(German title: BERBION: Die Stadt der Zukunft − Eine bedarfsangepasste ZERO-WASTE-Bioraffinerie)

The "BERBION project" is a long-term, innovative joint project, which is being carried out by 13 partners from science, business and the public sector over a period of 5 years and is being funded by the Federal Ministry of Education and Research. The results of the project are to be implemented in a specific case study - the Hamburg district of Bergedorf - once the project has been completed. The main objective here is to maximise the energy use of biomass produced in the city with minimal energy input. To this end, a holistic approach is to be developed that takes into account all the main municipal bioresources, the various bioconversion methods that can be used to generate energy, the demand for different energy sources and the material utilisation of the residues resulting from bioconversion. For the first time, the entire range of municipal biomass fractions that have not yet been utilised or have only been insufficiently utilised for energy generation (biowaste from households and gardens, from public areas, from industry and commerce, residual waste, wastewater and sewage sludge) will be considered. Different processes for the provision of energy (for the production of methane, hydrogen and ethanol) and their final utilisation in the form of electricity, heat and fuel are to be compared with each other and with conventional processes and also further developed. Efficient bioconversion is to be achieved in a fraction-adapted manner using different digestion methods (mechanical, physical, chemical, biological). Based on a detailed inventory of the bioresource streams, their nature and their intended utilisation options, collection and transport concepts will be developed and investigated. Methods such as life cycle assessment, cost-benefit analysis, evaluation of climate protection potentials, user-friendliness and short, medium and long-term feasibility, taking into account technical and management aspects, will be used to evaluate the individual utilisation options.

As part of the "BERBION" project, the Department of Bioprocess Engineering is investigating the biotechnological conversion of various waste fractions. These can be very inhomogeneous and complex in their composition, which is why it is necessary to determine the best possible process variant. Some of the resulting fractions are, for example, green waste (grass) and wooden waste containing lignocellulose, which can be converted by bioconversion. For other fractions, such as mixed samples from organic waste bins, it still needs to be clarified whether and to what extent the substances they contain are suitable for biotechnological conversion and how they can be used. The focus of the work carried out at the Department of Bioprocess Engineering is on the enzymatic conversion of the substrates to the corresponding sugar monomers and the fermentation of these to ethanol or other value-enhanced products. The development of these process steps is closely linked to the investigation of suitable pre-treatment methods (e.g. vapour pressure treatment of wooden substrates) and possible post-treatment steps (e.g. biogas production from fermentation residues), which are being worked on by the project partners. This results in synergies with other projects in the department (silage project, lignocellulose biorefinery. Furthermore, the Department of Bioprocess Engineering makes its extensive analytical methods available to the project partners.