## BART D ETERMINATION 

## R EPORT 

## A MERICAN 

## E LECTRIC 

## P OWER 

##  N ORTHEASTERN 

## P OWER 

## S TATION 

## U NIT 

## 2

Prepared by:

N.N. Dharmarajan  AEP

Vern Choquette  Principal Consultant Eugene Chen, PE  Senior Consultant Jeremy Townley  Consultant

T RINITY C ONSULTANTS 120 E. Sheridan Suite 205 Oklahoma City, OK 73104 (405) 228-3292

August 2008

Project 083701.0057AEP Trinity Consultants BART Determination Northeastern Po wer Station Unit 2Report 083701.0057 i 

## T ABLE OF 

## C ONTENTS



### 1. E XECUTIVE 

### S UMMARY 

### ........................................................................................ 1-1

2. B ACKGROUND 

### ...................................................................................................... 2-1 2.1 BART A PPLICABILITY 

### .......................................................................................... 2-1
2.1.1 CALPUFF M ODELING A NALYSES ......................................................................2-3 

### 2.2 BART D ETERMINATION 

### ....................................................................................... 2-3

3. BART A PPLICABILITY 

### A NALYSIS 

### ...................................................................... 3-1 3.1 BART-E LIGIBLE 

### S OURCES 

### ................................................................................... 3-1 3.2 S OURCE 

### E MISSIONS 

### D ATA 

### .................................................................................... 3-1
3.2.1 PM E MISSIONS ....................................................................................................3-1
3.2.2 S TACK PARAMETERS ...........................................................................................3-2



### 4. SO 2 

### BART D ETERMINATION 

### .............................................................................. 4-1 4.1 I DENTIFICATION OF 

### A VAILABLE 

### R ETROFIT 

### SO 2 

### C ONTROL 

### T ECHNOLOGIES 

### .......... 4-1

5. PM BART D ETERMINATION 

### .............................................................................. 5-1 5.1 I DENTIFICATION OF 

### A VAILABLE 

### R ETROFIT 

### PM C ONTROL 

### T ECHNOLOGIES 

### ........... 5-1

6. NO X 

### BART D ETERMINATION 

### .............................................................................. 6-1 6.1 I DENTIFY 

### A LL 

### A VAILABLE 

### R ETROFIT 

### T ECHNOLOGIES 

### .......................................... 6-1 6.2 E LIMINATE 

### T ECHNICALLY 

### I NFEASIBLE 

### O PTIONS 

### .................................................. 6-1
6.2.1 R EDUCED B URNER S ERVICE ...............................................................................6-2
6.2.2 I NDUCED F LUE G AS R ECIRCULATION (FGR) .....................................................6-2
6.2.3 L OW NO X B URNERS (LNB) WITH O VERFIRE A IR (OFA)...................................6-2 

### 6.3 E VALUATE 

### E FFECTIVENESS OF 

### R EMAINING 

### C ONTROL 

### T ECHNOLOGIES 

### ................ 6-3 6.4 E VALUATION OF 

### I MPACTS FOR 

### F EASIBLE 

### NO X 

### C ONTROLS 

### ................................... 6-3
6.4.1 C OSTS OF C OMPLIANCE ......................................................................................6-3
6.4.2 E NERGY AND N ON

- AIR I MPACTS ........................................................................6-4
6.4.3 R EMAINING U SEFUL L IFE ...................................................................................6-4 

### 6.5 E VALUATE 

### V ISIBILITY 

### I MPACTS 

### ........................................................................... 6-4 6.6 P ROPOSED 

### B ART FOR 

### NO X 

### .................................................................................... 6-5

A PPENDIX 

### A

– E MISSION 

### E STIMATES



### A PPENDIX 

### B

- E CONOMIC 

### A NALYSES



### A PPENDIX 

### C

– CALPUFF M ODELING 

### P ROTOCOL



### A PPENDIX 

### D

– M ODELING 

### I NPUT 

### /O UTPUT 

### F ILESAEP Trinity Consultants BART Determination Northeastern Po wer Station Unit 2Report 083701.0057 ii 

## L IST OF 

## F IGURES

T ABLE 3-1. C ONSTRUCTION D ATE S UMMARY ...................................................................................3-1

T ABLE 3-2. P RE -BART E MISSIONS S UMMARY ..................................................................................3-1

T ABLE 3-3. PM S PECIATION P ROFILE .................................................................................................3-2

T ABLE 3-4. S PECIATED PM E MISSIONS ..............................................................................................3-2

T ABLE 3-5. P OINT S OURCE S TACK P ARAMETERS ..............................................................................3-2

T ABLE 4-1. B ASELINE M AXIMUM 24-H OUR SO 2 E MISSION R ATES ...................................................4-1

T ABLE 4-2. A VAILABLE SO 2 C ONTROL T ECHNOLOGIES ....................................................................4-1

T ABLE 4-3. SO2 E MISSION E STIMATES (N ATURAL G AS )...................................................................4-1

