Background Bio-energy, including biogas, can contribute to meeting the EU’s ambitious "3 x 20%" objectives: 1) to reduce greenhouse gas emissions by 20%; 2) to reduce energy use by 20%; and 3) to achieve 20% renewable energy in the overall energy supply. Bio-energy can contribute to implementation of the EU Directive on the promotion of the use of energy from renewable sources (2009/28/EC). However, the development of biogas production is very different from one Member State to another and can be hampered by obstacles such as cost and technical and health risks. One area of interest is the production of biogas from wastewater treatment plants (WWTPs). Biogas generated by a WWTP contains three types of products: bio-methane (bio-CH4), bio-carbon-dioxide (bio-CO2) and a complex mix of minor elements (such as oxygen or nitrogen), biological elements (bacteria, viruses) and chemical molecules (e.g. aromatic hydrocarbons). Unlike landfill biogas, WWTP biogas is perennial, by nature relatively rich in methane and is available close to the existing territorial systems provided by industrial zones and the fuel and gas distribution infrastructure. Some of the beneficiary’s WWTPs – including the demonstration site - already have digesters and produce biogas that is re-used internally, particularly by cogeneration (combined heat and power). Objectives The Biovalsan project aims to demonstrate how the biogas produced by a WWTP can be separated for re-use of its components to enhance the energy efficiency of the plant, reduce greenhouse gas emissions and develop circular economic chains. The project will separate the bio-CH4 and bio-CO2 components from the rest of the complex biogas mixture generated by the beneficiary’s treatment plant in Strasbourg. It will use cryogenic distillation technology, which it will optimise during project implementation. It expects to demonstrate the technical reliability of the process with nominal biogas input capacity of 300-400 Nm3/hr. It will aim to define control procedures for each component to assist European standardisation. It will draw up specifications for putting bio-CH4 into the gas network and evaluate the health risks of all the components. It will establish a database of the hazardous substances, biological viruses and bacteria species. The project expects to demonstrate the cost-effectiveness and environmental benefits of the process from the re-use of each component: For bio-CH4, a combustible gas, the aim is to put it into the natural gas distribution network; For bio-CO2, which can be a gas, liquid or solid (dry ice), potential applications are to be investigated within the project; and For the complex mixture, the project team intends to use it in internal sludge thermal treatment (combustion), partly because of its high calorific value but mostly because combustion would be an efficient and reliable way to destroy the contaminants contained in the mixture. Expected results: Best operating conditions identified for optimum separation of biogas constituents using a cryogenic distillation industrial unit; More than 75% of the raw biogas flow recovered for external re-use; The feasibility of putting recovered bio-CH4 into the gas network demonstrated and 10 new parameters for doing so defined; Viable applications for bio-CO2 identified; More than 60% of renewable energy and heat recovered from sludge combustion incorporated in the WWTP; Target energy production capacity of 20 Gwh/yr; Overall reduction in CO2 emissions of 6 000 tonnes/yr; and The economic feasibility of the process demonstrated.