THE COUNTRY REPORT OF SWEDEN

Transcription

1 THE COUNTRY REPORT OF SWEDEN Cofiring of biomass - evaluation of fuel procurement and handling in selected existing plants and exchange of information (COFIRING) - Part 2 Bengt Hillring SLU

2 1. The Swedish energy system The Swedish energy supply in 1998 amounted to 1,730 PJ (1). Average energy supply the last 25 years has been 1,584 PJ. Crude oil and other oil products supplied in 1998 about 745 PJ, natural gas 32 PJ, coal 94 PJ, biofuels 331 PJ, hydropower 274 PJ and nuclear power 259 PJ. The total final energy use can be divided into three main categories; residential, commercial and service sectors, industry and domestic transportation. There are also losses in the energy system and energy used for foreign maritime trade and use for non energy purposes. For 1998 the total final energy use was about 1,422 PJ (1) divided into residential, commercial and service 562 PJ, industry 540 PJ, domestic transportation 320 PJ, losses 158 PJ and foreign transport etc. 151 PJ. There was also an electricity export from Sweden of about 40 PJ (10.7 TWh) for Sweden have a cold climate and a very strong forest products industry (including saw mills) supplying biofuels (mainly wood-fuels) internal or for external markets. Biofuels in the Swedish energy system includes different types of fuels and included in this category are: digester liqueurs from pulp mills, wood fuels (logging residues, sawdust, bark and energy plantations), waste of a biological origin, peat and straw and energy grasses. The development of the final energy use of different biofuels in the Swedish energy system during the past 10 years is shown in table 1. Table 1. Final energy use of different biofuels for all sectors , PJ. Data calculated from the source (1) Digest Liqueurs Wood fuels Waste Peat Bio. for electr Other Total* *Figures not balanced therefore differences may appear compared to total figures in (1). Losses are not included. There are some very significant trends in the biofuel use. The total use of all biofuels has increased from 234 PJ to 326 PJ or about 40% in 10 years and plays a significant 2

3 role in the Swedish energy supply system. Wood fuel use increased with nearly 60%. The increase is very strong for use of biofuels for heat production in district heating. Biofuel for electricity has not increased that much (40% from low levels) even if the production capacity has increased due to Governmental investment support for combined heat and power plants. During the five year period starting in 1991 there were 45 different projects that received support with an installed electricity production capacity of 326 MW e (2). Production of electricity is dependent on fuel prices and of prices on electricity. Electricity prices have decreased significantly due to the deregulation of the electricity market. The total electricity production for 1998 was 35 PJ (9.6 Twh e ) in CHP and 1 PJ (0.3 Twh e ) in condense production (1). The fuel supply to produce this electricity should also cover the losses in the production process, which means an estimation of double the electricity production in fuel supply. For PJ biofuels was reported as supply to CHP plants in district heating and 9 PJ biofuels was reported for electricity production in the industry (CHP or back-pressure power production. In the ten-year period to come, there will be a great volume of wood-fuel from forests made available at prices below today's price levels. About 130 PJ of felling residues and small trees (after technical and environmental restrictions) at a cost of SEK per GJ (3) will be available. This is above the 120 PJ of by-products from the forest industry that are already fairly completely exploited. 2. Combustion The Swedish stock of boilers consists of about 15,000 boilers larger than 1 MW with a dominance in the energy production of the 1,000 boilers larger than 10 MW (4). The large boilers counts for more than 60 % of the energy production. In many of the boilers for solid fuels it is possible to burn wood fuels. In the table below the installed effect on different energy carriers for boilers larger than 10 MW are presented. The table includes both industry, district heating and combined heat and power. 3

