Draft Technical Support Document (TSD)
for the Proposed Rule

Docket ID No. EPA-HQ-OAR-2021-0668

Non-EGU Sectors TSD

U.S. Environmental Protection Agency
Office of Air and Radiation
December 2021

1


-------
I able of Contents

1	Introduction/Purpose	3

2	Pipeline Transportation of Natural Gas	4

3	Cement and Concrete Product Manufacturing	8

4	Iron and Steel Mills and Ferroalloy Manufacturing	24

5	Glass and Glass Product Manufacturing	45

6	Boilers from Basic Chemical Manufacturing, Petroleum and Coal Products
Manufacturing, and Pulp, Paper, and Paperboard Mills	60

7	Municipal Waste Combustors	81

8	Feasibility and Installation Timing	87

2


-------
1 Introduction/Purpose

The purpose of this Technical Support Document (TSD) is to discuss the basis for the
proposed emissions limits and monitoring, recordkeeping, and reporting requirements for the
following unit types for sources in non-EGU industries: engines in Pipeline Transportation of
Natural Gas sources; kilns in Cement and Cement Product Manufacturing sources; boilers and
furnaces in Iron and Steel Mills and Ferroalloy Manufacturing sources; furnaces in Glass and
Glass Product Manufacturing sources; and high-emitting equipment and large boilers in Basic
Chemical Manufacturing, Petroleum and Coal Products Manufacturing sources and Pulp, Paper,
and Paperboard Mills. This TSD also includes a discussion of municipal waste combustors, for
which EPA is also considering whether emissions standards are necessary. This TSD provides
additional information to supplement the discussion in the preamble to the proposed rule on the
basis for EPA's proposed emissions limits for each non-EGU unit and industry. All non-EGU
emission limits identified in the proposed rule are designed to achieve emission reductions
through the installation of the control strategies identified in the Screening Assessment of
Potential Emissions Reductions, Air Quality Impacts, and Costs from Non-EGU Emissions Units
for 2026 ("Non-EGU Screening Assessment memorandum"), which is available in the docket for
this rulemaking. Finally, this TSD includes a discussion of the best information currently
available to EPA on the feasibility of controls and related installation timing needs for these non-
EGU industries.

3


-------
2 Pipeline Transportation of Natural Gas

Based on available information in the National Emissions Inventory (NEI), EPA has
determined that reciprocating engines are the largest collective sources of NOx emissions from
the Natural Gas Transportation Industry in the states affected by this proposed FIP. As explained
in the Non-EGU Screening Assessment memorandum, the largest potential NOx emission
reductions are from natural gas-fired spark ignition engines. Based on the NEI data, EPA has not
identified a potential for significant emission reductions from turbines and compression ignition
engines in the states covered by the proposed FIP. The process descriptions, background on each
engine type, and summaries of applicable "reasonably available control technology" (RACT)
emission limits and permit conditions, as well as a discussion of available NOx controls, are
summarized in an analysis developed by the Ozone Transport Commission entitled Technical
Information Oil and Gas Sector Significant Stationary Sources of NOx Emissions (October 17,
2012) ("OTC Engine Study"). The three types of engines for which EPA is proposing emission
limits in this proposed FIP are: 1) two stroke lean burn spark ignition engines, which are covered
on pages 17-28 of the OTC Engine Study; four stroke lean burn spark ignition engines, which are
covered on pages 30-42 of the OTC Engine Study; and four stroke rich burn spark ignition
engines, which are covered on pages 44-52 of the OTC Engine Study.

EPA is proposing an applicability threshold for spark ignition engines of 1000 hp or
more. Based on the Non-EGU Screening Assessment memorandum, engines with a potential to
emit of 100 tpy or greater had the most significant potential for NOx emissions reductions. EPA
reviewed available information in the NEI and determined that some engines above 1000 hp
reported emissions above 100 tpy, while engines smaller than 1000 hp generally reported
emissions below 100 tpy.1 Specifically, EPA only noted two engines below 1000 hp that emitted
more than 100 tpy, while over 200 engines over 1000 hp emitted greater than 100 tpy. In
addition to the NEI data, EPA observed that uncontrolled emissions from engines can be as high
as 16.8 grams per horsepower per hour (g/hp-hr).2 In addition, operating hours can be as high as
7000 hours in a given year.3 With these assumptions, EPA could justify regulating engines
around 800 hp or more. Given the variability with operating hours and the available data
indicating that average operating hours are below 7000 hours per year,4 EPA is proposing to
establish an applicability threshold of 1000 hp should capture the majority of potential emission
reductions.

1	See 2017 NEI Engines Emissions.xlsx, available in the docket for this rulemaking.

2	U.S. Environmental Protection Agency, Stationary Reciprocating Internal Combustion Engines: Technical Support
Document for NOx SIP Call (October 2003); U.S. Environmental Protection Agency, Assessment of Non-EGU NOx
Emission Controls, Cost of Controls, and Time for Compliance Final TSD, 5-8 (August 2016); Illinois
Environmental Protection Agency, Technical Support Document for Controlling Emissions from Stationary
Reciprocating Internal Combustion Engines and Turbines, 41 (March 19, 2007).

3	Illinois Environmental Protection Agency, Technical Support Document for Controlling Emissions from Stationary
Reciprocating Internal Combustion Engines and Turbines, 41 (March 19, 2007).

4	OTC Engine Study, 88 (October 17, 2012) (explaining that the average operating hours was around 35% or around
3066 hours a year); Illinois Environmental Protection Agency, Technical Support Document for Controlling
Emissions from Stationary Reciprocating Internal Combustion Engines and Turbines, 41 (March 19, 2007)
(assuming operating hours for engines at 7000 hours a year); U.S. Environmental Protection Agency, Assessment of
Non-EGU NOx Emission Controls, Cost of Controls, and Time for Compliance Final TSD, 5-6 through 5-9 (August
2016) (assuming operating hours of 2000 hours a year).

4


-------
Federal Rules Affecting Engines

Natural gas-fired spark ignition engines are subject to the New Source Performance
Standards (NSPS) for Stationary Spark Ignition Internal Combustion Engines (40 CFR part 60
subpart JJJJ) and National Emission Standards for Hazardous Air Pollutants (NESHAP) for
Stationary Reciprocating Internal Combustion Engines (40 CFR part 63 subpart ZZZZ).

Four Stroke Lean Burn Spark Ignition Engines

For four stroke lean burn spark ignition engines, EPA is proposing an emissions limit of
1.5 g/hp-hr. EPA believes that installation of selective catalytic reduction (SCR) system or a
combination of other controls technologies should be available for these engines to meet this
emission limit. As explained in the OTC Engine Study, most of the four stroke lean burn spark
ignition engines should be able to achieve 60 to 90% emission reductions with the installation of
layered combustion controls, such as the installation of turbochargers and inter-cooling, pre-
chamber ignition or high energy ignition, improved fuel injection control, air/fuel ratio control,
etc.5 Reduction in this range should be able to achieve an emissions limit of 1.5 g/hp-hr or less.
For some engines that can only achieve a 60% reduction from layered combustion controls,
information suggests that those engines should be able to install SCR to lower emissions to 1.5
g/hp-hr.6

Many states containing ozone nonattainment areas or located within the Ozone Transport
Region (OTR) have already adopted emission limits similar to the proposed emissions limit of
1.5 g/hp-hr. While some states have required limits equivalent to or even lower than 0.5 g/hp-hr,7
most states have adopted emission limits at or close to 1.5 g/hp-hr.8 Additional examples of state
RACT rules and permitted emission limits can be found in the "NOx Permit Limits and RACT
Tool spreadsheet" available in the docket. Many of these example RACT rules contain emission
limits based on engine manufacture dates and set higher emissions limits between 1.5 and 3.0
g/hp-hr for older engines.

In addition to RACT limits, some four stroke lean burn spark ignition engines may have
installed equipment to meet the emission limits contained within EPA's NSPS located at 40 CFR
60, Subpart JJJJ, which requires that these engines meet a NOx emissions limit of 1.0 g/hp-hr if
manufactured on or after July 1, 2010 and a NOx emissions limit of 2.0 g/hp-hr if manufactured
on or after July 1, 2007 but before July 1, 2010.9 Given that many of the newer engines subject
to this FIP are already required to meet the more stringent NSPS limits of 1.0 to 2.0 g/hp-hr,
EPA's proposed FIP is targeting an emission limit that older engines not subject to the NSPS
could still meet.

5	OTC Engine Study, 43.

6	Id.

7	See, e.g., South Coast Air Quality Management District Rule 1110.2, establishing a NOx emissions limit of 36
ppmvd, which is equivalent to about 0.5 g/hp-hr.

8	For example, see Colorado Air Quality Control Commission Regulation 7, Part E, Section I, Table 1 and Table 2
(establishing emissions limits at 0.7 to 2.0 g/hp-hr depending on engine construction dates).

9	See 40 CFR part 60, Subpart JJJJ Table 1.

5


-------
Based on the example RACT rules, applicability of the NSPS to newer engines, and the
feasibility of NOx reductions analyzed in the OTC Engine Study, EPA believes an emissions
limit of 1.5 g/hp-hr is achievable by the vast majority of two stroke lean burn spark ignition
engines and will achieve the necessary NOx reductions for engines that are not subject to
equivalent RACT requirements or the NSPS at 40 CFR 60, Subpart JJJJ.

Four Stroke Rich Burn Spark Ignition Engines

For four stroke rich burn spark ignition engines, EPA is proposing an emissions limit of
1.0 g/hp-hr. EPA believes that installation of non-selective catalytic reduction (NSCR) or a
combination of other control technologies should be available for these engines to meet this
emission limit. As explained in the OTC Engine Study, most of the four stroke rich burn spark
ignition engines should be able to achieve 90 to 99% emission reductions with the installation of
NSCR. OTC Engine Study at 45-46. A 90 to 99% emission reduction should result in an
emissions level of 1.0 g/hp-hr or less.

Many states containing ozone nonattainment areas or located within the Ozone Transport
Region (OTR) have already adopted emission limits similar to the proposed emissions limit of
1.0 g/hp-hr. While some states have required limits equivalent to or even lower than 0.2 g/hp-
hr,10 most states have adopted emission limits at or close to 1.0 g/hp-hr.11 Additional examples
of state RACT rules and permitted emission limits can be found in the "NOx Permit Limits and
RACT Tool spreadsheet" available in the docket. Many of these example RACT rules contain
emission limits based on engine manufacture dates and set higher emissions limits at or close to
1.0 g/hp-hr for older engines.

In addition to RACT limits, some four stroke rich burn spark ignition engines may have
installed equipment to meet the emission limits contained within EPA's NSPS located at 40 CFR
60, Subpart JJJJ, which requires that these engines meet a NOx emissions limit of 1.0 g/hp-hr if
manufactured on or after July 1, 2010 and a NOx emissions limit of 2.0 g/hp-hr if manufactured
on or after July 1, 2007 but before July 1, 2010. See 40 CFR part 60, Subpart JJJJ Table 1.
Further, some of these same units will have already installed NSCR to comply with EPA's
NESHAP for Stationary Reciprocating Internal Combustion Engines at 40 CFR Part 63 Subpart
ZZZZ. Even though the NESHAP at subpart ZZZZ does not regulate NOx emissions, the
installation of NSCR on these units should already provide the co-benefit of reducing NOx
emissions to the levels necessary to comply with the proposed FIP. Given that many of the newer
engines subject to this FIP are already required to meet the more stringent NSPS limits of 1.0 to
2.0 g/hp-hr, EPA's proposed FIP is targeting an emission limit that older engines not subject to
the NSPS could still meet.

Based on the example RACT rules, applicability of the NSPS to newer engines, and the
feasibility of NOx reductions analyzed in the OTC Engine Study, EPA believes an emissions

10	See Pennsylvania General Permit 5 for Natural Gas Production and Processing Facilities, establishing NOx
emissions limits for four stroke rich burn engines as low as 0.2 g/hp-hr.

11	For example, see Colorado Air Quality Control Commission Regulation 7, Part E, Section I, Table 1 and Table 2
(establishing emissions limits at 0.5 to 2.0 g/hp-hr depending on engine construction dates).

6


-------
limit of 1.0 g/hp-hr is achievable by the vast majority of two stroke lean burn spark ignition
engines and will achieve the necessary reductions.

Two Stroke Lean Burn Spark Ignition Engines

For two stroke lean burn spark ignition engines, EPA is proposing an emissions limit of
3.0 g/hp-hr. EPA believes that installation of layered combustion controls or a combination of
other control technologies should be available for these engines to meet this emission limit. As
explained in the OTC Engine Study, most of the two stroke lean burn spark ignition engines
should be able to achieve 60 to 90% emission reductions with the installation of layered
combustion controls, such as the installation of turbochargers and inter-cooling, pre-chamber
ignition or high energy ignition, improved fuel injection control, and air/fuel ratio control. OTC
Engine Study at 28. Available information suggests that some engines that can only achieve a
60% reduction from layered combustion controls will only be able to meet an emission limit of
3.0 g/hp-hr or greater. While some of these engines could install SCR to achieve greater
reductions, EPA does not have information indicating that manufacturers and models of two
stroke learn burn spark ignition engines generally can install the necessary combination of
layered combustion controls and SCR. OTC Engine Study at 28.

Many states containing ozone nonattainment areas or located within the OTR have
already adopted emission limits similar to the proposed emissions limit of 3.0 g/hp-hr. While
some states have adopted limits equivalent to or even lower than 0.5 g/hp-hr,12 most states have
adopted emission limits between 1.0 g/hp-hr and 3.0 g/hp-hr.13 Additional examples of state
RACT rules and permitted emission limits can be found in the "NOx Permit Limits and RACT
Tool spreadsheet" available in the docket. Many of these example RACT rules contain emission
limits based on engine manufacture dates and set higher emissions limits closer to 3.0 g/hp-hr for
older engines.

In addition to RACT limits, some two stroke lean burn spark ignition engines may have
installed equipment to comply with EPA's NSPS at 40 CFR part 60, subpart JJJJ, which requires
that these engines meet a NOx emissions limit of 1.0 g/hp-hr if manufactured on or after July 1,
2010 and a NOx emissions limit of 2.0 g/hp-hr if manufactured on or after July 1, 2007 but
before July 1, 2010. See 40 CFR part 60, Subpart JJJJ Table 1. Given that many of the newer
engines subject to this proposed FIP are already required to meet the more stringent NSPS limits
of 1.0 to 2.0 g/hp-hr, EPA's proposed FIP is targeting an emission limit that older engines not
subject to the NSPS could still meet.

Based on the example RACT rules, applicability of the NSPS to newer engines, and the
feasibility of NOx reductions analyzed in the OTC Engine Study, EPA believes an emissions
limit of 3.0 g/hp-hr is achievable by the vast majority of two stroke lean burn spark ignition
engines and will achieve the necessary reductions for engines that are not subject to equivalent
RACT requirements or the NSPS at 40 CFR part 60, subpart JJJJ.

12	See South Coast Air Quality Management District Rule 1110.2, establishing a NOx emissions limit of 36 ppmvd
or about 0.5 g/hp-hr.

13	For example, see Colorado Air Quality Control Commission Regulation 7, Part E, Section I, Table 1 and Table 2
(establishing emissions limits at 1.0 to 3.0 g/hp-hr depending on engine construction dates).

7


-------
3 Cement and Concrete Product Manufacturing

Process Description14

Portland cement is a fine powder, gray or white in color, that consists of a mixture of
hydraulic cement materials comprising primarily calcium silicates, aluminates and alumino-
ferrites. More than 30 raw materials are known to be used in the manufacture of portland cement,
and these materials can be divided into four distinct categories: calcareous, siliceous,
argillaceous, and ferrifrous (containing iron). These materials are chemically combined through
pyroprocessing (heat) and subjected to subsequent mechanical processing operations to form
gray and white portland cement. Gray portland cement is used for structural applications and is
the more common type of cement produced. White portland cement has a lower iron and
manganese content than gray portland cement and is used primarily for decorative purposes. The
six-digit Source Classification Code (SCC) for portland cement plants with wet process kilns is
3-05-006, and the six-digit SCC for plants with dry process kilns is 3-05-007.

A diagram of cement production installation is shown below.15

14	See generally EPA, "AP-42 Compilation of Air Emissions Factors," Chapter 11, Mineral Products Industry,
Section 11.6, Portland Cement Manufacturing, Final Section (January 1995).

15	See Krzysztof Kogut, Jerzy Gorecki, and Piotr Burmistrz, "Opportunities for reducing mercury emissions in the
cement industry," Journal of Cleaner Production, Volume 293, 126053, Figure 1: Diagram of cement production
installation (April 15, 2021); available at https://www.sciencedirect.com/science/article/pii/S0959652621002730
(URL dated 8 November 2021).

8


-------
1 - High limestone,

2-	Medium limestone,

3-	Low limestone,

4-	Ferrous additive,
S - Gypsum.

Balance boundary
of cement production

Flue gas
outlet

Dust from
bypass

a)

b)

c)

d)

Clinker cooler
additional air

Clinker

Blast furnace
cement

Bag filter
dust

Dust from
cement mill filter

Clinker cooler air

9


-------
Cement Kilns16

Cement kilns are used by the cement industry in the production of cement. Portland
cement, used in almost all construction applications, is the industry's primary product.

Essentially all of the Oxides of Nitrogen (NOx) emissions associated with cement manufacturing
are generated in the kilns because of high process temperatures.

To manufacture cement, raw materials such as limestone, cement rock, sand, iron ore,
clay and shale are crushed, blended, and fed into a kiln. These materials are then heated in the
kiln to temperatures above 2900°F to induce a chemical reaction (called "fusion") that produces
cement "clinker," a round, marble-sized, glass-hard material. The clinker is then cooled, mixed
with gypsum and ground to produce cement. Clinker is also defined as the product of a portland
cement kiln from which finished cement is manufactured by milling and grinding. See the
picture below.

10 cm

Nearly all cement clinker is produced in large rotary kiln systems. The rotary kiln is a
refractory brick-lined cylindrical steel shell equipped with an electrical drive to rotate it at 1-3
revolutions per minute, through which hot combustion gases flow counter-currently to the feed
materials. The kiln can be fired with coal, oil, natural gas, waste (solvents) or a combination of
these fuels.

