Biogas production has boomed in Germany due to legislative improvements. As of 2011, over 9000 biogas plants produced 9.2 TWh of electricity annually, equivalent to 2.9% of Germany's electricity generation. Continuous stirred-tank reactors and plug flow digesters are commonly used to produce biogas from agricultural residues and food waste. Future development requires reducing costs through improved technology and exploiting multiple markets for heat, electricity, and fuel to increase total efficiency and utilization of biogas.

1. Biogas - status quo in Germany Michael Seiffert, Frank Scholwin September 2011 Deutsches BiomasseForschungsZentrum gemeinnützige GmbH, Torgauer Str. 116, D-04347 Leipzig, www.dbfz.de

3. Basic aspects Advantages of biogas production decentralised energy supply diversification of agricultural income reduction of odour emission renewable energy – CO 2 -reduction reliable energy supply reduction of CH 4 -emission strengthening of rural infrastructure saving of mineral fertilizers

5. Status quo Germany Installed capacity Electrical power generation from biogas: 9,2 TWh el (real), equals approx. 50% of power generation from biomass in total, respectively 2,9 % of German brutto electrical power generation 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009* Number of biogas plants 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Installed electrical capacity [MWel] > 500 kWel > 70 to 500 kWel < 70 kWel install. el. power [MWel]

6. Status quo Germany Share of substrates n = 413

7. Biogas technologies Overview System Continuous Discontinuous Category Continuous stirred-tank reactor (CSTR) Plug flow digestor Batch/ Percolation Symbol Example Substrate characteristics Liquid, 12% total solids Viscous, up to 40% total solids Solid, structured, stackable, humidification through sprinkling

8. Biogas technologies Continous stirred tank reactor

10. Biogas technologies Plug flow reactor

12. Biogas technologies Batch/percolation

14. Applications in the food industry Milk processing Waste water treatment plant and solid organic waste digestion Radeberg, 56000 t/a; Production of clean wastewater and fertilizer and energy

15. Applications in the food industry Chewing gum production Anaerobic waste water treatment at WRIGLEY, Poland, 600 m³/d Production of clean wastewater and gas for process heat supply

16. Waste water treatment in a brewery, Samara, 2500 m³/d Production of clean wastewater and gas for process heat supply Example from Germany Capacity : 500.000 hl/a beer Substitution of fossil fuels for process heat supply with solid and liquid residues utilisation for biogas production Investment : 6,2 Mio € Annual result : 0,7 Mio € Methane produced : 7,9 Mio m³ Applications in the food industry Brewery

17. Applications in the food industry Potatoe processing Production of clean wastewater and green process heat Anaerobic waste water treatment at potato processing, Germany, 110 m³/d Example from Germany Capacity : 200.000 t/a potatos Substitution of fossil electricity with waste water for biogas production Investment : 1,2 Mio € Annual result : 0,35 Mio € Methane produced : 0,9 Mio m³

20. Economics Annual total costs Source: Bundesmessprogramm II, FNR, 2009 Depreciation Base rate Purchase of energy crops Other direct costs Labor costs Maintenance contracts Other operating costs Relative annual expenditures [% of total costs]

21. Economics Production costs Source: Bundesmessprogramm II, FNR, 2009 Production costs for electrical energy [€/kWh el ] Electrical utilization ratio [%]

24. Latest trends Integration of bioethanol and biogas production Sources: Agraferm, 2010, Verbio AG, 2010

26. Biogas production Status quo and prospects German Biomass Research Centre Torgauer Straße 116 D-04347 Leipzig www.dbfz.de Dr.-Ing. Michael Seiffert [email_address] Prof. Dr.-Ing. Frank Scholwin [email_address]