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Overview Of Talk . SO3 removal performance requirementsApplicability of injection of alkaline earth compounds - hydrated lime, magnesium hydroxideFull-scale injection applicationsResults of full-scale demonstrations of SO3 control with calcium and magnesium hydroxides Tests of improved hydrated
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1. Use of Alkaline-Earth Hydroxides for Reduction of Plume Visibility inCoal-Fired Power Plants
Lewis Benson
Carmeuse Technology
2. Overview Of Talk SO3 removal performance requirements
Applicability of injection of alkaline earth compounds - hydrated lime, magnesium hydroxide
Full-scale injection applications
Results of full-scale demonstrations of SO3 control with calcium and magnesium hydroxides
Tests of improved hydrated lime performance with higher surface area and humidification
Balance-of-plant effects
3. Performance Requirements for SO3 Control and Applicable Technology Retrofit
Return to pre-SCR SO3 in stack: ~50% reduction
Good fit for alkali injection
“Clear stack” - < ~5 ppm SO3, ~90% reduction
Potential fit for alkali injection
Demonstrated with SBS process
New Power Plant
< 2 ppm SO3
Wet ESP
Alkali injection ahead of baghouse
4. Conditions Favoring Alkali Injection Existing FGD system with difficult retrofit for a WESP
Existing FGD system with multiple absorber modules
Little impact on sale of fly ash
Problems with sulfuric acid corrosion in ductwork.
5. Compounds Tested for Injection for SO3 Control in Coal-fired Plants
6. Full-Scale Calcium Hydroxide Injection Applications Hydrated lime – pre-ESP
Zimmer – 1300 MW – 20 mo. in service
Cumberland – 2 x 1300 MW – in engineering
Hydrated lime – pre-wet FGD
Widows Creek 8 - 550 MW – 1 yr in service
650 MW – 3 mo. in service
7. Full-scale Magnesium Hydroxide Injection Applications Magnesium hydroxide
Zimmer – upper furnace - 20 mo. in service
Fuel Chem TIFI / TDI – furnace / air preheater
8. Pilot-scale Magnesium Hydroxide Injection Testing NETL DOE / Consol / Alstom / Allegheny Energy - 1.6 MW pilot
Injection ahead of Alstom pilot air preheater
4 moles Mg(OH)2 per mole SO3 inlet
>90% SO3 capture from ~10-30 ppmv SO3
10 day continuous operation with <240 F flue gas exit
Carmeuse / Consol / Alstom / Allegheny Energy – 1.6 MW pilot
SCR-like SO3 conc. ~50 ppmv
Demonstrate >90% SO3 capture, air preheater cleanliness with <240 F flue gas exit temperature for 3 month continuous operation
9. Key Properties of Hydrated Limesfor SO3 Control
10. Key Properties of Magnesium Compoundsfor SO3 Control
11. Magnesium-enhanced Lime (Thiosorbic®) Wet FGDwith Byproduct Mg(OH)2 Production
12. Injection Locations for Mg(OH)2 in NETL Demonstrations
13. SO3 Removal in Furnace in 1300 MW NETL Demonstration
14. SO3 Removal Across 1300 MW Furnace and SCR in NETL Demonstration No adverse impact on SCR catalyst or slagging
No significant adverse ESP impact
Opacity monitor readings reduced from 16-20% to 10-15%
Byproduct and commercial Mg(OH)2 gave similar results
No adverse impact on SCR catalyst or slagging
No significant adverse ESP impact
Opacity monitor readings reduced from 16-20% to 10-15%
Byproduct and commercial Mg(OH)2 gave similar results
15. Injection Locations for Mg(OH)2 and Ca(OH)2 for 1300 MW unit
16. Balance-of-Plant Issues with Mg(OH)2 and Hydrated Lime Injection in 1300 MW unit Furnace
Magnesium salt deposit on economizer tubes
ESP
Mg(OH)2
no significant effect
Hydrated lime
No significant adverse effect at addition rate of 3 TPH
No accumulation in ESP, downstream ducts
Slight build-up at air in-leaks
Flyash sales continue for concrete, other
17. Alkali Injection Short-term Performance Tests Hydrated lime – pre-wet FGD
650 MW
Hydrated lime – pre-ESP
Zimmer – 1300 MW
Gibson 5 - 625 MW
18. SO3 Reduction w/ Mg(OH)2 and Hydrated Lime Injection1300 MW, 3 TPH hydrated lime w/ 13 SSA, 75 gpm 15% commercial Mg(OH)2 slurry to furnace, SCR off
19. Effect of Specific Surface Area of Hydrated Lime on SO3 Reduction1300 MW, 1.8 TPH hydrated lime, 50 gpm byproduct Mg(OH)2 slurry to furnace, SCR off
20. Effect of Humidification on Hydrated Lime for SO3 Reduction625 MW, 1.8 TPH hydrated lime w/~23 SSA, pre-ESP, SCR off
21. Summary Injection of hydrated lime & magnesium hydroxide applicable for SO3 control
Full-scale injection applications
Options for hydrated lime injection location: pre-ESP, pre-FGD, pre-baghouse
Options for magnesium hydroxide injection: upper furnace, post furnace
Improved SO3 performance with higher surface area hydrated lime and humidification
22. Summary Furnace injection of Mg(OH)2 proven at 1300 MW for efficient capture of furnace-generated SO3; additional injection of hydrated lime ahead of ESP reduced stack SO3 <5 ppm
ESP performance with calcium or magnesium hydroxide depends on ESP design, improves with humidification
23. Contact information: Bob Roden – Carmeuse FGT Technical Marketing Manager – 412-777-0722 office: 412-889-9662 cell; bob.roden@carmeusena.com
Lew Benson – Carmeuse FGT Technical Manager – 412-777-0723; 412-818-9839 or 412-225-8816 cell; lew.benson@carmeusena.com
Mark Thomas – Cinergy – 513-287-3802: office: 513-312-0124 cell; mark.thomas@cinergy.com