1. Performance and Benefits of Flue Gas Treatment Using Thiosorbic Lime
Presented by
Carmeuse North America
Carmeuse North America makes no warranty or representation, expressed or implied, and assumes no liability with respect to the use of, or damages resulting from the use of, any information, apparatus, method or process disclosed in this document.

2. BACKGROUND ON CARMEUSE

3. Carmeuse North America
- Background
Part of the Carmeuse Group
Joint Venture of:
60% Carmeuse S.A. (Belgium)
40% Lafarge S. A. (France)
Carmeuse
$1 billion privately-held lime company founded in 1860
60 plants in 14 countries
Lafarge
$11 billion publicly-held construction materials company founded in 1833
Operations in 60 countries

4. Lime Plant Locations in U.S. and Canada
- Background
Lime Plant Locations in U.S. and Canada
testing
Carmeuse
While Carmeuse North America is the leading supplier, FGD lime is widely available
North America
plant locations

5. Carmeuse Provides:
- Background
Thiosorbic® Lime for flue gas desulfurization (FGD) in coal-fired plants
Access to Thiosorbic process technology
Carmeuse works in cooperation with major FGD equipment suppliers to provide the best system for the customers requirements
Technical support for FGD users
FGD start-up, operator training, and operations support
Over 25 years experience in FGD in coal-fired power plants

6. BENEFITS OF THE THIOSORBIC FGD PROCESS
- Thiosorbic® Process
BENEFITS OF THE THIOSORBIC FGD PROCESS

7. Benefits of Thiosorbic FGD process
- Thiosorbic® Process
Ultra-low SO2 emissions with high-sulfur fuel
99% SO2 removal with high-sulfur coal
Lower FGD capital cost
Lower FGD power consumption
Valuable by-products: wallboard-quality gypsum and magnesium hydroxide [Mg(OH)2]
25 year record of reliability
17,700 MW base of experience

8. Thiosorbic Wet FGD Applications 16 Stations – 34 Units – 17,700 MW

9. Thiosorbic FGD Process Description
- Thiosorbic® Process
Wet FGD process
Uses lime reagent with 3-6 wt.% MgO
Mg increases SO2 removal and allows low L/G
45 L/G (gpm/1000 acfm) for 99% removal with high-sulfur fuel
Low chemical scaling potential
Liquid in absorber slurry only 10% gypsum-saturated

10. Thiosorbic FGD Process
- Thiosorbic® Process
Thiosorbic FGD Process

11. FGD Process Comparison: Thiosorbic vs
FGD Process Comparison: Thiosorbic vs. Limestone Forced Oxidation (LSFO)
- Thiosorbic® Process
Higher SO2 removal
Up to 99% vs. 95% for LSFO
Lower Power Consumption
1.4% versus 2.0% for LSFO for high-sulfur coal
Higher Reagent Utilization
99.9% vs. up to 97% for LSFO
Better Gypsum Quality
98-99% pure, bright white vs. 95%, brown or tan for limestone

12. Comparison of Gypsum from Thiosorbic Lime with LSFO Gypsum
- Thiosorbic® Process
Comparison of Gypsum from Thiosorbic Lime with LSFO Gypsum

13. FGD Process Comparison: Thiosorbic vs. LSFO
- Thiosorbic® Process
Lower Capital Cost
8-12% lower capital cost
Much smaller absorbers
Fewer recycle pumps, fewer spray headers, smaller recirculation tank
Lower maintenance cost
Generate more valuable SO2 allowances

14. FGD Process Comparison: Absorber Size
- Thiosorbic® Process
These absorbers were supplied by the same FGD equipment supplier at two different sites. The difference in height is due solely to FGD process type. LSFO requires more absorber spray headers, greater L/G, more recirculation pumps, and a larger hold time in the recirculation tank, leading to a substantially taller, more costly absorber.
LSFO
125 ft
38.1 m
Thiosorbic
55 ft
16.8 m

15. Thiosorbic Absorber at Zimmer Station Example of compact absorber
Babcock & Wilcox design
Only 54 ft high (grade to top tangent line)
One operating recycle pump, one spare
Design L/G is 21 gal/1000 acfm (3 l/m3) for 91% SO2 removal
Achieved 96% SO2 removal in 1991 performance test on 3.5% sulfur coal

16. Thiosorbic Absorber At HMPL Station #2 Example of compact absorber
Wheelabrator design
Only 46 ft high (grade to top tangent line)
One operating recycle pump, one spare
Design L/G is 30 gal/1000 acfm (4 l/m3) for 95% SO2 removal
Achieved 96% SO2 removal in 1994 performance test on 3% sulfur coal

17. BENEFITS OF BYPRODUCT MAGNESIUM HYDROXIDE FROM THE THIOSORBIC PROCESS
- Byproduct Mg(OH)2 from the Thiosorbic® Process
BENEFITS OF BYPRODUCT MAGNESIUM HYDROXIDE FROM THE THIOSORBIC PROCESS

18. Thiosorbic FGD Process with Byproduct Mg(OH)2 Production

19. Benefits of Byproduct Magnesium Hydroxide
- Byproduct Mg(OH)2 from the Thiosorbic® Process
Thiosorbic process allows option for on-site production of magnesium hydroxide
Demonstrated for furnace injection and SO3 control in 800 MW and 1300 MW boilers
Reduces furnace-generated SO3 emissions by 90%
Substantially reduces visible plume opacity

