dte energy/ees coke pti 51-08c factsheet

STATE OF MICHIGAN

Rick Snyder, Governor

DEPARTMENT OF ENVIRONMENTAL QUALITY

AIR QUALITY DIVISION CONSTITUTION HALL ● 525 WEST ALLEGAN STREET ● P.O. BOX 30260 ● LANSING, MICHIGAN 48909-7760

www.michigan.gov/air

PUBLIC PARTICIPATION DOCUMENTS For

EES Coke Battery, LLC River Rouge, Michigan

PERMIT APPLICATION NUMBER

51-08C

October 1, 2014

EES Coke Battery, LLC Page 1 Permit No. 51-08C October 1, 2014

FACT SHEET October 1, 2014

Purpose and Summary The Michigan Department of Environmental Quality (MDEQ), Air Quality Division (AQD), is proposing to act on Permit to Install (PTI) application No. 51-08C from EES Coke Battery, LLC (EES Coke). The permit application is for a proposed modification to the existing coke oven battery. The proposed project is subject to permitting requirements of the MDEQ’s Rules for Air Pollution Control as well as state and federal Prevention of Significant Deterioration (PSD) regulations. Prior to acting on this application, the AQD is holding a public comment period and a public hearing to allow all interested parties the opportunity to comment on the proposed PTI. All relevant information received during the comment period and hearing, will be considered by the decision maker prior to taking final action on the application. Background Information and the Proposed Project EES Coke owns and operates a by-product recovery coke oven battery consisting of eighty-five, six-meter high ovens with an integral heating system; a by-product recovery plant; and a coke oven gas (COG) flare. The following emission control devices are part of the battery: overpressure bleeder flares, pushing emission control system (PECS) baghouse, and a quench tower. Material handling processes in support of the operation of the battery include coal and coke transfer as well as screening and transport. The coke oven battery converts coal into metallurgical coke for use in the iron and steel industry. The by-product recovery coke oven battery began operation in 1992. National Steel Corporation - Great Lakes Division originally owned and operated the battery as well as the steel-making operations on Zug Island in River Rouge, Michigan. The coke oven battery was modified in 1996 to correct emission rates of nitrogen oxides (NOx) and carbon monoxide (CO) to reflect actual operations after the battery was built. In 1997, National Steel Corporation sold the battery to EES Coke but continued to manage the coke operations. In 2003, the U.S. Steel Corporation (US Steel) acquired the iron and steel assets from the National Steel Corporation, and in 2004, EES Coke assumed sole responsibility for the coke operations. EES Coke (State Registration No. P0408) and US Steel (State Registration No. A7809) are considered to be the same stationary source. The by-product recovery coke oven battery, the by-product recovery plant and the material handling processes are all currently operating under to PTI Nos. 51-08, 71-13 (temporary PTI), and 124-09. Also, the source has a Renewable Operating Permit (ROP) identified as No. 199600132d which is currently in the process of being renewed. The project that EES Coke is proposing in this application is to remove the daily and annual heat input restrictions on the combustion of COG that is used to heat the battery, and to increase the material throughput limit on the amount of coal that can be processed in the battery. Some additional modifications to the material handling processes are also proposed.


Present Air Quality The facility is located in Wayne County, which is currently in attainment with the National Ambient Air Quality Standards (NAAQS) for CO, nitrogen dioxide (NO2), particulate matter that has an aerodynamic diameter less than or equal to a nominal 10 microns (PM10), particulate matter that has an aerodynamic diameter less than or equal to a nominal 2.5 microns (PM2.5), ozone, lead, and the 3-hour NAAQS for sulfur dioxide (SO2). This area is currently designated as nonattainment for the 1-hour NAAQS for SO2. There is no NAAQS for volatile organic compounds (VOC) nor greenhouse gases (GHGs) as carbon dioxide equivalent (CO2e). Pollutant Emissions The EES Coke facility is an existing PSD source and a major nonattainment source for SO2. This means that the potential emissions from the facility are greater than the PSD thresholds of 100 tons per year (tpy) for one or more regulated pollutants, and greater than 100 tpy for a nonattainment pollutant. The proposed project results in a significant net emission increase in NOx and GHGs. Therefore, the proposed project will be a major modification to an existing PSD source, and subject to the PSD regulations in Part 18 of the Michigan Air Pollution Control Rules and the federal PSD regulations. The following table provides the estimated net emission increase for each regulated pollutant from the proposed project:

Facility Emission Increases

Pollutant Net Emission Increase (tpy)

Significant Emission Rate (tpy)

Subject to PSD Review?

