Innovation provider

Axpo Kompogas AG


Flughofstrasse 54
8152 Glattbrugg
Tel.: + 41 (0) 44 809 / 77 - 77
Fax: + 41 (0) 44 809 / 77 – 00
E-Mail: info(at) Web


Input: Biowaste (including contaminants)
Process: Thermophil continuous dry fermentation
Key features: Concrete horizontal fermenters, separation unit, CHP generator
Output: Biogas (electric power, heat), compost, liquid fertilizer, separated contaminants
The KOMPOGAS fermentation system is well suited for the integration in existing composting facilities. The KOMPOGAS system – a dry fermentation system – is particularly suitable for such tasks, since no unnecessary water is conveyed through the circuit and the biogenous waste supplied to the facility does not have to be reduced to an unnecessarily fine degree. This allows further use of the existing composting system for curing the fermentation residue without requiring any additional structural material.

The new fermentation system can be constructed without imposing any major restrictions on ongoing operations. A complete interruption of operation is expected only for a very short time. During construction of the system, normal operation of the composting facility can continue as usual.

The material flow in the existing plant will remain as it is. In the existing processing section, the
biogenous waste will be screened to a size smaller than 80 millimetres. The larger fraction will then be freed from non-processible material by manual separation and from ferrous matter by a magnetic separator. It will then undergo size reduction in a screw-type mill, and the two material streams will merge again on a conveyor belt. Finally, the material will be discharged from the existing processing section to be transferred to the belt system of the new fermentation plant.

Here, the material will be standardized by screening and size reduction to a particle size smaller than 50 millimetres and be placed in intermediate storage in three enclosed holding containers.

The fermentation system is designed as a single or multiple line facility, i.e. the material is processed in three horizontal KOMPOGAS core modules with a useful capacity of 950 cubic metres each. The advantage of this approach is a very high operating reliability and a very uniform rate of gas production.
The biogas produced during the decomposition process will be converted in a cogeneration unit into electric and thermal energy. The electric power will be fed into the public grid as eco-power (power produced from regenerative biomass). The heat will be used for heating purposes in the facility.

The remaining fermentation substrate will then be dewatered, producing fermentation residue and press water. Part of the press water will be returned to the start of the process, and any surplus water will be used as liquid fertilizer or –where no demand for it prevails- be treated and discharged into the public sewage system. The fermentation residue is to be cured in a section of the existing composting building. At the end of the treatment process, a high-quality compost will be obtained.


See Innovative Aspects

Innovative aspects (ecologic, social and economic)

-   Approval of hygenization of the end product (especially liquid) for example with a process validation according to BioAbfV
-   Approval of marketability of liquid (for example Quality standard of "Bundesgütegemein schaft Kompost” RAL-GZ 245)
-   The system is expressively continuous 24h/d feed and dry digestion
-   Special criteria for the technology part:
  •   dry anaerobic digestion with continuous plug flow
  •   horizontal fermenter
  •   thermophile process > 50 degree Centigrade
  •   fully automated feed of the digesters
  •   no interruption of feeding on weekends and public holidays
  •   buffering of the wastes to be processed in an automated "bunker"
  •   the storage buffer has level out daily variations in material deliveries and pretreatment.
-    The volume is approx. 2 days capacity of the average daily delivered material:
  •   fully automated discharge system from the fermenters
  •   optional preparation for the end product for the post treatment in a composting
-     Process via mechanical dewatering like (screw press, decanter or centrifuge or similar)
  •   conditioning / hygienisation of the process water for the use as liquid fertilize

Application examples

  • 18,500 tpa of Biowaste
  • Commissioning 2010

  • 45,000 tpa of Biowaste
  • In operation since 2008
  • 40,000 tpa of Biowaste
  • In operation since 2008
  • 18,500 tpa of Biowaste
  • In operation since 2007
  • 18,500 tpa of Biowaste
  • In operation since 2007
  • In operation since 2007
  • 18,500 tpa of Biowaste
  • 39,000 tpa of Biowaste
  • In operation since 2004
  • 20,000 tpa of Biowaste
  • In operation since 1999



Current stage of development

Already on the market

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National Contact Point

Daniel de Graaf
Wörlitzer Platz 1
06844 Dessau-Roßlau

Tel. +49 (0)340 21033407
Fax. +49 (0)340 21043407