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The container is planted in the middle of fields and greenhouses. Inside, machines are connected to a 5m3 stainless steel tank, a "kind of big cow stomach", explains Alain Grenet, in charge of engineering and development at the Public Center for Training and Promotion of Horticulture (CFPH) Ecully, on the outskirts of Lyon, which includes a professional high school and an organic urban farm. The metal beast is in fact a micro-methanizer born from the Decisive project, an unprecedented experiment in the management of urban bio-waste.This miniaturized methane production plant is associated with a "vertical farm" where vegetables grow in hydroponics (above-ground cultivation technique supplied with a liquid solution).

Proximity is the basis of the Decisive project, which is attached to a radius of 2 km maximum within the perimeter of the metropolis. The objective: to limit imports of foodstuffs and exports of waste, to relocate on the scale of the district, the agglomeration. The conventional treatment of waste, which gives them little value, has become more widespread because "it is the only way for it to be profitable", underlines Alain Grenet. The micro-methanizer installed on the CFPH site produces too little gas for it to be possible to re-inject it into the collective network - the cost of the station required for the interface would be too high for a small structure. "But it's interesting to work on this question of autonomy: with direct treatment by a small unit on site, we lower the carbon impact of a site."

Ultimately, the Decisive container could be installed in the basement of a building, the basement of a factory, a supermarket ... This would prevent organic waste from traveling miles to be recycled or, while they are made up largely of water, ending up incinerated, as is the case in the metropolis of Lyon for those of individuals.