CO - 0 - 100 No GHGs (as CO2e)* 82,229 75,000 Yes NOx 668 40 Yes Particulate Matter (PM) - 0 - 25 No PM10 - 0 - 15 No PM2.5 1.4 10 No SO2 19.5 40 No VOC - 0 - 40 No Lead - 0 - 0.6 No Sulfuric Acid Mist (H2SO4)

1.6 3 No

Hydrogen Sulfide (H2S) 2.5 7 No Total Reduced Sulfur (TRS) / Reduced Sulfur Compounds (RSC)

2.7 10 No

* A recent decision by the Supreme Court (Utility Air Regulatory Group v. United States Environmental Protection Agengy (USEPA), No. 12-1146 (June 23, 2014)) determined that PSD review for GHGs is only required if one or more of the other regulated pollutants exceeds a PSD threshold.


Key Permit Review Issues The AQD staff evaluated the proposed project to identify all state rules and federal regulations which are, or may be, applicable. The tables in Appendix 1 summarize these rules and regulations. • PSD Regulations – The project was reviewed under the PSD rules which require Best

Available Control Technology (BACT) and an air quality impact analysis for each regulated air pollutant for which the project will result in a significant net emission increase. The pollutants subject to PSD review are NOx and GHGs (as CO2e) as discussed in Appendix 2 and Appendix 3.

• Minor Modification Determination for Nonattainment Pollutants – The facility is located in Wayne County which is currently designated as nonattainment for the 1-hour NAAQS for SO2. The facility is an existing major offset source for SO2. An increase in SO2 emissions above the significant level of 40 tpy will result in the proposed project being subject to nonattainment new source review (NANSR) for SO2. The emission increase of SO2 from the proposed project is 19.5 tpy which is less than the significant level. As such, the proposed SO2 increase is not subject to NANSR.

• Federal NESHAP Regulations - National Emission Standards for Hazardous Air Pollutants

(NESHAP) were established under 40 Code of Federal Regulations (CFR) Part 61 and Part 63. The existing by-product recovery coke oven battery is subject to the provisions of Subpart L (40 CFR Part 63); and the coke ovens, the pushing, soaking, quenching, and battery stacks are subject to the provisions of Subpart CCCCC (40 CFR Part 63). The by-product recovery plant is subject to the provisions of Subpart L (40 CFR Part 61), Subpart V (40 CFR Part 61), and Subpart FF (40 CFR Part 61). These standards were reviewed and permit conditions were updated to reflect any changes in the standards.

• Rule 225 Toxics Analysis – The MDEQ Rules for Air Pollution Control require the ambient

air concentration of any toxic air contaminant (TAC) be compared against health-based screening levels. Air dispersion modeling was used to evaluate the impact of TAC emissions from the proposed project. The TAC impacts from the proposed project were significantly less than their respective initial threshold screening level (ITSL) or initial risk screening level (IRSL), and will therefore comply with the requirements of R 336.1225 (Rule 225). For any TAC that is also a hazardous air pollutant (HAP), the provisions of Rule 225 do not apply because a residual risk standard in Subpart L (40 CFR Part 63) has been assessed for the by-product recovery coke oven battery.

• Rule 702 VOC Emissions – This rule requires an evaluation of the following four items to

determine what will result in the lowest maximum allowable emission rate of VOC:

a. BACT or a limit listed by the MDEQ on its own initiative

b. New Source Performance Standards (NSPS)

c. VOC emission rate specified in another permit

d. VOC emission rate specified in the Part 6 rules for existing sources


An evaluation of these four items determined that a VOC BACT limit per R 336.1702(a) would dictate the lowest maximum allowable emission rate of VOC from the coke oven battery. The analysis determined that VOC BACT is based on good combustion practices for the underfire combustion stack on the coke oven battery and COG flare, a limit on the volatile matter content of the coke produced, and proper operation of the PECS on the coke oven battery.

• Criteria Pollutants Modeling Analysis - Computer dispersion modeling was performed to

predict the ambient impacts of the emissions of NO2, PM10, PM2.5, and 3-hour SO2. Emissions from the proposed facility were evaluated against both the NAAQS and the PSD increments. The NAAQS are intended to protect public health. The PSD increments are intended to allow industrial growth in an area, while ensuring that the area will continue to meet the NAAQS. The maximum impacts are all below their applicable NAAQS and the PSD increments. The air quality impact analysis is summarized in Appendix 3.

A secondary formation assessment addresses the formation of ozone from the precursors of NOx and VOC, and the formation of PM2.5 from the precursors of NOx and SO2. The secondary formation assessment is also summarized in Appendix 3.

• Additional Impact Analysis – An additional impact analysis is required for a major

modification pursuant to R 336.2815 (Rule 1815). This analysis is necessary to evaluate the impacts from the proposed project for soils, vegetation, visibility and growth. The proposed project is not anticipated to have a negative impact on soils, vegetation, visibility, and will have no impact on growth.

• Other – The project will result in a significant emissions increase of NOx. The nearest

Class I areas (Seney, Otter Creek Wilderness Area, and Isle Royale) are located greater than 300 kilometers from the proposed project, and notification to the Federal Land Manager was not necessary for this project.

