Bavarian Center for Sustainable Fuels ZENK

Challenges

Since the Paris Climate Agreement, activities and measures towards renewable energy generation have been intensified worldwide. The European Union's Green Deal is also a milestone with regard to a sustainable energy supply and aims to make Europe the first continent to achieve climate neutrality.

Particular attention is being paid to the area of ​​mobility, as this sector presents unique framework conditions concerning the substitution of fossil fuels and the diversity of required modes of transportation.

At the federal level, achieving the German government's climate targets appears possible only if existing measures for generating renewable energy are utilized while simultaneously pursuing further developments. In light of the current global political situation, reducing dependence in the energy and mobility sectors is also a priority. To strengthen Bavaria's pioneering role in this area, the Bavarian Center for Sustainable Fuels (ZENK) will continue existing developments and promote new ones.

Objectives

The central goal of the Bavarian Center for Sustainable Fuels (ZENK) is the development of production routes for sustainable fuels based on renewable raw materials and energy.

To this end, a holistic refinery approach is pursued, linking individual process steps (from primary raw material conversion to the separation of product mixtures into fuel fractions) and combining various production routes to reduce CO₂ emissions and, through the use of carbon sinks, even achieve a CO₂-negative balance. A schematic representation of the ZENK overall concept is shown in the figure below.

The processes utilize biogenic residues, carbon dioxide (CO₂), and renewable electrical energy as raw materials, with a particular focus on input materials available in Bavaria (and specifically in the Straubing and Sulzbach-Rosenberg region). Regional application perspectives play a key role in the utilization of the produced fuels, for example, in the areas of agricultural and forestry machinery, inland navigation, commercial aviation, and heavy-duty transport.

The innovative approaches to be developed as components of an integrated sustainable refinery are largely based on processes already investigated or implemented at the Fraunhofer Institutes IGB and UMSICHT (with their locations in Straubing and Sulzbach-Rosenberg). These processes will be further developed, combined, integrated, and deployed on a pilot plant scale within the ZENK project.

At the Straubing site, the focus is on establishing a research infrastructure based on CO₂ and renewable H₂ (or synthesis gases from renewable sources) for the production of synthetic fuels. The synthesis route involves the intermediate steps of methanol synthesis, alcohol dehydration—such as methanol-to-hydrocarbons (MtH) or ethanol dehydration—and oligomerization, followed by the subsequent hydrogenation of (light) hydrocarbons.

The ZENK platform's research strand begins in the chemical-technical laboratory with the investigation of microkinetics, catalyst activity, and the use of raw materials from real (industrial) sources. This is followed by initial scaling in the laboratory, during which scaling effects such as temperature profiles and real catalyst fillings are understood.

Finally, the heterogeneously catalyzed processes are transferred to the ZENK pilot plant at the new Straubing-Sand facility, which provides pre-industrial data for process control on a kilogram-per-hour production scale. In 2025, the creation of the laboratory infrastructure was largely complete and the basic engineering of the free-standing pilot plant, including the HAZOP study, had been finalized.