Eija Alakangas VTT Energy

Transcription

1 THE COUNTRY REPORT OF FINLAND Cofiring of biomass - evaluation of fuel procurement and handling in selected existing plants and exchange of information (COFIRIN) - Part 2 Eija Alakangas VTT Energy

2 1. Introduction Finland is located in northern Europe. Almost its entire national territory is situated between 60 and 70 degrees northern latitude, and a quarter of its surface area lies north of the Arctic Circle. One-third of all people living north of the 60 th parallel are Finns. The mean annual temperature in Southern Finland is 4 to 5 degrees Celsius, in Lapland 2 to +3 degrees Celsius. In January, the mean annual temperature in the northern two thirds of the country is 10 to 15 C, in southern Finland it is 5 to 10 C. Even in southern Finland, 30% of the annual precipitation stems from snow, which remains on the ground for about 4 months. In the winter season, there is a very limited amount of full daylight, necessitating electric lighting until late morning and as of early afternoon. The growth season is four months long. Correspondingly, the population weighted average number of heating degree-days for Finland is 5 000, much higher than the figure for Sweden and Norway (4 000). Thus Finland has the coldest climate in Europe. Finland is large and sparsely populated: with 338,145 km 2, it is the fifth largest country in Europe and has a population of 5.2 million, i.e. 17 people per square kilometre. More than two-thirds of Finns live in urban areas; only 1.6% live north of the Arctic Circle. More than three-quarters (68%) of the country is covered by boreal coniferous forests, and 10% by lakes and other water systems, only 9% is cultivated area. Productive forestland is the most valuable natural resource of Finland. The only indigenous energy resources in the country are hydropower, wood, peat, wind and agrobiomass. The forest and paper, metal and engineering and chemical industries represent about 80% of Finland's industrial production. These industries are very energy-intensive, and the forest and paper industry alone accounts for 63% of industrial energy consumption. 2. Finnish Energy System One of the strengths of Finland's energy economy is the variety of the production structure. Use of wood and wood-based fuels plays an important role in this decentralised and diversified energy system. Increasing the use of wood and other renewable energy sources is an explicit goal of Finnish energy strategy. Renewable energy sources are important both in limiting carbon dioxide emissions and for ensuring the security of Finnish energy supply. Moreover, utilisation of wood has positive effects on employment on the local level. In 1999, renewable energy sources accounted for about 24% of all energy consumption in Finland (3). Of that figure, 20% was wood energy and the rest mostly hydropower. That is the third highest percentage in the EU, and for bioenergy, the highest (Figure 1). 81

3 Coal 11 % Natural gas 11 % Oil 28 % Hydro power 4 % Wood fuels 20 % (Ind. wood residues, black liquor, fire wood) Other 1 % Peat 6 % Nuclear power 17 % Net imports of electricity 3 % Wind energy 0 % Total energy consumption million toe Source: Energy Statistics Figure 1. Total energy consumption in Finland in 1999.(3) Table 1. Total energy consumption by energy source in Finland, PJ. (3) Energy source Oil Coal Natural gas Nuclear power Net imports of electricity Wind energy Hydro power Wood fuels, of which Black liquour Industrial wood residues Firewood (domestic) Peat MSW Other Total, PJ Mtoe For years, Finland has exploited the combined heat and power (CHP), as well as district heating, which operate with high power to heat ratio. The proportion of the combined 82

