Biogas recovery at the Valenton wastewater treatment plant

Recovery, treatment and feed into the network of methane produced by sewage sludge

For several decades now, at its wastewater treatment plant in Valenton, SIAAP has been capturing and exploiting on site around 80% of the biomethane generated by the degradation of organic matter contained in sewage sludge. Today, he wants to go further and recover the remaining 20%. It has therefore entrusted Artelia with the design and installation of a methanisation and treatment unit that will enable this unavoidable gas to be injected into the national grid.

CONTEXT & ISSUES

One of the largest in Europe, the Valenton wastewater treatment plant treats wastewater from the east and south-east of the Paris basin, a population of around 3.6 million. The plant already recovers a large proportion of the methane from the sewage sludge (currently 80%) and consumes it on site to run various thermal installations on the site. In recent years, the Paris urban area wastewater treatment authority) (SIAAP), which is responsible for the plant, has embarked on a more advanced energy efficiency and recovery programme, including the capture and injection of previously unused methane into the national gas network.

Artelia has been working with SIAAP for a number of years, helping to develop a master plan focused on a dual objective: improving the site’s energy autonomy and recovering the surplus biogas produced. In line with this plan, our teams have designed and are managing the installation of a high-capacity methanisation unit (1,800 Nm3/h), the largest built in France in a wastewater treatment plant, and facilities to purify this methane before injecting it into the network.

This additional biogas production is expected to supply 10,000 homes a year, prevent the emission of 9,000 tonnes of CO2 equivalent into the atmosphere and provide SIAAP with around €1.9 million in revenue from sales.

[1] https://www.lesechos.fr/pme-regions/ile-de-france/valenton-la-station-depuration-alimentera-10000-foyers-en-biogaz-dici-2023-1873264

Photo credits: AFA+SANAE architecture