The industrial production of beer often generates large volumes of by-products that are not used optimally. The European project "CHEERS" aims to convert unused by-products and waste of beer production such as bagasse, wastewater, CO2 and CH4 into innovative bio-based products.Currently, bagasse is used for low-quality animal feed; in the future, insect protein could be produced. CO2 from beer fermentation is currently released into the atmosphere and could be used to produce caproic acid or hypochlorite. Biogas from wastewater and sewage sludge treatment is currently used for CHP plants, in the future this could be used in the process for the production of caproic acid, hypochlorite, ectoine or high-quality cell protein. This will create circular instead of linear production processes. The project is coordinated by Mahou San Miguel and involves project partners from Spain, Germany, and the UK. The total project budget is 7.5 million euros, the research group Life Cycle Assessment (LCA) is funded with 500 000 euros by the State Secretariat for Education, Research and Innovation (SERI). The research group LCA at the ZHAW has the lead of Work Package 6 and is working there with the Spanish companies ainia and Mahou San Miguel, as well as with Earthwatch from the UK. In this work package, a techno-economic analysis (TEA), a life cycle sustainability assessment (LCSA) and an economic feasibility analysis are carried out.The TEA assesses the economic feasibility of the processes and highlights the most important parameters for the implementation of business models. The results are assessed through cost estimates and a risk analysis to identify weaknesses.The LCSA brings together three analyses:

• A Social Life Cycle Assessment (S-LCA), which is conducted based on the UNEP-SETAC guidance document.
• A life cycle assessment (LCA), which assesses environmental impacts throughout the life cycle and evaluates greenhouse gas emissions, primary energy demand and resource scarcity, as well as impacts on biodiversity.
• A life cycle costing (LCC), which summarises all costs associated with the life cycle of the products, namely investment costs and operational expenses.

Finally, an economic feasibility analysis is carried out that includes three business sizes - small, medium, and large breweries - to assess the scaling of the technology and products. Based on this analysis and the LCA results, a sustainable business model is developed. The assessment of the research group LCA identifies the environmental hotspots of this new circular brewery and thereby helps to reduce the environmental impact of the new, innovative products.