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