20. Mg(OH)2 Injection for SO3 Control
- Byproduct Mg(OH)2 from the Thiosorbic® Process
Mg(OH)2 Injection Location
Furnace
Selective Catalytic
Reduction
ESP
Thiosorbic
FGD

21. Furnace SO3 Removal vs. Mg:SO3 Ratio in 1300 MW Boiler
- Byproduct Mg(OH)2 from the Thiosorbic® Process
Furnace SO3 Removal vs. Mg:SO3 Ratio in 1300 MW Boiler
100%
90%
80%
70%
60%
50%
Full-scale demonstration of SO3 control with Thiosorbic byproduct Mg(OH)2
Full-scale demonstration of SO3 control with Thiosorbic byproduct Mg(OH)2
40%
30%
20%
10% 0% 1 2 3 4 5 6 7 8
Mg:SO3 Ratio

22. Reduction in Visible Opacity with By-product Mg(OH)2 Treatment
- Byproduct Mg(OH)2 from the Thiosorbic® Process
Reduction in Visible Opacity with By-product Mg(OH)2 Treatment
Untreated Treated

23. Benefits of Byproduct Magnesium Hydroxide
- Byproduct Mg(OH)2 from the Thiosorbic® Process
Increases melting point of boiler slag
Reduces strength of slag deposits; increases friability and fracture for ease of removal
Increases boiler efficiency
Cleaner heat transfer surfaces
Allows lower air heater outlet temperature

24. Benefits of Byproduct Magnesium Hydroxide
- Byproduct Mg(OH)2 from the Thiosorbic® Process
Benefits of Byproduct Magnesium Hydroxide
Provides FGD wastewater treatment: As, Cd, Pb, Ni, Hg below detection limits
Reduces size and operating costs of wastewater treatment system; no TSS removal and coagulation/lime precipitation steps required; no BOD (DBA) removal
Eliminates disposal of (RCRA-unexcluded) wastewater treatment sludge; allows co-mangement via return to furnace and combination with flyash

25. Full-scale Application of Byproduct Mg(OH)2 Injection for SO3 Control
- Byproduct Mg(OH)2 from the Thiosorbic® Process
Full-scale Application of Byproduct Mg(OH)2 Injection for SO3 Control
A 1400 MW installation begins operation 1st quarter 2004

26. Potential Cost Savings from Furnace Injection of Magnesium Hydroxide
- Byproduct Mg(OH)2 from the Thiosorbic® Process
Potential Cost Savings from Furnace Injection of Magnesium Hydroxide
Increase in plant efficiency due to cleaner boiler tubes and low acid dew point: 1% increase per 35 F lower air heater exit temperature
Coal savings due to use of lower temperature ash fusion coal

27. - Byproduct Mg(OH)2 from the Thiosorbic® Process
Factors Used to Determine Cost Benefits of Boiler Injection of Byproduct Mg(OH)2
- Byproduct Mg(OH)2 from the Thiosorbic® Process

28. - Byproduct Mg(OH)2 from the Thiosorbic® Process
Lower Life Cycle Cost with Thiosorbic Process and Byproduct Mg(OH)2 Compared with LSFO 40
base case 35
Increased availability & furnace efficiency
Increased availability & furnace efficiency, reduced fuel cost 30
Increasing cost
competitiveness of
Thiosorbic process
Lower life cycle cost for Thiosorbic process in area above each line 25
Limestone cost, $/ton 20 15 10
Based on 3% sulfur bituminous coal 5 40 45 50 55 60 65 70
Lime cost, $/ton

29. HYDRATED LIME INJECTION FOR SO3 CONTROL
- Hydrated Lime for SO3 Control
HYDRATED LIME INJECTION FOR SO3 CONTROL

30. Ca(OH)2 Injection for SO3 Control
- Hydrated Lime for SO3 Control
Hydrated lime [Ca(OH)2] has been demonstrated at 1300 MW for control of SO3 emissions after selective catalytic reduction (SCR)
Hydrated lime powder can be injected into flue gas immediately after the air heater and before the particulate collector, or injected after the particulate collector and before the Thiosorbic FGD system

31. Ca(OH)2 Injection for SO3 Control
- Hydrated Lime for SO3 Control
Ca(OH)2 Injection Locations
Selective Catalytic
Reduction
Furnace
ESP
Thiosorbic
FGD

32. Ca(OH)2 Injection for SO3 Control
- Hydrated Lime for SO3 Control
Hydrated lime injected before the particulate collector (e.g. ESP) is removed with fly ash
Hydrated lime injected before the Thiosorbic FGD system is removed by impingement with absorber spays
Results in complete utilization of the hydrated lime which substantially reduces reagent cost for SO3 control
90% removal of SCR-generated SO3 is possible at Ca:SO3 molar ratio of 8

33. Performance and Benefits of Flue Gas Treatment Using Thiosorbic Lime Conclusions:
The Thiosorbic process is a widely utilized FGD process with a 25 record of successful operation
The Thiosorbic lime FGD process provides better SO2 removal performance than the LSFO process
The Thiosorbic process allows lower FGD capital cost, lower power consumption, and lower life cycle cost than the LSFO process
Byproduct Mg(OH)2 provides efficient control of furnace SO3 emissions and additional operating benefits and cost savings
Hydrated lime provides efficient, low-cost control of SO3 formed during SCR