Project Name: Abwasserverband Zirl und Umgebung
(click to open fact sheet and detailed project description)
The wastewater treatment plant in Zirl is designed for 61,500 population equivalent and has an anaerobic digester with 1,350 m3. In Austria on average wastewater treatment plants can cover 43% of their energy demand by anaerobic digestion of sewage sludge.
By using organic waste as co-substrate the plant in Zirl reached to cover the whole electricity demand. They use co-substrates like faulty batches, expired bread, grease separation material and coffee grounds from Nespresso-taps. From a Truck-Load with 23 tons of Nespresso-taps biogas with an energy equivalent of 23.500 liters of fuel oil can be produced. All in all approximately 3,000 tons/year of organic waste is used as substrate additionally to the arising sewage sludge. The waste like Nespresso-taps is pre-treated by a private waste management company using a hammer mill.
The wastewater association in Zirl is cooperating with different partners from industry and science to further optimize the use of digester volume of wastewater treatment plants.
Technology at a glance
- Biogas production: 700.000 m3 / year
- Installed power: 175 kWel
- Digester: 1x 1.350 m3
- Substrates: expired food, faulty batches, grease separation material, coffee grounds, …
- Input waste/substrate: 3.000 t/year (68% sewage sludge, 32% organic waste)
- Operating hours: 8.000 h/year
External link to further information: www.avzirl.at
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