4 generation is among the highest in the world. About 76% of district heat for municipalities are produced by cogeneration. Combined heat and electricity generation based on locally available fuels like wood and peat accounts for the bulk of bioenergy production in Finland. Multifuel boilers fired with peat, wood fuels, coal and natural gas are widely used in Finland (Fig 2 and Table 2). Cofiring is natural solution in the plants over 1 MW th boiler capacity. Boiler capacity of the cofiring plants in Finland varies from 1 to 300 MW th. In Finland, the world s largest biomass cofiring plant (boiler 550 MW th ) is under construction. This plant will generate 240 MW e electricity, 100 MW th process steam and 60 MW th district heat. The plant will be commissioned in autumn Plant will use TJ fuel of which wood represents 40%, peat 45% and REF and coal 15%. The CFB boiler is designed for 100% coal or 100% biomass use, so it can change fuel utilisation flexibly according availability and price. Finland used 79.9 TWh of electricity in About 33% of electricity generated annually becomes from combined heat and power (CHP). In CHP the total efficiency is very high, 85 90% of the fuel input will be utilised. Cogeneration is widely utilised in Finland for heating communities and generating heat and power using wood residues from industrial processes. Industrial power plants and district heating plants account for 56% and 44% of CHP electricity respectively (3) Wood Municipal heat stations 0 7 Industrial heat stations Peat Cocomb of wood and peat Municipal CHP Industrial CHP Others 1 Figure 2. Number of boilers using wood, peat and also cocombustion of peat and wood in Finland (5). 83

5 Table 2. Current biomass users in Finland (source: VTT s own registers). BIOMASS USERS Amount Unit No. of biomass fuelled DH plants (> 1 MW) 160 pieces Installed capacity of biomass fuelled DH boilers 600 MW th No. of biomass fuelled CHP plants 33 pieces Installed capacity of biomass fuelled CHP boilers 3500 MW th 1250 MW e No. of biomass fuelled power plants 1 (peat) pieces Installed capacity of biomass fuelled boilers 150 MW e No. of biomass fuelled plants in pulp & paper industry 27 pieces Installed capacity of solid biomass fuelled boilers 3750 in pulp & paper industry 850 Installed capacity of recovery boilers in pulp & 4300 paper industry 590 MW th MW e MW th MW e No. of biomass fuelled plants in sawmills 50 pieces (excluding those integrated with pulp&paper) Installed capacity of biomass fuelled boilers in 390 sawmills 20 MW th MW e No. of biomass fuelled plants in other industries 55 pieces Installed capacity of biomass fuelled boilers in 1700 other industries 290 MW th MW e 3. Reasons for cofiring in Finland Cofiring is used for the following, specific reasons: ood availability of wood biomass: In Finland the forest industry is harvesting wood raw material for production of pulp or timber. In 1999 forest industry used 63.3 million m 3 solid, of which about 12% is bark and used in energy production (52.7 PJ). When harvesting raw material also forest residues can be used for energy production, and this is increasing in the future remarcable. Wood residues from debarking, and delimbing are already available in the plant in cost effective way. Waste to energy: In many cases disposing by burning is the only cost-effective available and environmentally sound way of waste treatment. A new promising way 84

6 to fulfil these targets and to utilise source sorted and quality controlled (standard SFS 5875) recycled fuels, as energy is to apply cocombustion or gasification of different fuels and wastes. Presupposing that the waste material composition is known i.e. waste material for fuel purpose has passed through the source separation and pre-treatment process. Energy taxation for fossil fuels and emissions regulations: Environmental regulations (emission limits for SO 2, NO x and particles ) and taxation of fossil fuels (CO 2 taxes for fossil fuels in heat generation, 102 FIM/CO 2 =17.2 /CO 2, table 3) have recently further increased interest in the use of biomass in energy generation. Support of biomass electricity production: In Finland wood based or peat fired (<40 MVA) electricity production is supported by state (25 FIM/MWh=1.2 /J). Climate conditions; In winter time wood fuels moist wood fuels especially logging residues can seldom meet the whole heat load demand, then peat or coal is used as peak load fuels. Better combustion: in steam boiler (steam temperature >480 o C hot corrosion and slagging and fouling problems can be avoided by using peat or coal (including sulphur), when burning alkaline content fuel like fresh forest residues (including needles). Technology development: Finnish manufacturers have developed technology for wood raw material and wood fuel production, combustion and gasification technology suitable for co-production and cofiring of wood, straw with peat and coal. In Finland wood fuels is mainly cocombusted with peat. Planning for cofiring: In Finland most of the boilers from 1 MW th output have been designed for multifuel combustion and the boiler can be operate by different fuel mixtures based on the availability biomass fuels and prices of fuels. Solution for large-scale power plants: In cocombustion even small amounts of biomass could substitute fossil fuels. The best case is if the boiler is already designed or retrofitted for cocombustion. An alternative solution could be a biomass fuelled gasifier connected to the existing coal-fired boiler (e.g. Lahden Lämpövoima-Kymijärvi plant). In Finland the pulp and paper industry has very strong influence on the use biomass energy and cofiring. The large forest resources mean also many sawn mills and their byproducts like bark and sawdust is used for energy production. Lack of own fossil fuels and cold climate has emphasised the effective use of the indigenous fuels, mostly based on biomass. The situation has created also very sophisticated boiler technologies and skilled equipment manufacturers and CHP -solutions. 85

