Bioenergy from biogas makes an important contribution to the energy transition: it is renewable, storable, and flexibly applicable – regardless of weather or time of day. The THMresearch project RegBioFerm, which the project team presented as part of the final lecture series of the 2025/26 winter semester, is investigating how the potential of biogas can be optimally utilized.
The project aims to utilize organic waste regionally for both material and energy recovery, thereby establishing a value chain. RegBioFerm is funded by the Federal Ministry for Economic Affairs and Energy (BMWi) with approximately €1.2 million. Initial research on the topic was conducted in 2012.
“Everyone produces this substrate every day: organic waste, such as kitchen scraps,” said Prof. Dr. Harald Weigand, spokesperson for the Competence Center for Sustainable Engineering and Environmental Systems (ZEuUS) and one of the project leaders, in his opening remarks. The project involves fermenting organic waste, producing biogas that can then be used as energy – for example, in combined heat and power plants. The remaining digestate is then composted and used as fertilizer. Environmental engineer Dr. Felix Brück cited the diverse composition of the substrate as one of the biggest challenges in biogas production. This is precisely where RegBioFerm comes in: The project team is developing a rotating fermenter, a so-called fermentation drum. “The fermenter is designed to make the process more efficient and to utilize organic waste more effectively,” he explained. The movement of the fermenter mixes the substrate more thoroughly with minimal energy input. This, in turn, has a positive effect on gas production.
In Germany, only a portion of the generated organic waste is currently used for energy production in biogas plants. A significant portion of this potential therefore remains untapped, even though large quantities of renewable energy could be generated from it.
RegBioFerm is divided into three areas: laboratory and model experiments, a life cycle assessment to evaluate environmental impacts, and the construction of a plant on a small industrial scale with the practical partner Brunnenhof, a waste management company from Biebesheim.
Daniel Krahe, a research associate in the project and THMgraduate, presented the results of the laboratory experiments. These showed that approximately 210 to 260 liters of methane can be produced per kilogram of organic waste. He emphasized that the process will be further optimized.
The project's life cycle assessment was presented by research assistant Hannah-Sophie Tscherney: "Against the backdrop of the energy transition and the goal of achieving climate targets, the project makes a contribution to the circular economy."
Speaking on behalf of the partner company Brunnenhof, which is currently building the rotary fermenter on a small industrial scale, Managing Director Steffen Geipert emphasized: "The goal is to use the generated biogas for energy production and to supply the digestate to our customers as compost." These customers are primarily fruit and vegetable farmers. In the long term, the aim is to provide customers not only with compost, but also with heat and energy directly on-site – generated from their own organic waste.
Prof. Theilen, also a project leader, highlighted the advantage of biogas over other renewable energy sources: its role during periods of low wind and solar output – when neither the sun is shining nor the wind is blowing. At the same time, it contributes to the circular economy. This is because organic waste is not disposed of, but rather, in the case of fermentation, used to generate energy.