biomass plant in Höör, Sweden
The municipality of Höör in Southern Sweden decided to invest in a new heating
plant for the town centre. Biomass was the preferred source of fuel as it had
already proven to be readily available and economically viable in Sweden.
The authorities set up strict emission permits as the plant is located in the
city centre close to residential areas and a school. To meet these low
emissions requirements the plant has been built based on new technology
developed by Petro Ett AB (previously Ekotrans Termik AB) and Ermatherm AB.
Financial resources / Economic Benefits
The method applied to reduce the emission is to combine
particle cleaning with flue gas condensation, which is an expensive part of the
installation. Ermatherm AB developed the method and Volvo Aero Supports, with
support from the Swedish research programme NUTEK, tested the prototype.
The biomass furnace has a capacity of 2.5 MW. The combination
of cleaning and condensing of the flue gas added a further 0.3-0.6 MW,
depending on the energy content of the bio fuel.
The biomass plant delivers about 15 GWh annually to the
district heating network, which is about 85 % of the heat used by the network.
Three 3.3 MW LPG boilers supply the remainder.
The furnace was supplied by Petro Ett AB: The furnace is
equipped with a flue gas recycling system, which contributes to accurate
control of the temperature and combustion of high energy content fuels. An
additional feature of the recycling system is the reduction in emission of
To reduce emission the flue gas is cleaned in a wet
electrostatic precipitator before it enters the condenser. Inside the
precipitator the flue gas comes into contact with the wet inside of the
cylindrical duct and the positive charged dust particles are attracted to the
water film on the wall. The flue gas exits the precipitator at the base, where
it then travels upwards through a scrubber column.
The project is described in the International Energy Agency's
CADDET Technical Brochure No. 156,
www.caddet-re.org and in the Swedish magazine 'Energimagasinet', No. 5,
(in Swedish. The contractor uses the plant as a reference plant for new
Financial resources / Economic
The total investment was SEK 11,000,000 (€ 1,200,000).
The electrostatic precipitator cost was SEK 1,600,000 (€
180,000), for which the Swedish National Energy Administration gave a grant of
SEK 380,000 (€ 42,000).
The payback period for the plant is approximately 4 years.
The plant delivers about 15 GWh a year, of which the biomass
plant delivers 13 GWh (85 %).
The installation of the wet electrostatic precipitator
increased efficiency and decreased emissions.
If the annual heat output of the biomass plant were to be
supplied from LPG boilers, approximately 1,200 tonnes of LPG would need to be
used, which would increase the emissions of carbon dioxide by about 3,000
Potential for replication
There are currently a number of similar projects in Sweden and
Norway. The potential for projects of this kind is increasing as environmental
regulations are getting stricter. The focus on lower emissions within the
European Union would contribute bolstering the potential for this technology.
PETRO ETT AB
Helsingborgsvägen 33, SE-262 72 Ängelholm
+46 0431 41 00 10
fax: +46 0431 41 00 20
Solbacksv. 20, SE-147 41 TUMBA
+46 8 530 689 50
fax: +46 8 530 311 73