4 Table 2 Installed boiler effect for boilers >10 MW th, 1993 Main energy carrier Number Installed effect, MW th Oil Natural gas LPG Coal Biofuels Digester liqueurs Refuse Peat Electricity Others Total Note: others includes boilers were it not where possible to identify one main energy carrier. Source: (4); based on an inquiry to 400 boiler owners. Of the boilers owned by the industry, wood fuels in different forms are mainly used by the forest products industry. Emission regulations regarding dust, carbon dioxide, nitrogen oxides and sulphur oxides are stated for each large boiler by the authorities. The boilers are operated in respect of fuels prices, taxes and other circumstances to optimise the energy production and minimise the cost. 3. District Heating There were about 220 companies supplying district heating in Sweden in 1997, supplying a nominal connected load of 22 GW through 9,600 km of mains. During the year they supplied 152 PJ of heat of which almost 57 % was supplied to residential users, almost 34 % to the service sector and over 9 % to industry. A total energy input of 175 PJ, made up of 129 PJ from fuels and 46 PJ from electric boilers, heat pumps and waste heat, was needed to supply this quantity of heat. Losses in the production and distribution system was 23 PJ. During the 1970s, oil was the predominant energy source for district heating. It s use has subsequently fallen steadily, and amounted to a little over 10% of gross energy input in The reduction in the proportion of heat supplied by oil is due to two main factors: to substitution of the oil by other fuels (primarily biofuels, peat etc.), and to the fact that there has been a surplus of electricity for several years, favouring the use of heat pumps and interruptible electric boilers. 4

5 In the last years systems with district cooling has been constructed in some large cities. The total deliveries in the country was 0.2 PJ in 1996 for comfort and environmental reasons, and the market is forecasted to increase very fast. 4. Production and use of biofuels Biofuels could be divided into: digester liquors from pulp mills wood fuels (logs, logging residues, bark, sawdust and energy plantations) refuse peat, and straw & energy grasses. They are used in four main areas: the forest products industry district heating plants the single-family house sector, and electricity production. 4.1 The forest products industry For cost reasons, the forest products industry has always used it s by-products for heat and some electricity production. Digester liquors remaining after chemical processing of wood to produce wood pulp can be burnt to recover certain chemicals. They can be produced and used only within the cellulose industry, and provided 112 PJ of energy (excluding electricity production) in Wood fuels in the form of raw materials residues are used in both the cellulose industry and in sawmills. They consist mainly of wood chips, bark and other waste from the manufacturing processes. Use is also made, although to a lesser extent, of wood fuels produced by on-site forest chipping of wood unsuited for other commercial purposes. In 1996, the cellulose industry used a total of 25 PJ of such materials for energy production, while sawmills and other woodworking industries used 32 PJ. 5

6 4.2 District heating plants A total of 83 PJ of biofuels were used in the district heating sector in Of this, wood fuels accounted for 45 PJ, unrefined tall oil for 6 PJ, refuse for 16 PJ and peat for 13 PJ. The use of wood fuels by the district heating sector has tripled over the last five years. In 1996, use increased by 8 PJ or somewhat less than 20 %. The main form of the fuels is felling waste and forest by-products, although processed fuels such as briquettes and pellets have also been increasingly used in recent years, as has tall oil (a residue from pulp production). Refuse has been used for district heating production since the 1970s, and has settled fairly steadily at over 15 PJ. The problems of removal of dioxin emissions have now been satisfactorily solved. Sorting at source reduces the quantity of domestic refuse that can be burnt, while the industry has a potential for the production of waste wood (pallets etc.), which at present are not used for energy production. The use of peat in 1996, amounted to a total of 13 PJ. Production is dependent on the weather, and can therefore vary from year to year. Production in 1996 amounted to 2.6 million m 3, which was somewhat under the average for the 1990s. During good years, stocks are built up for use in future years if less should be produced. Experimental use has been made of energy crops such as energy forests, straw and energy grass since the beginning of the 1990s. About 0.4 PJ of energy forest fuels, mainly Willow (Salix sp.), were used during 1996, but very much less quantities of straw and energy grass were used. However, there is considerable potential for greater use, and the 17,000 hectare that have been planted with energy forest will provide an increase in the short term. Due to differences in taxation between European countries; i.e. high taxes for landfilling in some countries and high taxes for fossil fuels in Sweden, significant amounts of biomass fuels has been imported commercially during the last year. Import consists of wood fuels, recycled wood, tall oil, crushed olive stones and peat. Quantities have increased in recent years, and are estimated as amounting to about PJ in Imports account for about % of the supply of biofuels for district heating plants, which means that they are a substantial raw materials source. In addition, they are imported at prices which are below those on the domestic market, and so their import represents a certain price press on indigenous biofuels. The potential of biofuels is considerable, both as a raw material and for its possible use in Sweden and in neighbouring countries, and so an increasingly important international trade in biomass 6

