Climate Relevance and Energy Efficiency of Biogenic Waste Recovery (KEVBA)

The report of the Federal Environment Agency compares the composting and digestion of biogenic waste in terms of climate relevance and energy efficiency. Greenhouse gas balances are calculated for open and partially closed composting as well as for wet and dry fermentation. In the fermentation processes, different variants of the digestate treatment as well as different uses of the biogas produced (electricity generation, heat use, biomethane production) are investigated. Composting has a worse greenhouse gas balance than fermentation. The greenhouse gas balances of the fermentation variants vary greatly depending on the waste. The best results are achieved in the processing of biogas into biomethane. Open digestate storage facilities can lead to high greenhouse gas emissions and should therefore be covered in gastight conditions.