T ABLE 5-1. E XISTING M AXIMUM 24-H OUR PM E MISSION R ATES .....................................................5-1

T ABLE 5-2. A VAILABLE PM C ONTROL T ECHNOLOGIES .....................................................................5-1

T ABLE 5-3. PM E MISSION E STIMATES ................................................................................................5-1

T ABLE 6-1. E XISTING M AXIMUM 24-H OUR NO X E MISSION R ATE .....................................................6-1

T ABLE 6-2. A VAILABLE NO X C OMBUSTION C ONTROL T ECHNOLOGIES ............................................6-1

T ABLE 6-3. C ONTROL E FFECTIVENESS OF T ECHNICALLY F EASIBLE NO X C ONTROL T ECHNOLOGIES 6-3

T ABLE 6-4. NO X C ONTROL C OSTS S UMMARY ...................................................................................6-4

T ABLE 6-5. N ORTHEASTERN U NIT 2 V ISIBILITY I MPACTS (98 TH P ERCENTILE I MPACT ) .....................6-5AEP Trinity Consultants BART Determination Northeastern Station Unit 2 083701.0057 1-1 

## 1. E XECUTIVE 

## S UMMARY

American Electric Power /Public Service Company of Oklahoma (AEP/PSO) operates the Northeastern (NE) Power Station, which is located at Section 4, T22N, R15E, in Rogers County, Oklahoma. The NE Power Station is currently operating in accordance with Oklahoma Department of Environmental Quality (DEQ) Title V Operating Permit, 96-288-TV, issued in June 30, 1999. The NE Power Station Unit 2 is considered eligible for the application of Best Available Retrofit Technology (BART) 1 as part of the Environmental Protecti on Agency (EPA) Regional Haze Rule.

On March 30, 2007, AEP submitted to the Oklahoma DEQ, the BART determination for its BART eligible facilities in Oklahoma, in accordance with OAC 252:100, Subchapter 8, Permits for Part 70 Sources, Part 11, Visibility Protection Standards, effective October 8, 2006. Among the items addressed in this letter was AEP’s intent to me et BART requirements for its natural gas-fired Northeastern Unit 2 boiler through the use of “current combustion control technology” as described in 40 CFR, Part 51, Regional Haze Regulations and Gu idelines for BART Determinations; Final rule (70 Fed. Reg. July 6, 2005) .

In a letter response dated December 12, 2007, the Oklahoma DEQ requested, among other items, a formal five-factor BART determination for North eastern Unit 2. Per the guidelines in 40 CFR Part
51 2 , a BART determination for SO 2 , NO X , and PM was performed using the five-step analysis that included the following:

1. Identifying all available retrofit control technologies;

2. Eliminating technically infeasible control technologies;

3. Evaluating the control effectiveness of remaining control technologies;

4. Evaluating impacts and document the results;

5. Evaluating visibility impacts

Based on the five-step analysis, AEP proposes the following as BART:

• PM – AEP proposes the use of natural gas for Northeastern Unit 2 as BART for PM. Continued use of natural gas will ensure an em ission rate lower than what could be achieved with add-on PM controls.

• SO 2 – AEP also proposes the use of natura l gas for Northeastern Unit 2 as BART for SO 2
. As with PM emissions, natural gas use is able to ensure SO 2 emissions lower than add-on SO 2 controls.

• NO X – AEP proposes emission rates of 0.28 lb/MMBtu as BART for NOx. This will be achieved by installing Low NOx burners (LNB)/overfire air (OFA) system

1 40 CFR 51 Appendix Y, Guidelines for BART Determinati ons Under the Regional Haze Rule

2 40 CFR 51, Regional Haze Regulations and Guidelines for Best Available Retrofit Technology (BART) DeterminationsAEP Trinity Consultants BART Determination Northeastern Station Unit 2 083701.0057 2-1 

## 2. B ACKGROUND

On July 1, 1999, the U.S. Environmental Protec tion Agency (EPA) published the final Regional Haze Rule (RHR). The objective of the RHR is to impr ove visibility in 156 specific areas across the United States, known as Class I areas. The Clean Air Act defines Class I areas as certain national parks (over 6,000 acres), wilderness areas (over 5,000 acres), national memorial parks (over 5,000 acres), and international parks that were in existence on August 7, 1977.

On July 6, 2005, the EPA published amendments to its 1999 RHR, often called the BART rule, which included guidance for making source-specific B est Available Retrofit Technology (BART) determinations. The BART rule defines BART-e ligible sources as sources that meet the following criteria:

(1) Have potential emissions of at least 250 tons per year of a visibility-impairing pollutant, (2) Were “in existence” between August 7, 1962 and August 7, 1977, and (3) Are listed as one of the 26 listed source categories in the guidance.

A source that meets these criteria is considered elig ible for BART and must then determine if BART applies.



