More than 1,400 t of turkey and horse dung are generated every year in the stables of the agricultural enterprise of the Bauer family. Since pig and cattle breeding are not activities of the enterprise, no additional liquid substrates were available for the desired biogas plant.
A forecasted total solids (TS) content of more than 14 % in the digester tank may be processed only with considerable wear of the stirrer components and high internal power consumption in a stirrer tank digester.
The biogas plant of the agricultural enterprise of the Bauer family is specifically geared for the utilization of difficult substrates with high dry solids contents. The heart of the plant is
a horizontal plug-flow digester with horizontal stirrer shaft, the so-called “reel stirrer”. The stirrer shaft does not generate any feed motion and thus keeps the mechanical load on the stirrer blades low. Another positive aspect of this specific technology is the avoidance of a complete blending of the digester contents, which allows for an efficient and defined decomposition of the fermentation substrates.
Specifications | |
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Plug-flow digester: | 900 m3 |
Post-fermentation store: | 1,885 m3 |
Substrate store: | 1,885 m3 |
Combined heating and power plant: | MDE gas motor CHP, 370 kWel |
Solids feed: | Fliegl PolyPro42 with weighing system; 42.0 m3 |
Plant control system: | Siemens with plant visualization |
Seperation: | Separator S 655, by Baur |
Gas analysis: | Pronova SSM 6000-4 |
Feedstock | |
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Horse dung: | approx. 600 t/a (planned as 01/01/2009) |
Turkey dung: | 850 t/a |
Corn silage: | 2,250 t/a |
Grass silage: | 300 t/a |
Gereal GPS: | 1,750 t/a |
Green rye GPS: | 1,260 t/a |