In Spain, the city of Seville is preparing to run its buses on orange juice

The city of Seville, capital of Andalusia, in the south of the country, is preparing to run its buses… with orange juice. The information sounds like an April Fool’s joke, but the matter is very serious. Let’s start at the beginning: Seville has some 40,000 orange trees, which are fragrant when they bloom and delight tourists in the city. Only, no luck, they produce oranges unsuitable for consumption: too bitter and perhaps also too polluted.

Also, each year, the town hall of Seville gets rid of 4,000 tons of oranges as best it can. A symbolic part is used in perfumery, a very small portion in marmalades, while the rest ends up in the recycling center. This could change, because for the past three years, a purification station has been transforming them into gas, for the moment on an experimental basis.

Biogas from sludge and oranges

“These oranges, we grind them, we obtain the orange juice which we subject to a digestion process called anaerobic: you have to imagine a giant stomach!explains Benigno López Villa, head of the environmental department of Emaesa, the municipal water company of Seville. We add the sludge from the treatment plant and we obtain a biogas very rich in methane.”

“We use this gas as fuel to power an engine which transforms it into electrical energy and this energy thus obtained is used to run the treatment plant.”

Benigno Lopez Villa

at franceinfo

It is therefore the mixture of sludge and oranges that makes it possible to produce biogas. Sewage treatment plants have known how to do this for twenty years with other organic residues, but the novelty is that oranges will make it possible to considerably increase the production of biogas in Seville.

Three to four buses could benefit from surpluses

What happened to the buses we were talking about? You get there ! From next season, the facilities will absorb all the oranges of Seville, that is to say a thousand times more oranges than until then. With, in addition, prospects for biogas surpluses.

Benigno López has an idea of ​​what he wants to do with it: “This biogas is composed of 64% methane, he explains. If the remaining 36% of impurities are purified, it can be used, for example, as vehicle fuel. For example for urban transport. Urban vehicles could refuel in the sewage treatment plant. We would like to have a bus line, which means between three and four buses in circulation powered only by this gas. Sevilla hope to run these first buses in the second season. We could therefore see in 2024 – 2025, buses running on LPG from the city’s famous orange trees, the circle is complete.