The plant

The St. Michaelisdonn biogas facility is a Cofermentationsplant. Per annum, 25,000 m³ of manure and 15,000 m³ of organic waste are utilized.

All organic matter that is utilized in the biogas plant is first homogenized in an intake tank where it is  pasteurized in a pasteurization unit at 70 C ° for one hour. After this the substratum is pumped out at a temperature of approx. 39 C° into the 2,300 m ³ Fermenter.

The Fermentation happens then in the mesophilen temperature range at approx. 38 C °, the dwell time in the Fermenter is 20 days.

After the substrate passes through the fermenter, it is stored temporarily in a storage tank , where more gas is produced. From here, after all the gas has been collected, our company trucks take the finished rotten organic matter  back to the farmers who supplied us with the liquid manure.

The produced biogas consists to 65 -70 % of methane and turns in 2 Combined heat and power units (CMP) to produce electricity and heat. The current electricity is feed into the public net. The installed electrical performance of the CMP is 240 kW each, the performance fed is 2.5 -- 3 MWh per annum.

A substantial technical component of the system is the heat exchanger. The three heat exchangers are wired into series and use the warmth of the biomass streams which have different temperatures, in an optimal way.

This causes a usage of only approx. 18 % through the Combined heat and power units (CMP) process. Thus a large percentage of the heat produced is available for other processes