Various types of kilns are in use: long wet kilns, long dry kilns, kilns with a preheater and
kilns with a precalciner. The long wet and dry kilns and most preheater kilns have only one fuel
combustion zone, whereas the newer precalciner kilns and preheater kilns with a riser duct have
two fuel combustion zones.

In a wet kiln, the ground raw materials are suspended in water to form a slurry and
introduced into the inlet feed. This kiln type employs no preheating of the dry feed.

The basic principle of a wet-process kiln is shown below.

16 See generally ST'APP A/AL APCO. Controlling Nitrogen Oxides Under the Clean Air Act: A Menu of Options,
72-73 (July 1994).

10


-------
slurry

calcining
sintering	dryii

In a long dry kiln, the raw materials are dried to a powder and introduced into the inlet
feed in a dry form, but this kiln type employs no preheating of the dry feed. Currently more
cement plants use the dry process because of its lower energy requirement.

In a precalciner kiln, the feed to the kiln system is preheated in cyclone chambers and
utilizes a second burner to calcine material in a separate vessel attached to the preheater before
the final fusion in a kiln that forms clinker.

The basic principle of a precalciner cement kiln is shown below.

blended dry feed

900 "C approx.

A kiln where the feed to the kiln system is preheated in cyclone chambers before the final
fusion in a kiln that forms clinker is referred to as preheater kiln.

11


-------
Raw
meal
feed

Preheater
exhaust

m

Kiln
inlet



Preheater
tower

Tertiary Air from
clinker cooler

Primary air & fuel

Clinker
cooler

Kiln

The majority of newer cement plants use the preheater and precalciner system. The basic
principle of a precalciner cement kiln is shown above.

Because the typical operating temperatures of these kilns differ, the NOx formation
mechanisms also differ among these kiln types. In a primary combustion zone at the hot end of a
kiln, the high temperatures lead to predominantly thermal NOx formation. In the secondary
combustion zone, however, lower gas-phase temperatures suppress thermal NOx formation.
Energy efficiency is also important in reducing NOx emissions. For example, a high thermal
efficiency equates to less heat and fuel consumed and, therefore, less NOx is produced.

Federal Rules Affecting Cement Plants

Cement plants are subject to the Portland Cement NESHAP (40 CFR part 63 subpart
LLL) and NSPS (40 CFR part 60 subpart F). Cement kilns that burn hazardous waste are subject
to the Hazardous Waste Combustor NESHAP (40 CFR part 63 subpart LLL). Cement kilns that
burn non-hazardous solid wastes are subject to the Commercial and Industrial Solid Waste
Incinerator Units (CISWI) rule (40 CFR part 60 subparts CCCC and DDDD).

Technology-Based Federal Regulations

The NSPS implementing Clean Air Act (CAA) section 111(b) for Portland Cement Plants
was first promulgated at 40 CFR part 60, subpart F on December 23, 1971 (36 FR 24876). EPA
conducted three additional reviews of these standards on June 14, 1974 (39 FR 20793),
November 12, 1974 (39 FR 39874) and December 14, 1988 (53 FR 50354). NOx emissions were
not regulated under part 60, subpart F at that time.

On June 16, 2008 (73 FR 34072), EPA proposed amendments to the NSPS for Portland Cement
Plants. The proposed amendments included revisions to the emission limits for affected facilities

12


-------
which commence construction, modification, or reconstruction after June 16, 2008. Among other
things, EPA proposed establishing a NOx emission limit for cement kilns at portland cement
plants.17

On September 9, 2010 (75 FR 54970) EPA finalized the proposed amendments to the
NSPS establishing a NOx emission limit, among other things, for portland cement plants that
commence construction, modification, or reconstruction after June 16, 2008. This final rule
became effective on November 8, 2010 and is codified at 40 CFR part 60 subpart F.

NOx Controls

The National Association of Clean Air Agencies (NACAA, formerly
STAPPA/ALAPCO) has recommended requiring combustion controls and Selective Non-
Catalytic Reduction (SNCR) to achieve NOx reductions of up to 70 percent on certain processes
at cement kilns.18 SNCR is a post combustion control technology used to reduce NOx emissions
without the presence of a catalyst. Reagent (Ammonia or Urea) is injected directly into flue gas
and reacts with NOx resulting in Nitrogen (N2) and water (H2O).

SNCR avoids the problems related to catalyst fouling (poisoning) that occur during use of
Selective Catalytic Reduction (SCR) technology, but requires injection of the reagents in the kiln
at a temperature between 1600 to 2000°F, which is much higher than the typical temperatures for
SCR operation (550-800°F). At these temperatures urea decomposes to produce ammonia which
is responsible for NOx reduction. Because of the temperature constraint, SNCR technology is
only applicable to preheater and precalciner kilns.19 Preheater and precalciner kilns require
relatively simple SNCR installations. In preheater/precalciner kiln design, the SNCR injection
ports can be installed in the combustion zone in the calciner, the oxidation zone of the upper air
inlet before the deflection chamber, or in the area after the mixing chamber before the inlet to the
bottom. SNCR has been installed and is currently operating on numerous kilns in Europe and the
U.S.

SCR is a process that uses ammonia in the presence of a catalyst to selectively reduce
NOx emissions from exhaust gases. This technology, at first, was widely used for NOx
abatement in other industries, such as coal-fired power stations and waste incinerators. In SCR,
anhydrous ammonia, usually diluted with air or steam, is injected through a grid system into hot
flue gases which are then passed through a catalyst bed to carry out NOx reduction reactions.
Ammonia is typically injected to produce a NFbiNOx molar ratio of 1.05-1.1:1 to achieve a NOx
conversion of 80 to 90 percent with an ammonia "slip" of about 10 ppm of unreacted ammonia in
the gases leaving the reactor. In the cement industry, basically two SCR systems are being
considered: low dust exhaust gas and high dust exhaust gas treatment. Low dust exhaust gas
systems require reheating of the exhaust gases after dedusting, resulting in additional cost. High

17	73 FR 34072 (proposed NSPS for Portland Cement Plants), Docket IN No. EPA-HQ-OAR-2007-0877.

18	STAPPA/ALAPCO, Controlling Nitrogen Oxides Under the Clean Air Act: A Menu of Options, 72-73 (July
1994).

19	EPA, NOx Control Technologies for the Cement Industry: Final Report, 6 (September 2000).

13


-------
dust systems are considered preferable for technical and economical reasons.20 While SCR
installations are not common at cement kilns in the U.S, EPA is aware of one SCR system that
has been installed on a cement kiln in Joppa, Illinois.21

The European Union Commission charged with establishing the Best Available
Techniques (BAT) to control NOx emissions from the production of cement outlines the
following control techniques tabulated below.

20	Official Journal of European Union Commission, Best Available Techniques (BAT) Conclusions Under Directive
2010/75/EU of the European Parliament and of the Council on Industrial Emissions for the Production of Cement,
Lime and Magnesium Oxide, March 26, 2013, at 42.

21	State of Illinois Clean Air Act Program Permit No. 95090119 (issued September 11, 2018, to Holcim US, Inc. -
Joppa Plant, 2500 Portland Road, Grand Chain, IL 62941), Section 4.1 Cement Kilns and Clinker Coolers, Kiln #1.
See also Lafarge, North America, Inc., Clean Air Act Settlement (overview of injunctive relief, available at
https://www.epa.gov/enforcement/lafarge-north-america-inc-clean-air-act-settlement (URL dated October 12,
2021)).

14


-------
Primary

Techniques/Measures

Description

Flame Cooling

The addition of water to the fuel or directly to the flame by using different injection methods, such
as injection of one fluid (liquid) or two fluids (liquid and compressed air or solids) or the use of
liquid/solid wastes with a high water content reduces the temperature and increases the
concentration of hydroxyl radicals. This can have a positive effect on NOx reduction in the
burning zone.

Low NOx Burners

Designs of low NOx burners (indirect firing) vary in detail but essentially the fuel and air are
injected into the kiln through concentric tubes. The primary air proportion is reduced to some 6 -
10% of that required for stoichiometric combustion (typically 10 - 15% in traditional burners).
Axial air is injected at high momentum in the outer channel. The coal may be blown through the
center pipe or the middle channel. A third channel is used for swirl air, its swirl being induced by
vanes at, or behind, the outlet of the firing pipe. The net effect of this burner design is to produce
very early ignition, especially of the volatile compounds in the fuel, in an oxygen-deficient
atmosphere, and this will tend to reduce the formation of NOx. The application of low NOx
burners is not always followed by a reduction of NOx emissions. The set-up of the burner has to
be optimized.

Mid Kiln Firing

In long wet and long dry kilns, the creation of a reducing zone by firing lump fuel can reduce NOx
emissions. As long kilns usually have no access to a temperature zone of about 900 -1000°C, mid-
kiln firing systems can be installed in order to be able to use waste fuels that cannot pass the main
burner (for example tires). The rate of the burning of fuels can be critical. If it is too slow,
reducing conditions can occur in the burning zone, which may severely affect product quality. If it
is too high, the kiln chain section can be overheated - resulting in the chains being burned out. A
temperature range of less than 1100°C excludes the use of hazardous waste with a chlorine content
of greater than 1%.

Addition of mineralizers to
improve the burnability of
the raw meal (mineralized
clinker)

The addition of mineralizers, such as fluorine, to the raw material is a technique to adjust the
clinker quality and allow the sintering zone temperature to be reduced. By reducing/lowering the
burning temperature, NOx formation is also reduced.

Staged combustion
(conventional or waste
fuels), also in combination

Staged combustion is applied at cement kilns with an especially designed precalciner. The first
combustion stage takes place in the rotary kiln under optimum conditions for the clinker burning
process. The second combustion stage is a burner at the kiln inlet, which produces a reducing

15


-------
Primary

Techniques/Measures

Description

with a precalciner and the
use of optimized fuel mix

atmosphere that decomposes a portion of the nitrogen oxides generated in the sintering zone. The
high temperature in this zone is particularly favorable for the reaction which reconverts the NOx
to elementary nitrogen. In the third combustion stage, the calcining fuel is fed into the calciner
with an amount of tertiary air, producing a reducing atmosphere there, too. This system reduces
the generation of NOx from the fuel, and also decreases the NOx coming out of the kiln. In the
fourth and final combustion stage, the remaining tertiary air is fed into the system as 'top air' for
residual combustion.

SNCR

Selective non-catalytic reduction (SNCR) involves injecting ammonia water (up to 25% NH3),
ammonia precursor compounds or urea solution into the combustion gas to reduce NO to N2. The
reaction has an optimum effect in a temperature window of about 830 - 1050°C, and sufficient
retention time must be provided for the injected agents to react with NO.

SCR

SCR reduces NO and NO2 to Nitrogen with the help of NH3 and a catalyst at a temperature range
of 300 - 400°C. This technique was initially started for NOx abatement in other industries (coal
fired power stations, waste incinerators) and is now available in the cement manufacturing
industry.

Reproduced from Official Journal of European Union Commission, Best Available Techniques (BAT) Conclusions Under Directive 2010/75/EU of the European
Parliament and of the Council on Industrial Emissions for the Production of Cement, Lime and Magnesium Oxide, March 26, 2013, Table 1.5.2.

16


-------
EPA's Menu of Control Measures (MCM) provides state, local and tribal air agencies
with information on existing criteria pollutant emission reduction measures as well as relevant
information concerning the efficiency and cost effectiveness of the measures.22 State, local, and
tribal agencies may use this information in developing emission reduction strategies, plans and
programs to assure they attain and maintain the NAAQS. The information from the MCM can
also be found in the Control Measures Database (CMDB), a major input to the Control Strategy
Tool (CoST), which EPA used in the NOx control strategy analysis included in the Non-EGU
Screening Assessment memorandum.23 Information about control measures to reduce NOx
emissions from cement kiln operations is tabulated below.

22	EPA, Menu of Control Measures for NAAQS Implementation, available at https://www.epa.gov/air-quality-
implementation-plans/menu-control-measures-naaqs-implementation (URL dated January 5, 2022).

23	EPA, Control Measures Database (CMDB) for Stationary Sources, available at

https://www.epa.gov/svstem/files/other-files/2021-09/cmdb 2021-09-02 O.zip (URL dated January 6, 2022).

17


-------
Source
Category

Emission

Reduction

Measure

Control
Efficiency
(%)

Description/Notes/Caveats

References

Cement kilns

Biosolid
Injection
Technology

23

This control is the use of biosolid injection to reduce
NOx emissions. This control applies to cement kilns.

EPA 2006b, EPA
2007c

Cement kilns

Changing feed
composition

25-40

This control is changing the cement formulation by
adding steel slag to lower the clinkering temperatures
and suppress NOx. The patented feed modification
technique known as the CemStar Process is a raw feed
modification process that can reduce NOx emissions
by about 30 percent and increase production by
approximately 15 percent. It involves the addition of a
small amount of steel slag to the raw kiln feed. Steel
slag has a chemical composition similar to clinker and
many of the chemical reactions required to convert
steel slag to clinker take place in the steel furnace. By
substituting steel slag for a portion of the raw
materials, facilities can increase thermal efficiency
and thereby reduce NOx emissions. This control is
applicable to wet- and dry-process kilns, as well as
those with preheaters or precalciners.

STAPPA/ALAPCO
2006

Cement Kilns

Process Control
Systems

<25

This control is the modification of the cement
production process to improve fuel efficiency,
increase capacity and kiln operational stability. NOx
reductions result from the increase in productivity and
reduced energy use. One process control that
specifically targets NOx emissions is continuous
emissions monitoring systems (CEMS). CEMS allow
operators to continuously monitor oxygen and carbon
monoxide (CO) emissions in cement kiln exhaust
gases. The levels of these gases indicate the amount of

STAPPA/ALAPCO
2006

18


-------
Source
Category

Emission

Reduction

Measure

Control
Efficiency
(%)

Description/Notes/Caveats

References







excess air in the combustion zone. At a given excess
air level, NOx emissions increase as the temperature
increases. Knowing the excess air level allows
operators to maintain a lower temperature and thereby
minimize NOx creation. Studies indicate that reducing
excess air by half can reduce NOx emissions by about
15 percent. This control is applicable to wet- and dry-
process kilns, as well as those with preheaters or
precalciners.



Cement

Manufacturing -
Dry Process

Selective Non-
Catalytic
Reduction -
Ammonia

50

This control is the reduction of NOx emission through
ammonia based selective non-catalytic reduction add-
on controls. SNCR controls are post-combustion
control technologies based on the chemical reduction
of nitrogen oxides (NOx) into molecular nitrogen (N2)
and water vapor (H2O). This control applies to dry-
process cement manufacturing operations with
uncontrolled NOx emissions greater than 10 tons per
year.

EPA 2006b, Pechan
2001, EPA 1998e,
EPA 2002a, EPA
1994h

Cement

Manufacturing -
Dry Process

Selective Non-
Catalytic
Reduction -
Urea

50

This control is the reduction of NOx emission through
urea based selective non-catalytic reduction add-on
controls. SNCR controls are post-combustion control
technologies based on the chemical reduction of
nitrogen oxides (NOx) into molecular nitrogen (N2)
and water vapor (H2O). This control applies to dry-
process cement manufacturing with uncontrolled NOx
emissions greater than 10 tons per year.

EPA 2006b, EPA
1998e, EPA 2002a,
EPA 1994h

Cement

Manufacturing -
Dry Process or
Wet Process

Low NOx
Burner

25

This control is the use of low NOx burner (LNB)
technology to reduce NOx emissions. LNBs reduce
the amount of NOx created from reaction between fuel
nitrogen and oxygen by lowering the temperature of

EPA 2006b, EPA
1998e, EPA 2002a,
EPA 1994h, EC/R
2000

19


-------
Source
Category

Emission

Reduction

Measure

Control
Efficiency
(%)

Description/Notes/Caveats

References







one combustion zone and reducing the amount of
oxygen available in another. This control applies to
dry-process or wet-process cement manufacturing
operations with indirect-fired kilns with uncontrolled
NOx emissions greater than 10 tons per year.



Cement

Manufacturing -
Dry Process or
Wet Process

Mid-Kiln Firing

30

This control is the use of mid-kiln firing to reduce
NOx emissions. Mid-kiln firing is the injection of
solid fuel into the calcining zone of a long kiln. This
allows for part of the fuel to be burned at a lower
temperature, reducing NOx formation. This control
applies to wet-process and dry-process cement
manufacturing operations with uncontrolled NOx
emissions greater than 10 tons per year.

EPA 2006b, EPA
1998e, EPA 2002a,
EPA 1994h, EC/R
2000

Cement

Manufacturing -
Wet Process

Selective
Catalytic
Reduction

90

This control is the selective catalytic reduction of NOx
through add-on controls. SCR controls are post-
combustion control technologies based on the
chemical reduction of nitrogen oxides (NOx) into
molecular nitrogen (N2) and water vapor (H20). The
SCR utilizes a catalyst to increase the NOx removal
efficiency, which allows the process to occur at lower
temperatures. This control applies to wet-process
cement manufacturing with uncontrolled NOx
emissions greater than 10 tons per year.

EPA 2007b

Reproduced from EPA, Menu of Control Measures for NAAQS Implementation, available at https://www.epa.gov/air-quality-implementation-plans/menu-
control-measures-naaqs-implementation (URL dated January 5, 2022).

20


-------
The table below presents NOx control techniques and the types of kilns on which they may be
applied.24

NOx Control Technique

Applicable Kiln Type

Long Wet

Long Dry

Preheater

Precalciner

Process Control Systems

Yes

Yes

yes

yes

CemStar

Yes

Yes

yes

yes

Low-NOx Burner a

Yes

Yes

yes

yes

Mid-Kiln Firing

Yes

Yes

no

no

Tire Derived Fuel b

Yes

Yes

yes

yes

SNCR

No

No

yes

yes

a Low-NOx burners can only be used on kilns that have indirect firing.
b Tire derived fuel can be introduced mid-kiln in a wet or long-dry kiln, or at the feed end of a
preheater or precalciner kiln.

Reproduced from EPA, "NOx Control Technologies for the Cement Industry, Final Report," EPA-457/R-00-002
(September 2000), at 76.

