Storage pit floating cover

for reservoirfor lagoonpit

NENUFAR is a custom floating cover designed to cover digestate storage tanks and recover the biogas produced, limiting emissions and preserving the nitrogen value of the digestate.

Main benefits:

• Additional biogas production for anaerobic plants through supplemental storage (indicative range: 50–500 m3/day).
• Custom floating cover for all tank shapes: circular, square and rectangular.
• Reduction of ammonia emissions, greenhouse gases and odours from storage.
• Preservation of digestate nitrogen value.
• Lower spreading and treatment costs through drainage of rainwater from the surface.

Biomethane Decree: sustainability criteria
The decree requires covered storage of digestate with biogas recovery for at least 30 days to qualify for incentives: NENUFAR is presented as a practical means to meet this requirement.

A simple and easy-to-install system:

• No epoxy resin is required to protect concrete since the biogas does not contact the concrete.
• No modification of existing pipes, mixers and pumps is necessary thanks to a gap between the cover and the wall.
• No central pole is required: the cover is fully floating.
• Biogas can be transferred to the existing plant using a blower, including over long distances, avoiding a biogas bridge issue between tank and digester.

1) Improve biogas plant yield

• Supplementary capture of biogas in reception tanks for slurry or digestate.
• Transfer of recovered biogas to the existing plant via blower.
• Example: SARL Eurek’Alias — NENUFAR cover diameter 19 m; 8,000 m3 digestate/year; indicative additional production: 200 m3/day of biogas.

2) Energy savings in the livestock sector

• Use of biogas to feed gas/propane boilers for heating, hot water production, etc.
• Possibility to install a boiler in a room or container powered by biogas from NENUFAR.
• Example: EARL Multiporc de l’Aire — NENUFAR cover diameter 20 m with a 240 kW biogas boiler; up to 80% energy self-sufficiency.

3) Energy resale

• Electricity production with small cogeneration units (e.g. 36 kW) fed by the recovered biogas.
• Example: GAEC Pécane — NENUFAR diameter 30.5 m with a 36 kW engine for electricity production.

Technical features / specifications:

• Commercial name: NENUFAR
• Application: floating cover for digestate storage tanks with biogas recovery.
• Indicative storage / additional production capacity: 50–500 m3/day (indicative value for storage generating additional production).
• Tank compatibility: circular, square, rectangular (custom covers).
• Installation: floating system without central pole; space provided for existing piping and devices.
• Gas management: possible connection to existing plants via blower for biogas transfer over significant distances.
• Environmental benefits: reduction of emissions (ammonia, greenhouse gases) and odours; preservation of nitrogen in digestate.
• Regulatory compliance: suitable to meet the covered storage requirement of at least 30 days set by the Biomethane Decree.
• Example sizes implemented: covers with diameters of 19 m, 20 m, 30.5 m (illustrative values).