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Estimated Mercury Emission Reductions in NC from Co-control as a Result of CSA
2004 NC DENR/DAQ
Hg & CO2 Workshop
Raleigh, NCApril 20, 2004
Steve Schliesser
Paul Grable
NC Division of Air Quality
Presentation Summary
NC Electric Utility Hg Control Features- Coal Characteristics- Boiler Types- Current & Planned Emission Controls
Statewide Hg Emission Estimates- From Existing Controls- From Planned Future Controls- Emission Reduction Schedule- Speciated Hg Emissions Conclusions & Plans
Hg Emissions and Control Study for Electric Utilities
Electric Utility Industry Is Primary Hg Emission Source in NC (75% Hg emissions)
Current Statistics- 48 Utility Boilers with 13,300 MW- Duke Power with 8,200 MW- Progress Energy with 5,100 MW- Variety of Conventional Boilers
- No Hg-specific emission controls
Electric Utility Company Plans
Plans Submitted for CSA All with Combustion Controls
- 46/48 with SCR / SNCR / Advanced NOx Controls (>98% State Capacity)
- NOx Controls Installed in 2001-09
22 SO2 Wet FGD Scrubbers on Largest Units (80% State Capacity)- SO2 Scrubbers Installed 2005 – 2013
- Largest Scrubbers Installed 2005 – 2009
Emissions Reductions Under Clean Smokestacks Act
0
5 0000
1 00000
1 5 0000
2 00000
2 5 0000
3 00000
3 5 0000
4 00000
4 5 0000
5 00000
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
450,000
500,000
1998 2007 2009 1998 2009 2013
NOx(tons/year)
SO2
(tons/year)
245,000
60,000 56,000
489,000
250,000
130,000
NC Electric Utility Boiler Characteristics
Current Design and Operation- All Eastern Bitmuninous Low-S Coal
- Favorable Hg Controllability Coal
- All T-Fired or Wall-Fired Boilers
- Most larger units with Cold-side ESPs
- Several small Hot-side ESPs
- No Wet FGD Scrubbers
Comparison of Average Coal Burned in NC vs USA
Coal Composition
Area Hg, lb/TBtu
Chlorine ppm
Cl/SO2 Ratio
NC 6.5 1400 1000
USA 7.0 700 300
Location and Size of NC Electric Utility Plants
DAQ Estimated Mercury Emissions Based on EPA and EPRI Correlations
EPA Estimates- Based on 1999 ICR data
(1100 boilers & 80 tests)- Results by category
(e.g., bituminous coal, cold-side ESP)
- Averaged category data without coal variables
- Used Sound Science- Results applicable for
large data sets- Predict 48 tons Hg
emissions in USA
EPRI Estimates- Based on 1999 ICR data
(1100 boilers & 80 tests)- Results by category
(e.g., bituminous coal, cold-side ESP)
- Correlated category data on key coal variables
- Used Sound Science- Results applicable for
large data sets- Predict 45 tons Hg
emissions in USA
NC-Relevant APCD Comparisons Of EPA and EPRI Hg Removal Predictions
APCD EPA EPRI
% Hg Removal
ESP Cold-side 29 40 - 48
ESP Hot-side 11 22 - 27
ESP - Cold / FGD 78 65 - 70
ESP - Hot / FGD 40 65
EPA and EPRI Mercury Emission Projections
Mercury Levels
Boiler input,
lb/yr
Emissions,
lb/yr
Removal,
%
Current Future Current Future
EPRI 4054 2365 1476 42 64
EPA 3989 2981 1414 25 66
EPA and EPRI Mercury Emission Projections For NC Electric Utilities
EPA and EPRI Mercury Projections for NC Utilities
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Boilers Input Current Hg Emissions Future Hg Emissions
Mercury Category
Estim
ated
Mer
cury
, lb/
yr
EPRI
EPA
Mercury Emission Reduction Schedule for NC Utilities Using EPRI Correlations
Mercury Emission Forecast For NC Utilities Using EPRI Correlations
0
500
1000
1500
2000
2500
2005 2006 2007 2008 2009 2010 2011 2012 2013
Year
Tota
l Mer
cury
Em
issi
ons,
lb/y
r
Duke
Progress
Total
Forecast Summary of Mercury Emission Estimates from NC
Electric Utility Boilers
Forecast Summary of Mercury Emission Estimates from NC Electric Utility Boilers (EPA/EPRI Avg)
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Boilers input Total Emissions Elemental Emissions Oxidized Emissions PM Emissions
Mercury Category
Mer
cury
Em
issi
ons,
lb/y
r
Current
Future
Removal Summary for Total and Speciated Mercury
Mercury Removal %
(Relative to Total Hg)
Total Elemental Oxidized PM
Current 33 80 55 97
Future 64 74 90 99.6
Tabulated Forecast Summary of Mercury Emission Estimates from
NC Electric Utility Boilers
Mercury Emissions, lb/yr (Rounded)
Boiler input Total Elemental Oxidized PM
Current 4020 2700 810 1800 100
Future 4020 1450 1040 390 20
NC Electric UtilitiesHg R&D Involvement
Hosted EPA Hg CEMS Project in 2002 in NC on Bituminous Coal w/ Cold-side ESP
Contract with Leading FGD Supplier Having DOE/EPRI Hg Control Evaluation Projects
Sponsor or Co-Sponsor of DOE/EPRI Projects
on Hg Control Performance
- In GA with Carbon Injection
- In NC with Hot-side ESP Sorbents
- In NC with FGD
- In NC with NOx Controls
ConclusionsNC Leading State For Electric
Utility :- Multi Pollutant Regulations- State-of-the-art NOx & SO2 Controls- Favorable Coal for Hg Control- Significant Hg Emission Reductions, including Oxidized Hg
Future DAQ Plans Continue Hg Control Evaluation
- Update / Refine Emission Control Analysis Complete 2nd Interim CSA Report Consider Adding MDN Site(s) in Piedmont to
Assess - Wet Deposition
- Benefits of FGD Scrubbers- Relationship Between Hg Emissions & Local Impact
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