## 2.1 BART A PPLICABILITY

Per the U.S. EPA’s BART Modeling Guidance, “an individual source will be considered to ‘cause visibility impairment’ if the emissi ons results in a change (delta ∆ ) in deciviews (dv) 3 that is greater than or equal to 1.0 deciview on the visibility in a Class I area...if the emissions from a source results in a change in visibility that is greater than or equal to 0.5 dv in a Class I area the source will be considered to ‘contribute to visibility impairment .’” To determine whether a BART-eligible source causes or contributes to visibility impairment, the U.S. EPA guidance requires the use of an air quality model, specifically recommending the CALPUFF modeling system, to quantify the impacts attributable to a single BART-eligible source. Because contribution to visibility impairment is sufficient cause to require a BART determination, 0.5 dv is the critical threshold for assessment of BART applicability.

Regional haze is quantified using the light extinction coefficient ( b ext ), which is expressed in terms of the haze index ( HI ) expressed in dv. The HI is calculated as shown in the following equation.

       

= 10 ln 10 ext b HI

The impact of a BART-eligible source is determined by comparing the HI attributable to a source to estimated natural background conditions. That is, a single-source visibility impact is measured as the

3 The deciview (dv) is a metric used to represent norma lized light extinction attributable to visibility-affecting pollutants.AEP Trinity Consultants BART Determination Northeastern Station Unit 2 083701.0057 2-2 change in light extinction versus background, and is referred to as ∆ dv. The background extinction coefficient is affected by various chemical sp ecies and the Rayleigh scattering phenomenon and can be calculated as shown in the following equation.



# ( ) Ray EC Coarse Soil OC NO SO background ext b b b b b b b b + + + + + + = −

3 4 1

, Mm

where:



### ( ) 

## [ ] ( ) 

### [ ] ( ) 

### [ ] [ ] [ ] [ ] 

# ( ) ( ) 

### [ ] 3 1 3 4 4

2 4

m μg in ion Concentrat Function Humidity Relative default by Mm 10 Scattering Rayleigh

EC 10 Mass Coarse 6

. 0 Soil 1 OC 4 NO

NH 3 SO

NH 3

3 4

= =

= = = = = = =

−

RH f b b b b b RH f b RH f b

Ray

EC Coarse Soil OC NO SO 

### ( ) 

## [ ] [ ] [ ] [ ] [ ] [ ]

molecules air to due scattering is Scattering Rayleigh carbon elemental of ion concentrat the denotes EC dusts coarse of ion concentrat the denotes Mass Coarse soils fine of ion concentrat the denotes Soil carbon organic of ion concentrat the denotes OC ion concentrat nitrate ammonium the denotes NO NH ion concentrat sulfate ammonium the denotes SO NH

3 4 4 2 4

Values for the parameters listed above specific to the natural background conditions at each Class I area are provided on an annual-average basis in the U.S. EPA’s Guidance for Estimating Natural Visibility Conditions under the Regional Haze Rule

. 4

Particulate species that affect visibility are em itted from anthropogenic (human-caused) sources and include coarse particulate matter (PMC), fine partic ulate matter (PMF), and elemental carbon (EC) as well as precursors to secondary organic aerosols (SOA) and fine particulate matter such as SO 2 and
NO X . The extinction coefficient due to emissions of visibility-affecting pollutants from a single BART-eligible source is calculated according to the following equation. 

# ( )

EC PMC PMF SOA NO SO source ext b b b b b b b + + + + + = −

3 4 1

, Mm

where:

4 U.S. EPA, Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Rule , Table 2-1, Attachment A, September 2003, EPA-454/B-03-005.AEP Trinity Consultants BART Determination Northeastern Station Unit 2 083701.0057 2-3 

### ( ) 

## [ ] ( ) 

## [ ] ( ) 

## [ ] [ ]

[ ] [ ] ( ) 

## [ ] 3 3 4 3 4 2 4 4

m μg in ion Concentrat Function Humidity Relative EC 10 PMC 6

. 0 PMF 1 SOA 4 NO

NH 3 SO

NH 3

= =

=

= = = = =

RH f b b b b RH f b RH f b

EC

PMC PMF SOA NO SO 

### ( ) 

## [ ] [ ] [ ] [ ] [ ] [ ] carbon elemental of ion concentrat the denotes EC PM coarse of ion concentrat the denotes PMC PM fine of ion concentrat the denotes PMF aerosols organic secondary of ion concentrat the denotes SOA ion concentrat nitrate ammonium the denotes NO NH ion concentrat sulfate ammonium the denotes SO NH

3 4 4 2 4



### 2.1.1 CALPUFF M ODELING 

### A NALYSES

As stated above, the BART Guidelines r ecommend using the CALPUFF modeling system to compute the 24-hour average visibility impa irment attributable to a BART-eligible source to assess whether the 0.5 ∆ dv contribution threshold is exceeded, and if so, the frequency, duration, and magnitude of any exceed ance events. As descr ibed further in the modeling protocol included in Appendix A, CALPUFF is a refined air quality modeling system that is capable of simulating the di spersion, chemical transformation, and longrange transport of multiple visibility-affecting pollutant emissions and is therefore preferred for BART applicability and determination analyses.