Key Aspects of Draft Permit Conditions The draft permit conditions contain the emission limits, material limits, process/operational restrictions, NESHAP requirements, monitoring, recordkeeping, and reporting requirements that are necessary for an enforceable permit that meets all regulatory requirements. The following is a brief discussion of the key aspects of the draft permit conditions: • NOx Emissions – The draft permit requires that the coke oven battery operate with staged

combustion for the underfire combustion system and in accordance with best combustion practices for the COG flare. For the underfire combustion system, the assessed BACT emission limitations represent proper operation of the staged combustion system along with the requirement to continuously measure the emissions of NOx from the underfire combustion stack. For the PECS, the BACT emission limitations assessed represent proper operation of the coke oven battery during pushing.

• SO2 Emissions – The draft permit has both short-term and long-term SO2 mass emission

limitations that are continuously measured on the underfire combustion stack from the coke oven battery.


• CO and VOC Emissions – The draft permit has short-term emission limitations to demonstrate good combustion control of CO and VOC emissions. Emissions of CO are measured continuously on the underfire combustion stack from the coke oven battery.

• Particulate Emissions – The draft permit includes emission limitations on PM in accordance with the original nonattainment review for the coke oven battery. Also, the draft permit includes emission limitations on PM10 and PM2.5 to demonstrate compliance with the air quality standards.

• Usage Limits - The draft permit includes limits on the input of dry coal, heavy tar sludge and No. 2 fuel oil charged to the battery.

• Process/Operational Restrictions - The draft permit requires all emission control devices to be installed, maintained, and operated in a satisfactory manner. Satisfactory manner includes operating and maintaining each control device in accordance with an approved Malfunction Abatement Plan (MAP).

• Federal Regulations – The draft permit includes the NESHAP requirements for emissions of HAPs. Proper operation of the coke oven battery, control equipment, periodic emission testing, and continuous emission monitoring will serve to make the emission limits enforceable as a practical matter.

• Emission Control Device Requirements – The draft permit includes emission control

device requirements. The coke oven battery will be required to control the following:

− NOx by staging combustion and proper operation of the coke oven battery.

− Particulate emissions by good combustion practices and proper operation of the PECS baghouse.

• Testing and Monitoring Requirements – The draft permit includes the following

requirements for the emission monitoring:

− Verify PM, PM10, PM2.5, and VOC emission rates through performance testing.

− Maintain a Continuous Emission Monitoring System (CEMS) for CO, NOx, and SO2 on the underfire combustion stack of the coke oven battery.

− Maintain a Continuous Opacity Monitoring System for the underfire combustion stack of the coke oven battery.

• Coal and Coke Material Handling Systems - The draft permit includes the following

requirements for the material handling systems:

- Visible emissions monitoring.

- A fugitive dust control program outlining control measures and work practice standards intended to minimize the opportunity for fugitive particulate emissions from vehicle traffic, material handling, and material storage piles. The facility’s existing fugitive dust control program will be amended to include the new material handling operations as approved by the AQD District Supervisor.


Conclusion Based on the analyses conducted to date, the AQD staff concludes that the proposed project would comply with all applicable state and federal air quality requirements. The AQD staff also concludes that this project, as proposed, would not violate any of the MDEQ rules, nor NAAQS and PSD increments. Based on these conclusions, the AQD staff has developed draft permit terms and conditions which would ensure that the proposed facility design and operation are enforceable and that sufficient monitoring, recordkeeping, and reporting would be performed by the applicant to determine compliance with these terms and conditions. If the permit application is deemed approvable, the delegated decision maker may determine a need for additional or revised conditions to address issues raised during the public participation process. If you would like additional information about this proposal, please contact Ms. Julie Brunner, AQD, at 517-284-6789.


Appendix 1 STATE AIR REGULATIONS

State Rule Description of State Air Regulations

R 336.1201

Requires an Air Use Permit for new or modified equipment that emits, or could emit, an air pollutant or contaminant. However, there are other rules that allow smaller emission sources to be installed without a permit (see Rules 336.1279 through 336.1290 below). Rule 336.1201 also states that the Department can add conditions to a permit to assure the air laws are met.

R 336.1205

Outlines the permit conditions that are required by the federal Prevention of Significant Deterioration (PSD) Regulations and/or Section 112 of the Clean Air Act. Also, the same types of conditions are added to their permit when a plant is limiting their air emissions to legally avoid these federal requirements. (See the Federal Regulations table for more details on PSD.)

R 336.1224

New or modified equipment that emits toxic air contaminants must use the Best Available Control Technology for Toxics (T-BACT). The T-BACT review determines what control technology must be applied to the equipment. A T-BACT review considers energy needs, environmental and economic impacts, and other costs. T-BACT may include a change in the raw materials used, the design of the process, or add-on air pollution control equipment. This rule also includes a list of instances where other regulations apply and T-BACT is not required.

