Background Transport is one of the main causes of diffuse greenhouse gas (GHG) emissions, established by the Kyoto Protocol, with about one third of anthropogenic emissions. The study of new technologies to mitigate emissions from the transport sector is of high strategic value to achieving the objectives of the European Union, within the framework of international protocols to combat climate change. New technologies promoting biomethane production will significantly contribute to improve air quality, especially in densely populated areas, as CO2 emissions of vehicles fuelled by biomethane are lower than emissions from vehicles fuelled by gasoline, and NOx emissions are considerably reduced compared to diesel engines. Objectives LIFE METHAmorphosis aims to change waste management usage, reduce energy consumption and produce high quality biomethane as a vehicle fuel thereby mitigating climate change and promoting sustainable mobility. It proposes to demonstrate at industrial-scale level, two innovative waste treatment systems: the UMBRELA system in urban waste plants, which combines a new anaerobic membrane process (AnMBR) with autotrophic nitrogen removal (Annamox ELAN®); and the METHAGRO system in agro-industrial and other organic waste treatment plants (for mainly slurry), which is a high efficiency system that combines pre-treatment processes. Both plants will be built, commissioned and operated. The aim is initially to monitor the quality of products or effluents obtained, and the optimal configuration of the operating systems for obtaining a high-quality product at the lowest energy and environmental costs. This will be targeted at improving the profitability of treatment plants. This will enable and encourage the reopening of many currently closed plants, thus producing a multiplier effect with significant environmental impact at European level. Moreover, the suitability of the use of the renewable biomethane derived by the waste streams will be tested in the automotive sector, in different vehicles, light and heavy, from an economic, regulatory, environmental and technical point of view. Expected results: The expected results from the innovative systems developed and tested for the treatment of urban effluents, based on the combination of AnMBR and ELAN technology and the recovery of agro-industrial waste (mainly slurry) will show: High efficiency and low pollution, thanks to a predicted 70% reduction in energy demand required in the process and an 80% reduction in CO2 emissions compared with existing systems; Increased production of biogas; Production and recovery of nitrogen; Increased profitability by obtaining products with high added value such as biomethane with more than 80% ofCH4 concentration; and Increased quality of the treated water, which can be reused. With the demonstration and implementation of the use of biomethane as transport fuel, the following results will be achieved: A reduction of 80% in CO2 emissions in the global balance, i.e. ‘well-to-wheel’ (WtW), compared to compressed natural gas (CNG) currently marketed; Reduction of GHG emissions; Up to 20.17 kT (kilotonne) of CO2 emissions avoided by the use of CNG in vehicles, as well as an annual reduction of particulate emissions of about 6.21 kg per vehicle, due to the METHAGRO system activity; Partial compliance with the objectives of the Spanish Energy Efficiency and Renewable Energy plans for 2011-2020, the Energy Efficiency Directive (2012/27/EU) and EU objectives in promoting biofuels.