Type of CHP system: Anaerobic digestion

Plant owner:

Nahwärme Antiesenhofen is a limited company owned by 7 associates operating already an wood chip fuelled district heating network.

Commissioned: 2002

Status of plant: Commercial

Contractor details:

CHP: G.A.S. Energietechnik Gräfeld, Germany delivered the complete package, 190 kW, efficiency 30%
Generator: three phase alternator
Fermenter: pipe fermenter of 160 m3 (Biogassystemtechnik Tulln) and a concrete fermenter of 1000 m3 (Bioenergetika)
SO2 removal by means of an air compressor.

Power generation: Gas engine

Cylinder head was changed once, the turbo charger renewed after 4 years of operation, extensive generator repair occured.

Main fuel:

Biogas

1280 m3 pig and cattle manure, 800 m3 from gastronomy (grease and left over); 320000 m3 landfill gas, and 640 m3 maize CCM

Nominal capacities & efficiencies:

Gross electrical output: 0,19 MWe

Net electrical output: 0,13 MWe

Heat output: 0,34 MJ/s

Electrical efficiency, gross: 30 %

Overall efficiency, gross: 80 %

Power to heat ratio: 0,5625

How is plant controlled:

The plant operation is controlled by the biogas yield.

Heat usage: Heating only

Energy usage:

The annual electricity production amounts to 450 MWh (according to experience with landfill gas – data with biogas not yet available), of which 5% is for own consumption in the biogas plant and the district heating plant, the remaining 427 MWh are fed into the public grid. Heat production amounts to 800 MWh, which is completly fed into the district heating network (incl. wood drying facility on the company land).

DH inlet temperature:95 °C

DH return temperature:45°C

Fuel storage:

The biogas storage has a size of 143 m3, the storage for landfill gas a capacity of 800 m3 corresponding to 3.5 h (biogas) resp. 8 h (landfill) of operation at full load.

Plant description:

Installed capacity of 190 kWel and 340 kWth, 8-cylinder MW engine, container solution (because of noise protection regulations), it is a combination of landfill gas – biogas fuelled plant
Authorisation: ElWOG 2001
The plant operator have a standardised service contract with a regional expert for engines (all 750 h service like change of oil, spark plug etc.

Digester capacity: 1160

Residence time: 60

Process temperature: mesophilic process, temperature: 38 °C

Annual gas production: 3700

Gas quality: 60 % methan, heating value: 6 kWh/m3

Wet fermentation, dry matter 15% , two-level process

Electricity sale info:

The feed in rate in Austria is regulated by law and depends on the type of biomass used and on the size of the plant.

Data collected and quality assured by: Austrian Energy Agency.

Contact person: Elvira Lutter