R 336.1225 to R 336.1232

The ambient air concentration of each toxic air contaminant emitted from the project must not exceed health-based screening levels. Initial Risk Screening Levels (IRSL) apply to cancer-causing effects of air contaminants and Initial Threshold Screening Levels (ITSL) apply to non-cancer effects of air contaminants. These screening levels, designed to protect public health and the environment, are developed by Air Quality Division toxicologists following methods in the rules and U.S. EPA risk assessment guidance.

R 336.1279 to R 336.1290

These rules list equipment to processes that have very low emissions and do not need to get an Air Use permit. However, these sources must meet all requirements identified in the specific rule and other rules that apply.

R 336.1299(2)(b) Adopts by reference the provisions of 40 CFR 63.40 to 63.44 (2002) and 40 CFR 63.50 to 63.56 (2002), the federal hazardous air pollutant regulations governing constructed or reconstructed major sources.

R 336.1301 Limits how air emissions are allowed to look at the end of a stack. The color and intensity of the color of the emissions is called opacity.

R 336.1331 The particulate emission limits for certain sources are listed. These limits apply to both new and existing equipment.

R 336.1370 Material collected by air pollution control equipment, such as dust, must be disposed of in a manner, which does not cause more air emissions.

R 336.1401 and R 336.1402 Limit the sulfur dioxide emissions from power plants and other fuel burning equipment.

R 336.1601 to R 336.1651

Volatile organic compounds (VOCs) are a group of chemicals found in such things as paint solvents, degreasing materials, and gasoline. VOCs contribute to the formation of smog. The rules set VOC limits or work practice standards for existing equipment. The limits are based upon Reasonably Available Control Technology (RACT). RACT is required for all equipment listed in Rules 336.1601 through 336.1651.

R 336.1702

New equipment that emits VOCs is required to install the Best Available Control Technology (BACT). The technology is reviewed on a case-by-case basis. The VOC limits and/or work practice standards set for a particular piece of new equipment cannot be less restrictive than the Reasonably Available Control Technology limits for existing equipment outlined in Rules 336.1601 through 336.1651.

R 336.1801 Nitrogen oxide emission limits for larger boilers and stationary internal combustion engines are listed.

R 336.1901

Prohibits the emission of an air contaminant in quantities that cause injurious effects to human health and welfare, or prevent the comfortable enjoyment of life and property. As an example, a violation may be cited if excessive amounts of odor emissions were found to be preventing residents from enjoying outdoor activities.


STATE AIR REGULATIONS

State Rule Description of State Air Regulations R 336.1910 Air pollution control equipment must be installed, maintained, and operated properly.

R 336.1911 When requested by the Department, a facility must develop and submit a malfunction abatement plan (MAP). This plan is to prevent, detect, and correct malfunctions and equipment failures.

R 336.1912 A facility is required to notify the Department if a condition arises which causes emissions that exceed the allowable emission rate in a rule and/or permit.

R 336.2001 to R 336.2060

Allow the Department to request that a facility test its emissions and to approve the protocol used for these tests.

R 336.2801 to R 336.2804

Prevention of Significant

Deterioration (PSD)

Regulations

Best Available Control

Technology (BACT)

The PSD rules allow the installation and operation of large, new sources and the modification of existing large sources in areas that are meeting the National Ambient Air Quality Standards (NAAQS). The regulations define what is considered a large or significant source, or modification.

In order to assure that the area will continue to meet the NAAQS, the permit applicant must demonstrate that it is installing the BACT. By law, BACT must consider the economic, environmental, and energy impacts of each installation on a case-by-case basis. As a result, BACT can be different for similar facilities.

In its permit application, the applicant identifies all air pollution control options available, the feasibility of these options, the effectiveness of each option, and why the option proposed represents BACT. As part of its evaluation, the Air Quality Division verifies the applicant’s determination and reviews BACT determinations made for similar facilities in Michigan and throughout the nation.

R 336.2901 to R 336.2903 and

R 336.2908

Applies to new “major stationary sources” and “major modifications” as defined in R 336.2901. These rules contain the permitting requirements for sources located in nonattainment areas that have the potential to emit large amounts of air pollutants. To help the area meet the NAAQS, the applicant must install equipment that achieves the Lowest Achievable Emission Rate (LAER). LAER is the lowest emission rate required by a federal rule, state rule, or by a previously issued construction permit. The applicant must also provide emission offsets, which means the applicant must remove more pollutants from the air than the proposed equipment will emit. This can be done by reducing emissions at other existing facilities.

As part of its evaluation, the AQD verifies that no other similar equipment throughout the nation is required to meet a lower emission rate and verifies that proposed emission offsets are permanent and enforceable.