7 fuels could develop in the future: the magnitude of this trade will depend on market development. 4.3 The single-family house sector About 43 PJ of wood fuels, mainly in the form of logs and chips, were used in single-family houses in Wood firing is commonest among property-owners with good access to forests, e.g. in agricultural or rural areas. 4.4 Electricity production 11 PJ of biofuels were used for electricity production. About 4 PJ of electricity was produced by wood fuels in combined heat and power plants. Remaining quantities was produced in industrial back-pressure plants in the cellulose industry, using digester liquors or by wood fuels. Biofuels other than wood and digester liquors are used only marginally for electricity production. 5. The Swedish energy taxation system The use of energy has been taxed since the 1950 s. Originally the objective was to finance the State's public spending. Taxes have been increased significantly the past 10 years while also the environmental element of taxation was given great importance. In table 3 the Swedish tax system for fuels and levels of 2000 are shown. 7

8 Table 3 Swedish taxes for fuel used for heat production for industry and other users in Values calculated after the source (5) User Industry Others Energy and Energy CO 2 Sulphur Total */GJ Energy CO 2 Sulphur Total */GJ environmental taxes Fuel Light fuel oil, SEK/m 3 (< 0,1 % S) Heavy fuel oil, SEK/m 3 (0,4 % S) Coal, SEK/1000 kg (0,5 % S) LPG, SEK/1000 kg Natural gas, SEK/1000 m 3 Peat, SEK/1000 kg (0,2 % S, 45 % moisture) Crude tall oil, SEK/m * One equals 8.60 SEK. Energy and environmental taxes in the present tax system distinguish between types of users and types of energy carriers. Users are divided into industry, SE-SIC 92:10-37 (6) and other users. The industry are exempt from energy tax (except for crude tall oil) and pays half of the carbon dioxide tax compared to other users, mainly due to international competition on the market for the industries products. Energy carriers (i.e. fossil fuels) that contain at least 5% of gaseous or liquid hydrocarbons by weight and that are sold or used for heating purposes are subject to both energy tax and carbon dioxide tax. Fuels that are used for electricity production are exempt from energy and carbon dioxide tax. Instead electricity is taxed at the end user. Special rules apply for simultaneous production of heat and electricity in combined heat and power plants (CHP) or back-pressure power stations. Biofuels are untaxed for all users, while sulphur tax is levied on peat. Since 1990 value added tax are levied for energy and fuels. 8

