Biogas roof for optimum storage volume with high-frequency welded polyester membranes
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3701 Arco Corporate Drive
NC 28273 Charlotte

Cogatec Double Membrane Gasholder

Optimum storage volume for your biogas plant

The Cogatec double membrane gasholder is the ideal biogas roof for storing biogas. The geometry of the different spherical shapes ensures that the optimum gas storage volume is utilised. Monitoring is carried out by our state-of-the-art laser measuring system. Our system enables a flexible mode of operation.

The roof system, designed for biogas plants, agricultural operations as well as sewage treatment and industrial plants, consists of two separate, high-frequency welded polyester membranes that are PVC-coated on both sides. The fabrics used impress with their low gas permeability, very high UV stability and the special, dirt-repellent top layer. The outer membrane of the double membrane gas reservoir absorbs the static loads caused by wind and snow loads. This allows the inner membrane to be operated almost without pressure, thus enabling a longer service life. Our membranes are provided with a keder in the clamping area, which diverts the forces arising from weather influences into the anchoring clamping rail in a form- and force-fitting manner.

Innovative roof construction for optimized gas storage volume, ideal spacing of the outer and inner diaphragms, separate attachment of the belt tensioning construction to the inner wall of the tank
Optimised gas storage volume
Our innovative roof construction enables an optimised gas storage volume due to the ideal spacing of the outer and inner membrane, as well as the separate fastening of the belt tensioning construction to the inner wall of the container.
Insulation options for double membrane gas storage tanks
Possible thanks to integrated insulation
We offer different insulation options for your double diaphragm gas storage tank.
Project-related design of the supporting air system for flexible operation with double diaphragm gas storage tanks
Special design for flex operation
For our double membrane gas storage tanks, the design and calculation of the support air system is carried out as standard on a project-specific basis. This especially supports the flex operation.
HUESKER: Biogas experts with many years of experience in the planning, production and realization of biogas projects
Engineered by biogas experts
Our years of experience in the planning, production and realisation of biogas projects make us experts in this field.
HUESKER double membrane gas storage tanks: Conformity with TRAS 120 standards
TRAS 120 conform
Our double membrane gas storage tanks meet the requirements of TRAS 120.
HUESKER double diaphragm gas cylinder: Energy-efficient control with differential pressure sensor
Energy efficient operation
Next to the support air fan is a differential pressure sensor for controlling the operating pressure. This enables the support air fan to be controlled as required.

Product variants

Discover the diversity of our gas storage tanks

Double Membrane Gasholder

The Cogatec double membrane gasholder is a roof system for storing biogas that is placed on top of a tank. The high-frequency welded membrane roof is attached to the container crown by means of a stainless steel clamping ring. To ensure the tightness of the clamping rails, the substructure is attached directly to the inside of the container.


(1) Outer membrane
(2) Inner membrane
(3) Over/underpressure protection
(4) Exhaust air duct with exhaust air flap​​​​​​​
(5) Belt substructure incl. tensioning net​​​​​​​
(6) Centre column cantilever with crown
(7) Inspection window​​​​​​​
(8) Support air fan​​​​​​​
(9) Laser level measurement

      Double Membrane Gasholder on Foundation

      The Cogatec double membrane gasholder on foundation is a free-standing biogas storage tank consisting of three membranes. The gas space of the ¾-sphere or other storage heights is formed between the inner and bottom membrane. The optimised laser measuring system ensures exact measurement of the filling level. Common applications are an additional storage volume for biogas plants (clean gas storage), sewage plant storage or industrial storage for process gases. With this application, operating pressures of up to 100 mbar can be run, depending on the storage tank size.


      (1) Outer membrane
      (2) Inner membrane
      (3) Floor membrane
      (4) Overpressure protection​​​​​​​
      (5) Inspection window​​​​​​​
      (6) Support air fan
      (7) Laser level measurement

      Double Membrane Gasholder - Special Shapes

      In addition to the standard spherical shape, we also offer the double membrane gasholders in various special shapes. These include, for example, the rectangular storage tank (first graphic), which is erected on a rectangular, closed container, or a hybrid ¾-ball in combination with a cylinder (second graphic), which stands on a concrete foundation.


      (1) Outer membrane
      (2) Inner membrane
      (3) Floor membrane
      (4) Support air fan
      (5) Exhaust air duct​​​​​​​
      (6) Laser level measurement

          Technical information

          • European high-tech PVC membranes, fabric-reinforced

          • Diameter of the biogas roof possible up to over 50 m

          • Substructure of pre-tensionable belt system and overlying desulphurisation net

          • High tear resistance, adapted to your membrane roof, with low gas permeability and high UV stability

          • Supply and exhaust air ducts made of stainless steel pipes

          • Any desired storage height can be realised

          • Level measurement of the biogas storage tank by laser

          Do you have any questions?

          Are you looking for quick answers to the most important questions about our double membrane gasholders, projects or subsidies? Find out now in our FAQ section! If you still can't find the answer you're looking for, simply contact us using our contact form!

          In various federal states, products to reduce CO² emissions are promoted. These include, for example, emission protection roofs for covering liquid manure tanks. We will be happy to advise you on the current subsidies. Just give us a call or use the contact form.

          We use fabric types II, III, IV, V for our double diaphragm gas storage tanks. They are offered in the colour variants moss green and light grey.

          We offer you various options for making your roof system as energy-efficient as possible. Feel free to contact us directly or via our contact form.

          It is difficult to give a flat rate price without knowing the exact project. Feel free to fill out the contact form and we will coordinate an on-site appointment with you to discuss all the details and provide a non-binding quote.

          For steel components, we use application-specific stainless steel (V2A and V4A). This results in a high resistance to corrosion.

          Whether your existing wooden beam construction can be reused always depends on the condition of the wooden beams. In most cases this is possible. After our field service has gained an overview, we can advise you on how to proceed.

          Yes, reuse is possible. Instead of the clamping hose, we recommend our clamping rail system for anchoring the membranes. The use of the rails increases the operational safety compared to a clamping hose.

          Depending on the condition of the centre column, reuse is possible. The HUESKER centre column head can be adapted to all commercially available columns so that the existing column can continue to be used.

          Further information
          you can find here