Two Finnish BIO-CHP power plants: - Rauhalahti power plant - Pursiala power plant

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1 Two Finnish BIO-CHP power plants: - Rauhalahti power plant - Pursiala power plant European Biomass CHP in Practice March 9th 10th 2006 Fernwärme Wien, Vienna Janne Kärki VTT Technical Research Centre of Finland P.O.Box 1603, FIN Jyväskylä FINLAND Tel , janne.karki@vtt.fi

2 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 2 Jyväskylän Energiantuotanto, Rauhalahti Power plant Etelä-Savon Energia, Pursiala power plant Jyväskylä Mikkeli

3 3 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Jyväskylän Energiantuotanto Oy, Rauhalahti Power plant The power plant generates electrical power, process steam for industry and district heat for the city of Jyväskylä. Production in 2005: district heat 802 GWh process steam 275 GWh net electricity about 418 GWh Steam can also be generated by the oil-fired boilers

4 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 4 Rauhalahti Power plant

5 5 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Rauhalahti Power plant Rauhalahti power plant was originally designed for peat and for coal when pulverised fuels were used. Fluidised bed boiler was installed in 1993 and the use of wood fuels was started. The main fuels are currently peat, by-products from sawmills and forest residues (wood chips, stumps). Also recycled fuels were used before Wood fuel feeding system was modified in The share of forest fuels, forest chips and stumps has been increasing significantly.

6 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 6 Rauhalahden voimalaitos

7 7 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 1. Polttoaineiden ominaisuudet Mikä on turpeen rooli seoksessa? Forest chips Sawdust REF Bark Peat Risutukkipaaleja

8 8 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 1. Polttoaineiden ominaisuudet Mikä on turpeen rooli seoksessa? Risutukkipaaleja

9 9 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Rauhalahti Power plant fuel usage [MWh] Fuels in Rauhalahti BFB-boiler from 2002 to % Peat Coal Oil Biomass REF 90 % 80 % 70 % 60 % 50 % 40 % 30 % 20 % 10 % 0 % REF Biomass Oil Coal Peat

10 10 VTT TECHNICAL RESEARCH CENTRE OF FINLAND New wood fuel crushing and chipping system has made possible the increment of: logging residue bundles stumps recycled wood baled agrobiomass and recycled fuel etc.

11 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 11 Rauhalahti Power plant the boiler The Rauhalahti plant was originally equipped with pulverised fuel boiler (commissioned in 1986). In 1993 new BFB boiler retrofit was installed by Kvaerner Power: Boiler capacity 295 MW th Electrical output 87 MW e District heat output 140 MW th Process steam output 40 MW th (max. 65 MW). Steam data: 110 kg/s, 135 bar, 533 C.

12 12 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Rauhalahti Power plant Year after year operation-time energy availability factor has been very high, ~99 %. There have been some operational difficulties with the challenging fuelblends in the BFB-boiler which have lowered the availability of the power plant in recent years. Energy availability factor tgde % - annual average 100,0 99,5 99,0 99,20 98,99 98,80 98,5 98,13 98,0 97,5 97,

13 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 13 Rauhalahti Power plant Bed material agglomeration Fouling at the superheaters

14 14 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Etelä-Savon Energia, Pursiala power plant Pursiala Heating Power Plant generates electrical power, process steam for wood thermal treatment plant and district heat in the city of Mikkeli. In 2004 district heat production was 375 GWh, process steam production 58 GWh and net electricity generation about 197 GWh. In addition to the green Norppa electricity sold in Finland, the company sold green certified electrical power to the Netherlands, a total of 80 GWh.

15 15 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Pursiala power plant The power plant has nowadays: 84 MW circulating fluidised-bed boiler 100 MW bubbling fluidised-bed boiler 27 MW bubbling fluidised-bed boiler for back-up heat production The plant is provided with an auxiliary water cooler (45 MW th max) to prime the power production. The new 100 MW BFB boiler began commercial production on The new boiler will yield about 32 MW of electrical power and 40 MW of district-heating energy. In the future the total heat production of the plant will be about 500 GWh and net electricity generation about 400 GWh.

16 16 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Pursiala power plant Previously, the main fuel of the power plant was peat, while in 2000 about 60 % of fuels were wood-derived ones. The use of wood has exceeded that of peat since All solid fuels are domestic and more than half are wood-derived ones. Wood fuel is composed of the by-products of the mechanical forest industries, green forest chips and sorted construction waste. In 2004 the share of wood fuels was 61 % and peat 38.6 %. Oil accounted only for 0.4 %. Wood and a peat are the fuels to be used in the new boiler also.

17 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 17 Pursiala power plant Fuel (GWh) Forest chips Industry by-products Recycled fuels Peat Oil Total In the future the total fuel usage will be about 1400 GWh (50 % peat, 50 % biomass).

18 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 18 There are two receiving stations at the plant. One is used mainly for receiving peat and the other for receiving wood fuels. The fuels are conveyed by flight conveyors from the receiving stations to the storage bins (1500 m 3). Biomass fuels are also stored in the plant s yard for the weekends.

19 19 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Pursiala power plant the CFB boiler The CFB boiler of Pursiala plant was commissioned by Foster Wheeler Oy in Specs: 84 MW th, 33 kg/s, 535 ºC, 114 bar Maximum district heat capacity is 54.4 MW, maximum electric output of generator is 28.7 MW. The flue gases are cleaned with a three-field electric precipatator with efficiency of more than 99.9% (of particles separated). Ash is used for landscaping of the old land area used for taking of soil.

20 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 20 Pursiala power plant the CFB boiler There have been some operational difficulties with the challenging fuelblends in the CFB-boiler The superheaters have suffered quite a lot of fouling during the recent years which have affected the production of the plant The availability (kgde) of the power plant was 97.8 % in 2004 (low because of the generator revision). Fouling at the superheaters

21 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 21 Acknowledgements Fortum Power and Heat Oy Etelä-Savon Energia Oy

22 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 22