Enterprise Europe Network

Compact digester offered for sewage plants of smaller and medium size under services agreement.

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External Id: 
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Partner keyword: 
Biogas and anaerobic digestion (AD)
Biotreatment / Compost / Bioconversion
Sludge Treatment / Disposal
Biomass and Biofuels
Engineering services
Production of electricity


A group of German consulting engineers, located in the south-west of Germany has developed an innovative planning concept of a compact digester for sewage plants of smaller and medium size and wants to offer its one-stop planning know-how and expertise. The company is interested in a services agreement.



Increasing energy costs require to exploit the energy contained in waste water or sewage sludge. Up to now sludge digestion has been primarily applied in bigger sewage plants. In the meantime sewage sludge which has been considered as problematic recently, has an excellent chance to become a useful energy resource also in smaller sewage plants.

Sludge digestion in general is considered as too expensive due to the complex construction of conventional digesters. Various surveys and operating experiences have shown that digestion of sludge can be achieved with less constructional, technical and financial costs without disregarding the operational safety.

The German group of consulting engineers has worked on the optimisation of the digestion process by developing a new planning concept for a compact digester, whereas the usual elementary construction of the rectangular digesters result in a compact building which is optimised by an annexe including the peripheral equipment.

Due to the piping, the system can be operated either in two stages or in two directions.
In case of maintenance or repairing, one of the hoppers can temporarily be put out of operation so that the remaining one can be used separately for a short time.

The biological rearrangement will be carried out by simple and centrally arranged stirring devices with external driving motors. Due to the low height of the construction the costs can be minimised.

They want to offer their planning service to interested partners, and are looking for a services agreement.

Advantages & innovations

Cooperation plus value: 
The compact digester developed by the German engineer group comprises the following substantial improvements: - elementary construction method - compact arrangement - biological rearrangement with low-cost centrally stirring devices - distribution of the total capacity onto several reactors to use the technical advantages of multi-level degradation kinetics - cheap gas storage and gas utilisation - optimisation of the digestion process by using several hoppers connected in series to exploit the positive effect of the cascade connection (Monod - / Michaelis-Menten kinetics) which leads to a 10 % higher degradation of organic dry residue; this means that waste material can be reduced and gas production can be increased by using the same hopper volume. - energy saving by generation of electricity obtained from gas: 15 - 20 kWh/EW/a - reduction of sludge quantity: 20 - 30 %

Partner sought

Cooperation area: 
The company is looking for partners who are active in the field of waste water treatment, sludge processing and recycling and/or water protection. The ideal partners would be urban or municipal authorities as well as private companies that are interested in acquiring the one-stop planning concept/design of the German engineers to establish a sewage plant of smaller and medium size with a compact digester.

Type and size

Cooperation task: 
SME 11-50,SME <10,>500 MNE,251-500,SME 51-250,>500