State of the art of biogas technology - Examples from Germany

1. State of the art of biogas technology - Examples from Germany October 2010, Jyväskylä, Finland Jens Giersdorf, German Biomass Research Centre (DBFZ) www.german-renewable-energy.com

2. Content German Biomass Research Centre (DBFZ) Biogas development in Germany Biogas technologies Economics of biogas production in Germany Recent trends and challenges

3. German Biomass Research Centre (DBFZ)

4. German Biomass Research Centre (DBFZ) DBFZ founded in 2008 as a non-profit company owned by the German Federal Ministry of Food, Agriculture and Consumer Protection (BMELV) 2009: 134 employees, 149 projects Application oriented technical, economic and environmental R&D activities Consultancies for private/public institutions Policy assessment for federal ministries Feasibility studies for bioenergy plants

5. Biogas development in Germany

6. Number of biogas plants and installed electricity power Electrical power generation from biogas (2009): 10.5 TWhel (real), equals 34% of power generation from biomass in total, respectively 1.8 % of German brutto electrical power generation Source: DBFZ 2010

7. Share of substrates (% FM) in German biogas plants n = 413 Source: Biogasmessprogramm II, FNR, 2009

8. Biogas technologies

9. Scheme of processes in a farm-based biogas plant Source: Biogas – an introduction, FNR, 2009

10. Types of biogas digestors

11. Continuous stirred-tank reactor (CSTR) Source: Handreichung Biogas, FNR, 2009; DBFZ 2010

12. Continuous stirred-tank reactor (CSTR) Advantages • Cost-effective construction > 300 m³ • Flexible flow-through/storage operation • Maintenance without reactor emptying Disadvantages • Cover sheet for large reactors is complex/expensive • Short circuit currents may occur, retention time insecure • Scum and sink layers may occur

13. Plug-flow digester Sources: Handreichung Biogas, FNR, 2009; Eisenmann AG 2010

14. Plug-flow digester Advantages • Cost-effective construction for small plants • Separation of fermentation steps in plug-flow • No scum nor sink layers, short retention time • Optimal retention time due to prevention of short circuit currents • Low heat losses due to compact construction form Disadvantages • Construction only for small plants feasible • Maintenance of stirring devices requires complete emptying of digester

15. Batch/percolation Source: Bekon 2010

16. Batch/percolation Advantages • Utilization of solid substrates • Modular construction, flexible adaption to demands, low investment • Few material handling equipment, reduced investment and maintenance costs, low process energy demand Disadvantages • Delayed operation of several modules for continuous production • Incomplete mixture: zones with reduced gas production may occur • Installation of security equipment required • Large quantities of inoculate needed for high biogas yields

17. Economics of biogas production in Germany

18. Investment costs Investment costs depend on…. Technical equipment of the plant Development costs of the property (road, canalization, etc.) Access to energy grid, heat grid, manure storage tank if necessary Substrate for digestion (biogenic waste treatment plants more expensive than energy crops due to higienisation)

19. Investment costs Specific investment costs [€/kWel] Relative frequency Installed electr. capacity [kWel] Total investment costs [Mio €] Total investment costs: 1 – 1.5 mio USD Specific investment costs: 3,800 – 5,000 USD/kWel Source: Bundesmessprogramm II, FNR, 2009

20. Operating costs Substrate costs Costs for spreading of digestate Maintenance costs Labor costs Process energy demand Costs for consumables Costs for depreciation and interest

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

22. Production costs for electrical energy Production costs for electrical energy [€/kWhel] Electrical utilization ratio [%] Source: Bundesmessprogramm II, FNR, 2009

23. Revenues • Revenues for electricity: • Feed-in-tariff • Substitution of expensive own consumption • Revenues from direct marketing/sales • Revenues for heat: • Constant heat demand, especially in summer • Costs for heat conduction • Alternative heat costs • Revenues for disposal: • Additional costs for treatment • Revenues free plant (without additional transport costs) • If applicable higher environmental regulations for the plant • Revenues for digestate (substitute for mineral fertilizer)

24. Composition of revenues Electr. Heat sales Digestate Heat savings Digestate sales Composition of revenues[€/a] Source: Bundesmessprogramm II, FNR, 2009

25. Important factors for success Optimal choice of biogas plant location of major importance Low substrate costs Year-round demand for heat and electricity Skilled employees with enthusiasm for the challenge „biogas plant“ Professional plant layout Long-term financing

26. Recent trends and challenges

27. Biomethane feed-in plants in Germany • About 38 biogas upgrading and feed-in plants operating (23,520 Nm³/h capacity) • High costs for upgrading of biogas to natural gas quality requires large plants (> 2 MWel) • Gas grid can be used as storage facility • Optimization of heat use and/or satisfaction of peak loads • Several feed-in plants planned, but development slowed down

28. Biomethane feed-in plants in Germany

29. Integration of bioethanol and biogas production Sources: Agraferm, 2010, Verbio AG, 2010

30. Challenges Optimization (acceleration) of process biology Improvement of heat utilization concepts Optimization of „dry fermentation“ to increase use of ligno-cellulosic substrates (agricultural residues) Reduction of biomass/methane losses during the production process Promotion of biomethane application (esp. as transport fuel)

31. Thank you for your attention! Contact: Jens Giersdorf jens.giersdorf@dbfz.de Deutsches BiomasseForschungsZentrum German Biomass Research Centre Torgauer Straße 116 04347 Leipzig, Germany www.dbfz.de Tel./Fax. +49(0)341 – 2434 – 112 / – 133