State RACT Rules

EPA reviewed information provided in a SIP submission from the Texas Commission on
Environmental Quality (TCEQ) concerning NOx control technologies that have been
implemented at portland cement plants.25

Texas, Ellis County -Three companies currently operate four kilns in Midlothian, Ellis
County. Since 2015, no cement plant is using wet kilns.

Ash Grove Cement Company (Ash Grove) operated three kilns in Ellis County. However,
a 2013 consent decree with EPA required by September 10, 2014 shutdown of two kilns and
reconstruction of kiln #3 with SNCR with an emission limit of 1.5 pounds of NOx per ton of
clinker and a 12-month rolling tonnage limit for NOx of 975 tpy. The reconstructed kiln is a dry
kiln with year-round SNCR operation and is subject to the 1.5 lb NOx/ton of clinker emission
standards in the NSPS for Portland Cement Plants. The TCEQ has the delegated authority to
enforce this standard through the agency's general NSPS delegation and the NSPS satisfies
RACT for Ash Grove.26

24	EPA, "NOx Control Technologies for the Cement Industry, Final Report," EPA-457/R-00-002 (September 2000),
at 76.

25	See TCEQ, Appendix F, Reasonably Available Control Technology Analysis, Dallas-Fort Worth Serious
Classification Attainment Demonstration SIP Revision, TCEQ Project Number 2019-078-SIP-NR, available at
https://www.tceq.texas.gov/assets/public/implementation/air/sip/dfw/dfw_ad_sip_2019/DFWAD_19078SIP_Appen
dix_F_pro.pdf (URL dated October 12, 2021).

26Delegation Documents for State of Texas, see https://www.epa.gov/tx/region-6-delegation-documents-state-texas-
0

21


-------
Holcim U.S., Inc. (formerly Holnam) currently has two dry preheater/precalciner
(PH/PC) kilns equipped with SNCR. On January 14, 2009, EPA approved the current source cap
of 5.3 tons per day (tpd) NOx for Holcim at 30 TAC §117.3123 as satisfying RACT for 1997 8-
hours ozone NAAQS.27

Texas Industries, Inc. (TXI) currently operates one dry (PH/PC) kiln #5. The permitted
capacity of this kiln is 2,800,000 tons of clinker per year, and it has a permitted emissions factor
of 1.95 lb NOx/ton of clinker. Based on these permit limits, this kiln is therefore limited to a
maximum of 7.48 tpd NOx, compared to the current 30 TAC §117.3123 source cap of 7.9 tpd
NOx. Kiln #5 typically operates well below the source cap, at an average emission factor below
1.5 lb NOx/ton of clinker. EPA approved this limit as RACT on February 22, 2019 (84 FR
5601). The current NOx Source Cap (tpd) for Ellis County cement plants is shown below.

Cement Plant

NOx Cap - tpd

Ash Grove

4.4

Holcim

5.3

TXI

7.9

Total

17.6

Emission Limits and Compliance Requirements in the Proposed Rule.

In setting the emission limits for Long Wet kilns, EPA considered a range of emission
limits from 3.88 to 6.0 lb/ton of clinker produced. In particular, EPA notes that it has approved a
Texas rule requiring 4.0 lb/ton of clinker. See 74 FR 1927 (January 14, 2009) (approving Texas
Administrative Code (TAC), title 30, chapter 117, section 117.3110(a)(1)(B), among other
provisions).

For Preheaters, EPA based the emission limit of 3.8 on EPA-approved Texas and Illinois
standards. See, e.g., Appendix F, Reasonably Available Control Technology Analysis,
https://www.tceq.texas.gov/assets/public/implementation/air/sip/dfw/dfw_ad_sip_2019/DFWAD
_19078SIP_Appendix_F_pro.pdf (URL dated October 12, 2021); Illinois 35 IAC 217.224(a).

For Preheater/Precalciners, EPA based the emission limit of 2.8 lb/ton on Maryland and
Illinois's approved standards and example permit limits. See MDAQMD Rule 1161 (C)(2);
Mitsubishi Cement Corporation Lucerne Valley Federal Operating Permit 11800001; Illinois 35
IAC 217.224(a); January 14, 2009 (74 FR 1927), Docket ID No. EPA-R06-OAR-2007-1147; and
January 14, 2009 (74 FR 1903), Docket ID No. EPA-R06-OAR-2007-0524 both dockets
available at www.regulations.gov, also 30 TAC 117.3110(a)(4).

Performance Test and Monitoring

Notwithstanding any other provisions of the Act, EPA is proposing to require that
performance tests be conducted on semiannual basis and conducted in accordance with the
requirements of 40 CFR 60.8.

27 January 14, 2009 (74 FR 1927).

22


-------
EPA is specifically soliciting comment on whether it is feasible or appropriate to require
affected units (kilns) to be equipped with continuous emission monitoring systems (CEMS) to
measure and monitor the NOx concentration (emissions level) instead of conducting
performance tests on semiannual basis.

We are also soliciting comment on whether it is appropriate for the affected units (kilns)
to use continuous parametric monitoring systems (CPMS28) instead of CEMS to monitor the
NOx concentration (emissions level). We note that CPMS, also called parametric monitoring,
measures a parameter (or multiple parameters) that is a key indicator of system performance. The
parameter is generally an operational parameter of the process or the air pollution control device
(APCD) that is known to affect the emissions levels from the process or the control efficiency of
the APCD. Examples of parametric monitoring include kiln feed rate, clinker production rate,
fuel type, fuel flow rate, specific heat consumption, secondary air temperature, kiln feed-end
temperature, preheater exhaust gas temperature, induced draught fan pressure drop, kiln feed-end
percentage oxygen, percentage downcomer oxygen, primary air flow rate, ammonia feed rate and
slippage.

28 Basic Information about Air Emissions Monitoring, https://www.epa.gov/air-emissions-monitoring-knowledge-
base/basic-information-about-air-emissions-monitoring (URL dated November 10, 2021).

23


-------
4 Iron and Steel Mills and Ferroalloy Manufacturing+

Process Description

The steel and iron making processes are iterative processes during which iron is first produced
and then further refined to steel. The most common furnace types used for iron and steel
production are blast furnaces, basic oxygen process furnaces (BOF), electric arc furnaces (EAF),
annealing furnaces and ladle metallurgy furnaces (LMF).

NOx emissions from iron and steel production are most often thermal NOx from the combustion
of fossil fuels and other raw materials in furnaces or ancillary processes. The mixture of air and
fuel in the furnace react to form NOx. Fuel and prompt NOx are also generated through
oxidation of nitrogen compounds within the fossil fuels and the oxidation of hydrogen cyanide
(HCN), respectively.

Iron

The raw materials used for iron production can include iron ore, coke, sinter, and stone.
Production of coke involves carbonization of coal at high temperatures to concentrate the carbon.
Commercial coke is generally made in one of two ways: (1) by-product coking and (2) non-
recovery/heat recovery coking. A majority of the coke produced in the United States comes from
by-product coking, where the coal is carbonized in large ovens and the resulting gas is collected
and processed to recover various carbon-based by-products, such as naphthalene, benzene,
toluene and xylene. In facilities using the non-recovery coking process, the ovens are heated
differently from recovery coking operations such that no external heat source is required and
instead of recovering chemical byproducts, heat is recovered and can be used to produce steam
and electricity. The high temperatures required in coke ovens for carbonization allows the coal to
soften, liquify, and re-solidify into a solid and porous material called "coke." The process of the
coal entering the coke oven (or raw material in a blast furnace as discussed below) is called
"charging," and once the process is complete, the coke is "pushed" from furnaces, typically into
a quenching car. Often situated in front of a bank of coke ovens, a separate machine is
responsible for opening the coke oven doors, charging and pushing the raw material, and closing
the oven again. This machine is often termed a larry car, or charging and pushing machine,
among other terms. The car containing the pulverized coal then discharges the coal into the coke
oven and the head of the pusher utilizes roller supports to push finished coke into the car, then
the car transports the coke to a quench tower for water-based quenching. After a period of
cooling, this newly produced coke is mixed with the other raw materials as it is charged into the
blast furnace. Taconite is a hard, banded rock containing low-grade iron ore used to make iron
and steel, mined in the Mesabi Iron Range in Northern Minnesota, and is the predominant iron
ore in the United States. Processing taconite begins with crushing and grinding the ore and using
magnetic separation or flotation to extract the iron. Typically, 33 percent of the taconite ore
results in usable product for iron production.29 The taconite ore is further processed through
pelletization, creating either acid or flux pellets by combining the ore with a binder, typically

29 See generally EPA, AP 42 Compilation of Air Pollutant Emission Factors, Chapter 11, Mineral Products Industry,
Section 11.23, Taconite Ore Processing, Final Section - Supplement C (February 1997), available at

https://www3.epa.gov/ttnchiel/old/ap42/chl l/s23/fmal/cl ls23 Jeb 1997.pdf

24


-------
moistened bentonite clay or limestone, in a balling drum and consequently fired at high
temperatures to harden, a process referred to as induration. Types of indurating furnaces include
the vertical shaft furnace, straight grate and grate/kiln furnaces, the latter being the most
common. NOx emissions are generated in gas waste streams from induration furnaces, in higher
concentrations when producing flux pellets due to higher temperature requirements.

Production of sinter recovers the raw material value of many waste materials generated at iron
and steel plants that would otherwise be landfilled or stockpiled.30 Sinter, a hard-fused material,
can be a compilation of ore fines, coke, blast furnace dust, mill scale, recycled hot and cold fines
from the sintering process, limestone, calcite fines, and other supplemental materials to meet the
correct specifications for use in a blast furnace for iron production.

A blast furnace is a counter-flow pressurized reactor. The raw material, referred to as "burden,"
is entered at the top of the furnace, and the gases (primarily N2, CO, and CO2) driving the
reactions within the furnace, move upward. Blast furnace gas is ideally recirculated within the
vessel. The shape and structure of the burden allows the hot gases to permeate the raw material
as it moves upward through the furnace. Incoming air is preheated in a series of stoves, which is
then blasted into the furnace. As the raw material and gases react, a layer of molten iron forms at
the bottom of the furnace, and the top contains a layer of molten slag, which contains the
impurities within the raw materials. Because it is less dense, it floats at the top of the blast
furnace. A skimmer gathers the slag as it leaves the blast furnace and carries to a slag pit, while
the molten iron is carried through troughs to a torpedo car, or refractory-lined rail car. The
torpedo car is then transferred to the BOF for steel production.

Steel

Prior to steel refining, desulfurization of the molten iron must occur, typically in a BOF Shop by
adding carbide-lime or lime-magnesium to the hot metal to create a reaction to remove sulfur. A
BOF is described as basic due to the refractory lining of the furnace made from dolomite and
magnesite, or "basic," alkaline materials that won't be altered by high temperatures, corrosion or
abrasion during charging and blowing. In the BOF vessel, metal scrap is charged first, followed
by molten iron from the blast furnace. Oxygen is blown into the BOF vessel, oxidizing the
carbon within the steel. This creates CO and CO2, and the vessel is rotated. The resulting refined
steel can be tapped out at the bottom of the rotated vessel to avoid needing to skim slag from the
top of the molten steel. Ambient air emissions are generated at the charging, melting, refining,
and slag handling stages of the BOF steelmaking and refining operations, and the highest
emissions come from the oxygen blowing stage.31 These resultant gases are treated through
semi-wet, wet-open or wet-suppressed combustion practices in a large main collection stack.
These control methods regulate temperature and humidity for ESP or baghouse emission
controls, draw excess air into the exhaust system to combust carbon dioxide prior to scrubbing

30See EPA, Office of Air Quality Planning and Standards, Available and Emerging Technologies for Reducing

Greenhouse Gas Emissions from the Iron and Steel Industry (September 2012), available at

https://www.epa.gov/sites/default/files/2016-ll/documents/iron-steel-ghg-bact-2012.pdf.

31 See ITP Steel, Energy Use in the U.S. Steel Industry: An Historical Perspective and Future Opportunities

(September 2000), available at https://www.energy.gov/eere/amo/downloads/itp-steel-energy-use-us-steel-industry-

historical-perspective-and-future.

25


-------
for particulate control, or conversely, exclude excess air for combustion of CO after scrubbing,
respectively. Other emission sources from the BOF Shop, like charging and tapping, typically
have control measures before entering the primary exhaust collection, such as charging hoods.

EAFs are utilized to melt scrap steel using radiant heat from an electric arc formed between
electrodes placed inside the vessel during melting. While usage of electricity for steel melting
allows some NOx generated to be transferred to a utility generating plant, oxygen and natural gas
are often used to preheat the ladles that transfer hot metal to the EAF, causing an additional
source of NOx emission. Ladle metallurgy, also known as secondary steelmaking, is the process
of refining the metal chemistry of the molten steel produced by addition of ferroalloys to reach
the steel product specifications. LMFs can refine steel more efficiently by transferring the steel
from BOFs or EAFs to a ladle and adding aluminum and other alloys for more precise
deoxidation. A vacuum degassing system added over the ladle allows further refinement of the
molten steel, forcing the steel into the degassing system by inserting argon gas. Oxygen or
nitrogen in the degassing system removes carbon from the steel by way of carbon monoxide or
carbon dioxide formation. Other gases are used for removal of hydrogen. After steel is fully
refined to the desired specifications, the molten steel is transferred to a tundish, or ladle, before
casting. A tundish or ladle is a refractory-lined vessel for even distribution, temperature, and
composition of steel. To minimize heat loss and damage to the refractory from the molten steel,
the tundish and the ladle are preheated to high temperatures to be comparable to that of the
molten metal. While the process generates NOx emissions through combustion, preheating a
ladle or tundish is a crucial step in decreasing energy consumption of the process, as heating a
cold ladle has been demonstrated to achieve less than 10% efficiency and variable metal
quality.32 Similarly, annealing and galvanizing steel processes and associated annealing and
reheat furnaces involve reheating steel products with gas fired burners and are also a source of
NOx emissions. Annealing involves a supplemental heating process to change the hardness
properties of the final steel produced and ensure homogeneity. The galvanizing process coats
iron or steal in a coating of molten zinc to protect and seal, limiting rust and corrosion. Reheat
furnaces are used in hot rolling mills to heat steel slabs for rolling into sheets and represent 67%
of the energy used in a steel industry.33

Ferroalloys

Like iron and steel, ferroalloys are produced in a variety of furnace types, including EAFs and
LMFs. Ferroalloy refers to a chemical compound in which an alloy incorporates reactive
elements, in many cases into iron and steel, to create distinctive qualities in a metal product.
Mainly chromium, manganese, and silicon are introduced in the iron and steel making process,
but ferroalloys can also commonly include boron, cobalt, columbium, copper, nickel,
molybdenum, phosphorus, titanium, tungsten, vanadium, and zirconium. For example,
incorporation of chromium increases corrosive resistance in stainless steels, silicon is added to

32	See Alsoufi, Mohammad & Yunus, Mohammed & Asadulla, Mohammed, Economical and Technical Way of
Ladle Pre-heating by the Use of Flameless Oxyfuel (HSD/LPG) Gas in the Steel Industry, Elixir International
Journal, 95, 40776-40781 (2016).

33	Marinos Rosado, Diego & R.Ch, Samir R. & Gutierrez, Jordan & Huaraz, Miguel & Carvalho, Joao &
Mendiburu, Andres. Reheating Furnaces in the Steel Industry: Determination of the Thermal Powers in the
Combustion of Coke Oven Gas, Linz-Donawitz Gas and Blast Furnace Gas, 10.26678/ABCM.ENCIT2020.CIT20-
0016 (2020).

26


-------
help remove oxygen in steel production and manganese helps to counteract unwanted effects of
sulfur in iron and steel production, such as brittleness of steel and lessened corrosion resistance.
Like iron and steel, ferroalloys are produced in a variety of furnace types, including EAFs and
LMFs.

Several diagrams of the iron, steel and ferroalloy processes are shown below.

UPTAKE

STOCK
HOUSE

BUSTLE

Y PIP5U

IRON A SLAG C
NOTCHES	-J

DUST-

COLD
BLAST

xHOT BLAST
TUYERES

HOT METAL SLAG
CAR LADLE

CLEANED

GAS

DOWNCOMER

SKIP CAR

WASTE GAS
COMBUSTION BRICK	STACK

CHAMBER CHECKERWORK

GAS CLEANING
, EQUIPMENT

SKIP BRIDGE

OLTEN MOLTEN
SLAG	IRON

BLAST
FURNACE

BLAST

CHUTES -
ORE, COKE A
LIMESTONE

Figure: Blast furnace diagram. Source: Dutta S.K., Chokshi Y.B. (2020) Blast Furnace Process.
In: Basic Concepts of Iron and Steel Making. Springer, Singapore. https://doi.org/10.10Q7/978-
981-15-2437-0 2

Oxygen

SUh'I Ladle

Figure: Basic oxygen furnace diagram. Source: Park, Tae & Kim, Beom & Kim, Tae & Jin, II &
Yeo, Yeong. (2018). Comparative Study of Estimation Methods of the Endpoint Temperature in
Basic Oxygen Furnace Steelmaking Process with Selection of Input Parameters. Korean Journal
of Metals and Materials. 56. 813-821. 10.3365/KJMM.2018.56.11.813.