## 2.2 BART D ETERMINATION

BART-eligible sources that are found to cause or contribute to visibility impairment at a Class I area are required to make a BART determination. The BART Guidelines define BART as follows:

BART means an emission limitation based on th e degree of reduction achievable through the application of the best system of continuous emission reduction for each pollutant which is emitted by...[a BART-eligible s ource]. The emission limitation must be established, on a case-by-case basis, taking in to consideration the technology available, the costs of compliance, the energy and non-air quality environmental impacts of compliance, any pollution control equipment in use or in existence at the source, the remaining useful life of the source, and the de gree of improvement in visibility which may reasonably be anticipated to result from th e use of such technology. The BART analysis identifies the best system of continuous emission reduction taking into account:

(1) The available retrofit control options, (2) Any pollution control equipment in use at the source (which affects the availability of options and their impacts), (3) The costs of compliance with control options, (4) The remaining useful life of the facility, (5) The energy and non-air quality environmental impacts of control options [ , and ] (6) The visibility impacts analysis.AEP Trinity Consultants BART Determination Northeastern Station Unit 2 083701.0057 2-4 Further, the BART rule indicates that the five b asic steps in a BART analysis can be summarized as follows:

1. Identify all available retrofit control technologies;

2. Eliminate technically infeasible control technologies;

3. Evaluate the control effectiveness of remaining control technologies;

4. Evaluate impacts and document the results;

5. Evaluate visibility impacts

As summarized in Section 3, AEP conducted a BA RT applicability analysis for the Northeastern 2 unit determined that it is indeed subject to BART . The BART determinations for each of the three visibility affecting pollutants (SO 2 , NOx, and PM) can be found in Sections 3 through 5.AEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 3-1 

## 3. BART A PPLICABILITY 

## A NALYSIS



## 3.1 BART-E LIGIBLE 

## S OURCES

In order to determine what specific units constitu te the “BART-eligible” source, the construction dates of the each of the plant’s units must be exam ined. A summary of all units at the Northeastern Station is provided below. As seen from this table, the Northeastern Station has three units that were “in existence” within the 15-year BART window (A ugust 7, 1962-August 7, 1977). The coal fired units, NE3 and 4, are addressed under separate cover. Northeastern Unit 2, the natural gas-fired unit, is addressed in the sections below.

T ABLE 3-1. C ONSTRUCTION D ATE S UMMARY

Unit
No. Heat Duty (MMBtu/hr) Manufacturer Construction Date

1 1,817 Babcock and Wilcox RB-321 Feb, 1961
2 4,754 Babcock and Wilcox UP-60 Mar, 1970
3 4,775 Combustion Engineering #4974 Apr, 1974
4 4,775 Combustion Engineering #7174 Apr, 1974



## 3.2 S OURCE 

## E MISSIONS 

## D ATA

In developing baseline emissions, Trinity utilized a combination of operating records and continuous emission monitoring (CEM) data provided by AEP over a period extending from 2001-05. Modeled emissions are based on the highest hourly emissi on rate (on 24-hour calendar day average) that occurred from 2001 to 2005. A summary of these emissi ons is presented in Table 3-2 below. A more detailed analysis of historical em issions is included in Appendix A.

T ABLE 3-2. P RE -BART E MISSIONS S UMMARY

Unit No. NO x PM SO 2 H 2 SO 4 lbs/hr lbs/hr lbs/hr lbs/hr NE2 3,385 35.4 2.90 0.30

Please note that the NE2 operated entirely on natural gas from 2001-05.



### 3.2.1 PM E MISSIONS

PM emissions are not directly entered into the model but are instead speciated into constituent components. The PM emissions from the boilers can be speciated according to the Federal Land Managers’ guidance to potentially include the following:AEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 3-2 S Coarse particulate matter (PM C , considered PM 2.5-10 )

S Fine particulate matter (PM F , considered PM <2.5 )

S Sulfates (SO 4 )

S Secondary organic aerosols (SOA)

S Elemental carbon (EC)

Based upon FLM guidance, PM emissions from natural gas combustion consists of primarily coarse (25%) and fine (75%). 5 A summary of speciated PM emissions is presented in Table 3-3 below.

T ABLE 3-3. PM S PECIATION P ROFILE

Particulate Matter Species Fraction PM Coarse (Soil) 25% Elemental Carbon (EC) 0%
PM Fine 75% Secondary Organic Aerosols (organic carbon) 0%

Total 100%

A summary of speciated PM emissions from the Northeastern units is presented below.

T ABLE 3-4. S PECIATED PM E MISSIONS

Unit No. PM (coarse) 4 PM (fine) 4 EC 4 SOA 4

lbs/hr lbs/hr lbs/hr lbs/hr
NE2 8.9 26.6 0 0



### 3.2.2 S TACK PARAMETERS

Table 3-5 provides a summary of source exhaust parameters.

