Ljungby Energi AB Biomass CHP Plant, Ljungby Sweden

Transcription

1 Ljungby Energi AB Biomass CHP Plant, Ljungby Sweden Ljungby Energi AB, an energy company owned by the municipality of Ljungby. The company Ljungby Energi AB is serving the municipality of Ljungby with energy. Ljungby is a municipality in the south of Sweden. Vimmerby was founded as town about 700 years ago. The number of inhabitants of Vimmerby is about Ljungby Energi AB owns one production plant named Ljungsjöverken. There are six boilers on the plant. There are two LPG fired boilers, one oil boiler, one landfill gas boiler, one wood chip/peat fired boiler and one waste fired boiler. The waste fired boiler is a steam boiler, steam with data 16 bar and 220 o C that means a steam temperature 20 o C over saturation temperature, with a steam turbine of type Curtis. The boiler effect is 18 MW and the turbine have an effect of 1,7 MW. The boiler is equipped with a semidry flue gas cleaning system. The number of employees in the company Ljungby Energi AB is around 34. Ljungby Energi AB operates the boiler plant, district heating net, electricity net and computer net in Ljungby. 1

2 Project background D3b case 3 Ljungby Energi AB needed more effect to the district-heating grid of Ljungby. A feasibility study was made and the most favourable alternative was a waste fired boiler with limited power production. In the beginning of the 2000 th it was not so usual with limited power production. Most of the plants that hade been built hade other steam data in aspects of super heating temperature and pressure. The boiler was started in January Project description The aim with the project was to build a boiler for fuels like biomass and waste. The plant should fully fill the EU requirements. The plant should also be fully automatic. The fuel should be taken in the region around Ljungby. The decision was to build a boiler with limited steam data and a size that was suitable for the municipality of Ljungby. For that reason the boiler have an effect of 18 MW. The reach the high environmental data the boiler have a SNCR-system for NO x -reduction. The boiler is grate fired. The boiler in Ljungby was the first built with this concept in Sweden. The main innovation The main innovation in the Ljungby project has to build a small plant with high environmental data in an economical way. Plant description The plant is a grate fired boiler with an effect of 18 MW. The plant is build outside Ljungby. Ljungby Energi owns five more production units but the new 18 MW waste/biomass fired boiler is the main boiler. The other boilers are one biomass/peat fired boiler with an effect of 7 MW including flue gas condenser, two gas fired boilers with an effect of 6,3 MW each, one oil fired boiler with an effect of 10 MW and one 0,2 MW landfill gas fired boiler. Al five boilers are hot water boilers. The heat from the boilers is delivered to the municipality of Ljungby. Picture 1. Boiler lift. 2

3 Picture 2. Turbine. Technical details The waste/biomass fired boiler is grate. The plant in Ljungby contains three boilers fuelled with biomass. The largest boiler is a grate boiler with an output of 8 MW th from the boiler. The outlet temperature from the boiler is 200 o C. The plant is full automatic, there are only personnel at the plant during normal office time and one person on duty on nights and weekends. Thermal power output boiler (MW) 18 Power output (MW) 1,7 Efficiency according to DIN (%) Combustion equipment Grate Operation pressure (bar) 16 Steam temperature (C o ) 220 Fuel Waste and biomass Table 1. Boiler data for the new boiler. Number of persons Total number of employees 35 Personnel for boiler plant 13 Personnel on duty on not office time, 5 in five shifts. Table 2. Number of employees at Ljungby Energi. Annual operating time for plant (h) 8760 Annual operating time for new 6000 boiler (h) Table 3. Annual operating time for plant and different parts 3