FEDERAL AIR REGULATIONS

Citation Description of Federal Air Regulations or Requireme nts

Section 109 of the Clean Air Act –

National Ambient Air Quality Standards (NAAQS)

The United States Environmental Protection Agency has set maximum permissible levels for seven pollutants. These NAAQS are designed to protect the public health of everyone, including the most susceptible individuals, children, the elderly, and those with chronic respiratory ailments. The seven pollutants, called the criteria pollutants, are carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter less than 10 microns (PM10), particulate matter less than 2.5 microns (PM2.5), and sulfur dioxide. Portions of Michigan are currently non-attainment for either ozone or PM2.5. Further, in Michigan, State Rules 336.1225 to 336.1232 are used to ensure the public health is protected from other compounds.


FEDERAL AIR REGULATIONS

Citation Description of Federal Air Regulations or Requireme nts

40 CFR 52.21 – Prevention of

Significant Deterioration

(PSD) Regulations

Best Available Control

Technology (BACT)

The PSD regulations allow the installation and operation of large, new sources and the modification of existing large sources in areas that are meeting the NAAQS. The regulations define what is considered a large or significant source, or modification.

In order to assure that the area will continue to meet the NAAQS, the permit applicant must demonstrate that it is installing BACT. By law, BACT must consider the economic, environmental, and energy impacts of each installation on a case-by-case basis. As a result, BACT can be different for similar facilities.

In its permit application, the applicant identifies all air pollution control options available, the feasibility of these options, the effectiveness of each option, and why the option proposed represents BACT. As part of its evaluation, the Air Quality Division verifies the applicant’s determination and reviews BACT determinations made for similar facilities in Michigan and throughout the nation.

40 CFR 60 – New Source Performance

Standards (NSPS)

The United States Environmental Protection Agency has set national standards for specific sources of pollutants. These New Source Performance Standards (NSPS) apply to new or modified equipment in a particular industrial category. These NSPS set emission limits or work practice standards for over 60 categories of sources.

40 CFR 63—National

Emissions Standards for Hazardous Air

Pollutants (NESHAP)

The United States Environmental Protection Agency has set national standards for specific sources of pollutants. The National Emissions Standards for Hazardous Air Pollutants (NESHAP) (a.k.a. Maximum Achievable Control Technology (MACT) standards) apply to new or modified equipment in a particular industrial category. These NESHAPs set emission limits or work practice standards for over 100 categories of sources.

Notes: An “Air Use Permit,” sometimes called a “Permit to Install,” provides permission to emit air contaminants up to certain specified levels. These levels are set by state and federal law, and are set to protect health and welfare. By staying within the levels set by the permit, a facility is operating lawfully, and public health and air quality are protected. The Air Quality Division does not have the authorit y to regulate noise, local zoning, property values, off-site truck traffic, or lighting. These tables list the most frequently applied state and federal regulations. Not all regulations listed may be applicable in each case. Please refer to the draft permit conditions provided to determine which regulations apply.


Appendix 2 – Best Available Control Technology Anal ysis (Rule 336.2810)

By-Product Recovery Coke Oven Battery

A requirement of PSD New Source Review is a BACT analysis. For review of this application, the top-down BACT approach per the USEPA DRAFT New Source Review Workshop Manual (October 1990) was utilized. The top-down approach considers all available emission reduction options and proceeds in a five-step process as follows: 1. Identify all control technologies; 2. Eliminate technically infeasible options; 3. Rank the remaining control technologies by control effectiveness; 4. Evaluate the most effective controls and document the results; 5. Select BACT (e.g., the most effective option not rejected is BACT). BACT for NOx NOx is generated thermally when nitrogen reacts with oxygen in the combustion air in a high temperature environment, and from oxidation of organic nitrogen compounds in the fuel (fuel NOx). Fuel properties have a significant impact on NOx formation. In a coke oven battery, metallurgical coke is produced from the heating of bituminous coal to vaporize volatile constituents and concentrate the carbon for steel making. NOx emissions result from the combustion of fuel to heat the battery, and from the process of producing metallurgical coke from coal. The coke oven battery consists of 85 individual ovens that are heated with an underfire combustion system. A by-product of heating the coal to produce coke (coking) is COG. The COG from the battery is processed on-site in the by-product recovery plant that removes tars, light oils and ammonia. The COG is then used to heat the battery, sent to US Steel or sent offsite. Any excess COG is combusted in the on-site COG flare. The coke oven battery was originally permitted to be heated with a mix of blast furnace gas (BFG) and COG. Due to a system failure in the coke oven battery, BFG is no longer combusted in the underfire combustion system that is used to heat the battery. The combustion of only COG to heat the battery results in higher emissions of NOx due to the nature of the fuel. The coke oven battery operates at temperatures in excess of 1,800°F and under positive pressure. During the coking process, NOx can be emitted as fugitives from door leaks, bypass bleeder flares, and soaking and pushing at the end of the coking process. Soaking is the start of opening a coke oven in preparation of pushing the still hot coke out of the oven. The proposed modification of the coke oven battery is to remove the heat input limits on the combustion of COG and to increase the allowable coke production. The project results in a significant increase in NOx emissions requiring a BACT analysis.