7 The main solutions for cofiring in Finland are: circulating (CFB) and bubbling (BFB) fluidised bed combustion grate firing mixing of biomass with coal or feeding grinded biomass by own burners to boiler and combustion in pulverise coal fired boiler (see Fortum case project) retrofits (conversion of boilers to fluidised bed, grate) separate gasification for biomass and the combustion of produced gas in (main) boiler (Lahti plant). Table 3. Energy taxes for heat production in Finland and fuel prices in October Source: Ministry of Trade and Industry and Eletrowatt-Ekono (2). Fuel EXCISE TAXES FOR FUELS IN HEAT PRODUCTION FUEL PRICES CO 2 g/mj 1996 FIM/MWh (euro/j) (1 st January- 30 th August) 1998 As 1 st September 1998 October 2000 including energy taxes and excluding VAT FIM/MWh FIM/MWh (22%) FIM/MWh (euro/j) (euro/j) (euro/j) FIM/MWh (euro/j) Peat 106* 3.5 (0.16) (0.19) (0.22) (0.42) ( ) Wood (2.1) Heavy oil (0.76) 19.6 (0.91) Light oil (0.83) 29 (1.34) Natural gas 56.1** 5.6 (0.26) 7.1 (0.33) Coal (0.77) 24.1 (1.12) Electricity, class I = Electricity tax rebate for wind power plants Electricity class II = Electricity tax rebate for wood and peat CHP, hydro plants euro/mwh (2.82 euro/mwh) 22.9 (1.06) 32.7 (1.51) 8.3 (0.38) 28.4 (1.31) euro/mwh 20.2 (3.40 euro/mwh) FIM/kg (1.31) FIM/l (1.75) FIM/m n (0.48) FIM/t (1.63) euro/mwh 25 (4.20 euro/mwh) 133 (6.2) 198 (9.3) 78.5 (3.7) 68 coast (3.2) 74 inland (3.5) - 1 euro= 5,94573 FIM * not used for the basis of the tax, tax is 9 FIM/MWh ** 50% reduction of the tax - 86

8 Heating and power plants and forest industrial boilers combust forest chips typically mixed with other fuels such as peat, wood and bark residues from forest industries, and coal. Forest chips consisted only one fourth of their total use of wood-based fuels. An even more important source of energy for them was peat. Therefore, mixing and cofiring of forest chips with other solid fuels play an important role in Finnish energy system. A comprehensive study of prices of forest chips has been performed earlier for the years 1982, 1995 and now for 1999 (4) Small stems delimbed Small stems undelimbed Logging residues Forest chips average Figure 3. Prices of forest chips in Finland in 1982,1995 and 1999 ( /MWh) (4). Figure 3 and table 4 shows that not only real but even nominal prices have radically decreased in the last two decades: the average price of forest chips at heating plants (forest industries and large CHP plants excluded) was 3.97 /J (85 FIM/MWh) in 1982 but only 3.08 /J (66 FIM/MWh) in 1995 and 2.48 /J (53 FIM/MWh) in 1999 (4). 87

