Increases in NO x Emissions in Coal-Fired, SCR-Equipped Electric Generating Units T. F. McNevin, Ph.D. Division of Air Quality New Jersey Department of.

1

Increases in NOx Emissions in Coal-Fired, SCR-Equipped Electric Generating Units

T. F. McNevin, Ph.D.Division of Air Quality

New Jersey Department of Environmental Protection

NJ Clean Air CouncilPrinceton South Corporate Centre

Ewing, NJJanuary 14, 2015

2

Increases in NOx Emissions in Coal-Fired, SCR-Equipped Electric Generating Units

• Clean Air Act Amendments (1990)– NOx RACT

–OTC NOx Budget Program (1999)• Northeast, Mid-Atlantic States

– “NOx SIP Call” NOx Budget Program (2003-04)• 20 Eastern States

– CAIR (2009)– CSAPR (2012…..)

3

Increases in NOx Emissions in Coal-Fired, SCR-Equipped Electric Generating Units

• Clean Air Act Amendments (1990)– NOx RACT

–OTC NOx Budget Program (1999)• Northeast, Mid-Atlantic States

– “NOx SIP Call” NOx Budget Program (2003-04)• 20 Eastern States

– CAIR (2009)– CSAPR (2012…..)

4

Increases in NOx Emissions in Coal-Fired, SCR-Equipped Electric Generating Units

• Clean Air Act Amendments (1990)– NOx RACT

–OTC NOx Budget Program (1999)• Northeast, Mid-Atlantic States

– “NOx SIP Call” NOx Budget Program (2003-04)• 20 Eastern States

– CAIR (2009)– CSAPR (2015…..)

5

What has been Happening?

6

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

NO

x(t

ons)

NJ Ozone Season NOx Emissions

7

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

NO

x(t

ons)

PA Ozone Season NOx Emissions

8

What is NOx?

• Oxides of Nitrogen

N2 + O2 --> NO, NO2

9

What is NOx?

• Oxides of Nitrogen

N2 + O2 --> NO, NO2

10

Why is NOx a Concern?

11

What has been Happening?

• Hundreds of coal-fired EGUs have installed SCR

12

Selective Catalytic Reduction (SCR)

NOx + NH3 catalyst N2 + H2O

TiO2, V2O5, WO3,

Pt, Pd, zeolites

350° - ~1,100 °F

> 90% reduction

13

Coal-Fired EGUs in Eastern US

14

OTC Modeling Domain

15

CAIR States

16

CSAPR States

17

18

Eastern Half of US

CSAPR

CAIROTC Domain

19

2014 Ozone Season Excess NOx

in Top 25 Emitters

• OTC Domain 37,750 tons

• CAIR States 36,626 tons

• CSAPR States 32,403 tons

20

What has been Happening?

• Hundreds of coal boilers have installed SCR

• Emission rates fell dramatically 2003-09

21

Ozone Season NOx Emission Rates of SCR-Equipped Coal-Fired EGUs in Eastern US with Number of Units.

0.289

0.256

0.289

0.222

0.247

0.199

0.096

0.081 0.082 0.0860.095

0.086

0.1010.111

0.132 0.130

0

50

100

150

200

250

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

Uni

ts

lb N

Ox

/ m

mBT

U

Rate Number of Units

22

What has been Happening?

• Hundred of coal boilers have installed SCR

• Emission rates fell dramatically 2003-09

• Emission Rates began increasing after 2009

23

Ozone Season NOx Emission Rates of SCR-Equipped Coal-Fired EGUs in Eastern US with Number of Units.

0.289

0.256

0.289

0.222

0.247

0.199

0.096

0.081 0.082 0.0860.095

0.086

0.1010.111

0.132 0.130

0

50

100

150

200

250

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

Uni

ts

lb N

Ox

/ m

mBT

U

Rate Number of Units

24

2013 Ozone Season

• Top 200 Boilers = 66% of NOx

– 198 Coal-fired EGUs– 79 SCR Equipped• Best Observed Rate (BOR), lb/mmBTU

– ≈68%, 2013 Emission Rate > BOR– Ratio (79 Units): 1.0 – 9.2, Mean = 3.3

25

Ozone Season NOx Emission Rates of Coal-Fired Units in OTC Modeling Domain with Reduced SCR Operations within the 2013 Top 200 Emitters.

0.245

0.103

0.085 0.085

0.095

0.112

0.097

0.126

0.175

0.230 0.232

0.000

0.050

0.100

0.150

0.200

0.250

0.300

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

lb N

Ox

/ m

mBT

U

26

Ozone Season NOx Emission Rates of Coal-Fired Units in OTC Modeling Domain with Reduced SCR Operations within the 2013 Top 200 Emitters.

0.245

0.1030.085

0.085

0.095

0.112

0.097

0.126

0.175

0.2300.232

0.000

0.050

0.100

0.150

0.200

0.250

0.300

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

lb N

Ox

/ m

mBT

U

27

What Happened?

• Collapse of CAIR allowance costs– $4,600/ton January 2009, $51/ton October 2012• Oversupply of allowances• Market uncertainty

– Less than forecast electric demand

28

Total US Annual Electrical Generation.

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

TWh

1.3% Annualized Growth from 2000

-0.7% Annualized Growth from 2007

What Happened?