EES Coke Battery, LLC Page 11 Permit No. 51-08C October 1, 2014 During the BACT analysis, several combustion and post combustion control technologies were reviewed for the control of NOx emissions. Combustion and post combustion control technologies were identified and evaluated as follows:

Process Combustion and Post Combustion Controls

Underfire Combustion System

• Staged combustion

• Low-NOx Burners (LNBs)

• Selective Catalytic Reduction (SCR)

• Selective Non-Catalytic Reduction (SNCR)

• Non-Selective Catalytic Reduction (NSCR)

• EMx (SCONOx)

COG Flare and Bypass Bleeder Flares

• Good combustion practices

PECS • Post combustion controls on the PECS stack

• Best operating/work practice standards

Fugitive Sources – Door leaks, Soaking, Pushing

• PROven® (Pressure Regulated Oven)

• Work practice standards

Underfire Combustion System The review of combustion and post combustion controls for the underfire combustion system on the coke oven battery is summarized below. • Staged combustion is commonly used on coke oven batteries to lower NOx emission rates. The

first stage of combustion takes place in a zone consisting of high temperature and little or no excess air. The second stage of combustion consists of lower temperatures and more excess air. Therefore, thermal NOx formation is inhibited in the first stage due to no excess air and in the following stage due to lower combustion temperature. The NOx formation is minimized by completing combustion in an air-lean environment.

• LNBs control fuel and air mixing ratios in the burner in order to reduce flame temperature and

reduce thermal NOx formation. LNBs are used on boilers but not on coke oven batteries. The fuel used in a coke oven battery is not combusted through burners, but in heating flues contained within the walls that separate the individual coke ovens. This technology has not been used on coke oven batteries and is considered a technically infeasible control alternative.

• SCR is a post combustion system that can reduce NOx emissions at 80% to 95% efficiency. SCR

consists of an ammonia injection system and a catalytic reactor. Ammonia is injected into the flue gas where it reacts with NOx in the presence of the catalyst to form molecular nitrogen and water. This reaction occurs at flue gas temperatures of 600°F to 800°F. The efficiency of the SCR system operation depends on catalyst reactivity, routine replacement of the catalyst, and maintaining a proper ammonia injection rate. Coke ovens do not contain sections within the unit where the temperature is consistently in the range where SCR can be effectively utilized. This technology has not been used on coke oven batteries and is considered a technically infeasible control alternative.

EES Coke Battery, LLC Page 12 Permit No. 51-08C October 1, 2014 • SNCR involves injecting urea or ammonia into the exhaust gases where temperatures exceed

1,500°F. The urea or ammonia then reacts with NOx forming elemental nitrogen and water without the need for a catalyst. Instead of a catalyzed reaction, the NOx reduction reactions are driven by the thermal decomposition of urea or ammonia and the subsequent chemical reaction reduction of NOx. SNCR systems can control NOx with efficiencies up to about 75%. The ideal temperature window for SNCR is 1,600°F to 2,100°F. The temperature window and location for injecting urea or ammonia into the gas stream is highly variable in the underfire combustion system of the coke oven battery. Therefore, SNCR is not considered a technically feasible option for a coke oven battery since there is not an appropriate temperature window for urea or ammonia injection and adequate reduction of NOx in the exhaust gases.

• NSCR is similar to an SCR but uses a different catalyst and different process conditions. NSCR requires specific operating ranges for oxygen content, and inlet concentrations of NOx, CO and VOC because the catalyst promotes the reaction of these compounds to reduce the emissions of each. The ideal temperature window for SNCR is 800°F to 1,200°F. This technology has been used for internal combustion engines, but is not considered a technically feasible control alternative for a coke oven battery.

• EMx (SCONOx) works by oxidizing nitrogen oxide to NO2, and collecting the NO2 compounds as

nitrates or nitrites on a potassium carbonate catalyst bed. The catalyst bed is regenerated with steam and a hydrogen vapor stream, to produce water and diatomic nitrogen. EMx (SCONOx) operates best when treating gases that have a steady temperature in the range of 300°F to 700°F. This technology has been used for combustion turbines, but is not considered a technically feasible control alternative for a coke oven battery.