27


-------
BF-BOF Steelmaking

Additions	Scrap Oiygen Additions	Additions

Slag	Slag	Slag	Slat

Figure: Flow of processes from ironmaking to steelmaking to ferroalloy "additions". Source:
Frank Nicolaas Hermanus Schrama, Elisabeth Maria Beunder, Bart Vanden Berg, Yongxiang
Yang & Rob Boom (2017) Sulphur removal in ironmaking and oxygen steelmaking, Ironmaking
& Steelmaking, 44:5, 333-343, DOI: 10.1080/03019233.2017.1303914

Federal Rules Affecting Iron and Steel Mills and Ferroalloy Manufacturing

Iron and steel manufacturing facilities are subject to the NESHAP for Integrated Iron and Steel
Manufacturing Facilities (40 CFR Part 63 Subpart FFFFF) and NESHAPs for Iron and Steel
Foundries (40 CFR Part 63 Subpart EEEEE). 40 CFR Part 60 Subpart AA - AAa contains NSPS
for Electric Arc Furnaces (EAFs) and Argon-Oxygen Decarburization Vessels (AOD). BOFs are
regulated under the NSPS for Basic Oxygen Process Furnace (BOPF) Primary Emissions,
codified at 40 CFR Part 60 Subpart N, and secondary BOF emissions are regulated under 40
CFR Part 60 Subpart Na. Open-pit mines are subject to the Standards of Performance for
Metallic Mineral Processing Plants (40 CFR Part 60 Subpart LL) and taconite facilities are
subject to the NESHAPs for Taconite Iron Ore Processing (40 CFR Part 63 Subpart RRRRR). 40
CFR Part 61 Subpart L contains NESHAPs for Benzene Emissions from Coke By-Product
Recovery Plants, and coke ovens are subject to 40 CFR Part 63 Subpart CCCCC, NESHAPs for
Coke Ovens: Pushing, Quenching, and Battery Stacks. 40 CFR Part 713 establishes reporting
requirements for Mercury that apply to iron and steel mill and ferroalloy manufacturing, to
satisfy the Toxic Substances Control Act (TSCA). Iron and steel production contributes to a
considerable portion of the anthropogenic atmospheric mercury emissions worldwide. Iron, Steel
Mills and Ferroalloy manufacturing is also subject to the continuous emission monitoring
requirements of 40 CFR Part 75 and the iron and steel manufacturing point source category
requirements of 40 CFR Part 420, with subcategories for sintering, ironmaking, cokemaking,
steel making, vacuum degassing etc, based on NSPS, best available technology (BAT) and other
federal limit applications to effluent in this industry. 40 CFR Part 424 contains the point source
category regulations for ferroalloy manufacturing. 40 CFR Part 98 - Mandatory Greenhouse Gas
Reporting - contains subpart F, K, and Q with requirements for aluminum production, ferroalloy
production, iron and steel production, respectively.

Technology-Based Federal Regulations

The NESHAPs for Integrated Iron and Steel Manufacturing Facilities (40 CFR Part 63 Subpart
FFFFF) were promulgated in 2003 (68 FR 27646) and amended in 2006 (71 FR 39579) to
include a new compliance option, revised emission limitations, modified performance testing for
certain emission units, added corrective action requirements, and clarified monitoring,
recordkeeping and reporting requirements. The NESHAPs for Iron and Steel Foundries (40 CFR
Part 63 Subpart EEEEE) were promulgated April 22, 2004 (69 FR 21923) and amended in 2008

28


-------
(73 FR 7210) and 2020 (85 FR 56080). The 2008 amendments similarly added new compliance
options at existing foundries and clarified certain operational flexibility provisions. However, in
2020 EPA conducted a risk and technology review of the standards concluding that no new cost-
effective controls for major or area sources are available and, thus, did not make any substantive
changes to the standards. The 2020 amendments removed exemptions for periods of startup,
shutdown, and malfunction, and revised the monitoring, recordkeeping and reporting elements to
establish electronic performance test results.

CAA Section 112(d) is satisfied by implementing maximum achievable control technology
(MACT) standards expressed as emissions limits by source category based on emissions levels
currently being achieved by the most efficient, lower-emitting and efficiently controlled sources.
Generally available control technology (GACT) standards are established for area sources with
less stringency than MACT standards These standards are re-evaluated every eight years to
assess health risks. Amendments to the national emission standards for coke oven batteries were
proposed August 9, 2004 (69 FR 48338) that included more stringent requirements for certain
by-product coke oven batteries to address health risks remaining after implementation of the
1993 national emission standards. The updated MACT standards were finalized April 15, 2005
(70 FR 19992), and existing sources were required to comply by July 14, 2005.

NOx Controls

In iron and steel production, three different mechanisms yield three different types of
NOx: thermal NOx, fuel NOx, and prompt NOx.34 NOx formation is dependent on "the
efficiency of the plant, on the nitrogen content of the fuel, and on the related oxygen content in
the waste gas."35 Thermal NOx forms during high-temperature combustion processes by
oxidation of nitrogen, fuel NOx through oxidation of the fuel-bound nitrogen, and prompt NOx
from the oxidation of the intermediate compound, hydrogen cyanide (HCN).36 The formation of
thermal and fuel NOx can be distinguished depending on temperature and concentration, dwell
time and type of fuel. The formation of thermal NOx starts at 1300 °C and rises greatly with an
increasing temperature.37

EPA's Alternative Control Techniques Document - NOx Emissions from Iron and Steel
Mills provides data on uncontrolled NOx emissions from specific iron and steel process
facilities.

Uncontrolled NOx emissions from Coke Plants



DDin ai 3% O?

lb/MMBtu

lb/ton

n (No. Samples)

8

11

12

Min. Value

254

0.10

0.15

34	EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills," EPA-453/R-94-
065 (September 1994), at 2-4.

35	Joint Research Centre of the European Commission, "Best Available Techniques (BAT) Reference Document for
Iron and Steel Production," Industrial Emissions Directive 2010/75/EU (2013), at 32.

36	EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills," EPA-453/R-94-
065 (September 1994), at 2-4.

37	Joint Research Centre of the European Commission, "Best Available Techniques (BAT) Reference Document for
Iron and Steel Production," Industrial Emissions Directive 2010/75/EU (2013), at 32.

29


-------
Max. Value

1452

2.06

2.15

Avg. Value

802

0.66

0.88

Std. Dev.

448

0.72

0.64

Reproduced from EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills,"
EPA-453/R-94-065 (September 1994), at 4-11.

Uncontrolled NOx emissions from Blast Furnaces and Blast Furnace Stoves



ppm a, 3% 0?

lb/MMBtu

lb/ton

n (No. Samples)

1

11

10

Min. Value



0.002

0.003

Max. Value



0.057

0.072

Avg. Value

28

0.021

0.037

Std. Dev.



0.019

0.022

Reproduced from EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills,"
EPA-453/R-94-065 (September 1994), at 4-12.

Uncontrolled NOx emissions from Basic Oxygen Furnace
During O2 Blow Period		



ppm (avg)

ppm (a), 3% O?

lb/ton

n (No. Samples)

12

7

7

Min. Value

12.3

18

0.042

Max. Value

84.0

180

0.222

Avg. Value

24.0

58

0.119

Std. Dev.

19.6

56

0.059

Reproduced from EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills,"
EPA-453/R-94-065 (September 1994), at 4-13.

During Non O2 Blow Period



ppm (avs)

ppm (a), 3% O?

lb/ton

n (No. Samples)

2

2

-

Min. Value

14.3

200

-

Max. Value

14.5

366

-

Avg. Value

14.4

283

-

Reproduced from EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills,"
EPA-453/R-94-065 (September 1994), at 4-13.

Uncontrolled NOx emissions from Electric-Arc Furnace
EAF With Concurrent Oxy-fuel Firing		



ppm (ava)

lb/ton

lb/heat

n (No. Samples)

6

6

6

Min. Value

80

0.50

83

Max. Value

110

0.60

100

Avg. Value

98

0.54

89

Std. Dev.

10

0.05

8.2

Reproduced from EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills,"
EPA-453/R-94-065 (September 1994), at 4-14.

EAF Without Concurrent Oxy-fuel Firing

ppm (avg)

30


-------
n (No. Samples)

2

Min. Value

7

Max. Value

17

Avg. Value

12

Reproduced from EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills,"
EPA-453/R-94-065 (September 1994), at 4-14.

Uncontrolled NOx emissions from Reheat Furnaces



lb/MMBtu

DDm (a), 3% O?

lb/ton

n (No. Samples)

28

14

11

Min. Value

0.023

65

0.054

Max. Value

0.909

740

0.327

Avg. Value

0.226

292

0.198

Std. Dev.

0.198

166

0.084

Reproduced from EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills,"
EPA-453/R-94-065 (September 1994), at 4-16.

For the iron and steel mills source category, the NACAA (formerly STAPPA/ALAPCO) has
recommended requiring emission "reductions from reheat furnaces using low NOx burners
(LNB) and flued gas recirculation (FGR) (to achieve reductions of 50 percent or more), from
annealing furnaces using SCR and low NOx burners (to achieve reductions of 95 percent or
more) and from galvanizing furnaces using low NOx burners and FGR (to achieve reductions of
75 percent or more)."38 LNBs reduce the amount of NOx created from reaction between fuel
nitrogen and oxygen by lowering the temperature of one combustion zone and reducing the
amount of oxygen available in another. FGR includes the recirculation of cooled flue gas, which
reduces temperature by diluting the oxygen content of combustion air and by causing heat to be
diluted in a greater mass of flue gas. The reduction of temperature lowers the NOx concentration
that is generated. More specifically, the use of Selective Catalytic Reduction (SCR) with LNB is
recommended for annealing furnaces, and LNB with FGR is recommended for galvanizing
furnaces.

SCR is a process that uses ammonia in the presence of a catalyst to selectively reduce
NOx emissions from exhaust gases. This technology, at first, was widely used for NOx reduction
in other industries, such as coal-fired power stations and waste incinerators. In SCR, anhydrous
ammonia, usually diluted with air or steam, is injected through a grid system into hot flue gases
which are then passed through a catalyst bed to carry out NOx reduction reactions. As ammonia
is injected into the flue gas, it is converted to NOx, molecular nitrogen (N2) and water (H2O). To
prevent ammonia salt formation, which can lead to salt blocking the catalyst, a temperature of at
least 320 °C is required. Because 90% of the NOx in flue gas from coal-fired boilers is nitric
oxide (NO), a molar ratio of NH3 to NOx of approximately 1:1 is needed to maximize NOx
removal and reduce the amount of unreacted ammonia emissions. The figure below shows the
typical configuration of a catalytic NOx converter.39 Three SCR systems can be considered

38	STAPPA/ALAPCO, Controlling Nitrogen Oxides Under the Clean Air Act: A Menu of Options, 78-79 (July
1994).

39	Joint Research Centre, Institute for Prospective Technological Studies, Remus, R., Roudier, S., Delgado Sancho,
L., et al., Best available techniques (BAT) reference document for iron and steel production : industrial emissions
Directive 2010/75/EU: integrated pollution prevention and control, Publications Office (2013), available at
https://op.euror)a.eu/en/r)ublication-detail/-/r)ublication/eaa047e8-644c-4149-bdcb-9dde79c64al2/language-en.

31


-------
depending on the placement of the control: low dust exhaust gas, high dust exhaust gas and tail
end gas treatment. The high dust gas treatment places the SCR between the economizer and the
air preheater and is the most common placement because it eliminates the need to re-heat flue
gas to the desired temperature.40 Low dust and tail-end exhaust gas systems require reheating of
the exhaust gases after dedusting, resulting in additional cost.

In the Steel, Iron and Ferroalloy Sector, the combination of LNBs and SCR has been shown to be
capable of achieving up to 90 percent reduction of NOx emissions from annealing furnaces and
80 percent when SNCR is used in conjunction with LNBs.41 SCR alone was found to achieve 85
percent NOx emission reductions when firing an annealing furnace by coal41. FGR used in
conjunction with LNBs was shown to achieve 77 percent reduction of NOx emissions on reheat
furnaces and 60 percent on galvanizing furnaces 41.

Figure: Catalytic NOx converter

40	See Schreifels, Jeremy & Wang. Shuxiao & Hao. Jiming. Design and Operational Considerations for Selective
Catalytic Reduction Technologies at Coal-fired Boilers, Frontiers of Energy and Power Engineering in China. 6. 98-
105. i0.1007/sl 1708-012-0171-4 (2012).

41	See EPA, Nitrogen oxides: Why and How they are Controlled. Clean Air Technology Center (MD-12), Technical
Bulletin No. EPA-456/F-99-006R (1999), available at http://www. epa. gov/ttncatcl/dirl/fnoxdoc.pdf.

32


-------
(C)

Figure: High dust (a), low dust (b) and tail end (c) techniques for SCR placement. Source:
Schreifels, Jeremy & Wang, Shuxiao & Hao, Jiming (2012). Design and operational
consi derations for selective catalytic reduction technologies at coal-fired boilers. Frontiers of
Energy and Power Engineering in China. 6. 98-105. 10.1007/sl 1708-012-0171-4.

Selective non-catalytic reduction (SNCR) is another post-combustion control technique used in
many industries to reduce NOx emissions. SNCR differs from SCR in that it does not require a
catalyst, but the absence of catalyst allows for NOx control at higher operating temperatures, in
some cases in the range of 900 to 1000 °C. Similar to SCR, the process involves the conversion
of NOx to molecular nitrogen and H20 by injecting ammonia into the flue gas. In this system,
optimal temperature is important, as temperatures above the upper range lead to increased NOx
formation and temperatures below the lower range lead to ammonia slip42 For annealing
furnaces, SNCR has been shown to reduce NOx emissions by 60 percent43 and when used in

42See Mukhtar, Umar Alhaji et al. "NOx Emission in Iron and Steel Production: A Review of Control Measures for
Safe and Eco-Friendly Environment." Arid Zone Journal of Engineering, Technology and Environment 13 (2017):
848-857.

*13 See EPA, Alternative control techniques document report for emissions from iron and steel mills. Office of Air
Quality Planning and Standard, Research triangular park, EPA-453/R-94-065 (1994).

33


-------
conjunction with LNBs, SNCR has been shown to reduce NOx emissions by 89 percent for oil
and gas fired units and 80 percent for coal fired units.44

The table below summarizes controlled NOx emissions data and estimates and potential percent
reductions for reheat furnaces and annealing furnaces.





Emissions

Emissions

Emissions

Percent
Reduction

Furnace Type

Control

(lb/MMBtu)
Regenerative

(lb/MMBtu)
Recuperative

(lb/MMBtu)
Cold-Air

Reheat

LNB

0.27

0.068

0.046

66

LNB + FGR

0.18

0.046

0.031

77



LNB

0.48

0.20

0.07

50



LNB + FGR

0.38

0.16

0.07

60

Annealing

SNCR

0.38

0.16

0.07

60

SCR

0.14

0.06

0.02

85



LNB + SNCR

0.19

0.08

0.03

80



LNB + SCR

0.095

0.04

0.015

90

Reproduced from EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills,"
EPA-453/R-94-065 (September 1994), at 2-8.

The European Union Commission charged with establishing Best Available Techniques (BAT)
to control NOx emissions from iron and steel production describes control techniques for select
emission units associated with iron and steel production.

For Coke Oven Plants, BAT to reduce emissions includes incorporating low-nitrogen oxides
techniques in construction of new batteries (only applicable to new plants). The BAT-associated
emission level for nitrogen oxides is 350 - 500 mg/Nm3 for new or substantially revamped
plants (less than 10 years old) and 500 - 650 mg/Nm3 for older plants with well-maintained
batteries and incorporated low- nitrogen oxides (NOx) techniques.45

For Blast Furnaces, BAT is to reduce emissions by using desulphurised and dedusted surplus
coke oven gas, dedusted blast furnace gas, dedusted basic oxygen furnace gas and natural gas,
individually or in combination. BAT-associated emissions levels for nitrogen oxides are 100
mg/Nm3.46

The European Integrated Pollution Prevention and Control Bureau (EIPPCB) at the European
Commission's Joint Research Centre - Institute for Prospective Technological Studies (IPTS)
created a reference document in the framework of the implementation of the aforementioned

44	Midwest Regional Planning Organization (MRPO). 2005. Iron and Steel Mills Best Available Retrofit
Technology (BART) Engineering Analysis.

45	Official Journal of European Union Commission, Best Available Techniques (BAT) Conclusions Under Directive
2010/75/EU of the European Parliament and of the Council on Industrial Emissions for Iron and Steel Production,
(February 28, 2012), Section 1.4.49.

46	Official Journal of European Union Commission, Best Available Techniques (BAT) Conclusions Under Directive
2010/75/EU of the European Parliament and of the Council on Industrial Emissions for Iron and Steel Production,
(February 28, 2012), Section 1.5.65.

34


-------
Industrial Emissions Directive (2010/75/EU) that describes the general primary and secondary
methods for reducing NOx emissions from iron and steel production.

These measures can be applied individually or in combination. Injection of reduction fuel, such
as a mixture of recycled exhaust gas and natural gas, between the last burner level and the upper
air can reduce NOx but is not efficient in combination with the usage of low-NOx burners at the
same time. Air and fuel staging can be used to influence the size of the combustion area and the
dwell time in the flame and these staging methods yield similar NOx reductions.47 The NOx
reduction efficiencies of the aforementioned measures are summarized below.

Applied primary measure

NOx reduction efficiency (%)

Low-NOx burner

28

Flue-gas recirculation

13

Upper air injection for residual combustion
with sub-stoichiometric burners

23

Injection of reduction fuel

13

Low-NOx burner plus flue-gas recirculation

38

Reproduced from Joint Research Centre of the European Commission, "Best Available Techniques (BAT)
Reference Document for Iron and Steel Production," Industrial Emissions Directive 2010/75/EU (2013), at 60, 62.

This report also describes measures for reducing NOx at certain sources. For Coke Plants,
the European Commission identified flame temperature reduction in the heating chamber as the
most effective way of reducing NOx formation. Three effective methods are listed: waste gas
recirculation to reduce the flame temperature, staged air combustion to make combustion
conditions more moderate, and lowering of coking temperatures which requires a lower heating
chamber temperature. Additionally, structural changes can be made to the heating chamber to
improve thermal conductivity, such as using thinner bricks, which reduces the heating chamber
temperature and therefore reduces NOx formation.48

EPA's Alternative Control Techniques Document for NOx Emissions from Iron and
Steel49 notes that while Coke ovens are among the major NOx emission sources at iron and steel
mills, coke ovens with NOx controls in the United States have not been found. The document
instead cites the Japan Iron and Steel Federation's report of installation of SCR units on coke
ovens. The report also identifies low-air-ratio combustion, denitrification, and flue-gas
recirculation of fuel as NOx control techniques applicable to coke ovens.50

EPA's Menu of Control Measures (MCM) provides state, local and tribal air agencies with
information on existing criteria pollutant emission reduction measures as well as relevant

47	Joint Research Centre of the European Commission, "Best Available Techniques (BAT) Reference Document for
Iron and Steel Production," Industrial Emissions Directive 2010/75/EU (2013), at 59-60.

48	Joint Research Centre of the European Commission, "Best Available Techniques (BAT) Reference Document for
Iron and Steel Production," Industrial Emissions Directive 2010/75/EU (2013), at 257.