T ABLE 3-5. P OINT S OURCE S TACK P ARAMETERS

Emission
unit Latitude (decimal degrees) Longitude (decimal degrees) Exit Velocity

(ft/s) Stack Height (feet) Stack
Diameter (feet) Exit Temperature (Fahrenheit)

NE2 36.42767 95.7007 53 183 18 249

The base elevation of each of the units is 194 meters (636 feet) above MSL based upon visual inspection of USGS topographic maps.

5 http://www2.nature.nps.gov/air/ Permits/ect/ectGasFiredCT.cfmAEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 4-1 

## 4. SO 2 

## BART D ETERMINATION

A summary of existing SO 2 emissions as described in Section 3 is included below.

T ABLE 4-1. B ASELINE M AXIMUM 24-H OUR SO 2 E MISSION R ATES

Emission
Unit SO 2 Emission Rate

(lb/hr) NE2 2.90



## 4.1 I DENTIFICATION OF 

## A VAILABLE 

## R ETROFIT 

## SO 2 

## C ONTROL 

## T ECHNOLOGIES

The first step of a BART determination is the identification of all available retrofit SO 2 control technologies. A list of control technologies was obtained by reviewing the U.S. EPA’s Clean Air Technology Center, control equipment vendor information, publicly-available air permits, applications, and BART analyses, and technical literature published by the U.S. EPA and Regional Planning Organizations (RPOs).

T ABLE 4-2. A VAILABLE SO 2 C ONTROL T ECHNOLOGIES

SO 2 Control Technologies

Dry Sorbent Injection Spray Dryer Absorber (SDA) i.e., Semi-Dry Scrubber Wet Scrubber Circulating Dry Scrubber (CDS)

All of the technologies listed in Table 4-2 involve removing the SO 2 in the exhaust gas, which is known as flue gas desulfurization (FGD). AEP prop oses to restrict fuel u sage at the Northeastern Power Station Unit 2 to natural gas only. Commercia l-grade natural gas is intrinsically low in sulfur content, and results in low sulfur emissions. The facility’s existing Title V operating permit (No. 96- 288-TV) provides an estimate of SO 2 emissions from the combustion of natural gas, as summarized below.

T ABLE 4-3. SO2 E MISSION E STIMATES (N ATURAL G AS )

SO 2 Emission
Unit lb/hr TPY

NE2 2.80 12.25AEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 4-2 SO 2 emissions from Northeastern Unit 2 are sufficien tly low from natural gas usage that no add-on control technology could be considered economica lly feasible. As a result, AEP determines that natural gas usage is BART for Nort heastern Power Station Unit 2.AEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 5-1 

## 5. PM BART D ETERMINATION

A summary of existing PM emissions as descr ibed in Section 3 is included below.

T ABLE 5-1. E XISTING M AXIMUM 24-H OUR PM E MISSION R ATES

Emission
Unit PM Emission Rate

(lb/hr) NE2 35.4



## 5.1 I DENTIFICATION OF 

## A VAILABLE 

## R ETROFIT 

## PM C ONTROL 

## T ECHNOLOGIES

The first step of a BART determination is the id entification of all available retrofit PM control technologies. A list of control technologies was obtained by reviewing the U.S. EPA’s Clean Air Technology Center, control equipment vendor information, publicly-available air permits, applications, and BART analyses, and technical literature published by the U.S. EPA and Regional Planning Organizations (RPOs).

T ABLE 5-2. A VAILABLE PM C ONTROL T ECHNOLOGIES

PM Control Technologies
Electrostatic Precipitator (wet or dry) Baghouse (Fabric Filter)

AEP proposes to restrict fuel usage at the Northeastern Power Station Unit 2 to natural gas only. As with SO 2 , the use of pipeline quality natural gas inheren tly results in low particulate emissions. The facility’s existing Title V operating permit (No. 96-288-TV) provides an estimate of PM emissions from the combustion of natural gas, as summarized below.

T ABLE 5-3. PM E MISSION E STIMATES

PM Emission
Unit lb/hr TPY

NE3 35.42 155.15

These emission estimates for this unit from natural gas usage are sufficiently low that no add-on control technology could be considered economica lly feasible. As a result, AEP determines that natural gas usage is BART for PM fo r Northeastern Power Station Unit 2.AEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 6-1 

## 6. NO X 

## BART D ETERMINATION

The existing maximum daily NO X emission rates that were modeled for the BART applicability determination are summarized in Table 6-1.

T ABLE 6-1. E XISTING M AXIMUM 24-H OUR NO X E MISSION R ATE

Unit ID NO X Hourly Emission Rate NO X Emission Rate (lb/hr) (lb/MMBtu) NE2 3,385 0.71



## 6.1 I DENTIFY 

## A LL 

## A VAILABLE 

## R ETROFIT 

## T ECHNOLOGIES

Step 1 of the BART determination is the identification of all available retrofit NO X control technologies. A list of control technologies was obtained by reviewing the U.S. EPA’s Clean Air Technology Center, control equipment vendor information, publicly-available air permits, applications, and BART analyses, and technical litera ture published by the U.S. EPA and the RPOs.

