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Double-membrane biogas cover

Biogas stands as a key renewable energy derived from organic waste and slurry. In addition to the standard biogas floating covers, Genap has developed a specialised double-membrane cover, which can be applied in biogas facilities. The cover is also suitable for fermenting silos, where biogas is both produced and stored. This dual-layered cover system for slurry silos is designed and fabricated exclusively by Genap.

Construction of a double-membrane biogas cover

The distinctive dome shape, formed by two layers (membranes), maximises storage capacity while also providing resistance to external elements such as rain, wind, and snow. A fan inflates the space between the two membranes to keep the outer ‘protective’ membrane taut. The inner membrane flexes with the volume of gas produced, acting as a reservoir for the generated biogas. For each biogas covering, we conduct a static calculation to ensure the structure can withstand the snow and wind loads applicable to the specific location, considering local laws and regulations.

  • Adaptable gas storage capacity
  • Tailored cover solutions including static assessments
  • Complete setup with ventilation and a gas level monitoring system

Extra information

Technical data

  • Up to 40 metres in diameter
  • Up to 20 mbar gas pressure
  • Membranes are welded at high frequencies
  • Over- and underpressure protection
  • Including fan unit and gas level indicator
  • 5 year warranty (diminishing)


  • Delivery according to TRAS 120 possible
  • Foil membranes up to 1300 g/m2 quality
  • Colour options: grey and green or on request
Bert Gijsbers
Your agriculture specialist
Bert Gijsbers
Sales Manager Agriculture Europa