GAMES – Gas Diffusion Electrodes for Coupled Microbial Electrochemical Syntheses
Electrochemistry with Biotechnology
The increasing share of renewable energies in the overall energy mix affords the storage of temporary energy or local energy surpluses. Aside from battery technology as a storage possibility, electrochemical synthesis is a further technological option for storage and direct usage. An electrochemical synthesis transforms electrical energy into chemical energy and, thus, enables safe and manageable storage and the use for the synthesis of chemicals. However, using CO2 as a raw material for electrochemical synthesis only allows a very limited spectrum of possible products. For the most part, only C1-compounds can be obtained through a high selectivity and electron efficiency. In turn, the pure biosynthesis from CO2 needs an external energy source, for instance, H2. In order to enable a value-added synthesis based on CO2, “GAMES” examines the development of exemplary processes for a coupled electrochemical-microbial synthesis. In a first step, CO2 is reduced to formiat at a gas diffusion electrode. This formiat is then or in situ transformed biotechnologically into industrially relevant recyclable materials.
Extension of the Process Window
In the project “GAMES”, five partners jointly work on the industrial implementation of CO2 via the intermediate formiat to recyclable materials such as methane, the biopolymer polyhydroxy butyric acid (PHB), isopropanol, and ectoine. Based on the applicants’ previous work, electrochemical, microbiological, biotechnological, and process technological aspects are combined to develop new synthesis routes for technically relevant chemicals. The research work is targeted to extend the process window of microbial electrosynthesis, the development of biocompatible drop-in electrolyses, the construction and evaluation of a broadly applicable electrolysis reactor, as well as the practical operation of the systems. By extending the process window in the direction of higher temperatures and/or higher salt contents, ideally electrochemical target valuesand bioprocessing aspects, for example, can be addressed. The higher salt contents result in higher conductivities, which positively
effect the energy efficiency of processes. Higher temperatures usually result in higher electrochemical turnover rates. From a biotechnological point of view, it is expected that this results in less challenges with regard to contamination safety.
Diverse Processes and Products
By the cooperation of the SME Gaskatel GmbH, ifn Forschungs- und Technologiezentrum GmbH, and three application-oriented research organizations (DECHEMA-Research institute Helmholtz-Zentrum für Umweltforschung GmbH – UFZ, and Technical University Mittelhessen-University of Applied Sciences), innovative solutions for the transformation of CO2 into bio-based products of the chemical industry will be developed in the course of the project GAMES. Among the desired project results are particularly:particularly:
• the development of a universal test rig,
• new gas diffusion electrodes for the transformation of CO2 into formiat in biological media,
• new processes and reactors for the production of bio-based chemicals,
• use of CO2 and electrical energy as cheap substrates for fermentations,
• new added value for biogas plant operators, as well as
• the continuous extension of the process window of microbial electrosynthesis for the production of
biopolymers and basic chemicals.
Prof.-Dr.-Ing. Dirk Holtmann
Karlsruher Institut für Technologie (KIT)
Institut für Bio- und Lebensmitteltechnik
Telefon: 0721/608 - 421 31