T ABLE 6-2. A VAILABLE NO X C OMBUSTION C ONTROL T ECHNOLOGIES

NO X Control Technologies

Burner Tuning Burners Out of Serv ice (placing select ed burners out of service)

Induced Flue Gas R ecirculation (IFGR)

Low NO X Burners (LNB)/overfire air (OFA)

NO X emissions controls, as listed in Table 6-2, ar e categorized as combustion controls. Combustion controls, including induced flue gas recircul ation (IFGR), overfire air (OFA), and Low NO X Burners (LNB), reduce the peak flame temperature a nd excess air in the furnace which minimizes NO X formation. Post-combustion controls, such as selective catalytic reduction (SCR) and selective noncatalytic reduction (SNCR) were not examined in this analysis. As described in Appendix Y to Part 51, U.S. EPA states that the use of combustion control technology is highly cost-effective in achieving emission reductions under BA RT for gas-fired applications. 6



## 6.2 E LIMINATE 

## T ECHNICALLY 

## I NFEASIBLE 

## O PTIONS

Step 2 of the BART determination is to eliminate technically infeasible NO X control technologies that were identified in Step 1.

6 Federal Register, Vol 20, No. 128, 7/6/2005, p. 39172AEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 6-2 

### 6.2.1 B URNERS 

### O UT OF 

### S ERVICE

This option involves shutting off selected bur ners, resulting in reduced fuel usage and therefore lower emissions. This option w ould essentially reduce the maximum firing rate of the boiler, and places a load limit on the unit. AEP estimates that NOx emissions can be reduced 20-25%. Implementation of this option will reduce the maximum firing rate of the unit, thereby creating an artificial load limit. Although this does not preclude this option from being physically implemented, the resulting load limits would effectively result in the shutdown of the units. As a r esult, this option is considered technically infeasible.



### 6.2.2 I NDUCED 

### F LUE 

### G AS 

### R ECIRCULATION 

### (IFGR)

IFGR uses flue gas as an inert material to redu ce flame temperatures. In a typical flue gas recirculation system, flue gas is collected fro m the heater or stack and returned to the burner via a duct and blower. The addition of flue gas reduces the oxygen content of the “combustion air” (air + flue gas) in the burner. The lower oxygen level in the combustion zone reduces flame temperatures; which in turn reduces thermal NO X formation. When operated without additional controls, the average NO X control efficiency range for FGR is 30 percent to 40 percent. This control opti on would also place load limits on the boiler and also call for plant equipment upgrades. As with the Burners Out Of Service option, IFGR is considered technically infeasible.



### 6.2.3 L OW 

### NO X 

### B URNERS 

### (LNB) WITH 

### O VERFIRE 

### A IR 

### (OFA)

LNB technology utilizes advanced burner design to reduce NO X formation through the restriction of oxygen, lowering of flame temperature, and/or reduced residence time. LNB is a staged combustion process that is designed to split fuel combustion into two zones. In the primary zone, NO X formation is limited by either one of two methods. Under staged fuel-rich conditions, low oxygen levels limit flame temperatures resulting in less NO X formation. The primary zone is then fo llowed by a secondary zone in which the incomplete combustion products formed in th e primary zone act as reducing agents. Alternatively, under staged fuel-lean cond itions, excess air will reduce flame temperature to reduce NO X formation. In the secondary zone , combustion products formed in the primary zone act to lower the local oxygen concentration, resulting in a decrease in NO X formation.

OFA diverts a portion of the total combustion air from the burners and injects it through separate air ports above the top level of burners. Staging of the combustion air creates an initial fuel-rich combustion zone with a lower peak flame temperature. This reduces the formation of thermal NO X by lowering combustion temperature and limiting the availability of oxygen in the combustion zone where NO X is most likely to be formed.AEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 6-3 OFA as a single NO X control technique may reduce NO X emissions by 25 to 55 percent. When combined with LNB, reductions of up to 60 percent may result. 7 This technology is considered a technically feasible option.



## 6.3 E VALUATE 

## E FFECTIVENESS OF 

## R EMAINING 

## C ONTROL 

## T ECHNOLOGIES

The third step in the BART analysis is to rank the technically feasible options according to effectiveness.

T ABLE 6-3. C ONTROL E FFECTIVENESS OF T ECHNICALLY F EASIBLE NO X C ONTROL T ECHNOLOGIES

Control Technology Estimated Control Efficiency (%)

LNB w/ OFA ~30-60



## 6.4 E VALUATION OF 

## I MPACTS FOR 

## F EASIBLE 

## NO X 

## C ONTROLS

Step four for the BART analysis procedure is the impact analysis. The BART determination guidelines list four factors to be considered in the impact analysis:

▲ Cost of compliance
▲ Energy impacts
▲ Non-air quality impacts; and
▲ The remaining useful life of the source

Evaluation of a fifth factor, visibility impacts, is addressed separately in Section 6.5.



