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Acto inauguración LIFE NIMBUS
Representatives of the LIFE NIMBUS partners in front of the bus powered by biomethane generated from treatment plant sludge.

The European LIFE NIMBUS project opens its plant for the production of biomethane from treatment plant sludge

· This initiative, led by Cetaqua, Water Technology Centre, promotes the circular economy and proposes a green energy and transportation model in the metropolitan area of Barcelona that uses biomethane generated from treatment plant sludge to power a bus.

· Aigües de Barcelona, Transports Metropolitans de Barcelona (TMB) and the Universitat Autònoma de Barcelona (UAB) are participating in the project, which has just begun pilot-scale testing to validate the technologies.

The consortium of the LIFE NIMBUS European project today celebrated the start-up of the plant to produce biomethane from treatment plant sludge, which will power a public bus in the metropolitan area of Barcelona. The bus, part of the Transports Metropolitans de Barcelona (TMB) fleet, will be the first to run on biomethane obtained from wastewater sludge, reducing its carbon footprint by over 85% thanks to the use of a renewable high-quality, emission-neutral fuel.

The transport sector consumes about 30% of total energy in Europe. However, less than 10% of the fuels used are renewable. In the light if this situation, the European Union aims to raise this figure to over 30% by 2030. LIFE NIMBUS, a research project co-funded by the European Commission as part of the LIFE programme, aims to promote more sustainable transport through the circular economy. The initiative is aligned with the Biogas Roadmap, approved in Spain in 2022, which identifies the challenges and opportunities for developing this renewable gas and aims to increase national production four- fold by 2030.

During the opening ceremony, emphasis was placed on the importance of research and cooperation between the public and private sectors to provide solutions to decarbonise transportation. In this regard, Aigües de Barcelona’s CEO, Rubén Ruiz, insisted on the “need to promote innovation through alliances and public-private partnerships to meet the main challenges arising from the climate emergency.” “Waste recovery projects to promote sustainable mobility in cities are necessary for an ecological transformation in our environment and are a clear example of our commitment to a model that respects the environment, based on the circular economy and sustainable development,” he added. For his part, Cetaqua’s General Manager, Carlos Montero, stressed the “importance of involving the end user in the project from the ideation phase and ensuring they are given follow-up and are involved in its development.” By doing so, he added, “we are able to streamline the results transfer.”

Universitat Autònoma de Barcelona’s rector, Javier Lafuente, highlighted how the start-up of the plant is a “good example of transferring knowledge generated in the laboratories for the improvement of society, one of the missions of the University. UAB is involved in the production of biomethane from hydrogen using biological systems, which are much more sustainable than conventional ones. In addition, the project demonstrates pilot-scale bioelectrochemical production of hydrogen from wastewater for the first time, with very encouraging results from the laboratory. This technology fits perfectly with the current paradigm shift, whereby water treatment must become an opportunity to recover resources, in terms of both materials and energy.”

The CEO of TMB, Gerardo Lertxundi, thanked the entire TMB team for making this project possible, stressing that “it is a sustainable circular economy project to which TMB is fully committed.“ He said, “It is a strategic project for TMB and we hope it will continue in order to be able to achieve large-scale biomethane use.”

A boost to ecofactories to promote the circular economy

LIFE NIMBUS has led to the design and construction of a demo biological methanation plant at the El Baix Llobregat ecofactory, managed by Aigües de Barcelona. This initiative is another example of Agbar’s commitment to innovation and sustainability, which promotes the ecofactory concept as a solution to promote the circular economy and reduce environmental impact.

The ecofactory converts the traditional wastewater treatment plant (WWTP) into a facility that generates valuable resources. In this case, the treatment plant sludge will be used as a fuel gas to boost green transport in the metropolitan area of Barcelona, helping the city to move towards the proposed climate neutrality by 2050.

“This initiative tests various technologies, focusing on the production of biomethane, a high-quality, renewable fuel. In addition, LIFE NIMBUS promotes power-to-gas technology to store surplus renewable energies. The project framework only considers the operation of a biomethane-powered bus, but operations could be scaled up to a larger volume, depending on the results obtained,” stated Oriol Casal, project manager of the LIFE NIMBUS project at Cetaqua.

An example of public-private partnerships for more sustainable urban transport

This project, whose acronym stands for Non-IMpact BUS and which proposes a green energy and transport model for Barcelona, is headed by Cetaqua, Water Technology Centre, with the participation of Aigües de Barcelona, the El Baix Llobregat WWTP management company, Transports Metropolitans de Barcelona (TMB), which has provided a bus from its fleet with a daily route of 100 km, and the Universitat Autònoma de Barcelona (UAB) GENOCOV research group, which designed, constructed and developed the bioelectrochemical technology (BES), facilitating more efficient hydrogen production, using less electricity. The project is also supported by the Barcelona Metropolitan Area (AMB).

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