49	EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills," EPA-453/R-94-
065 (September 1994).

50	EPA, "Alternative Control Techniques Document - NOx Emissions from Iron and Steel Mills," EPA-453/R-94-
065 (September 1994), at 5-19.

35


-------
information concerning the efficiency and cost effectiveness of the measures.51 State, local, and
tribal agencies may use this information in developing emission reduction strategies, plans and
programs to assure they attain and maintain the NAAQS. For NOx emission control from iron
and steel operations the MCM's control measures are tabulated on the subsequent pages.

51 EPA, Menu of Control Measures for NAAQS Implementation, available at https://www.epa.gov/air-quality-
implementation-plans/menu-control-measures-naaqs-implementation (URL dated January 5, 2022).

36


-------
Source
Category

Emission

Reduction

Measure

Control
Efficiency
(%)

Description/Notes/Caveats

References

Iron & Steel - In-
Process
Combustion -
Bituminous Coal

Selective
Catalytic
Reduction

90

This control is the selective catalytic reduction of NOx through
add-on controls. SCR controls are post-combustion control
technologies based on the chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2) and water vapor (H20). The
SCR utilizes a catalyst to increase the NOx removal efficiency,
which allows the process to occur at lower temperatures. This
control is applicable to operations with in-process combustion
(Bituminous Coal) in the Iron & Steel industry with uncontrolled
NOx emissions greater than 10 tons per year.

EPA 2010b

Iron & Steel - In-
Process
Combustion -
Natural Gas and
Process Gas -
Coke Oven Gas

Low NOx
Burner

50

This control is the use of low NOx burner (LNB) technology to
reduce NOx emissions. LNBs reduce the amount of NOx created
from reaction between fuel nitrogen and oxygen by lowering the
temperature of one combustion zone and reducing the amount of
oxygen available in another. This control is applicable to
operations with in-process combustion (Natural Gas or Coke
Oven Process Gas) in the Iron & Steel industry with uncontrolled
NOx emissions greater than 10 tons per year.

EPA 2010b

Iron & Steel - In-
Process
Combustion -
Natural Gas and
Process Gas -
Coke Oven Gas

Selective
Catalytic
Reduction

90

This control is the selective catalytic reduction of NOx through
add-on controls. SCR controls are post-combustion control
technologies based on the chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2) and water vapor (H20). The
SCR utilizes a catalyst to increase the NOx removal efficiency,
which allows the process to occur at lower temperatures. This
control is applicable to operations with in-process combustion
(Natural Gas and Process Gas - Coke Oven Gas) in the Iron &
Steel industry.

EPA 2010b

Iron & Steel - In-
Process
Combustion -

Low NOx
Burner and

55

This control is the use of low NOx burner (LNB) technology and
flue gas recirculation (FGR) to reduce NOx emissions. LNBs
reduce the amount of NOx created from reaction between fuel

EPA 2010b

37


-------
Process Gas -
Blast Furnace
Stoves

Flue Gas
Recirculation



nitrogen and oxygen by lowering the temperature of one
combustion zone and reducing the amount of oxygen available in
another. This control is applicable to operations with in-process
combustion (Process Gas - Coke Oven/ Blast Furnace) in the Iron
& Steel industry with uncontrolled NOx emissions greater than
10 tons per year.



Iron & Steel - In-
Process
Combustion -
Residual Oil

Selective
Catalytic
Reduction

90

This control is the selective catalytic reduction of NOx through
add-on controls. SCR controls are post-combustion control
technologies based on the chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2) and water vapor (H20). The
SCR utilizes a catalyst to increase the NOx removal efficiency,
which allows the process to occur at lower temperatures. This
control is applicable to operations with in-process combustion
(Residual Oil) in the Iron & Steel industry with uncontrolled NOx
emissions greater than 10 tons per year.

EPA 2010b

Iron & Steel
Mills -
Annealing

Low NOx
Burner

50

This control is the use of low NOx burner (LNB) technology to
reduce NOx emissions. LNBs reduce the amount of NOx created
from reaction between fuel nitrogen and oxygen by lowering the
temperature of one combustion zone and reducing the amount of
oxygen available in another. This control is applicable to iron and
steel annealing operations with uncontrolled NOx emissions
greater than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e, EPA
2002a, EPA
1994e

Iron & Steel
Mills -
Annealing

Low NOx
Burner and
Flue Gas
Recirculation

60

This control is the use of low NOx burner (LNB) technology and
flue gas recirculation (FGR) to reduce NOx emissions. LNBs
reduce the amount of NOx created from reaction between fuel
nitrogen and oxygen by lowering the temperature of one
combustion zone and reducing the amount of oxygen available in
another. This control is applicable to iron and steel annealing
operations with uncontrolled NOx emissions greater than 10 tons
per year.

EPA 2006b,
Pechan 2001,
EPA 1998e, EPA
2002a, EPA
1994e

Iron & Steel
Mills -
Annealing

Low NOx
Burner and
Selective

90

This control is the use of low NOx burner (LNB) technology and
selective catalytic reduction (SCR) to reduce NOx emissions.
LNBs reduce the amount of NOx created from reaction between

EPA 2006b,
Pechan 2001,
EPA 1998e, EPA

38


-------


Catalytic
Reduction



fuel nitrogen and oxygen by lowering the temperature of one
combustion zone and reducing the amount of oxygen available in
another. SCR controls are post-combustion control technologies
based on the chemical reduction of nitrogen oxides (NOx) into
molecular nitrogen (N2) and water vapor (H20). The SCR
utilizes a catalyst to increase the NOx removal efficiency, which
allows the process to occur at lower temperatures. This control is
applicable to iron and steel annealing operations with
uncontrolled NOx emissions greater than 10 tons per year.

2002a, EPA
1994e

Iron & Steel
Mills -
Annealing

Low NOx
Burner and
Selective Non
Catalytic
Reduction

80

This control is the use of low NOx burner (LNB) technology and
selective catalytic reduction (SCR) to reduce NOx emissions.
LNBs reduce the amount of NOx created from reaction between
fuel nitrogen and oxygen by lowering the temperature of one
combustion zone and reducing the amount of oxygen available in
another. SCR controls are post-combustion control technologies
based on the chemical reduction of nitrogen oxides (NOx) into
molecular nitrogen (N2) and water vapor (H20). The SCR
utilizes a catalyst to increase the NOx removal efficiency, which
allows the process to occur at lower temperatures. This control is
applicable to iron and steel annealing operations with
uncontrolled NOx emissions greater than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e, EPA
2002a, EPA
1994e

Iron & Steel
Mills -
Annealing

Selective
Catalytic
Reduction

90-99

This control is the selective catalytic reduction of NOx through
add-on controls. SCR controls are post-combustion control
technologies based on the chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2) and water vapor (H20). The
SCR utilizes a catalyst to increase the NOx removal efficiency,
which allows the process to occur at lower temperatures. This
control applies to iron and steel annealing operations with NOx
emissions greater than 10 tons per year.

EPA 2006b, EPA
1998e, EPA
2002a, EPA
1993 c, EPA
2007d, Sorrels
2007

Iron & Steel
Mills -
Annealing

Selective Non

Catalytic

Reduction

60

This control is the reduction of NOx emission through selective
non-catalytic reduction add-on controls. SNCR controls are post-
combustion control technologies based on the chemical reduction
of nitrogen oxides (NOx) into molecular nitrogen (N2) and water

EPA 2006b,
Pechan 2001,
EPA 1998e, EPA
2002a, EPA

39


-------






vapor (H20). This control applies to iron and steel mill annealing
operations with uncontrolled NOx emissions greater than 10 tons
per year.

1994e, EPA
1993c

Iron & Steel
Mills - Cupola
Melt Furnaces

Selective
Catalytic
Reduction

90

This control is the selective catalytic reduction of NOx through
add-on controls. SCR controls are post-combustion control
technologies based on the chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2) and water vapor (H20). The
SCR utilizes a catalyst to increase the NOx removal efficiency,
which allows the process to occur at lower temperatures. This
control applies to NOx emissions from the cupola melt furnaces
at iron and steel operations.

RTI 2011

Iron & Steel
Mills -
Galvanizing

Low NOx
Burner

50

This control is the use of low NOx burner (LNB) technology to
reduce NOx emissions. LNBs reduce the amount of NOx created
from reaction between fuel nitrogen and oxygen by lowering the
temperature of one combustion zone and reducing the amount of
oxygen available in another. This control is applicable to iron and
steel galvanizing operations with uncontrolled NOx emissions
greater than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e, EPA
2002a, EPA
1994e

Iron & Steel
Mills -
Galvanizing

Low NOx
Burner and
Flue Gas
Recirculation

60

This control is the use of low NOx burner (LNB) technology and
flue gas recirculation (FGR) to reduce NOx emissions. LNBs
reduce the amount of NOx created from reaction between fuel
nitrogen and oxygen by lowering the temperature of one
combustion zone and reducing the amount of oxygen available in
another. This control is applicable to iron and steel galvanizing
operations with uncontrolled NOx emissions greater than 10 tons
per year.

EPA 2006b,
Pechan 2001,
EPA 1998e, EPA
2002a, EPA
1994e

Iron & Steel
Mills -
Reheating

Low Excess
Air

13

The reduction in NOx emissions is achieved through the use of
low excess air techniques, such that there is less available oxygen
convert fuel nitrogen to NOx. This control applies to iron & steel
reheating furnaces.

EPA 2006b, EPA
1993 a, Pechan
2001, EPA
1998e, EPA
1994e, ERG 2000

40


-------
Iron & Steel
Mills -
Reheating

Low NOx
Burner

66

This control is the use of low NOx burner (LNB) technology to
reduce NOx emissions. LNBs reduce the amount of NOx created
from reaction between fuel nitrogen and oxygen by lowering the
temperature of one combustion zone and reducing the amount of
oxygen available in another. This control is applicable to iron and
steel reheating operations with uncontrolled NOx emissions
greater than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e, EPA
2002a, EPA
1994e

Iron & Steel
Mills -
Reheating

Low NOx
Burner and
Flue Gas
Recirculation

77

This control is the use of low NOx burner (LNB) technology and
flue gas recirculation (FGR) to reduce NOx emissions. LNBs
reduce the amount of NOx created from reaction between fuel
nitrogen and oxygen by lowering the temperature of one
combustion zone and reducing the amount of oxygen available in
another. This control is applicable to reheating processes in iron
and steel mills with uncontrolled NOx emissions greater than 10
tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e, EPA
2002a, EPA
1994e

Iron Production -
Blast Furnace -
Blast Heating
Stoves

Low NOx
Burner and
Flue Gas
Recirculation

77

This control is the use of low NOx burner (LNB) technology and
flue gas recirculation (FGR) to reduce NOx emissions. LNBs
reduce the amount of NOx created from reaction between fuel
nitrogen and oxygen by lowering the temperature of one
combustion zone and reducing the amount of oxygen available in
another. This control is applicable to reheating processes in iron
production operations with blast heating stoves and uncontrolled
NOx emissions greater than 10 tons per year.

EPA 2006b, EPA
1998e, EPA
2002a, EPA
1994e

41


-------
State RACT Rules

Ohio NOx RACT rules limit NOx emissions from blast furnaces to 0.06 lb/mmBtu without
requiring specific control technology.

Sterling Steel permit, issued 2019: Low-NOx natural gas fired burners designed to emit no more
than 0.073 lb NOx/mmBtu, Ohio RACT limit is 0.09 lb/mmBtu

On and after July 18, 2013, "Charter Steel" or any subsequent owner or operator of the "Charter
Steel" facility NOx emissions for bar mill reheat furnace P029, rated at 165.0 mmBtu/hr, shall
not exceed 0.11 lb/mmBtu.

United States Steel Lorain Tubular Operations has NOx emission limitations from the Ohio NOx
RACT rules ranging from 0.068-0.15 lb/mmBtu for the five reheating furnaces at the facility.

Nucor Kankakee BACT permit limit issued January 2021 limit NOx emissions from ladle
preheaters to 0.1 lb/mmBtu, 2021.

Ohio NOx RACT rules limit NOx emissions from Cleveland-Cliffs Inc ladle preheaters to 0.1
lb/mmbtu.

Ohio NOx RACT rules limit NOx emissions from reheat furnaces not subject to source-specific
NOx limits to 0.09 lbs/mmbtu.

Ohio NOx RACT rules limit NOx emissions at Cleveland-Cliffs Inc annealing furnaces to 0.1
lb/mmbtu. Permit limits for Nucor, AR, was 0.0915 lb/mmBtu.

Cleveland-Cliffs Inc. in Ohio has a source specific NOx emission limitation of 0.06 lb/mmBtu
for Blast Furnace Stoves. Also, for "basic oxygen furnaces (BOF)," there is a NOx emission
limitation of 0.1 lb/mmBtu52 contained in the Ohio NOx RACT rules.

Wisconsin's NR 428.22(l)(c)(c), Subchapter IV - NOX Reasonably Available Control
Technology Requirements53 establishes limits for a reheat, annealing or galvanizing furnace with
a maximum heat input capacity equal to or greater than 75 mmBtu/hr and 0.08 lb/mmBtu.

Pennsylvania's RACT II rule54 created to satisfy the 2008 National Ambient Air Quality
Standards (NAAQS) for ozone, set NOx emission limits for Cleveland Cliffs Steel
Corporation/Butler Works, previously AK Steel Corporation of 0.036 lb/mmBtu for the main
plant boiler.

Emission Limits and Compliance Requirements in the Proposed Rule

In setting a NOx emission limit for blast furnaces, EPA considered a range of emission
rates from 0.02 lb/mmBtu to 0.05 lb/mmBtu as calculated based on potential use of low-NOx
burners, flue gas recirculation, and SCR. EPA notes that it has approved an Ohio SIP rule of 0.06

52	See paragraph N, https://codes.ohio.gov/ohio-administrative-code/rule-3745-110-03

53	See https://docs.legis.wisconsin.gov/code/admin_code/nr/400/428/iv/20

54	See https://www.dep.pa.gov/About/Regional/NorthwestRegion/Community-Information/Pages/RACT-II.aspx

42


-------
lb/mmBtu without specifically requiring use of NOx-reducing control technology. See OAC
3745-110-03(N). Use of these technologies separately or in combination can achieve 20-90%
reduction efficiency at blast furnace stoves. In this rulemaking, EPA is requiring each facility to
tailor its NOx reduction technology to meet a NOx limit of 0.03 lb/mmBtu.

For basic oxygen furnaces, EPA based the emission limit of 0.07 lb/ton of steel on
performance testing data from basic oxygen furnaces without NOx reduction controls at
integrated iron and steel mills in the United States. EPA projects minimally 50% NOx reduction
efficiency is achievable by use of low-NOx technology, including potential use of FGR and
selective catalytic reduction. Most BOF vessels and associated BOF Shops in the United States
are equipped with capture technology and existing particulate matter control devices. The
existing configurations of these shops would accommodate the addition of NOx controls or
additional design of a capture system capable of integrating such technology with these
structures.

For vacuum degassers utilized in secondary steelmaking, EPA based the limit of 0.03
lb/mmBtu on existing permit limits of 0.05 lb/mmBtu. EPA projects minimally 40% NOx
reduction efficiency is achievable by use of low-NOx technology, including use of selective
catalytic reduction.

For ladle and tundish preheaters, EPA based the emission limit of 0.06 lb/mmBtu on
existing permit limits. The majority of recently issued permits limit NOx emissions from ladle
and tundish preheaters to 0.1 lb/mmBtu based on prevailing operating rates compared to natural
gas usage. EPA projects minimally 40% NOx reduction efficiency is achievable by use of low-
NOx technology, including potential use of low-NOx burners and selective catalytic reduction.

For EAFs, EPA based the emission limit of 0.15 lb/ton of steel on projected reduction
efficiency of 40-50% as compared to existing permit limits for EAFs. EPA considered a range of
baseline emission data and permit limits from mini mills, integrated iron and steel facilities, and
ferroalloy facilities ranging from 0.20 lb/ton to 0.35 lb/ton. EPA projects minimally 40% NOx
reduction efficiency is achievable by use of low-NOx technology, including potential use of low-
NOx burners and selective catalytic reduction.

For LMFs, EPA based the emission limit of 0.1 lb/ton of steel on projected reduction
efficiency of 40-50% as compared to existing permit limits for LMFs. EPA considered a range of
baseline emission data and current permit limits from 0.20 lb/ton to 0.35 lb/ton. EPA projects
minimally 40% NOx reduction efficiency is achievable by use of low-NOx technology,
including potential use of low-NOx burners and selective catalytic reduction.

For reheat furnaces, EPA based the emission limit of 0.05 lb/mmBtu on projected
reduction efficiency of 40-50% based on sampled operating and emission rates compared to
natural gas usage. EPA projects minimally 40% NOx reduction efficiency is achievable by use of
low-NOx technology, including potential use of newer generation low-NOx burners or
optimization of existing burners.

43


-------
For annealing furnaces, EPA based the emission limit of 0.06 lb/mmBtu on projected
reduction efficiency of 40-50% based on current permit emission limits and operating rates
compared to natural gas usage. EPA projects minimally 40% NOx reduction efficiency is
achievable by use of low-NOx technology, including potential use of newer generation low-NOx
burners or optimization of existing burners, or combination of low-NOx burners, flue gas
recirculation, and/or selective catalytic reduction.

For taconite production kilns, EPA requires work practice standards that mirror
requirements from the 2013 and 2016 Minnesota Regional Haze Taconite Federal
Implementation Plans. EPA projects minimally 40% NOx reduction efficiency is achievable by
use of low-NOx technology, including potential use of newer generation low-NOx burners or
optimization of existing burners.

For coke ovens (charging) and coke ovens (pushing), EPA based the emission limit of
0.15 lb/ton for charging and 0.015 lb/ton for pushing on projected reduction efficiency of 40-
50% based on current permit emission limits and production-based push/charge cycles. EPA
projects minimally 40% NOx reduction efficiency is achievable by use of low-NOx practices,
staged pushing and hood configurations, and potential use of add-on NOx control technology at
larry cars and pushing/charging machines, including potential use of low-NOx burners, flue gas
recirculation, and/or the addition of selective catalytic reduction to mobile hoods and particulate
matter control devices.