### 6.4.1 C OSTS OF 

### C OMPLIANCE

Per the BART Guidelines, the costs of complianc e analysis for each cont rol option consists of comparisons of the average cost effectiveness and the incremental cost effectiveness, which are defined in Section IV.D.4 as follows:

Average cost effectiveness means the total an nualized costs of control divided by the annual emissions reduction (the differen ce between baseline annual emissions and the estimate of emissions after controls), using the following formula:

Average cost effectiveness (dollars per t on removed) = Control option annualized cost ÷ (Baseline annual emissions – Annual emissions with Control option)

7 "Assessment of Control Technology Options for BART -Eligible Sources: Steam Elec tric Boilers, Industrial Boilers, Cement Plants and Paper and Pulp Facilities" Northe ast States for Coordinated Ai r Use Management (NESCAUM), March 2005AEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 6-4 ...the incremental cost effectiveness calcul ation compares the costs of performance level of a control option to those of the n ext most stringent option, as shown in the following formula (with respect to cost per emissions reduction):

Incremental Cost Effectiveness (dollars per incremental ton removed) = (Total annualized costs of control option) – (Total annualized costs of next control option) ÷ (Control option annual emissions) – (Next control option annual emissions)

Compliance costs associated with implementing the evaluated control systems were developed in-house by AEP, a nd represent both annual operating costs and annualized capital costs associated with retrofit construction. A detailed summary of those costs is included in Appendix B, while estimates of annual polluta nt reductions for the evaluated control technologies are included in Appendix A. The average cost effectiveness of this control options is summarized in Table 6-4. Please not e that since no other options were examined, incremental cost effectiveness is not relevant (and not included).

T ABLE 6-4. NO X C ONTROL C OSTS S UMMARY

Average Cost
Effectiveness Incremental Cost
Effectiveness Emission Unit Control Strategy $/ton $/ton

NE2 Low NOx Burner
w/ Overfire Air 573 --



### 6.4.2 E NERGY AND 

### N ON



### - AIR 

### I MPACTS

Energy and non-air impacts from an LNB retrof it are minimal. Derating of output from the unit is not expected, or considered insignificant.



### 6.4.3 R EMAINING 

### U SEFUL 

### L IFE

The remaining useful life of the Northeaster n units do not impact the annualized capital costs of potential controls because the useful lives of the units are anticipated to be at least as long as the capital cost recovery period, which is 20 years.



## 6.5 E VALUATE 

## V ISIBILITY 

## I MPACTS

In order to determine the change in visibilit y impact from the various NOx control options considered, calculated emissions were modeled in CALPUFF. As discussed in the modeling protocol included in Appendix A, visibility impacts were eval uated each of the four nearby Class I areas.

Pre-BART baseline emissions for each unit are mode led and summarized below. Subsequent control scenarios incorporated calculated NOx emissions fro m post-control scenarios, and incorporated allAEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 6-5 other pollutants at baseline emissions. Per BART determination procedures, visibility impacts are presented below on a unit-by-unit basis.

T ABLE 6-5. N ORTHEASTERN U NIT 2 V ISIBILITY I MPACTS (98 TH P ERCENTILE I MPACT )

Class I Area Pre-BART LNB w/ OFA Visibility Improvement ∆ dv ∆ dv % Caney Creek 0.675 0.276 59% Hercules-Glades 0.314 0.126 60% Upper Buffalo 0.390 0.157 60% Wichita Mountains 0.421 0.162 62%



## 6.6 P ROPOSED 

## B ART FOR 

## NO X

AEP has determined that the NO X BART for Northeastern Unit 2 is LNB w/ OFA. As seen from the modeled visibility improvement and calculated averag e cost effectiveness, this control option cannot be considered either technically or economically infeasible. Based upon the control effectiveness estimates of LNB w/ OFA, AEP proposes a BART NOx emission rate of 0.28 lb/MMBtu.AEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 

