A state-of-the-art facility

1. Energy from Coal A state-of-the-art facility

2. A Coal based electric generation power plant in gilettewyoming

3. 1 conveyor 4 bag house 2 silos 5 boiler 3 scrubbers 6 turbine 7 air Cooled Condenser Plant Layout 1 2 3 5 4 7 6

4. How much power? • 385 MW (megawatts) • of energy is generated by this plant. • Enough for 308,000 homes in the midwest.

5. Where does the power go? • 135 rural electric electric systems receive energy from Dry Fork.

6. Where does the power go? • These stations are in nine states including Minnesota.

7. How much Coal is used? • The plant consumes 220 tons of coal per hour. • Coal comes from the nearby Dry Fork Mine.

8. Limited Supply Issues • The mine has enough coal to supply 308,000 homes with electricity for about 60 years.

9. Transportation issues • Sub-bituminous coal supplies are obtained from the near-by Dry Fork Mines.

10. The conveyor system • Coal travels from the mine to the power plant over a one-mile conveyor system.

11. Safety Issues employees • It took 1300 people to build the plant.

12. Safety Issues employees • There was not a single lost-time incident in the 6-million man hours it took to build the plant.

13. Safety at the mine • In order to prepare the coal for extraction it must be exploded.

14. Safety at the mine • Holes are dug in the ground and explosives (ammonium nitrate)is inserted in the holes. • Precautions are taken so miners are safe from the explosion.

15. Safety at the mine • The ammonium nitrate is stored safely in tanks on the mine site.

16. Heat Issues • The largest piece of machinery is the boiler. (186 ft. tall) • Here water is heated to make steam at 1,050 degrees. • The steam turns the turbines.

17. Heat Issues • The turbine uses 563,220 horsepower to spin the generator at a constant rate of 3600 rpms (revolutions per minute) to produce the current.

18. Heat Issues • Once steam exits turbine it goes to the air-cooled condenser. • Steam is cooled back to water. • Water is returned to the boiler. • Dry Fork is a zero discharge station.

19. Clean air issues • Dry Fork has spent $336 million on technologies to capture and remove toxins from the air. • It also spends $5 million annually to operate these technologies. scrubber

20. Clean air issues • The scrubber is a reflux circulating fluid bed scrubber. • It uses lime to remove 95% of the sulfur dioxide emissions.

21. Clean air issues • The scrubber also removes some of the mercury, • It is the largest scrubber of this design in the world. Mrs. Lewis

22. Clean Air Issues • There are 20 low NOx burners • Here air is injected into the boiler above the combustion zone to lower combustion temp and reduce NOx emission.

23. Clean air issues • A SCR (selective catalytic reduction) device is used to remove NOx by injecting ammonia into the flue after the burning. • This is like the catalytic converter in your car.

24. Clean Air Issues • Mercury is captured in the bag house with the fly ash by injecting activated carbon post combustion. • The fly ash is transported to a land fill.

25. Ash disposal • Bottom ash is collected from the boiler using a dry-chain driven system. • Ash goes to the landfill or is sold to road construction companies as an ingredient in concrete.

26. Ash Disposal • The area identified for ash disposal is large enough to accept ash for the 60 year life of the mine.

27. Wildlife and land reclamation • The mine land is being reclaimed on a regular basis. • Many animals are regularly seen on the mine landscape.

28. reclamation • An Environmental engineer was hired to plan the reclamation.

29. http://www.wmpa.org/pdf/DFS-Dry-Fork-Station-Brochure-7-11.pdfhttp://www.wmpa.org/pdf/DFS-Dry-Fork-Station-Brochure-7-11.pdf Information Resource