We are looking for: • Recycling or by-product streams to integrate this process • Upscaling expertise • End users of the target products for the various application areas to obtain product specifications • Partners for the construction and operation of a pilot plant for 12 months, e.g., as a container solution The Helmholtz Centre for Environmental Research (UFZ) and the German Biomass Research Centre (DBFZ) have jointly developed a process for producing specialty chemicals from regional biomass. Based on an anaerobic fermentation process with mixed bacterial cultures, the complex biomass is microbially converted into the target products caproic and caprylic acid. In the subsequent downstream processing, the fatty acids are extracted from the fermentation broth and processed. These acids are used, for example, as additives in lubricants, cleaning agents, or animal feed, or can be further esterified in a subsequent step. Integrating the production process into existing biogas plants enables combined material and energy utilization of biomass, i.e., the production of biogas, fertilizer, and platform chemicals, thus increasing the flexibility of the biogas plant. By using inexpensive waste materials as feedstock for the production of basic chemicals, the process is environmentally friendly and resource-efficient. Additionally, it can also reduce disposal costs for organic waste. UFZ expertise: • Anaerobic fermentation processes • Efficient conversion of biomass to carboxylated platform chemicals or methane • Chain extension with lactic acid and ethanol, combination with syngas fermentation UFZ experts: Dr. Heike Sträuber, Dr. Flávio Baleeiro

Background: Electrobiotechnology combines the use of renewable electrical energy and bio-based resources, as well as CO2, for the sustainable synthesis of chemicals and fuels ("power-to-chemicals"). Advantages of this process over conventional (electrochemical) syntheses include potentially higher selectivities and yields. Challenge: Current reactor systems for bioelectrochemical syntheses are small-scale, home-built systems with minimal process control, making syntheses incomparable and preventing systematic process development toward commercially viable syntheses. To close the gap between research and application, standardization of microbial electrosyntheses and their comparability with conventional biosyntheses are essential. Innovation: This upgrade kit expands conventional bioreactors for use in microbial electrosynthesis. An open reaction chamber with an ion-selective membrane is placed inside the bioreactor and attached to the reactor lid. In addition to the usual connections for stirrers, measuring probes, aeration and degassing, etc., the lid contains additional openings for electrodes, each extending into the inner and outer reaction chambers, respectively, making the system suitable for bioelectrosynthesis. The upgrade kit also provides a basis for the development of a standardized electrobioreactor up to an industrial scale.

High energetic potential in wastewater • Currently, wastewater treatment in industrialized countries is an energy-intensive process. It is estimated that 20% of municipal electricity consumption in Germany is used for wastewater treatment (K. Fricke, Energy Efficiency of Municipal Wastewater Treatment Plants, Federal Environment Agency, Dessau-Roßlau, 2009). • At the same time, wastewater has a considerable energy content • Example calculation: sewage treatment plant size 4, 55000 PE (2.5 million m3 wastewater annually), if only domestic wastewater is used, 450 MWh per year would be possible (at only 10% efficiency) The UFZ approach - bioelectrochemistry