9 The energy tax is still for financing the public spending requirements but in later years the emphasis has changed to the need to control the use of energy in order to achieve different policy objectives. The carbon dioxide tax was introduced in 1991 at the level of 0.36 SEK (0.04 ) per kg CO 2 emitted. The industry pays half the CO 2 tax compared to other users. Sulphur tax was also introduced in 1991 and amounts at present to SEK 30 (3.49 ) per kg of sulphur emission on coal and peat and to SEK 27 (3.14 ) per m 3 for each tenth of a percent by weight of sulphur in oil. An environmental levy on the emission of oxides of nitrogen (NO x ) was introduced in 1992 at the rate of SEK 40 (4.65 ) per kg of NO x emissions from boilers, gas turbines and stationary combustion plants with an annual energy production of 25 GWh or more. The system is neutral relative to the national budget, as payments are in proportion to the amount of energy produced and the levels of emission. Repayment is made to the operators of the plants with the lowest emissions, while those with the highest emissions are net payers. 6. Fuel prices Fuels are traded mainly on an international market and today even biofuels are internationally traded to some extent. In table 4 examples of prices from 1998 is given. Prices are given without taxes. Table 4 Swedish fuel prices without taxes 1999, /GJ. Calculations are made from (1), (5) and (7). Biofuel prices given for the district heating sector while fossil fuels are given for all users. Light fuel oil Heavy fuel oil Coal Sod peat Forest fuel Byproducts Recovered wood-fuel Upgraded wood-fuel (pellets&bri guettes) In table 4 we can see that untaxed fossil fuels are very competitive for use for electricity production while wood-fuels and peat compete very well after taxation in heat production. However in some market segments wood-fuels are competitive even 9

10 without taxes. This gives a base for combined use of fossil fuel and biofuel to minimise the energy taxes.. There are also other reasons than monetary to do cofiring between fuels. There might be technical reasons if the base fuel has too low heat value due to moisture and fuels with higher heat value are added. However, there are not always fossil fuels that are an alternative due to a green policy from the owner. 7. Cofiring There are two main categories of interest in co-firing in Sweden: the forest products industry and combined heat and power plants (CHP) supplying district heating networks. In the AFB-net co-firing project the Swedish part are five studies on co-firing plants distributed as in table 5. Table 5 Plants to be studied in the Swedish part of the ALTENER co-firing project Large Small Heat and power plant Linköping Enköping Knivsta Forest products industry Frövifors Fors Fors - Medium sized forest products industry with a CFB boiler at 55 MW th and 9.6 MW e output. Co-firing between different wood-fuels and coal. Enköping - CHP boiler in district heating at 55 MW th and 23 MW e with a vibration grid. Co-firing a mixture of wood-fuels from forest residues and Salix cultivated in local farms near-bye. Frövifors - Large forest products industry with a BFB (about 100 MW th, 25 MW e ). Co-firing between different biofuels (mainly wood-fuels) and oil. Linköping - Large CHP block in district heating with two boilers (one with a spreader stoker and the other with a moving grate) and three steam turbines (30 MW e, 40 MW e and 30 MW e respectively). Fuel used in cofiring are rubber tyres and coal in the first boiler and biofuels in the second boiler. 10

11 Knivsta - A grid boiler in district heating at 15 MW th. Cofiring between different wood-fuels (sawdust and other residues) and recycled wood-fuels. References 1. Energy in Sweden. Facts and Figures Eskilstuna: Swedish National Energy Administration, Hillring, B. National Strategies to Increase the Use of Bioenergy - Policy Instruments from Sweden. Biomass and Bioenergy. Vol. 14, Nos. 5-6, pp , Lönner, G., Danielsson, B-O., Hektor, B., Nilsson, P-O., Parikka, M., & Vikinge, B. Costs and access of wood-fuel in the medium term. Uppsala: Swedish University of Agricultural Sciences, Department of Forest-Industry-Market Studies. Report No 51, In Swedish. Summary in English. 4. NUTEK. Database for heat, power and combined heat and powerplants 10MW. Stockholm: Swedish National Board for Industrial and Technical Development. Info (In Swedish). 5. Prices for biofuels, peat etc. Bris blad 3/2000 Swedish National Energy Administration, Eskilstuna. Periodical. (In Swedish). 6. SCB, SE-SIC 92 - Swedish Standard Industrial Classification Report 1991, Statistics Sweden, Stockholm, Hillring, B. Regional Prices in the Swedish Wood-Fuel market. Paper accepted for publication in Energy - The International Journal. Vol. 9, pp ,