Staged combustion is considered the only technically feasible NOx control technology for this application, and the coke oven battery currently operates using staged combustion. The coke oven battery was originally permitted with NOx short-term emission limits of 563.5 pounds per hour (pph) for combustion of rich gas (85% by volume of COG / 15% by volume of BFG) and 132.7 pph for combustion of lean gas (10% by volume of COG / 90% by volume of BFG). Also, long-term NOx emission limits of 493.6 tpy of rich gas and 581.2 tpy of lean gas, and 959.5 tpy for all combustion gases. In order to develop BACT emission limitations for this application, the current performance of the coke oven battery was reviewed along with emission limitations from other coke oven batteries. It is proposed that BACT for NOx emissions from the underfire combustion system is based on the combustion control technology of staged combustion. BACT is represented by emission limits of 1.25 pound per million British thermal unit (lb/MMBtu) on a 24-hour rolling average, and 0.75 lb/MMBtu on a 12-month rolling average. To protect PSD increment and the National Ambient Air Quality Standard (NAAQS), mass emission limits of 563.5 pph and 1,411 tpy on a 12-month rolling time period will apply at all times. Compliance with these limits will be monitored using a NOx CEMS to measure NOx emissions in the exhaust gas from the underfire combustion stack. COG Flare and Bypass Bleeder Flares The COG flare is used to combust excess COG that is not used in the underfire combustion system of the coke oven battery and by other offsite sources. The flare oxidizes sulfur and organic compounds, and the only feasible alternative to reduce NOx emissions is to operate the flare according to good combustion practices. Good combustion practices include proper maintenance and operation of the flare, and maintaining an automatic ignition system.

EES Coke Battery, LLC Page 13 Permit No. 51-08C October 1, 2014 The individual coke ovens are equipped with bypass bleeder flares so that emissions of raw COG are not released to the ambient air during the coking process. Good combustion practices and maintaining an automatic ignition system are used on the bypass bleeder flares. PECS When a coke oven has completed coking the coal, the oven doors are removed and the still hot coke is pushed out the side of the battery. The emissions from pushing are captured by a hood and directed to a baghouse. The exhaust gas temperature of the pushing emissions control system is approximately 110°F. This temperature is below the feasible temperatures of any post combustion controls for NOx. Best operating/work practice standards are used while pushing to minimize NOx emissions. These standards include not pushing coke out of the oven until the coking cycle is complete, and emissions due to coking are minimized. Based on stack testing from the PECS stack, a NOx emission limit of 2.61 pph was assessed as BACT and protective of PSD increment and NAAQS. Compliance with the NOx emission limit will be demonstrated through stack testing of the PECS every two (2) years. Fugitive Sources NOx can be emitted from many fugitive sources on the coke oven battery such as door leaks, soaking, and pushing. During the coking cycle, the PROven® technology has been utilized on coke oven batteries. This technology regulates the pressure within each oven chamber to minimize fugitive leaks. Since this technology is built into the design of a coke oven battery, this technology is not technically feasible on the existing coke oven battery. Work practice standards such as repairing and maintaining doors, door seals, and jambs minimize fugitive leaks from the coke ovens during coking, and proper maintenance of the PECS. Fugitive emissions from soaking and pushing are also minimized through not pushing coke out of the oven until the coking cycle is complete.

BACT for GHGs (as CO 2e) GHGs are generated when fuel is combusted. GHGs are regulated as a single air pollutant defined as the aggregate mix of six well-mixed GHGs. The six GHGs are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). Some of these GHGs have a higher global warming potential than others. To address this, GHGs are converted to carbon dioxide equivalents (CO2e). Emissions of gases other than CO2 are translated into CO2e by using the gases’ global warming potential. Total GHG emissions are calculated by summing the CO2e emissions of all six constituent GHGs. Efficient combustion results in the conversion of carbon in the fuel to CO and CO2, with only trace amounts of CH4 and N2O. HFCs, PFCs, and SF6 are not produced with the combustion of COG. Since CH4 and N2O have higher global warming potential, less efficient combustion results in higher CO2e emissions. Combustion of BFG in the underfire combustion system of the coke oven battery results in higher emissions of CO2 then when combusting COG. Since BFG can no longer be combusted to heat the battery, a reduction in GHGs will occur with the proposed increase in combustion of COG. The BFG that is no longer being combusted in the battery will be used to heat various processes at US Steel or flared at US Steel causing a net increase of GHGs for the proposed project. A BACT analysis is required for each proposed emission unit at which a net emissions increase in the pollutant will occur as a result of a physical change or change in method of operation. The coke oven battery is undergoing a change in the method of operation that results in a net reduction of GHG emissions. Therefore, BACT does not apply to the emission of GHGs from the coke oven battery. BACT also does not apply to emission units at US Steel that combust BFG. A physical change or change in the method of operation is not occurring at US Steel due to the combustion of BFG. Therefore, a BACT analysis for GHGs is not required for any emission units affected by the proposed project.


