• Digestion and post composting

AD & Post-composting

Get the maximum out of organic waste: Biogas, renewable energy, nutrients and organic matter/humus

  1. Which treatments are suitable for the fermentation of biodegradable waste and/or green waste?
    The solid state fermentation process or the dry fermentation process. The dry substance (DS) should be 25 % – 35 %.
  2. What is fermentation?
    Fermentation is the conversion of biological material with help from bacterial, fungal or cell cultures in an airfree environment.
  3. Which waste can be fermented?
    Household biodegradable waste, other biological waste
  4. Which substances can be gained from a fermentation facility?
    Biogas, compost, liquid fertiliser

The delivered waste will be added into the fermenter as a substrate either directly or by being blended with tempering water with a DS of between 25 % and 35 %.

If required, an inoculum, which will be extracted at the end of the fermentation process, is added to the substrate. A thermophilic process of up to 55 °C takes place inside the fermenter. Using a natural biological fermentation process, a gaseous source of energy, methane gas, is hereby produced. Thin menthane gas can be used in two ways. On the one hand, it can be directly fed into a CHP (combined heat and power unit) as a biogas and it will be further processed to be used by vehicles. This biological waste treatment os conducted whilst taking humans and the environment into consideration thanks to the closed units which ensure very low odour emissions. The output from the fermenter has a DS of approximately 15 % – 20 % and will be added to a separating unit.

In this separating unit, the output will be separated between solid and a liquid digested residue. The liquid digestate will either be supplied to the agriculture industry as liquid fertiliser or added to the soil put into the fermenter as tempering water. The solid digestate is transported to a further decomposition facility to produce compost.

Conditioning and hygienisation are conducted in the further decomposition process.

For this purpose, the output from the fermenters is brought before the further decomposition facility using a wheeled loader on the surface. Through mixing in the fresh green waste, a quicker, aerobic rotting process should be conducted in order to faster hygienise the material and to reduce the water content of the material enough for compost conditioning.

In order to reach the hygienisation temperatures as quickly as possible, the GORE® Cover System is used in the further decomposition facility.

The heaps are completely covered and consequently all odour emissions are minimised.

Six weeks of further composition using GORE® Cover System results in high quality compost.