Methanization unit at the Reyran water treatment plant, Fréjus (83)

Sludge treatment and recovery / Biomethane

The Val Estérel Mediterranean Agglomeration Community, strongly committed to the energy transition of its territory, has entrusted OTV Sud with the implementation of a methanization unit and the valorization of biogas into biomethane at the Reyran water treatment plant in Fréjus.


  • To reduce the volume of sludge and the constraints and costs of disposal
  • To limit GHG emissions
  • To produce biogas from sludge and transform this biogas into biomethane that can be injected into the GRDF (French electricity company) network
  • To produce high quality sludge for the agricultural sector


  • Integration of an anaerobic digestion unit and biogas valorization into biomethane on an existing site
  • Complete sludge treatment process:  thickening + digestion + centrifugation (existing dehydration) - reducing the volume of sludge to be evacuated by at least 30%.
  • Biogas valorization: 
  • MemGasTM membrane technology:  state-of-the-art separative technique to purify biogas (64% methane) into biomethane (>97% methane)
  • Energy recovery:  Energido
  • Veolia's innovative solution for recovering heat from wastewater. The hot water produced keeps the sludge in the digester at 35°C.



  • High performance:  99% of the biogas is transformed into biomethane
  • Easy to operate:  fully automated
  • Compact:  easy to integrate on an existing site (container)
  • Reduced carbon footprint:  1500T CO2 equivalent - reduction of road traffic.
  • Production of green energy generating a significant annual income


  • 350,000 P.E.
  • 10 million m3 of treated wastewater
  • 10,000 tons of sludge recovered on site
  • 556,000 Nm3/h of biomethane produced
  • 6,000 MWh/year produced
  • 2,000 households heated
  • 750,000 €/year generated by the resale