Project promoted by Seat turns organic waste into biofuel

There is a new way to drive engines, and it begins in the household rubbish bin.

This is the aim of the Life Methamorphosis project: to achieve biomethane from organic waste, turning it into renewable gas in five steps.

Each inhabitant of the city of Barcelona generates about 1.5 kilos of waste daily. 2.5 million kilos of rubbish every day of which only 40% is recycled. “With all the organic waste that is generated we can produce enough biomethane to power 10,000 cars to travel around 15,000 kilometres every year”, points out Andrew Shepherd, the Seat engineer who heads the Methamorphosis project. Of all the rubbish collected at the Ecoparc 2 in Barcelona, biomethane is produced using the organic waste from the brown containers and whatever is useful from the grey containers. All of this raw material will be turned into biofuel.

The transformation process begins once all the organic waste is selected onsite at the Ecoparc and fed into 26-metre tall anaerobic digesters, the same height s an 8-storey building, each with a capacity of 4,500 cubic metres. As there is no oxygen in the digesters, a decomposition process begins which generates gases. About 30 days later, biogas with 65% methane is produced.

“This biogas still lacks the sufficient quality to power a Seat gas engine, so it has to be refined”, explained Shepherd. Furthermore, everything is put to use, as the organic waste that is not turned into biogas is used as fertilizer.

At this point, the mixture contains methane and carbon dioxide, but it requires refining to obtain a high enough quality for cars. The Seat engineer points out, “One of the greatest efforts we are making with our project is to ensure that the gas is of the highest quality. At the end of the study, we'll test the impact of the exclusive use of our biomethane on the engines of the four vehicles we're testing”. Following this refining stage, the gas is compressed and stored.

The biomethane is now ready for use in any gas powered vehicle. Refuelling at the project's gas station takes less than three minutes. “This biomethane can be injected into the gas supply network. They have the same chemical composition, so it can be used directly or mixed with conventional gas”, said Shepherd.

Although the Methamorphosis pilot project generates enough biomethane to fuel the four vehicles used in the test, the Ecoparc 2 has the potential to produce much more. If all the biogas at the Ecoparc 2 were refined into biomethane, 3,750 Seat Leon cars could drive around the world every year.

“We're tackling very important issues today with this renewable gas, such as contributing to the circular economy, and reducing waste and greenhouse gases, as its production and use generates 80% fewer CO2 emissions than petrol”, concluded Shepherd.

There are currently three Seat Leon and one Arona working with this biomethane to test its effect on their engines after being driven a minimum of 30,000 kilometres each.

The Life Metamorphosis project aims to mitigate climate change thanks to the use of biomethane from waste treatment plants as vehicular fuel. In addition to Seat, other businesses participating in the project include Aqualia, FCC, Naturgy, Área Metropolitana de Barcelona (AMB) and the Institut Català d'Energia (ICAEN).