Description of Biomass Cogeneration Plant Alperstedt
Heat for the two greenhouse systems was supplied by two autarkic boiler houses with each three hot water boilers and an installed heat capacity of each 25 MW. The constantly rising prices for fuels gave reason to a new energy supply concept.
The change to wood chips became indispensable to remain further successful on the market.
Peak loads of heat consumption and back-up solutions are still covered with heating oil.
Technical Data
The layout of the technical system was performed consequently as combined heat and power unit in view of our customers’ heat requirements. They need approximately 63,000 MW of heat energy annually for the cultivation of tomatoes. This demand is met now by bio-energy. Only during peak loads, fossil fuels like heating oil are used. The combined generation of heat and electricity takes place year-round.
The cogeneration plant works according to the principle of combined heat and power generation in a cyclical process – i.e., the steam generated in the boiler from the heat carrier is reduced at 8 bar (g) to a pressure of -0.14 bar through a turbine. The thermal energy contained in the steam is transformed into mechanical rotational energy and further with a generator into electrical energy, which is then finally introduced into the public 20kV grid.
General
| Rated thermal output | 11700 kW |
| Effective rated thermal output | 10400 kW |
| Burner chamber temperature | 950 °C |
| Decoupled capacity of thermal oil plant | 9900 kW |
| Product / type | Mawera / FSR 10.000 |
Thermo-Oil Plant
| Maximum medium temperature | 315 °C |
| Effective rated output | 7900 kW |
| Maximum pressure | 13 bar |
| Total oil content | 24000 l |
| Circulation amount | 209 m³/h |
| Product / type | Maxxtec / IT-A-7.700-70 |
ORC-Plant
| Maximum medium temperature | 310 °C |
| Maximum pressure | 10 bar |
| Electrical capacity | 1750 kW |
| Heat extraction | 8100 kW |
| Temperatures at heat extraction | 100 / 60 °C |
| Product / type | Turboden |
Auxiliary Boiler Wood Chips
| Rated thermal output | 6900 kW |
| Burner chamber temperature | 950 °C |
| Hot water output | 6000 kW |
| Water capacity in boiler | 17 m³ |
Flue Gas Treatment
| Content of particulate matter after each combustion | approx. 500 mg/m³ |
| Content of particulate matter after multicyclone at each combustion | 150 mg/m³ |
| Content of particulate matter after electrostatic precipitator at each combustion | 20 mg/m³ |
| Year | Heat production p.a. | Electricity production p.a. |
| 2007 | 57137 MWh | 10230 MWh |
| 2008 | 62007 MWh | 12368 MWh |
| 2009 | 62304 MWh | 10067 MWh |
| 2010 | 70125 MWh | 11602 MWh |
| 2011 | 67252 MWh | 11750 MWh |
