HAW-Hamburg: Research projects

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The International Energy Agency (IEA) assumes that the demand for electrical storage capacity will increase by a factor of around 50 by 2040. Power-to-gas (PtG) concepts are promising approaches for this. In the project EmSpe, a new microbial technology for the development of a storage system for renewable energies in the form of methane was explored: electromethanogenesis. In contrast to other PtG concepts with methane as a product, it consists of a single-stage system. Electricity-based methane is produced within a reactor by applying a voltage and adding carbon dioxide with the help of special microorganisms. In contrast to other processes that produce methane from electricity, electromethanogenesis does not require separate electrolysis and the associated additional system components for the production of hydrogen. By directly absorbing electrons or the hydrogen formed on site at the cathode, the very poor solubility of hydrogen in aqueous systems can moreover be circumvented.

The exact processes involved in converting electrical energy into methane have not yet been fully explored. It is still unclear whether electromethanogenesis involves direct electron absorption by the microorganisms or whether the transfer takes place via the intermediate product hydrogen.

Results

The project EmSpe identified reaction conditions (e.g. pH, temperature and different pressures) under which the production of biomethane from electricity and carbon dioxide is possible. The research results show that hydrogen is required as an intermediate product in electromethanogenesis and that direct conversion of electricity to methane does not takt place on a relevant scale. EmSpe thereby closes a gap in the understanding of electromethanogenesis and provides a further basis for future energy storage with simultaneous utilisation of exhaust gases containing carbon dioxide.

Project Team:

Benjamin Rößler , Dr. Sandra Off

Project Leader

Prof. Dr. Hans Schäfers

Duration

04/2022 - 08/2024

Budget

206.200 €

Funding

Federal Ministry of Education and Research

Unit

CC4E - Competence Center for Renewable Energies and Energy Efficiency

Contact

Prof. Dr. Hans Schäfers

Professor für intelligente Energiesysteme und Energieeffizienz

Department of Environmental Engineering

Leiter CC4E

Competence Center Erneuerbare Energien und Energieeffizienz

T +49 40 428 75-5895

hans.schaefers (at) haw-hamburg (dot) de