Appendix 3 - Air Quality Impact Analysis (R 336.2803, R 336.2804, 40 CFR 52.21(c) and (d))

For this project, the air quality impact analysis involves modeling of NO2, SO2, PM10, and PM2.5 emissions against the PSD increment and the NAAQS. The air quality impact analysis is performed in two phases: (1) a preliminary analysis, and (2) a full impact analysis. The preliminary analysis models only the increase in potential emissions from the proposed modification. PRELIMINARY ANALYSIS The USEPA has promulgated significant impact levels (SIL) for a majority of the criteria pollutants. If the modeled ambient air impact, for each pollutant is less than the SIL, the emissions for that pollutant will not be considered to cause or contribute to any violation of the federal air quality standards. If the results determine the modeled impacts exceed the SIL, then a facility-wide NAAQS and PSD increment modeling analysis is required. Use of the SIL for PM2.5 needs additional consideration due to recent federal court action. The USEPA guidance issued March 4, 2013, which states that if the SIL is less than the difference between the background concentration and the NAAQS, this is sufficient for the permitting authority to determine that a source with a PM2.5 modeled impact less than the SIL will not cause or contribute to a violation of the NAAQS. In this case, the PM2.5 SILs qualify for this purpose, for these reasons: 1. The court decision does not preclude the use of SILs for PM2.5, but requires that the USEPA

correct the error in the SIL regulations for PM2.5 in 40 CFR 51.166(k)(2) and 40 CFR 52.21(k)(2). In the interim, the USEPA believes permitting authorities may continue to apply SILs for PM2.5 to support a permitting decision;

2. The regional background, as defined by the most representative monitor is 26.1 µg/m3 (24-hr) and 11.4 µg/m3

(annual); 3. The addition of net impacts less than the SIL (1.2 µg/m3

24-hr and 0.3 µg/m3 annual) will be less

than the NAAQS (35 µg/m3 24-hr and 12 µg/m3 annual).

If it can be demonstrated that the project emissions will not increase ambient concentrations by more than the prescribed SIL shown below in Table 1, no further modeling is required.

TABLE 1 PRELIMINARY ANALYSIS

Pollutant Averaging Time

SIL (µg/m 3)

Predicted Impact (µg/m 3)

Additional Modeling?

NO2 1-hr 7.6 6.78 None NO2 Annual 1 0.46 None SO2 3-hr 25 3.71 None PM2.5* 24-hr 1.2 0.92 None PM2.5* Annual 0.3 0.22 None PM10 24-hr 5 3.97 None * The PM2.5 significant impact levels were vacated and remanded by the U.S. Court of Appeals on

January 22, 2013. Preliminary modeling for the project indicates that NO2, SO2, PM10, and PM2.5 ambient impacts from the project will be below the respective SIL, and a full impact analysis is not required.

EES Coke Battery, LLC Page 15 Permit No. 51-08C October 1, 2014 SECONDARY FORMATION ASSESSMENT The USEPA’s draft guidance specifies that only the secondary impacts of significant precursor emissions need to be assessed. For this project, NOx emissions exceed the significant threshold of 40 tpy and NOx is a precursor to the formation of PM2.5 and ozone. The following methodology is consistent with the USEPA’s guidance for conducting a qualitative analysis for the purpose of demonstrating that the secondary formation of PM2.5 and ozone from the NOx precursor will not cause or significantly contribute to a violation of the NAAQS. For PM2.5, recent examples of secondary pollutant impacts from the USEPA demonstrate that the use of the interpollutant trading ratio (ITR) for NOx is adequate to demonstrate compliance with secondary PM2.5 impacts. The trading ratio for NOx to PM2.5 is generally accepted to be 200 to 1. This means that for every 200 tons of NOx emitted, 1 ton can be assumed to convert to secondary PM2.5. As such, the secondary PM2.5 impact can be determined by reducing the NOx predicted impact by the 200 to 1 ratio. Table 2 demonstrates possible secondary PM2.5 impacts.

TABLE 2 ANALYSIS OF SECONDARY PM2.5 IMPACTS

Parameter Short -Term Impact (µg/m 3)

Long -Term Impact (µg/m 3)

Direct emissions PM2.5 impact 0.92 0.22 NOx ITR 200/1 conversion to secondary PM2.5 0.034 0.002 Combined PM2.5 impact (direct + secondary) 0.95 0.22 PM2.5 24-hour and annual SIL 1.2 0.3

Based on the above analysis, the proposed project is predicted to have an insignificant impact on the formation of secondary PM2.5. For ozone, the USEPA Cross-State Air Pollution Rule (CSAPR) modeling was used to approximate a single source ozone impact. The CSAPR analysis looked at the emissions difference between a current base case and a future control scenario and predicted an ozone reduction via a photochemical model. For this project, a ratio was applied to the calculated CSAPR ozone reduction (0.3 ppb) using the project NOx increase (668 tpy) and the CSAPR NOx decrease (6,799 tpy). The projected increase in ozone from the project was calculated as follows: 668/6,799 x 0.3 ppb = 0.029 ppb. This impact is added to the design value (DV) of the most representative monitor (Allen Park) for comparison to the NAAQS.

TABLE 3 ANALYSIS OF SECONDARY OZONE IMPACTS

Parameter 8-Hour Impact (ppb) Allen Park monitor DV (2011-2013) 72.0 Predicted ozone impact 0.029 Combined ozone impact (DV + secondary) 72.03 Ozone 8-hour NAAQS threshold 75

Based on the above analysis, the proposed project is predicted to have an insignificant impact on the formation of ozone.

dte energy/ees coke pti 51-08c factsheet

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