4 The fuel storage during normal operation is a normal bin. During the summer period when there is no need for heat the fuel is stored in plastic sack on a large field for usage in the winter. The method for storage of the waste fuel is not so common. Fuel storage type for daily usage Bin Fuel storage size (m 3 ) Transport equipment for transport of Scoop fuel from fuel inlet. Fuel storage during summer period Plastic sacks when boiler not are in operation. Other transport equipment Table 4. Fuel storage. Energy data The annual heat production is shown in table 5 and 6 below. Fuels/Raw material The plant has six boilers. In the six boilers could six different fuels be used. The fuels are gas from landfill gas, gas, oil, peat, biomass and waste. Fuel for the main boiler, the waste/biomass fired boiler, is delivered from the municipality of Ljungby and some other municipalities close to Ljungby. Fuel Amount (MWh) Proportion (%) Waste Gas, oil 5,4 4,7 Bark, 3,3 2,9 wood chip Landfill 1,8 1,6 gas Peat 21,4 18,8 Table 5. Fuel usage in the Ljungby district heating plant. Fuel Amount Proportion (MWh) (%) Waste 100 Table 6. Fuel usage in new boiler in Ljungby district heating plant. The average transport distance for the fuel is diameter of 45 km. During the winter in ordinary days are three to four lorry s delivering fuel to the plant The fuel demand is approximately ton per year. The plant produces about 6000 tonnes of bottom ash and 800 tones of fly ash each year. 4

5 Picture X. Storage tank for fly ash. Economical data The investment in 2000 was approx thousand Swedish kronor or approx thousand Euro. The investment include boiler with all equipment for waste firing, flue gas cleaning and turbine. Today will the same plant cost approx thousend Swedish kronor. Environmental impact By firing biomass the CO 2 emissions can be reduced. The plant is fully filling al regulations for combustion of waste. The values for emissions that should be kept are as shown in table 7. The values in table 7 are measured continuously. Some emissions that are shown in table 8 are only measured at inspections. To keep this values are the boiler equipped with textile filter and a semi-dry system for injection of chalk, active carbon and water. The consumption is 65 kg/h of chalk and 2,2 kg/h of activated carbon at 100 % load. To reduce the NOx are a SNCR-system installed. Of this reason there are limits on ammonia emissions. Because of the restrictions on emissions is it mostly common to build larger plants, than this plant, for waste incineration. Emission Daily average value (mg/nm 3 ) Half hour average values (mg/nm 3 ) Dust TOC HCl HF 1 4 SO NO x CO NH Table 7, Emissions from the new boiler in Vimmerby. Emission at inspection Dioxines <0,1 ng/m 3 (ntg) Hg <0,03 ng/m 3 (ntg) Cd <0,03 ng/m 3 (ntg) 5

6 Table 8, Emissions. Owner of the plant Ljungby Energi AB is the owner of the plant. The municipality of Ljungby owns the company. Users All energy produced in the plant is delivered to the district-heating grid of Ljungby. In the village of Ljungnby is about 50 % of the households to the district heating grid. Main manufacturers and service suppliers Contractor Consortium with ETK and Babcox ETK Box 71 S Luleå Sweden Phone: +46 (0) Babcok&Wilcox Völund Falökevej 2 Stenvinkelsgatan 3C S-6705 Esbjer Denmark Phone: +45 (0) Table of the main data Boiler (or rector) Type grate, 18 MW th Steam values (if steam boiler) Temperature 220 o C, pressure 16 bar, steam (t/h) Heat output (process of district heat) 18 MW th Electricity output 1,7 MW e Annual biomass fuel utilisation 125 Annual heat production 114 GWh Annual electricity production 6 GWh Total investment of the plant thousand Swedish kronor and EUR Investment aids No aid Other important data (please specify) Additional information Bo Carlsson Plant manager Ljungby Energi AB Box 262 S Ljungby 6

7 Tel. +46 (0) D3b case 3 Bo.karlsson@ljungby-energi.se Järnforsen Produced by OPET Sweden, WSP 1/2004 Rolf Ingman rolf.ingman@wspgroup.se Links to pages of Ljungby Energi AB and owners: Produced by OPET Sweden, Rolf Ingman. rolf.ingman@wspgroup.se the author, date and 7