Digestate as Fertilizer

Reference plants
Regeb Bersenbrück
Presented technology: Vacuum evaporation
Manufacturer of the upgrading unit:
Arnold & Partner AG
Manufacturer of the biogas plant:
BioConstruct
Commissioning year: 2011
GERMANY
Installed capacity:
1,300 kW el
Biogas plant Bersenbrück, vacuum evaporator from Arnold
Amount of produced digestate:
30,000 t /a
At the biogas plant in Bersenbrück, the digestate is mechanically
separated from the repository and separated into a liquid and
solid phase. The separated liquid digestate filtrate is heated in
the Arnold evaporator by the waste heat from the CHP unit in heat
exchangers and then evaporated under vacuum. The digestate is
thus thickened and concentrated. The multi-stage arrangement
multiplies the evaporation capacity at a constant heating capacity
and thus guarantees the recycling of the entire quantity of digestate
produced. The system installed in Bersenbrück requires just
0.28 kW therm
for 1 litre of water evaporation. In order to prevent ammonia
from evaporating, the pH value of the digestate is lowered
by means of sulphuric acid before evaporation. All the nutrients
contained in the starting product can be found in the thickened
concentrate. Thus a maximum separation of liquid and nutrients is
achieved without unwanted by-products!
The condensate is discharged into the receiving water. Transport
and disposal costs are greatly reduced by reducing the volume of
liquid digestate by around 70%.
Nutrient contents [kg/t FM]
Concentrated digestate after vacuum evaporation
30
25
20
15
10
5
0
N ges.
27 %
NH 4
P 2
O 5
S K 2
O CaO Org.-C TM
30
25
20
15
10
5
0
Dry matter content (DM) [%]
Operator
Regeb Energieerzeugung und
-Verteilung Bersenbrück
Hermann-Kemper-Str. 5
49593 Bersenbrück
Germany
Contact person: Christian Rauf
Telephon: +49 5439 609626
Mail: g.erpenbeck@regeb.de
Generated products: Liquid digestate, solid digestate,
dischargeable water
Use of the digestate: Spreading as fertilizer, drag hose spreader,
injection technique, soil incorporation e.g. cultivator)
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