EnKoBio - Energy-efficient biological waste treatment by conditioning
Because of specific regulations of the Renewable Energies Act, mainly anaerobic dry fermentation processes are applied when it comes to the processing of separately collected biowaste in Germany. The dry fermentation of biowaste is carried out either in the Plug-flow or in the percolation process. In Germany, both techniques are applied in almost equal proportions.
Fluctuations in the biogas yield cannot entirely be explained by the techniques and their technical efficiency and are mainly based on the qualitative characteristics of the biowaste used. They are influenced both by seasonal fluctuations as well as by waste management conditions such as container sizes, fee models or disposal systems and additionally by the settlement structure in the collection areas. Due to the high qualitative fluctuation range, mechanical pretreatment of biowaste is necessary in order to ensure a constant biogas yield.
The aim of EnKoBio is to describe the quality of fermentation input from separately collected biowaste depending on different waste management systems. With an extensive monitoring of five technically different fermentation plants the relation of the impact of waste management systems on the quality and the results of the process-typical energy production will be documented for the first time. The manipulation of characteristics in real plant operation is achieved by the use of typical processing techniques such as comminution, screening and sorting in the dry fermentation plant of the "Gesellschaft für Bioabfallwirtschaft in Landkreis und Stadt Aschaffenburg mbH" (GBAB) in Aschaffenburg, Germany. The mechanical processes are tested under technical conditions and analyzed for qualitative and quantitative effects. For the analytical evaluation of the biogas yield, the fermentation boxes of the GBAB plant are equipped with gas measurement technology as well as with sampling points for the percolate.
Recommendations for users and plant operators are provided in a guideline for optimized biowaste preconditioning. The project described above is funded by the German Federal Ministry of Economics and Energy (BMWi).