Characterization of electromethanogenesis for optimal energy storage

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. The challenge in the EmSpe project is to research a new microbial technology for the development of a storage system for renewable energies in the form of methane, electromethanogenesis. In contrast to other PtG concepts with methane as a product, this consists of a single-stage system. Within a reactor, electricity-based methane is produced by applying a voltage and adding carbon dioxide and with the help of special microorganisms. In contrast to other processes that produce methane from electricity, electromethanogenesis does not require separate electrolysis for the production of hydrogen and the associated additional system components. The direct absorption of electrons or the hydrogen formed on site at the cathode also avoids the very poor solubility of hydrogen in aqueous systems.

The exact processes involved in converting electrical energy into methane are not yet fully understood. It is still unclear whether electromethanogenesis involves direct electron uptake by the microorganisms or whether the transfer takes place via the intermediate product hydrogen.  The EmSpe project aims to contribute to answering this question. It will identify reaction conditions (e.g. pH, temperature and various pressures) under which the production of bio natural gas from electricity and carbon dioxide is possible. EmSpe thus closes a gap in the understanding of electromethanogenesis and, if successfully implemented, provides a further basis for future energy storage with the simultaneous use of exhaust gases containing carbon dioxide. Electromethanogenesis can contribute to the sustainable production of fossil-free biogas.

Federal Ministry of Education and Research
CC4E - Competence Center for Renewable Energies and Energy Efficiency