For boilers, EPA based emission limits of 0.2 lb/mmBtu for coal and residual oil boilers, 0.18
lb/mmBtu for distillate oil boilers, and 0.08 lb/mmBtu for natural gas boilers on existing RACT
and BACT rules. EPA projects minimally 20% NOx reduction efficiency is achievable by use
and optimization of low-NOx burners, flue gas recirculation, and/or the addition of selective
catalytic reduction to existing capture and control systems.

Performance Test and Monitoring

EPA is specifically proposing to require each owner or operator of an affected unit to install,
calibrate, maintain, and operate a CEMS for the measurement of NOx emissions discharged into
the atmosphere from the affected unit or shop, as applicable. EPA is soliciting comments on
alternative monitoring systems and methods that are equivalent to CEMS to demonstrate
compliance with the emission limits

44


-------
5 Glass and Glass Product Manufacturing

Process Description55

Commercially produced glass can be classified as soda-lime, lead, fused silica,
borosilicate, or 96 percent silica. Soda-lime glass consists of sand, limestone, soda ash, and
cullet. Glass products are classified by both chemical composition and by the type of product
produced. The main product types are flat glass, container glass, pressed and blown glass, and
fiberglass. The manufacturing of such glass occurs in four phases: (1) preparation of raw
material, (2) melting in the furnace, (3) forming and (4) finishing. The procedures for
manufacturing these types of glass are the same for all products except for the forming and
finishing process. Container glass and pressed/blown glass use pressing, blowing or pressing and
blowing to form the desired product. Flat glass, which is the remainder, is formed by float,
drawing, or rolling processes. The North American Industry Classification System (NAICS)
code for glass and glass product manufacturing is 3272.

A diagram of a typical glass manufacturing process is shown below.

Conditioning & forming

Waste heat flow

ni ii it

3

Heat recovery
system

Finishing

>

Electricity, heating
arid cooling

Reproduced from Andriy Redko, et al. "Glass Manufacture, Industrial waste heat resources,'' ScienceDirect (2020),
Fig. 9.26, available at https://www.sciencedirect.com/topics/engineering/glass-manufacture.

Glass Melting Furnace

Glass melting furnaces are used by the glass industry in the production of glass. The glass
melting furnaces contribute to most of the total emissions from the glass plant. Essentially all of
the Oxides of Nitrogen (NOx) emissions associated with glass manufacturing are generated in

55 See generally EPA, AP-42 Compilation of Air Emissions Factors, Mineral Products Industry, Chapter 11. Mineral
Products Industry-, Section 11.15, Glass Manufacturing, Final Section (October 1986, reformatted January 1995).

45

Malting & refining

Batch
preparation


-------
the melting furnaces due to the high process temperatures. Nitrogen oxides form when nitrogen
and oxygen react in the high temperatures of the furnace.

To manufacture glass, raw materials such as sand, limestone, soda ash, and cullet are
crushed, mixed, and fed into the furnace. These materials are then heated in the furnace to
temperatures around 3000°F to induce fusion which produces molten glass. After molten glass is
produced, it then goes to be shaped by pressing, blowing, pressing and blowing, drawing, rolling,
or floating to produce the desired product. The end products undergo finishing which include
annealing, grinding, polishing, coating, and/or decorating. During the inspection process, any
damaged or undesirable glass is transferred back to the batch plant to be used as cullet. Cullet is
defined in EPA's NESHAP regulations as recycled glass that is mixed with raw materials and
charged to a glass melting furnace to produce glass.56

Glass manufacturing furnaces can vary between the various categories of glass produced.
This is because the different types of glass vary in composition and quality specifications.
Therefore, each type of glass produced requires different energy inputs to fuse the raw materials.
As a result, the emissions from similar furnaces producing different types of glass can vary
significantly.

Nearly 50 percent of the glass manufacturing furnaces are a regenerative design, with two
chambers containing refractory "checker bricks" for capturing heat. The flow of combustion air
(influent) and flue gas (effluent) alternate passing through the checkers to recover heat and
provide heat, respectively. Recuperative glass melting furnaces are also used which rely on heat
exchanges to continuously preheat combustion air. Natural gas is commonly used as the source
of heat from the industry. However, oil and electricity, as well as a combination of both, are also
used.57

A diagram of a glass melting furnace is provided below.

56	See definitions in 40 CFR Part 63, Subpart SSSSSS, "National Emission Standards for Hazardous Air Pollutants
for Glass Manufacturing Area Sources."

57	Lake Michigan Air Directors Consortium (LADCO), Interim White Paper - Midwest RPO Candidate Control
Measures, "Source Category: Glass Manufacturing" (December 2, 2005), available at https://www.ladco.org/wp-
content/uploads/Documents/Reports/Control/white_papers/glass_fiberglass_manufacturing_plants.pdf

46


-------
Burner

Combustion air
blower

Reproduced from Ravi Jain, et al." Glass Furnace, Energy and Environmental Implications,'
available at https://www.sciencedirect.com/topics/engineering/glass-furnace.

ScienceDirect (2012),

Glass melt	_

surface	Throat	Refiner

Bridge wall

Sidewall

Checkers

Stack

Forehearth

Batch
feeder

The components of a continuous glass furnace are provided below.

Reproduced from Mathieu Hubert, PHD, et al, "IMI-NFG Course on Processing in Glass."7.e///g/j (2015), available
at https://www.lehigh.edu/imi/teched/GlassProcess/Lectures/Lecture03_Hubert_industglassmeltfurnaces.pdf.

The furnace operation is the main source of pollution at a glass manufacturing plant. The
reaction of nitrogen and oxygen in the furnace creates NOx emissions. This occurs in the
combustion zone and in the checkers in the production of flat glass furnace where temperatures
can reach up to 2300°F. Particulate emissions result from the volatilization of materials that later
form condensates and from material handling. Sulfur dioxide (S02) emissions are the product of
oxidation of sulfur containing compounds in fuels and in the raw materials formulations. VOC
emissions may be associated with the use of lubricants, mold release agents and coating used in
the decoration of finished products.

47


-------
Federal Rules affecting Glass Plants

Glass plants are subject to the Glass Manufacturing NESHAP (40 CFR Part 63 Subpart
SSSSSS) and NSPS (40 CFR Part 60 Subpart CC). Glass manufacturing furnaces that burn
hazardous waste are subject to the Hazardous Waste Combustor NESHAP (40 CFR Part 63
Subpart SSSSSS).

Technology-Based Federal Regulations

The NSPS implementing Clean Air Act (CAA) section 111(b) for Glass Manufacturing
Plants was first promulgated at 40 CFR part 60, Subpart CC on October 7, 1980 (45 FR 66751).
EPA conducted three additional reviews of these standards on October 19, 1984 (49 FR 41030),
February 14, 1989 (54 FR 6674), and October 17, 2000 (65 FR 61759). The NSPS applicable to
the glass manufacturing industry only provides standards for particulate matter from sources and
does not provide standards or averaging times for NOx.

NOx Controls

The NACAA (formerly STAPPA/ALAPCO) has recommended requiring "combustion
modifications, process changes and post-combustion controls [Selective Non-Catalytic
Reduction] (SNCR)" to limit NOx emissions from the glass furnaces source category.58 SNCR is
a post combustion control technology used to reduce NOx emissions without the presence of a
catalyst. The NACAA has also noted that "RACT limits of 5.3-5.5 lbs NOx/ton of glass removed
have been adopted, as well as limits as low as 4.0 lbs NOx/ton of glass removed" and
recommended "[requiring] sources to coordinate installation of controls with routine furnace
rebuilds to lower costs."59

The European Union Commission charged with establishing the Best Available
Techniques (BAT) to control NOx emissions from the production of glass outlines the control
techniques tabulated below.

58	STAPPA/ALAPCO, Controlling Nitrogen Oxides Under the Clean Air Act: A Menu of Options, 78-79 (July
1994), available at https://p2infohouse.org/ref/02/01245/3017101.pdf.

59	Id.

48


-------
Primary

Techniques/Measures

Description

Combustion Modifications



(i) Reduction of
air/fuel ratio

The technique is mainly based on the following features:
minimization of air leakages into the furnace
careful control of air used for combustion
modified design of the furnace combustion chamber

(ii) Reduced

combustion air
temperature

The use of recuperative furnaces, in place of regenerative furnaces, results in a reduced air preheat
temperature and, consequently, a lower flame temperature. However, this is associated with a lower
furnace efficiency (lower specific pull), lower fuel efficiency and higher fuel demand, resulting in
potentially higher emissions (kg/ton of glass)

(iii) Staged

combustion

Air staging - involves sub-stoichiometric firing and the addition of the remaining air or
oxygen into the furnace to complete combustion.

Fuel staging - a low impulse primary flame is developed in the port neck (10 % of total
energy); a secondary flame covers the root of the primary flame reducing its core
temperature

(iv) Flue-gas

recirculation

Implies the reinjection of waste gas from the furnace into the flame to reduce the oxygen content
and therefore the temperature of the flame. The use of special burners is based on internal
recirculation of combustion gases which cool the root of the flames and reduce the oxygen content
in the hottest part of the flames

(v) Low-NOx
burners

The technique is based on the principles of reducing peak flame temperatures, delaying but
completing the combustion and increasing the heat transfer (increased emissivity of the flame). It
may be associated with a modified design of the furnace combustion chamber

(vi) Fuel choice

In general, oil-fired furnaces show lower NOx emissions than gas-fired furnaces due to better
thermal emissivity and lower flame temperatures

Special furnace design

Recuperative type furnace that integrates various features, allowing for lower flame temperatures.
The main features are:

specific type of burners (number and positioning)
modified geometry of the furnace (height and size)

two-stage raw material preheating with waste gases passing over the raw materials entering
the furnace and an external cullet preheater downstream of the recuperator used for
preheating the combustion air

49


-------
Electric melting

The technique consists of a melting furnace where the energy is provided by resistive heating. The
main features are:

electrodes are generally inserted at the bottom of the furnace (cold-top)

nitrates are often required in the batch composition of cold-top electric furnaces to provide

the necessary oxidizing conditions for a stable, safe and efficient manufacturing process

Oxy-fuel melting

The technique involves the replacement of the combustion air with oxygen (>90% purity), with
consequent elimination/reduction of thermal NOx formation from nitrogen entering the furnace. The
residual nitrogen content in the furnace depends on the purity of the oxygen supplied, on the quality
of the fuel (% N2 in natural gas) and on the potential air inlet

Chemical reduction by fuel

The technique is based on the injection of fossil fuel to the waste gas with chemical reduction of
NOx to N2 through a series of reactions. In the 3R process (which is proprietary), the fuel (natural
gas or oil) is injected at the regenerator entrance. The technology is designed for use in regenerative
furnaces.

Selective catalytic reduction
(SCR)

The technique is based on the reduction of NOx to nitrogen in a catalytic bed by reaction with
ammonia (in general aqueous solution) at an optimum operating temperature of around 300 - 450
°C. One or two layers of catalyst may be applied. A higher NOX reduction is achieved with the use
of higher amounts of catalyst (two layers)

Selective non-catalytic
reduction (SNCR)

The technique is based on the reduction of NOx to nitrogen by reaction with ammonia or urea at a
high temperature. The operating temperature window must be maintained between 900 and 1,050 °C

Minimizing the use of
nitrates in the batch
formulation

The minimization of nitrates is used to reduce NOx emissions deriving from the decomposition of
these raw materials when applied as an oxidizing agent for very high quality products where a very
colourless (clear) glass is required or for other glasses to provide the required characteristics. The
following options may be applied:

Reduce the presence of nitrates in the batch formulation to the minimum commensurate with
the product and melting requirements.

Substitute nitrates with alternative materials. Effective alternatives are sulphates, arsenic
oxides, cerium oxide.

Apply process modifications (e.g. special oxidizing combustion conditions)

Reproduced from Official Journal of European Union Commission, Best Available Techniques (BAT) Conclusions Under Directive 2010/75/EU of the European
Parliament and of the Council on Industrial Emissions for the Manufacture of Glass, February 28, 2012, Table 1.10.2.

50


-------
EPA's Menu of Control Measures (MCM) provides state, local and tribal air agencies
with information on existing criteria pollutant emission reduction measures as well as relevant
information concerning the efficiency and cost effectiveness of the measures. State, local, and
tribal agencies may use this information in developing emission reduction strategies, plans and
programs to assure they attain and maintain the NAAQS. The information from the MCM can
also be found in the Control Measures Database (CMDB), a major input to the Control Strategy
Tool (CoST), which EPA used in the NOx control strategy analysis included in the Non-EGU
Screening Assessment memorandum.60 Information about control measures to reduce NOx
emissions from glass manufacturing operations is tabulated below.

60 EPA, Control Measures Database (CMDB) for Stationary Sources, available at

https://www.epa.gov/svstem/files/other-files/2021-09/cmdb 2021-09-02 O.zip (URL dated January 6, 2022).

51


-------
Source
Category

Emission

Reduction

Measure

Control
Efficiency
(%)

Description/Notes/Caveats

References

Glass

Manufacturing -
Container

Cullet
Preheat

25

This control is the use of cullet preheat technologies to reduce NOx
emissions from glass manufacturing operations. This control is
applicable to container glass manufacturing operations.

EPA 2006b,
EPA 1998e,
EPA 1994f

Glass

Manufacturing -
Container

Electric
Boost

10

This control is the use of electric boost technologies to reduce NOx
emissions from glass manufacturing operations. This control applies
to container glass manufacturing operations.

EPA 2006b,
EPA 1998e,
EPA 1994f

Glass

Manufacturing -
Container

OXY-
Firing

85

This control is the use of Oxy-firing in container glass manufacturing
furnaces to reduce NOx emissions. Oxygen enrichment refers to the
substitution of oxygen for nitrogen in the combustion air used to burn
the fuel in a glass furnace. Oxygen enrichment above 90 percent is
sometimes called "oxy-firing."

EPA 2006b

Glass

Manufacturing -
Container

Selective
Catalytic
Reduction

75

This control is the selective catalytic reduction of NOx through add-
on controls. SCR controls are post-combustion control technologies
based on the chemical reduction of nitrogen oxides (NOx) into
molecular nitrogen (N2) and water vapor (H20). The SCR utilizes a
catalyst to increase the NOx removal efficiency, which allows the
process to occur at lower temperatures. This control applies to glass-
container manufacturing processes with uncontrolled NOx emissions
greater than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994f

Glass

Manufacturing -
Container

Selective
Non-
Catalytic
Reduction

40

This control is the reduction of NOx emissions through selective non-
catalytic reduction add-on controls. SNCR controls are post-
combustion control technologies based on the chemical reduction of
nitrogen oxides (NOx) into molecular nitrogen (N2) and water vapor
(H20). This control applies to glass-container manufacturing
operations with uncontrolled NOx emissions greater than 10 tons per
year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994f,
EPA 1993 c

Glass

Manufacturing -
Container

Low NOx
Burner

40

This control is the use of low NOx burner (LNB) technology to
reduce NOx emissions. LNBs reduce the amount of NOx created
from reaction between fuel nitrogen and oxygen by lowering the
temperature of one combustion zone and reducing the amount of

EPA 2006b,
EPA 1998e,
EPA 2002a,
EPA 1994f

52


-------






oxygen available in another. This control applies to flat glass and
container glass manufacturing operations with uncontrolled NOx
emissions greater than 10 tons per year.



Glass

Manufacturing -
Container

Electric
Boost

10

This control is the use of electric boost technologies to reduce NOx
emissions from glass manufacturing operations. This control applies
to flat glass manufacturing operations.

EPA 2006b,
EPA 1998e,
EPA 1994f

Glass

Manufacturing -
Container

OXY-
Firing

85

This control is the use of Oxy-firing in flat glass manufacturing
furnaces to reduce NOx emissions. Oxygen enrichment refers to the
substitution of oxygen for nitrogen in the combustion air used to burn
the fuel in a glass furnace. Oxygen enrichment above 90 percent is
sometimes called "oxy-firing."

EPA 2006b

Glass

Manufacturing -
Container or Flat
Glass

Selective
Catalytic
Reduction

75

This control is the selective catalytic reduction of NOx through add-
on controls. SCR controls are post-combustion control technologies
based on the chemical reduction of nitrogen oxides (NOx) into
molecular nitrogen (N2) and water vapor (H20). The SCR utilizes a
catalyst to increase the NOx removal efficiency, which allows the
process to occur at lower temperatures. This control applies to flat-
glass manufacturing operations with uncontrolled NOx emissions
greater than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994f,
EPA 1993 c

Glass

Manufacturing -
Flat

Selective
Non-
Catalytic
Reduction

40

This control is the reduction of NOx emission through selective non-
catalytic reduction add-on controls. SNCR controls are post-
combustion control technologies based on the chemical reduction of
nitrogen oxides (NOx) into molecular nitrogen (N2) and water vapor
(H20). This control applies to flat-glass manufacturing operations
with uncontrolled NOx emissions greater than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994f,
EPA 1993 c

Glass

Manufacturing -
Flat

OXY-
Firing

85

This control is the use of Oxy-firing in glass manufacturing furnaces
to reduce NOx emissions. Oxygen enrichment refers to the
substitution of oxygen for nitrogen in the combustion air used to burn
the fuel in a glass furnace. Oxygen enrichment above 90 percent is
sometimes called "oxy-firing."

EPA 2007b

Glass

Manufacturing -
Flat

Cullet
Preheat

25

This control is the use of cullet preheat technologies to reduce NOx
emissions from glass manufacturing operations. This control is
applicable to pressed glass manufacturing operations.

EPA 2006b,
EPA 1998e,
EPA 1994f

53


-------
Glass

Manufacturing -
Flat

Electric
Boost

10

This control is the use of electric boost technologies to reduce NOx
emissions from glass manufacturing operations. This control applies
to pressed glass manufacturing operations.

EPA 2006b,
EPA 1998e,
EPA 1994f

Glass

Manufacturing -
General

Low NOx
Burner

40

This control is the use of low NOx burner (LNB) technology to
reduce NOx emissions. LNBs reduce the amount of NOx created
from reaction between fuel nitrogen and oxygen by lowering the
temperature of one combustion zone and reducing the amount of
oxygen available in another. This control is applicable to pressed
glass manufacturing operations with uncontrolled NOx emissions
greater than 10 tons per year.

