LARGE-SCALE BIOMASS GASIFICATION PLANT INTEGRATED TO A COAL-FIRED BOILER

Transcription

1 Fuel conversion at the Vaasa power plant: LARGE-SCALE BIOMASS GASIFICATION PLANT INTEGRATED TO A COAL-FIRED BOILER BioGaC Project, Study Visit at Vaasa November 25, 2014 Mauri Blomberg 1

2 Large-scale biomass gasification plant integrated to a coal-fired boiler Contents: 1. Vaskiluodon Voima Oy, Vaasa power plant 2. Background of the project 3. The gasification plant project 4. Vaskiluoto gasification plant 5. Procurement of biomass 2

3 Vaskiluodon Voima Oy Vaskiluodon Voima was established in the late 1960s and is equally owned by the energy companies EPV Energia Oy and Pohjolan Voima Oy. Company s power plants, situated in Vaasa and Seinäjoki, together generate 1,2 2.5 TWh/a of electricity and around 800 GWh/a of district heat. The power plants production of district heating covers approximately 60% of the needs of the city of Vaasa and 90 % of needs of the city of Seinäjoki. As fuel Vaasa power plant uses coal, biomass and peat. Seinäjoki power plant s main fuels are biomass and peat. Vaasa Power Plant FINLAND Seinäjoki Power Plant 3

4 Vaasa power plant Vaskiluoto 2 Vaskiluoto 2 Investments were made in several phases: Coal-fired boiler 1982 Desulphurization plant 1993 New turbine plant 1998 Biomass gasification plant 2013 In technical terms, the plant is fit for use until 2030 Technical specifications: Electricity output 230 MW District heating 175 MW Production: Electricity 0,9-1.7 TWh/a District heating 450 GWh/a; covering approximately 60% of the Vaasa area s district heating demand 4

5 Vaskiluoto 2 - Process Diagram Boiler Plant 560 MW Turbine Plant Generator 230 MW e Vaasa Coal, Biomass, Peat District Heating 175 MW 5

6 Vaskiluoto 2 - Process Diagram FGD -PLANT BOILER PLANT TURBINE PLANT 43 bar / 570 C 250 MWe LIMESTONE SILO 190 kg / s 185 bar / 536 C HP IP LP G CONDENSER GAVO LUVO ABSORBER ESP FEED WATER 175 MW dh VAASA GYPSUM DEWATERING GYPSUM SILO FLY- ASH SILO 80 t/h COAL MILLS 4 PCS COAL SILOS DISTRICT HEATING NETWORK t/a 6

7 1. Vaskiluodon Voima Oy, Vaasa power plant 2. Background of the project 3. The gasification plant project 4. Vaskiluoto gasification plant 5. Procurement of biomass 7

8 Fuel conversion - from coal to biomass Main drivers for the project + European emissions trading system and feed-in tariff for forest biomass + Taxation of fossil fuels used for district heating + National pressure to decrease the use of coal in CHP-plants + The possibility to extend the lifecycle of the existing power plant Reduction of emissions Domestic biomass to replace coal Cost-efficient electricity and heat production Possibility of producing competitively condensing power remains 8

9 Technical options for reaching the targets 1. A new CFB-boiler to replace the existing pulverized coal-fired boiler + Technically a good solution + Enables use of a wide range of biomass and other fuels - High investment costs and long outage - Uncertain investment environment 2. To add biomass grinding equipment to the current plant + An inexpensive technical solution - Need for higher cost dry biomass, which can be ground to a sufficiently fine grade (normal forest chips are not feasible) - With use of local biomass, only relatively small amount of coal could be replaced 9

10 Technical options for reaching the targets 3. Integration of a biomass gasification plant to the existing coal-fired boiler + Enables use of a wide range of biomass and other fuels + A retrofit investment that is a relatively inexpensive solution + The existing coal-fired boiler can be utilized + Short project time and the need for only a few weeks outage of the existing power plant - Technical risks of a new technology - Some process risks with the existing coal-fired boiler As a conclusion, gasification was seen as the best suitable technology for the Vaasa power plant. 10

11 1. Vaskiluodon Voima Oy, Vaasa power plant 2. Background of the project 3. The gasification plant project 4. Vaskiluoto gasification plant 5. Procurement of biomass 11

12 The gasification plant project key data Project budget Project s overall budget is below 40 million euros Ministry of Employment and the Economy granted an investment aid of 10,8 million euros for the project (renewable energy, new technology) Main equipment supplier Metso Power Oy Time schedule of the project Signing of the main equipment contract, May 6, 2011 Handing over of the gasification plant to Vaskiluodon Voima, Jan. 31,

13 The gasification technology The gasification plant has a fuel input of 140 MW and can replace around percent of the coal currently used at Vaasa power plant. Gasification of wood, peat and field biomass results in product gas that is fired together with coal in the existing boiler The gasification plant can be fired exclusively with forest biomass. The gasification plant uses peat as the reserve fuel Coal-fired boiler Gasifier Fuel receiving and storage Biomass dryer 13

14 Power plant s size and efficiency 100 MW, fuel Small power plant, efficiency 25 % 25 MW green electricity 100 MW, fuel 400 MW, coal Large power plant, efficiency 40 % 40 MW green electricity MW coal electricity 14

15 The gasification plant layout Fuel sampling Fuel crushing and sieving Forest chip dryer Gasifier Fuel receiving Fuel storage silos 15

16 Gasification plant benefits The gasification plant reduces the use of coal by 25 40% Main conclusions: 1. The gasification plant makes possible to use a wide range of bio fuels. Possible to continue heat and power generation cost efficiently 2. The gasification plant reduces the use of coal by 25-40%. 3. The investment reduces power plant s CO2-emissions by tons/yr. 4. Positive impacts on the regional economy and employment: The fuel used for gasification is domestic and locally produced; EUR 15 million will be injected into the regional economy annually (Earlier this money was used on imported coal and CO2-emission rights). The gasification plant results in a direct, permanent net employment effect of approximately 100 person-years. 16

17 1. Vaskiluodon Voima Oy, Vaasa power plant 2. Background of the project 3. The gasification plant project 4. Vaskiluoto gasification plant 5. Procurement of biomass 17

18 Bio fuels for the gasification plant The fuel required for the gasification plant (900 GWh/a) is procured locally within 100 kilometers of the plant: Forest chips 90 % (50 100%) Reed canary grass, grain and straw 0 % (0 5%) Peat 10 % (0 50%) Amount : 30 trailer-trucks a day 18

19 Bio fuels for the gasification plant 1. Forest chips Forest residue chips Stem wood chips Stump wood chips (mainly from spruce trees) 2. By-products of wood-processing industry Sawdust Bark 3. Recycled construction wood chips 19

20 Mauri Blomberg Managing Director Vaskiluodon Voima Oy