve the theoretical models of PEM electrolysis, they are continuously updated according to the latest findings from the literature. However, literature datasets are often incomplete or significantly deviate from each other. To understand these variations and obtain experimental results at the stack level rather than the cell level, a 10 kW PEM electrolysis test rig is built within the project. The focus of the test rig is the investigation of undesired gas crossover of the product gases through the membrane under different operating conditions.

Development of a Power-to-Methanol Process

Site-specific solutions are required for essential chemical sites in Germany, such as Burghausen/ChemDelta Bavaria, to achieve climate neutrality in the future while remaining economically viable. In the H2-Reallabor project, container concepts, so-called living labs, are developed to investigate possible solutions and increase their technical readiness level. The container solutions are constructed and measurements are conducted location-independently and later tested under real conditions in an industrial environment.

The direct conversion of hydrogen from electrolysis and carbon dioxide to methanol (power-to-methanol) is investigated in one of several containers. The carbon dioxide is captured in another container, which will be carried out in an industrial environment from the flue gas of a residue incineration plant. As part of the project, the Institute of Plant and Process Technology is working on the development and scaling of the digital twin of the power-to-methanol plant. In addition, various possibilities for the material and heat integration of PEM electrolyzers for hydrogen production and methanol synthesis are evaluated and requirements for PEM electrolyzers for optimal integration are derived. In the preceding carbon capture container, the institute is also investigating the selection and design of the absorber and desorber columns of an amine wash process.

The focus of research in the area of conversion at the LES is divided into two parts:

On the one hand, high-temperature solid oxide cell systems are being developed and investigated. The research focuses on reversible operation (fuel cell and electrolysis) with carbon-containing gases (biogas, synthesis gas, etc.) in order to utilize the advantages of the system for efficient and system-beneficial application in the energy system.

On the other hand, the synthesis of methane is being researched. For this purpose, various reactor concepts for different process configurations (CO2-PtX, biomass gasification with electricity integration, innovative biogas conversion) are examined and optimized. The work takes place both simulatively and experimentally.

Website: Research at LES
Contact: Florian Kerscher, Sebastian Fendt

The SWW is researching the microbiological methanation of hydrogen and carbon dioxide in a trickle bed reactor under thermophilic conditions. As the end product, CH₄ should be as pure as possible.
The goal is to develop a simple and robust system for decentralized operation e.g. on wastewater treatment plants in order to use their existing infrastructure (gas storage, CHP, etc.) for energy storage. The gas-tight but pressureless system is inoculated with digestate from the digester of sewage or biogas plants.

Website: Research at SWW
Contact: Prof. Dr.-Ing. habil. Konrad Koch

Microbiological methanation - Transition to commercial application

The research at the Chair I of Technical Chemistry in the area of PtX focuses on the structural and kinetic characterization of catalysts for the hydrogenation of carbon oxides. In order to understand and to improve the hydrogenation catalysts in terms of their catalytic properties, comprehensive basic research on structure-activity relationships is necessary.

The hydrogenation reactions in the PtX processes are generally characterized by their high heat of reaction. Therefore, the kinetic description of product formation rates and, based thereon, application-related reactor modeling studies are of special interest.

Furthermore, CO_x streams are also often contaminated with traces of sulfur. For this reason, the investigation and description of deactivation processes caused by poisoning phenomena or by sintering due to the high thermal stress are further aspects that are addressed at the Chair I of Technical Chemistry. In order to understand hydrogenation catalysts in terms of their catalytic properties, comprehensive information on structure-activity relationships are indispensible.

At the Chair I of Technical Chemistry we pursue the approach to characterize interesting catalyst systems by means of static and transient analysis methods in different states, and thus to establish relationships between structural and morphological changes of the catalyst under reaction conditions and intrinsic activity. Based on these findings, existing catalysts can be further improved. Key approaches therein are the application of different catalyst preparation methods and the addition of promoters to the catalyst.
Knowledge of the reaction kinetics is essential for the design of chemical reactors in order to predict product and heat production rates. For this purpose, we use kinetic test stands to carry out measurements under conditions free from heat and mass transport limitations. The kinetic description is accomplished by parameter estimation of mechanistic approaches with the help of simulation software.

Website: Research at TC1
Contact: Tabea Gros

The implementation of electrochemical Power-to-X (PtX) processes is seen as an essential step towards decarbonization of the mobility and chemical sector. However, these technologies are at least CO₂ neutral or even consuming only if sustainable wind and solar power is available. During the so-called "dark ages" when neither wind is blowing nor the sun is shining, PtX processes, on the other hand, have to operate or shut down 81% of their operations with electricity generated from fossil fuels or nuclear energy.

The Werner Siemens Chair of Synthetic Biotechnology (WSSB) is therefore working on new plant concepts that enable continuous operation of PtX processes through synergistic integration of biotechnological processes. In this context, WSSB has had initial success with the algae-mediated conversion of CO₂ and biogenic H₂ into high-energy aviation fuels. In this field, WSSB has been cooperating with the Chair of Biochemical Engineering (Prof. Dr.-Ing. Weuster-Botz) for many years. In the future, this technology is to be supplemented by synergistic processes such as syngas fermentation. The latter process biotechnologically converts CO₂ and "green" hydrogen into low-molecular substances (e.g. ethanol, acetic acid), which, however, are not suitable for modern, high-energy fuel solutions. Therefore, syngas products need to be refined in a further biocatalytic step, such as the conversion of acetic acid into yeast oil, which was developed by WSSB, for the subsequent synthesis of biodiesel.

In this field, WSSB is globally visible and uses synergies with the chairs of Technical Chemistry I (Prof. Dr.-Ing. Hinrichsen) and II (Prof. Dr. Lercher) or Bioprocess Engineering. In order to avoid this refinement step in the future, WSSB is working on the identification of new, extremophilic cell factories that convert syngas directly into high-energy products.

Website: Research at WSSB
Contact: Prof. Dr. Thomas Brück

The SWW is researching the microbiological methanation of hydrogen and carbon dioxide in a trickle bed reactor under thermophilic conditions. As the end product, CH₄ should be as pure as possible.
The goal is to develop a simple and robust system for decentralized operation e.g. on wastewater treatment plants in order to use their existing infrastructure (gas storage, CHP, etc.) for energy storage. The gas-tight but pressureless system is inoculated with digestate from the digester of sewage or biogas plants.

Website: Research at SWW
Contact: Prof. Dr.-Ing. habil. Konrad Koch

Microbiological methanation - Transition to commercial application