EPA 1998e,
EPA 2002a,
EPA 1994f

Glass

Manufacturing -
Pressed

OXY-
Firing

85

This control is the use of Oxy-firing in pressed glass manufacturing
furnaces to reduce NOx emissions. Oxygen enrichment refers to the
substitution of oxygen for nitrogen in the combustion air used to burn
the fuel in a glass furnace. Oxygen enrichment above 90 percent is
sometimes called "oxy-firing"

EPA 2006b

Glass

Manufacturing -
Pressed

Selective
Catalytic
Reduction

75

This control is the selective catalytic reduction of NOx through add-
on controls. SCR controls are post-combustion control technologies
based on the chemical reduction of nitrogen oxides (NOx) into
molecular nitrogen (N2) and water vapor (H20). The SCR utilizes a
catalyst to increase the NOx removal efficiency, which allows the
process to occur at lower temperatures. This control applies to
pressed-glass manufacturing operations, and uncontrolled NOx
emissions greater than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994f,
EPA 1993 c

Glass

Manufacturing -
Pressed

Selective
Non-
Catalytic
Reduction

40

This control is the reduction of NOx emissions through selective non-
catalytic reduction add-on controls. SNCR controls are post-
combustion control technologies based on the chemical reduction of
nitrogen oxides (NOx) into molecular nitrogen (N2) and water vapor
(H20). This control applies to pressed-glass manufacturing
operations with uncontrolled NOx emissions greater than 10 tons per
year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994f,
EPA 1993 c

Reproduced from EPA, Menu of Control Measures for NAAQS Implementation, available at https://www.epa.gov/air-quality-implementation-plans/menu-
control-measures-naaqs-implementation (URL dated January 5, 2022)

54


-------
In 1994, the Emission Standards Division of the Office of Air Quality Planning and Standards of
the U.S. Environmental Protection Agency issued a report detailing alternative control
techniques (ACTs) for NOx emissions from glass manufacturing facilities. The table below
summarizes the NOx control technologies identified in EPA's ACT document for glass
manufacturing.61Since 1994, the demand for flat, container, and pressed/blown glass has
continued to increase annually.62To meet this demand, the glass manufacturing industry is has
also continued to grow. The flat glass industry alone is expected to grow in 10 - 20% annually
due to the increase of flat glass demands within the building construction and car manufacturing
industry.63 Nitrogen oxides remain to be one of the primary air pollutants produced during the
production and manufacturing of glass products. However, current federal regulations only focus
to control emissions of particulate matter, metals, and organic hazardous air pollutants.

Currently, there is no NSPS that provides standards or averaging times for NOx from glass
manufacturing furnaces. The growth of the glass manufacturing industry along with the
continued absence of an NSPS that regulates NOx emission from the industry, calls for the need
of NOx standards for this industry. However, over the last decades the glass industry has
participated in various pollution prevention efforts including the 33/50 program, Green Lights
and Energy Star programs.64 Since 1994, various studies have been conducted by the glass
manufacturing industries to help identify preferred techniques for the control of NOx. While
these studies reveal some new trends in the glass industry, they generally reveal that the 1994
EPA report is still accurate.65

Technology

NOx Reduction (%)

Combustion modifications



Low NOx burners

40

Oxy-firing

85

Process modifications



Modified furnace

75

Cullet preheat

25

Electric boost

10

Post combustion modifications



SCR

75

SNCR

40

State RACT Rules

61	EPA, Alternative Control Techniques Document— NOx Emissions from Glass Manufacturing, EPA-453/R-94-
037 (June 1994) at 2-7.

62	U.S. Department of Energy, Glass Industry of the Future - Energy and Environmental Profile of the U.S. Glass
Industry, (April 2002), Pages 6-9.

64	See id.

65	The use of recycled glass (cullet) has also increased in practice within the glass manufacturing industry over the
past decades. The use of cullet reduces the energy intensity needed to produce glass, therefore reducing emissions.
Increased in energy efficiency has also been accomplished through improved control systems, the development and
use of advanced refractory materials, and technologies such as oxy-firing and electric boost which increase
production capacity.

55


-------
Federal emission control regulations for glass manufacturing facilities historically
focused on particulate and arsenic emissions. However, regulations for the control of NOx
emissions have also been adopted in a few states. EPA reviewed various RACT NOx rules from
states located within the Ozone Transport Region (OTR). EPA chose to review these RACT
NOx rules because several OTR states implement Ozone Transport Commission (OTC) model
rules and recommendations. During its review, EPA observed that most of the states within the
OTR have adopted RACT regulations for the glass manufacturing sector that do not specify NOx
limits.66 Examples of OTR states that do not specify NOx limits for glass manufacturing
furnaces include New York, Connecticut, and Maryland.

EPA focused its review on rules adopted by OTR states that contain specific RACT NOx
limits for glass manufacturing furnaces. EPA reviewed Pennsylvania's RACT rule since it
contains RACT NOx limits on a 30-day rolling average for various glass melting furnace types.
Pennsylvania's NOx RACT rule requires owners or operators of a glass melting furnace to
comply with the following emission limits: 4.0 pounds of NOx per ton of glass pulled for
container and fiberglass furnaces, 7.0 pounds of NOx per ton of glass pulled for pressed/blown
and flat glass furnaces, and 6.0 pounds of NOx per ton of glass pulled from all other glass
melting furnaces.67

EPA also reviewed New Jersey's RACT rule since it contains a more stringent daily
averaging period compared to Pennsylvania's RACT rule. New Jersey's NOx RACT rule
requires each owner or operator of a glass manufacturing furnace to comply with the following
emission limits: 4.0 pounds of NOx per ton of glass removed for container, pressed/blown,
borosilicate, and fiberglass furnaces.68 Under New Jersey's RACT rule, an owner or operator of
a flat glass manufacturing furnace shall not emit more than 9.2 pounds of NOx per ton of glass
removed. New Jersey's RACT rule also incorporates OTC model recommendations.69

Maryland's RACT rule requires owners or operators to optimize combustion by
performing daily oxygen tests and maintain excess oxygen at 4.5% or less.70 The San Joaquin

66	RACT NOx rules of the following OTR states CT, DC, DE, MD, ME, NH, NY, RI, VA, and VT do not establish
specific NOx limits for glass manufacturing sources. These RACT regulations require owners or operators to submit
RACT case-by-case analysis. See, Title 6 of New York's Codes, Rules, and Regulation (NYCRR) Part 220-2.3,

https://govt.westlaw.com/nycrr/Document/Iff7c8565a0761 ldf8ec9d72f92627052?viewType=FullText&originationC
ontext=documenttoc&transitionType=CategoryPageItem&contextData=(sc.Default), Section 22a-174-22e of CT's
NOx RACT regulation, https.V/eregulations. ct.gov/eRegsPortal/Browse/RCSA/Title_22aSubtitle_22a-
174Section_22a-174-22e/, and Title 26, Subtitle 11, Chapter 26.11.09 of MD's NOx RACT regulation,
http://www. dsd.state.md. us/comar/comarhtml/26/26.11.09.08.htm.

67	Title 25, Part I, Subpart C, Article III, Section 129.304 of PA's NOx RACT regulation provides emission rates for
Glass Manufacturing Furnaces. See https://casetext.com/regulation/pennsylvania-code-rules-and-regulations/title-
25-environmental-protection/part-i-department-of-environmental-protection/subpart-c-protection-of-natural-
resources/article-iii-air-resources/chapter-129-standards-for-sources/control-of-nox-emissions-from-glass-melting-
furnaces/section-129304-emission-requirements.

68	Title 7, Chapter 27, Subchapter 19 of New Jersey's NOx RACT regulation provides NOx emission rates for Glass
Manufacturing Furnaces. See https://www.nj.gov/dep/aqm/currentrules/Subl9.pdf.

69	Id.

70	Title 26, Subtitle 11, Chapter 26.11.09 of MD's NOx RACT regulation provides operation standards for Glass
Manufacturing Furnaces. See http://www.dsd.state.md.us/comar/comarhtml/26/26.ll.09.08.htm.

56


-------
Valley air district in California has adopted RACT NOx emission limits that are based on both
30-day rolling and daily averages.71

The following table displays the San Joaquin Valley air district's emission limits for container
glass, fiberglass, and flat glass melting furnaces.72

Type of Glass Produced

Tier 2 NOx limit

Tier 3 NOx limit

Tier 4 NOx limit

Container Glass

4.0 A

1.5 B

not available

Fiberglass

4.0 A

1.3

3.0 v "

not available

Flat Glass

i) 2 v

5.5 A

3.7 x

Standard Option

7.0 H

5.0 B



Flat Glass

i) 2 "v

5.5 1

3.4 '

Enhanced Option

7.0 H

5.0"

2.t) H

Flat Glass

Farh Fnhanccd Option

y.2A
7.1) H

not available

3.4 A

i i) »

A Block 24-hour a\ erage
B Rolling 30-day average

c Not subject to California Public Resources ("ode Section 19511
D Subject to California Public Resources Code Section l
-------
For Pressed/Blown and Fiberglass Manufacturing Furnaces, EPA considered a range of
emission limits from 1.0 - 7.0 lb/ton of glass produced. EPA based the proposed emission limit
of 4.0 lb/ton on EPA-approved New Jersey and Pennsylvania RACT rules for glass melting
furnaces. EPA also observed that the 4.0 lb/ton limit was consistent for these types of glass
manufacturing furnaces with states located in the OTR. See 76 FR 52283 (August 22, 2011).

For Flat Glass Manufacturing Furnaces, EPA considered a range of 5.0 - 9.2 lb/ton of
glass produced. EPA based the proposed emission limit of 9.2 lb/ton on the NOx limits in the
New Jersey and San Joaquin Valley air district's federally approved RACT rules.

In determining the averaging time for the limits, EPA reviewed the NSPS for glass
manufacturing plants codified in 40 CFR Part 60 Subpart CC. EPA also referred to the various
state RACT NOx rules that contain specific NOx emission limits for the glass manufacturing
industry. We note that the NSPS for glass manufacturing furnaces establishes standards only for
particulate matter and does not establish standards or averaging times for NOx. In order to
determine an appropriate averaging time for the proposed NOx emission limits, EPA focused its
review on the various RACT NOx rules from states located in the OTR. The OTR states have
adopted emission limits with varying averaging times. Based on EPA's review, the OTR states
varied between a 30-day rolling average or a more stringent daily average.74 EPA also reviewed
RACT NOx regulations for the glass manufacturing sector outside the OTR and observed that
30-day rolling averages and daily averages varied throughout the states.75 In the preamble to this
proposed rule, EPA is proposing to require owners and operators of glass manufacturing furnaces
to comply with the proposed NOx emission limit on a 30-day rolling average time frame. EPA
believes that this averaging time frame is consistent with other statewide RACT NOx regulations
for this particular sector. A 30-day operating day rolling average strikes a balance between short
term (hourly or daily) and long term (annual) averaging periods, while being flexible and
responsive to fluctuations in operation and production.

department-of-environmental-protection/subpart-c-protection-of-natural-resources/article-iii-air-
resources/chapter- 129-standards-for-sources/control-of-nox-emissions-from-glass-melting-furnaces/section-
129304-emission-requirements.

74	Pennsylvania's RACT NOx emission limits are based on 30-day rolling average. See Title 25, Part I, Subpart C,
Article III, Section 129.304, see https://casetext.com/regulation/pennsylvania-code-rules-and-regulations/title-25-
environmental-protection/part-i-department-of-environmental-protection/subpart-c-protection-of-natural-
resources/article-iii-air-resources/chapter-129-standards-for-sources/control-of-nox-emissions-from-glass-melting-
furnaces/section-129304-emission-requirements. New Jersey's and Massachusetts' rules contain more stringent
daily averages. Title 7, Chapter 27, Subchapter 19 of New Jersey's NOx RACT regulation provides NOx emission
rates for Glass Manufacturing Furnaces. See https://www.nj.gov/dep/aqm/currentrules/Subl9.pdf. 310 CMR Section
7:19 of Massachusetts regulations provides RACT NOx emission limits for Glass Manufacturing Furnaces. See
https://www.mass.gov/doc/310-cmr-700-air-pollution-control-regulations/download. Title 26, Subtitle 11, Chapter
26.11.09 of Maryland's NOx RACT regulation provides operation standards for Glass Manufacturing Furnaces. See
http://www.dsd. state, md. us/comar/comarhtml/26/26.11.09.08. htm.

75	The San Joaquin Valley air district's RACT NOx emission limits are based on both 30-day rolling and daily
averages. See San Joaquin Valley Unified Air Pollution Control District, Rule 4354, "Glass Melting Furnaces"
(amended May 19, 2011), available at https://www.valleyair.org/rules/currntrules/R4354%20051911.pdf.
Wisconsin's NOx emission limits are based on a 30-day rolling average. See Wisconsin's Administrative Code NR
Section 428.22 (November 29, 2021), available at https://casetext.com/regulation/wisconsin-administrative-
code/agency-department-of-natural-resources/environmental-protection-air-pollution-control/chapter-nr-428-
control-of-nitrogen-compound-emissions/subchapter-iv-nox-reasonably-available-control-technology-
requirements/section-nr-42822-emission-limitation-requirements.

58


-------
Performance Test and Monitoring

EPA is proposing to require that performance tests be conducted on a semiannual basis in
accordance with the applicable reference Test Methods of 40 CFR 60, Appendix A, or other
methods and procedures approved by EPA through notice-and-comment rulemaking.

EPA is specifically proposing to require each owner or operator of an affected unit to
install, calibrate, maintain, and operate a CEMS for the measurement of NOx emissions
discharged into the atmosphere from the affected unit. EPA is soliciting comments on alternative
monitoring systems and methods that are equivalent to CEMS to demonstrate compliance with
the emission limits.

59


-------
6 Boilers from Basic Chemical Manufacturing, Petroleum
and Coal Products Manufacturing, and Pulp, Paper, and
perboard Mills

A. Applicability andform ofproposed emissions limits for industrial boilers.

EPA proposes to establish regulatory requirements for boilers that have a design capacity
of 100 mmBtu/hr or greater within the Basic Chemical Manufacturing, Petroleum and Coal
Products Manufacturing, and Pulp, Paper, and Paperboard Mills industries. The rationale for this
proposal is consistent with EPA's findings at Step 3 with respect to Tier 2 non-EGU industries in
that it applies to certain boilers located at facilities identified as a Tier 2 industry within the Non-
EGU Screening Assessment memorandum, which can be found within the docket for the
proposed rule. As described within the Non-EGU Screening Assessment memorandum, EPA
reviewed the projected 2026 emissions data to identify large boilers within the Tier 2 industries,
defined as boilers projected to emit more than 100 tons per year in 2026. Boilers meeting this
threshold were found in three of the five Tier 2 industries, as identified in Table 1 below.

Table 1: Tier 2 Industries with Large Boilers and Associated NAICS Codes

Industry

NAICS Code

Basic Chemical Manufacturing

325lxx

Petroleum and Coal Products Manufacturing

324lxx

Pulp, Paper, and Paperboard Mills

322lxx

EPA is not currently aware of boilers meeting this size classification within the other Tier
2 or Tier 1 industries but proposes to require that any such boilers would also be subject to the
requirements of the FIP. Based on a review of the potential emissions from industrial boilers of
various fuel types as described in this section, we believe that use of a boiler design capacity of
100 mmBtu/hr reasonably approximates the selection of 100 tpy used within the Non-EGU
Screening Assessment memorandum. Therefore, EPA proposes to establish NOx emissions
limits for all new and existing boilers found within any of the 23 covered states that are within a
Tier 1 or Tier 2 industry and have a design capacity of 100 mmBTU/hr or greater. EPA solicits
comment on alternative applicability thresholds, such as one based strictly on potential to emit.

EPA reviewed a number of state RACT rules to determine the typical form of emission
limits within them. Based on this review, EPA found that NOx limits for industrial boilers most
often take the form of design capacity expressed as mass of NOx emitted per million BTUs
combusted per hour. EPA's proposed NOx emissions limits for this source category take the
same form.

Specifically, EPA is proposing to establish an applicability threshold based on a design
capacity of 100 mmBtu/hr or greater. NOx emissions from boilers rated at 100 mmBtu/hr or
greater can be significant, particularly if they do not operate NOx control equipment. Based on
our review of the potential emissions from industrial boilers of various fuel types we conclude
that use of a boiler design capacity of 100 mmBtu/hr reasonably approximates the selection of
100 tons/year used within the Non-EGU Screening Assessment memorandum. An evaluation of

60


-------
potential NOx emissions from various fossil-fueled industrial boilers with a design capacity of
100 mmBtu/hr is provided below.

1. Potential emissions from coal-fired industrial boilers

The potential emissions from a coal-fired industrial boiler with a design capacity of 100
mmBtu/hr was estimated using an average NOx emission factor from EPA's emission factor
reference document, AP-4276, along with an approximate heating value for coal from Appendix
A of AP-42. The emission factor used was derived by calculating the average of 13 "A" rated
NOx emission factors from AP-42's Table 1.1-3 - Emission Factors for SOx, NOx, and CO from
Bituminous and Subbituminous Coal Combustion. The average of the 13 values was 14.1 lbs
NOx per ton of coal burned. The heating value from Appendix A for bituminous coal is 13,000
BTUs per pound, which equates to 26 million BTUs per ton of coal. The following calculation
provides the maximum potential emissions from an industrial boiler with these parameters:

(14.1 lbs NOx/ton coal) * (1 ton coal/26 mmBtu) * (100 mmBtu/hr) * (8,760 hr/yr) *(1
ton/2000 lbs) =237.5 tons NOx/year.

The above represents the maximum potential emissions from a coal-fired boiler emitting
at the rate shown in the equation; boilers operating less than 8,760 hours per year would emit
proportionally less than the maximum amount illustrated in the above equation.