## A PPENDIX 

## A

– E MISSION 

## E STIMATESUnit 2PM (coarse) PM (fine)lb/mmBtu lb/hr lb/mmBtu lb/hr lb/mmBtu lb/hr lb/mmBtu lb/hr lb/hr lb/hrCase 1 Baseline Case -- 0.71 3,384.8 0.0006 2.85 0.000074 0.3 0.007 35.4 8.9 26.6Case 2 LNB w/ OFA 60% 0.28 1,353.91Sulfuric acid emissions based upon the following:SO2Conversion to SO3= 10%SO3Conversion to H2SO4= 100%MW H2SO4= 98 lb/lbmolMW SO3= 80 lb/lbmolMW SO2= 64 lb/lbmolSample Calculation:0.0006 lb SO2 0.1 lb SO3lb mol SO3lb molH2SO498 lb H2SO4mmBtu 1 lb SO280 lb SO3lb mol SO3lb mol H2SO42Baseline emission data for PM is not available. A conservative estimate was made using U.S. EPA emission factors, AP-42 (7/98) Table 1.4-2Please note that for natural gas usage, PM10 emissions can be considered equivalent to total PM.PM10= 7.6 lb/MMSCF0.0075 lb/MMBtuNatural gas heating value = 1020 BTU/scf3Condensible/filterable PM speciation were based on the following profiles:For Natural Gas fired combustion turbines. http://www2.nature.nps.gov/air/Permits/ect/ectGasFiredCT.cfmFilterable 25%Condensible 75%PercentReductionNOxBART Emissions Modeling InputsNortheastern Power StationPM10Speciation3=0.000074 lbs H2SO4mmBtuPM (total)2SO2H2SO4(as SO4from SO2)1American Electric PowerNortheastern Power StationEmission Estimates (lbhr)Printed on 8/27/2008Page 1 of 2Trinity Consultants083701.0057Unit IDUnit 2Unit 2NOxReduction (%)(lb/MMBtu)1tpyCase 1 Baseline Case -- 0.48 9,995Case 2 LNB w/ OFA 41% 0.28 5,9301Baseline emission factor based upon annual average. Provided by AEP via email, 8/20/2008Northeastern Power PlantAnnual Emission Estimates(MMBtu/hr)4754Annual Ave Firing RateAmerican Electric PowerNortheastern Power StationEmission Estimates (Annual)Printed on 8/27/2008Page 2 of 2Trinity Consultants083701.0057Northeastern StationCALPUFF Visibility ResultsPeak Impact 98th PercentilePollutant Class I AreaControlTechnology (∆dv)% Reductionfrom Baseline (∆dv)% Reductionfrom BaselineNOx Caney Creek Baseline 1.810 -- 0.675 --LNB w/ OFA 0.751 59% 0.276 59%Herc-Glades Baseline 1.164 -- 0.314 --LNB w/ OFA 0.482 59% 0.126 60%Upper Buffalo Baseline 1.456 -- 0.390 --LNB w/ OFA 0.601 59% 0.157 60%Wichita Mts Baseline 1.698 -- 0.421 --LNB w/ OFA 0.703 59% 0.162 62%PM10Caney Creek Baseline 0.002 -- 0.001 --Herc-Glades Baseline 0.001 -- -- --Upper Buffalo Baseline 0.002 -- 0.001 --Wichita Mts Baseline 0.002 -- 0.001 --SO2Caney Creek Baseline 0.001 -- -- --Herc-Glades Baseline -- -- -- --Upper Buffalo Baseline 0.001 -- -- --Wichita Mts Baseline 0.001 -- -- --AEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 

## A PPENDIX 

## B

- E CONOMIC 

## A NALYSESPrinted: 8/27/2008

Economic Analysis for Low NOx Burners w/ Overfire Air

Capital Cost Summary Capital Cost

TOTAL CAPITAL INVESTMENT a TCI = $3,450,000

Annual Cost Summary Annual Cost

DIRECT OPERATING COSTS Low-NOx burners are not expected to incur any additional significant direct operating costs

TOTAL DIRECT COSTS (DC) DC = $0

INDIRECT OPERATING COSTS Administrative Charges (2% of TCI) b $69,000

Insurance (1% of TCI) b $34,500

Property Taxes (1% of TCI) b $34,500

Capital Recovery (CRF x TCI) 20 years @ 8.00% interest CRF = 0.1019 $351,390

TOTAL INDIRECT COSTS (IC) IC = $489,390

TOTAL ANNUALIZED COST (TAC = DC + IC) TAC= $489,390

Cost Effectiveness Summary

Annual Control Cost: $489,390

NOx to be Removed (tpy): c 854

CONTROL COST EFFECTIVENESS ($/ton): $573

a Cost of purchasing and installing Low-NOx burners provided by AEP via email (8/21/2008). b Direct and indirect cost factors taken from OAQPS Control Cost Manual, Sixth Edition, January 2002. c LNB w/OFA NOx Removal Rate = 41% Annual Capacity Factor = 0.21 Provided by AEP via email, 8/20/2008 Baseline (pre-BART) emission factor = 0.48 Based upon an annual average Annual Average Firing Rate = 4754 MMBtu/hr, as listed in Permit No. 96-288-TV.

Sample Calculation:

0.48 lb 4754 MMBtu 8760 hrs ton 0.21 capacity factor 0.41 NOx Removal Rate = 854 tons NOx MMBtu hr yr 2000 lb year

American Electric Power
N ortheastern Power Statio n Cost Analysis (LNB wOFA) Trinity Consultants
083701.0057AEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 

## A PPENDIX 

## C

– CALPUFF M ODELING 

## P ROTOCOLAEP Trinity Consultants BART Determination Northeastern Power Station Unit 2 083701.0057 

## A PPENDIX 

## D

– M ODELING 

## I NPUT 

## /O UTPUT 

## F ILES



### Control Scenario Description Model Run Number
NOx SO 2

Case 1 Baseline Case Run 1 Run 1

Case 2 LNB w/ OFA Run 2 --