Valoriza Agua has developed an innovative project, known as Smart-Met-Value, the aim of which is to obtain biofuel for vehicular use by transforming biogas production waste into energy.
The adjective “renewable” has reached energy like natural gas, which represents 20% of the primary energy consumed in Spain.
Producing renewable gas contributes to reducing our society's dependency on energy from abroad and minimising its environmental impact. These two aims guide the actions of the member states of the European Union and are behind the idea out of which was born the Smart-Met-Value research project, a project developed by Valoriza Agua at the waste water treatment plant (WWTP) in Guadalajara (Spain).
This project transforms the gas that results from treating waste and mud into renewable biofuel that can be used as fuel for vehicles. This initiative reduces the emission of greenhouse gases and makes the cost of fuel cheaper.
Smart-Met-Value collects the biogas generated in the anaerobic digestion processes at the plant in the Alcarria region and cleans it to obtain quality biomethane.
“In the market, we have six viable technologies to undertake the cleaning of this biogas originating in the digester, and trigger the separation of the desired methane from other gases, which are mainly nitrogen oxides, sulphydric acid and cyclohexanes”, explained Juan Pous de la Flor, Director of R&D&i Certificationes at Sacyr.
These technologies, stated Pous de la Flor, consume a large amount of energy and reagents, and so the cost of the gas obtained is much higher than that of natural gas. “Therefore, the product obtained is not cost-effective from the economic point of view”, he said.
The project led by Valoriza Agua develops alternative and innovative technology through which, via an initial physical-chemical process, the “methane gas is refined in a large proportion and the sulphydric acid and solid particles in suspension are eliminated”.
“The subsequent refining process eliminates the cyclic aromatics and humidity, leaving renewable natural gas of excellent use for combustion engines. The successive stages of the project have been to develop the infrastructure and logistics for collecting gas from the digesters, its innovative treatment and its availability in the form of a ‘gas station’ at our plants”, says Pous de la Flor.
The environmental benefits this technology contributes are many, as the use of this renewable natural gas in vehicles replaces fuels derived from oil, which pollute far more. The gas generated by the WWTP in Guadalajara supplies the plant's vehicles. The reduction in emissions of CO2 and other gases that affect human health is substantial: 40% less carbon dioxide enters the atmosphere and nitrous oxides are cut by more than 60%.
“The project has become a clear example of the circular economy, a predominant idea in the European Union, that consists of using the waste produced and the emissions from our industries within the production cycle to replace traditional fossil fuels”, maintained the Director of R&D&i Certifications.
At the current time, following the final inspection from the Centro para el Desarrollo Tecnológico e Industrial (CDTI, Centre for Technological and Industrial Development), the Guadalajara facility can refine three normal cubic metres of biogas an hour from the digesters, through which it is possible to fuel a two-vehicle inspection fleet for the company for its own use, which do around 100 km a day.
In addition, stemming from the results of the research, those in charge of the project have put forward, as part of the same project, a design for a new plant that is ten times larger, which would mean 30 normal cubic metres could be treated an hour and, therefore, the collection of renewable fuel for a fleet of waste collection trucks consisting of seven to nine units.
The project has received contributions from Fundación Gómez Pardo, belonging to the School of Mining and Energy Engineering of Universidad Politécnica de Madrid, and Universidad Alfonso X El Sabio. It has had a budget of 834,867 euros, obtaining financing from the CDTI, cofinanced by the European Regional Development Fund through the Multiregional Operational Programme for Intelligent Growth 2014-2020.