• Collapse of allowance costs– $4,600/ton January 2009, $51/ton October 2012• Oversupply of allowances• Market uncertainty

• Less than forecast electric demand– 2008-13 Top 200 NOx emitters, GLOAD -1.7%

• Increased gas-fired generation

29

30

Increased gas-fired generationPercentage of Total US Annual Electrical Generation by Fuel Type

What Happened?

• Oversupply of allowances• $4,600/ton January 2009, $51/ton October 2012

• Oversupply of allowances• Market uncertainty

• Less than forecast electric demand– 2008-13 Top 200 NOx emitters, GLOAD -1.7%

• Increased gas-fired generation– April 2012, Coal = Gas = 32%

31

32

Gas Got Cheap

33

What’s Driving Gas Pricing?

34

What’s Driving Gas Pricing?

35

0.00

0.05

0.10

0.15

0.20

0.25

$-

$1.00

$2.00

$3.00

$4.00

$5.00

$6.00

$7.00

$8.00

lb /

mm

BTU

Total Allowance Costs ($/MWh) Natural Gas ($/mcf) Emission Rates (lb/mmBTU)

Total Monthly Average Ozone Season Allowance Costs at 3.0 lb NOx / MWh, Monthly Average Natural Gas Electrical Generation Costs, "53 SCR Boiler" Average Ozone Season Emission Rates.

36

Gas Got Very Competitive

37

0.00

0.05

0.10

0.15

0.20

0.25

$-

$1.00

$2.00

$3.00

$4.00

$5.00

$6.00

$7.00

$8.00

lb /

mm

BTU

Total Allowance Costs ($/MWh) Natural Gas ($/mcf) Emission Rates (lb/mmBTU)

Total Monthly Average Ozone Season Allowance Costs at 3.0 lb NOx / MWh, Monthly Average Natural Gas Electrical Generation Costs, "53 SCR Boiler" Average Ozone Season Emission Rates.

Approximate SCR Ammonia Cost / MWh

38

Low

Alabama Arkansas Georgia Maryland

0.077 0.068 0.061 0.074

High

Missouri New Hampshire

New York Pennsylvania

0.376 0.274 0.323 0.247

Arizona Colorado Kansas Montana Nevada Texas Wyoming

0.076 0.067 0.087 0.079 0.064 0.056 0.057

CAIR-region States with Representative Low and High Average NOx Emission Rates, (lb/mmBTU), of SCR-Equipped Coal-Fired EGUs in the 2013 Ozone Season.

Average 2013 Ozone Season NOx Emission Rates, (lb/mmBTU), of SCR-Equipped Coal-Fired EGUs in Western States that are not in the CAIR Cap and Trade Program.

Reduced, “Sub-Optimal” SCR Operation

NOx Emission Rates, lb/mmBTU

Plant Location Best Year 2009 2010 2011 2012 2013 PA 0.044 (2003) 0.113 0.212 0.316 0.414 0.424

MO 0.090 (2009) 0.090 0.108 0.230 0.627 0.609

KY 0.123 (2006) 0.127 0.320 0.307 0.349 0.812

WV 0.071 (2004) 0.080 0.260 0.206 0.304 0.300

NC 0.070 (2004) 0.132 0.104 0.116 0.243 0.247

IL 0.071 (2004) 0.127 0.124 0.137 0.214 0.245

39

40

Reduced, “Sub-Optimal” SCR Operation?

41

1 2

57

12 11

14

4 5

10

14

20

2428

16 16

28

34

44

42

49

0

10

20

30

40

50

60

2008 2009 2010 2011 2012 2013 2014

EGU

s

Ozone Season

Numbers of SCR-Equipped EGUs in Top 25, 50, and 100 NOx Emitters in CAIR States

Top 25 Top 50 Top 100

420

1,000

2,000

3,000

4,000

5,000

6,000

7,000

2008 2009 2010 2011 2012 2013

NO

x(t

ons)

NJ EGU Ozone Season NOx Emissions

430

10,000

20,000

30,000

40,000

50,000

60,000

2008 2009 2010 2011 2012 2013

NO

x(t

ons)

OH EGU Ozone Season NOx Emissions

440

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

2008 2009 2010 2011 2012 2013

NO

x(t

ons)

MD EGU Ozone Season NOx Emissions

450

10,000

20,000

30,000

40,000

50,000

60,000

70,000

2008 2009 2010 2011 2012 2013

NO

x(t

ons)

PA EGU Ozone Season NOx Emissions

460

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

2008 2009 2010 2011 2012 2013

NO

x(t

ons)

MO EGU Ozone Season NOx Emissions

47

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

lbs/

mm

BTU

Year

Ozone Season NOx Emission Rates of PA Coal-Fired EGUs with SCR

OTC Program "NOx SIP Call" Program CAIR Program

48

49

50

51

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014Ozone Season

Fraction of PA SCR-Equipped, Coal-Fired NOx vs. Total NOx Emissions

52

53

Total Excess NOx Emissions (tons) from Coal-Fired SCR-Equipped EGUs in 2013

Top 200 Emitters in Eastern US

Total = 255,900 tons

2010 2011 2012 2013 201427,600 41,100 59,000 61,500 66,700

54

Increases in NOx Emissions in Coal-Fired, SCR-Equipped Electric Generating Units

T. F. McNevin, Ph.D.Division of Air Quality

New Jersey Department of Environmental Protection

NJ Clean Air CouncilPrinceton South Corporate Centre

Ewing, NJJanuary 14, 2015