In Toulouse, the largest methanization unit in France
Toulouse Métropole yesterday inaugurated an anaerobic digestion plant which produces biogas from water purification sludge and reinjects it into the city network.
Producing gas from sludge from wastewater treatment… Anaerobic digestion plants are on the rise. In Ginestous, on the site of the wastewater treatment plant, Toulouse Métropole yesterday inaugurated the largest methanization unit in France, according to the vice-president in charge of water, Robert Médina.
Every day, the water purification plant produces 125,000 m3 of sludge. After a first treatment, these are found in two large silos, the methanizers or “digesters”. There, with a temperature maintained at 37 ° C, the bacteria transform this material into biogas composed mainly of methane. After treatment, this gas becomes biomethane, a clean gas equivalent to natural gas, and it is evaluated in the town gas network.
Zero odor at the end of 2022
The current process has serious advantages. It allows sludge to be used by recycling it and the residual quantity to be reduced by half. It also avoids the production of 10,000 tonnes of CO2 per year, or 4,700 fewer cars. At a time of environmental transition, methanation produces “green” in significant proportions. The 50 GW / h injected by a network of drivers and supplying hot water to the equivalent of 11,000 inhabitants (or supplying 230 gas buses per year). The gas sold is also remunerated at € 3.7 million per year to the Metropolis.
Finally, for residents of the Ginestous, Sept-Deniers and Minimes neighborhoods, who have long been confronted with bad odors from the wastewater treatment plant, the methanizer is an important step in the “zero odor” plan promised by the Metropolis and its delegatee Suez.
In addition to the quantity of sludge divided by two, there is the installation of airlocks in sensitive areas and the next move of the green waste compost bin. In September 2022, there should be no more odors… President of the Collective against the Ginestous 2000 plan, invited yesterday with other residents, Marcel Martin, by conceding a better to the Seven-Deniers, assisted the deadline before being said to himself.
“The will, locally, it exists”, commented Jean-Luc Moudenc, the president of the Metropolis, about the ecological transition which, for him, passes in particular by “the intercommunalities”. Regional Councilor, Stéphanie Sense regretted the “failure” of the COP26 and pleaded for “the commitment of the Region” within the framework of its Green Pact. The anaerobic digestion unit cost 33.7 M € TTC financed by the Metropolis (21.3 M €), the Water Agency (9.6 M €), the Region (1.7 M €), ADEME (1.08) and GRDF.