9 Table 4. Average prices of wood fuels paid by heating plants in 1995 and VAT excluded. Source: Wood Energy Technology Programme (4). Source Change FIM/MWh /MWh FIM/MWh /MWh % Industrial residues: Bark Sawdust Chips Forest biomass: Delimbed stems Whole trees Small trees, average Logging residues Forest chips, average Future Prospects The target is to increase the use of renewable energy sources at least by 50% (3 Mtoe) by the year 2010 from the level of the year % of this increase is expected to consist of bioenergy, 3% of wind power, 3% of hydropower, 4% of heat pumps and less than 0.5% of solar power. This target involves an increase in the share of renewable energy sources by 5 6 percentage units in the total energy consumption compared to that in 1995 (1.5). The most rapid growth is scheduled for wind and solar energies, the use of which should be increased many-fold. The target of bioenergy has been divided to various sectors of use, and different biofuels are chosen on the basis of their competitiveness. According to estimates available, the additional amount of wood fuels available from the industry would equal to Mtoe. Forest fuels and firewood represent Mtoe, wastes Mtoe, and agrobiomass Mtoe, depending on the production level of the forest industry and the price level of fuels. The total amount would be equal to Mtoe. The total target amount of use would be 2.8 Mtoe, the percentages being 50% industrial wood residues, 30% forest fuels, and 20% recovered fuels (1,5). The share of renewable energy sources in power production would increase to 8.3 TWh (2,010 MW) from the level in 1995, if the power consumption were as presented in the 88

10 scenario of the Finnish Ministry of Trade and Industry, issued in autumn The major part, 75%, would be generated from biofuels (6.2 TWh, 1,050 MW). The percentage of bioenergy in the additional power generation is assessed to remain above 70% also in the vision for the year 2025, when the new technologies with a high powerto-heat ratio are expected to be in extensive use in combined power and heat production. The share of wind power in additional power generation would be 1.1 TWh (500 MW) and that of hydropower 1.0 TWh (420 MW) by the year The target of hydropower concerns small-scale hydropower plants of < 10 MW, and renovation and overhaul of old hydropower plants; it does not include any new large-scale hydropower plants. The percentage of solar energy would be less than 1%, i.e TWh (40 MW)(1,5). Increase in the use of renewable energy sources will reduce greenhouse gas emissions if replacing fossil fuels and peat. The achievement of the targets would reduce greenhouse gas emissions by about million tonnes of CO 2 equivalent, based on the present level of promotion measures. In the reduction of greenhouse gas emissions, Mt CO 2 equivalent would comprise methane emissions from landfills and the rest would be carbon dioxide emissions from energy generation. A hypothetical reduction of about 10 Mt CO 2 could be achieved through the assessed additional use of renewable energy sources over the period of This value indicates, how much higher the greenhouse gas emissions would be in Finland, if the target value of about 3 Mtoe set in the Action Plan were generated from fossil fuels (1,5). 89

11 References 1. Action Plan for Renewable Energy, March Ministry of Trade and Industry, Energy Department. Publications 1/2000 p. 38 p. 2. Alakangas, E. & Janka, P. Fiscal measures and subsidies, ENE39/T0099/99. ENER IURE project- analysis of the legislation regarding renewable energy sources in the E.U. member states- Phase II, March 2000, 27 p. 3. Energy Statistics Energy 2000:2, Statistics Finland, Helsinki 2000, 147 p. 4. Hakkila, P. & Nousiainen, I., Forest chips in Finland use, epxeriences and prices. Nordic Treasure Hunt, seminar 30 th August 2000, Jyväskylä, VTT Symposium p Helynen S, Holttinen, H., Lund, P., Sipilä, K., Wolff, J, & Alakangas, E., Background report for the Action Plan of Renewable Energy Sources.VTT Energy. Finnish Ministry of Trade and Industry Energy Department. Studies and Reports 24/1999. In Finnish, English abstract. 112 p. 90