2. Potential emissions from oil-fired industrial boilers.

The potential emissions from a residual and a distillate oil-fired industrial boiler with a design
capacity of 100 mmBtu/hr was estimated in a manner similar to the approach described above for
a coal-fired industrial boiler. For a residual oil-fired industrial boiler, a NOx emission factor of
47 lbs NOx per 1,000 gallons of oil burned was taken from Table 1.3-1, Criteria Pollutant
Emission Factors for Fuel Oil Combustion, of section 1.3, Fuel Oil Consumption, of AP-42, and
a heating value of 150,000 BTUs per gallon for residual oil as reported in Appendix A to AP-42
was used. The heating value equates to 150 million BTUs per 1,000 gallons used. The following
calculation provides the maximum potential emissions from an industrial boiler with these
parameters:

(47 lbs NOx/1,000 gallons) * (1,000 gallons/150 mmBtu) * (100 mmBtu/hr) *(8,760

hr/yr) *(1 ton/2000 lbs) = 137.2 tons NOx/year.

For a distillate oil-fired boiler, an emission factor of 24 lbs NOx/1,000 gallons from Table 1.3-1
was used in conjunction with a heat rate of 140,000 BTUs per gallon from Appendix A.
Substituting these values into the above equation yields a result of 75.1 tons per year. Although
this result is below 100 tons per year, the emission factor used, which was the only one available
for industrial boilers of this size and fuel type within AP-42 is rated "D", meaning there is likely
to be a fairly wide range in emission rates from individual boilers of this type.

The above analysis represents the maximum potential emissions from a residual and a
distillate-fired industrial boiler emitting at the rates shown in the equations above; boilers

76 Compilation of Air Pollutant Emission Factors, Volume I: Stationary Point and Area Sources; U.S. EPA, Office of
Air Quality Planning and Standards; available at: https://www.epa.gov/air-emissions-factors-and-auantification/ap-
42-compilation-air-emissions-factors

61


-------
operating less than 8,760 hours per year would emit proportionally less than the maximum
amounts illustrated in the above equations.

3. Potential emissions from a natural gas-fired industrial boiler.

The potential emissions from a natural gas-fired industrial boiler with a design capacity
of 100 mmBtu/hr was estimated in a manner similar to the approach described above for coal and
oil-fired industrial boilers. For a natural gas-fired industrial boiler, a NOx emission factor of 235
lbs NOx per million standard cubic feet (SCF) used was obtained from Table 1.4-1, Emission
Factors for Nitrogen Oxides (NOx) and Carbon Monoxide (CO) from Natural Gas Combustion,
of section 1.4, Natural Gas Consumption, of AP-42. The emission factor represents the average
of the emission factors for a pre and a post-NSPS natural gas-fired industrial boiler. A heating
value of 1,050 BTUs per SCF as reported in Appendix A to AP-42 was used in the calculation.
The heating value equates to 1,050 mmBtu per million SCF. The following calculation provides
the maximum potential emissions from an industrial boiler with these parameters:

(235 lbs NOx/mm SCF) * (1 mm SCF/1,050 mmBtu) * (100 mmBtu/hr) * (8,760 hr/yr)
*(1 ton/2000 lbs) = 98 tons NOx/year.

The above analysis represents the maximum potential emissions from a residual and a
distillate-fired industrial boiler emitting at the rates shown in the equations above; boilers
operating less than 8,760 hours per year would emit proportionally less than the maximum
amounts illustrated in the above equations.

B. Proposed Emissions Limitations and Rationale

A review was performed of NOx emissions limits for industrial boilers with design capacities of
100 mmBtu/hr or greater that have been adopted by states and incorporated into their SIPs.

Based on that review, the following NOx emissions limits for coal, oil, and gas fired industrial
boilers appear to be reasonable, achievable limits for industrial boilers:

62


-------
Table 2: Recommended NOx Emissions Limits for Industrial Boilers > 100 mmBtu/hr

Unit type

Emissions limit
(lbs NOx/mmBtu)

Additional Information

Coal

0.20

Limits reviewed ranged from 0.08 to 1.0.
Proposed limit will likely require a
combination of combustion controls or
post-combustion controls.

Residual oil

0.20

Limits reviewed ranged from 0.15 to 0.50.
Proposed limit will likely require
combustion controls.

Distillate oil

0.12

Limits reviewed ranged from 0.10 to 0.43.
Proposed limit will likely require
combustion controls.

Natural gas

0.08

Limits reviewed ranged from 0.06 to 0.25.
Proposed limit will likely require a
combination of combustion controls or
post-combustion controls.

EPA's Menu of Control Measures (MCM) document contains numerous examples of
NOx control equipment that has been demonstrated to effectively reduce emissions from
industrial boilers. Table 7 below provides information pertaining to industrial boilers from the
MCM, indicating that 9 different control technologies or combinations of technologies have been
shown to reduce NOx emissions from industrial boilers with control efficiencies ranging from 35
to 90 percent. This information from the MCM can also be found in the Control Measures
Database (CMDB), a major input to the Control Strategy Tool (CoST), which EPA used in the
NOx control strategy analysis included in the Non-EGU Screening Assessment memorandum.77

Additional information on EPA's analysis of state-adopted emission limits for industrial
boilers with design capacities of 100 mmBtu/hr or greater fueled by coal, oil, or natural gas, and
the control technologies available to reduce NOx emissions from this equipment is provided
below.

1. Coal-fired industrial boilers

For coal-fired industrial boilers subject to the requirements of the proposed FIP, EPA is
proposing to establish an emission limit of 0.20 lbs/MMBtu on a 30-day rolling basis. Various
forms of combustion and post-combustion NOx control technology exist that should enable most
existing facilities to be retrofit with equipment that will enable them to meet this emissions limit.
Additionally, many states containing ozone nonattainment areas or located within the Ozone
Transport Region (OTR) have already adopted emission limits similar to the recommended
emission limit. Furthermore, some coal-fired industrial boilers may have installed combustion or
post-combustion control equipment to meet the emission limits contained within EPA's NSPS

77 EPA, Control Measures Database (CMDB) for Stationary Sources, available at

https://www.epa.gov/svstem/files/other-files/2021-09/cmdb 2021-09-02 O.zip (URL dated January 6, 2022).

63


-------
located at 40 CFR 60 Subpart Db, which requires that coal-fired industrial boilers meet a NOx
emissions limit of between 0.5 and 0.8 lbs/MMBtu depending on unit type.78

There are two main types of NOx control technology that can be retrofit to most existing
industrial boilers, or incorporated into the design of new boilers, to meet the proposed emissions
limit. These two control types are combustion controls and post-combustion controls, and in
some instances both types are used together. As noted within EPA's "Alternative Control
Techniques Document - NOx Emissions from Industrial / Commercial / Institutional (ICI)
Boilers" (hereafter "ICI Boiler ACT"),79 the type of NOx control available for use on a particular
unit depends primarily on the type of boiler, fuel type, and fuel-firing configuration. We note that
although the ICI Boiler ACT also addresses emissions from commercial and institutional boilers,
we are not proposing emissions limits for those types of boilers; rather, we are only proposing
limits for certain types of industrial boilers. For example, Table 2-3 of the ICI Boiler ACT
indicates which types of combustion and post-combustion NOx controls are suitable to various
types of coal-fired ICI boilers. We note that one type of combustion control, staged combustion
air, and one type of post-combustion control, SNCR, are indicated as being compatible with all
coal-fired unit types. Additional resources are available that document the availability of NOx
control equipment for industrial boilers, including a document prepared by the Northeast States
for Coordinated Air Use Management entitled, "Applicability and Feasibility of NOx, S02, and
PM Emission Control Technologies for Industrial, Commercial, and Institutional Boilers"
(November 2008, revised January 2009); the "EPA Air Pollution Control Cost Manual," Section
4, Chapter 1: Selective Noncatalytic Reduction, April, 2019 and Chapter 2, Selective Catalytic
Reduction, June 2019; and a document issued by the Institute of Clean Air Companies entitled,
"Typical Installation Timelines for NOx Emissions Control Technologies on Industrial Sources,"
December, 2006.

Table 3 provides examples of NOx emission limits for coal-fired ICI boilers rated at 100
mmBTU/hr or greater that have been adopted by various states.

Table 3 - NOx emission limits, averaging times, and state citations for coal fired ICI boilers

State

Emission limit
(lbs/mmBTU)

Averaging time

State rule citation and website

CT

0.1280 ozone
season;

0.15 non-ozone
season

Daily block
average for units
with CEMS, for
other units, as
developed during
stack testing. For
non-ozone season,
rate is avg. for
non-ozone season.

Section 22a-174-22e of the Regulations of
Connecticut State Agencies, at paragraph
(d)(2)(C):

httDs://eregulations. ct.gov/eRegsPortal/Brows
e/RCSA/Title 22aSubtitle 22a-

174Section 22a-174-22e/

78	40 CFR 60.44b.

79	EPA, Alternative Control Techniques Document - NOx Emissions from Industrial / Commercial / Institutional
(ICI) Boilers, EPA-453/R-94-022 [DATE],

80	Beginning in 2023.

64


-------
MA

0.12

One-hour, unless
equipped with
CEMS, then daily.

Regulation 310 of the Code of Massachusetts
Regulations (CMR), 7.00, Air Pollution
Control, Section 7.19, RACT for Sources of
NOx, at paragraph (4)(b):
https://www.mass.gov/doc/310-cmr-700-air-

Dollution-control-regulations/download

DE

0.38

24 hour rolling
basis.

Title 7, Natural Resources and Environmental
Control, Section 1112, Control of Nitrogen
Oxide Emissions, at Table 3-1:
https://regulations.delaware.gOv/AdminCode/t
itle7/1000/l 100/1112. shtml

NY

0.08-0.20

CEMS or 1-hour
average.

Title 6, Dept. of Environmental Conservation;
Chapter III. Air Resources; Subchapter A.
Prevention and Control of Air Contamination
and Air Pollution; Part 227. Stationary
Combustion Installations; Subpart 227-2.
RACT for Major Sources of NOx.

NY NOx RACT Regulation

2. Oil-fired industrial boilers

Most oil-fired boilers are fueled by either residual (heavy) oil or distillate (light) oil.
Based on our review of available information as described below, the proposed NOx emission
limit for residual oil-fired boilers is 0.20 lbs/mmBtu, and the proposed emission limit for
distillate oil-fired boilers is 0.12 lbs/mmBtu, with both limits based on a rolling, 30-day average
basis. As with coal-fired industrial boilers, a number of combustion and post-combustion NOx
control technology exist that should enable most facilities to meet these emission limits, and
numerous examples exist of states that have already adopted emission limits similar to EPA's
proposed emissions limits. Table 2-3 of the ICI Boiler ACT indicates that two types of NOx
combustion control, low-NOx burners and flue gas recirculation, are commonly found on oil-
fueled industrial boilers, and that SNCR, a post-combustion control technology, is suitable to
most oil-fueled industrial boilers other than those of the packaged firetube design. Some oil-fired
industrial boilers may have already installed combustion or post-combustion control equipment
to meet the emission limits contained within EPA's NSPS located at 40 CFR 60 Subpart Db,
which requires that distillate oil-fired units meet a NOx emission limit of between 0.1 to 0.2
lbs/MMBtu depending on heat release rate, and residual oil-fired units meet a NOx emission
limit of between 0.3 to 0.4 lbs/MMBtu also depending on heat release rate.81 The additional
resources noted in the paragraph above discussing coal-fired industrial boilers also contain useful
information regarding effective NOx control equipment for residual and distillate fueled
industrial boilers.

81 40 CFR 60.44b.

65


-------
Table 4 provides examples of NOx emission limits for oil-fired ICI boilers rated at 100
mmBTU/hr or greater that have been adopted by various states.

Table 4 - NOx emission limits, averaging times, and state citations for oil-fired ICI boilers
rated at 100 mmBTU/hr or greater		

State

Emission limit

(lbs/mmBTU)

Averaging time

State rule citation

CT82

Residual oil: 0.20
Other oil: 0.15

Daily block
average for units
with CEMS, for
other units, as
developed during
stack testing.

Section 22a-174-22e of the Regulations of
Connecticut State Agencies, at paragraph
(d)(3)(C):

httDs://eregulations.ct.gov/eRegsPortal/Bro
wse/RCSA/Title 22aSubtitle 22a-
174Section 22a-174-22e/

MA

0.15

One-hour, unless
equipped with
CEMS, then daily.

310 CMR 7.19, at paragraph (4)(b):
https://www.mass.gov/doc/310-cmr-700-

air-pollution-control-regulations/download

DE

0.25 all boilers
except cyclone
boilers; cyclone
boilers, 0.43

24 hour rolling
basis.

Title 7, Natural Resources and
Environmental Control, Section 1112,
Control of Nitrogen Oxide Emissions, at
Table 3-1:

httDs://regulations.delaware.gov/AdminCod
e/title7/l 000/1100/1112.shtml

NY

0.15-0.20

CEMS or 1-hour
average.

Same citation as shown in Table 3.

NJ

Distillate - 0.10
Other liq. - 0.20

If CEMs, daily
avg., otherwise,
periodic stack test

Title 7, New Jersey Administrative Code,

Chapter 27, Subchapter 19, Control and

Prohibition of Air Pollution from Oxides of

Nitrogen, available at:

http s ://www. ni. gov/dep/aq m / currentrul e s/S

ubl9.odf

3. Gas-fired industrial boilers

The proposed NOx emission limit for gas-fired boilers is 0.08 lbs/mmBtu on a 30-day
rolling average basis. As with fossil-fuel-fired boilers mentioned above, numerous combustion
and post-combustion NOx control technology exist that should enable most facilities to meet
these emission limits, and many examples exist of states that have already adopted emission
limits similar to EPA's proposed emissions limits. Table 2-3 of the ICI Boiler ACT indicates the
same control technologies suitable to application to oil-fired boilers are also likely to be effective

82 Rates shown for CT are applicable during the ozone season.

66


-------
at controlling NOx emissions from gas-fired industrial boilers. Some gas-fired industrial boilers
may have already installed combustion or post-combustion control equipment to meet the
emission limits contained within EPA's NSPS located at 40 CFR 60 Subpart Db, which requires
that gas-fired units meet a NOx emission limit of between 0.1 to 0.2 lbs/MMBtu depending on
heat release rate. The additional resources noted in the discussion of coal-fired industrial boilers
also contain useful information regarding effective NOx control equipment for gas-fired
industrial boilers.

Table 5 provides examples of NOx emission limits for gas-fired ICI boilers rated at 100
mmBTU/hr or greater that have been adopted by various states.

Table 5 - NOx emission limits, averaging times, and state citations for gas-fired ICI boilers

with design capacity of 1C

0 mmBTU/hr or greater:

State

Emission limit
(lbs/mmBTU)

Averaging time

State rule citation

CT83

0.10

Daily block
average for units
with CEMS, for
other units, as
developed during
stack testing.

Section 22a-174-22e of the Regulations of
Connecticut State Agencies, at paragraph
(d)(3)(C):

httDs://eregulations. ct.gov/eRegsPortal/Brows
e/RCSA/Title 22aSubtitle 22a-

174Section 22a-174-22e/

MA

0.06

One-hour, unless
equipped with
CEMS, then daily.

310 CMR 7.19, at paragraph (4)(b):
https://www.mass.gov/doc/310-cmr-700-air-

Dollution-control-regulations/download

DE

0.20

24 hour rolling
basis.

Title 7, Natural Resources and Environmental
Control, Section 1112, Control of Nitrogen
Oxide Emissions, at Table 3-1:
https://regulations.delaware.gOv/AdminCode/t
itle7/1000/l 100/1112. shtml

NY

0.08

CEMS or 1-hour
average.

Same as citation shown in Table 3.

NJ

0.10

If CEMS, daily
average;

otherwise, periodic
stack test.

Title 7, New Jersey Administrative Code,
Chapter 27, Subchapter 19, Control and
Prohibition of Air Pollution from Oxides of
Nitrogen, available at:

httD s: //www. ni. gov/deo/acim/currentrul e s/ Sub
19.pdf

4. Industrial boilers using other fuels

83 Rates shown for CT are applicable during the ozone season.

67


-------
Based on our review of available data, our expectation is that there will be less than 100
industrial boilers subject to these requirements, the majority of which will be powered by coal,
oil, or natural gas. However, there may be industrial boilers rated at 100 mmBtu/hr or greater
located at one of the indicated industries powered by other fuels such as wood or industrial
process gas. EPA solicits comment on whether EPA should establish emission limits for such
other types of fuels should as part of the final FIP.

I). What types of NOx controls are available to meet the proposed emission limits, and what
are the approximate costs per ton of NOx removed?

EPA believes that the NOx control technologies for industrial boilers mentioned above can be
retrofit to existing boilers, or incorporated into the design of new boilers, in a cost-effective
manner. Information developed for a prior air pollution transport rule referred to as the Cross
State Air Pollution Rule (CSAPR) include the following document: "Final Technical Support
Document (TSD) for the Cross State Air Pollution Rule for the 2008 Ozone NAAQS; Docket ID
No. EPA-HQ-OAR-2015-0500; Assessment ofNon-EGUNOx Emission Controls, Cost of
Controls, and Time for Compliance Final TSD" (hereafter "CSAPR Non-EGU TSD"). The
analysis contained within that report was obtained primarily from the Control Strategy Tool
(CoST), which is software that produces emission reduction and cost estimates for various non-
EGU control strategy options. A summary of the results from the CoST model are provided in
Table 3 of the CSAPR Non-EGU TSD, and a summary of the information applicable to
industrial boilers is provided in Table 6 below.

Table 6: CoST Results from the CSAPR Non-EGU TSD for Industrial Boilers

Non-EGU Source Group

Control Technology

Current Estimate of NOx



Recommended by CoST

$/ton, CoST (2011$)

Boilers and Process Heaters;

SCR

$2,235

External Combustion Boilers





Coal Boilers

SNCR

$2,413

ICI Boilers - Residual Oil

LNB & SNCR

$2,850

ICI Boilers

Low NOx Burners & SCR

$3,456

The information above indicates that there are cost effective NOx control options that can be
used on industrial boilers.

E. Compliance Assurance Requirements

Boilers subject to the requirements of this section of the proposed FIP should
demonstrate compliance in a manner similar to the emissions monitoring requirements found
within the NSPS for industrial, commercial, and institutional (ICI) boilers at 40 CFR Part 60
Subpart D, at section 60.46b. Those requirements include, among other provisions, the
performance of an initial compliance test and installation of a CEMS. The proposed FIP includes
a CEMS opt out requirement similar to that within 40 CFR Part 60 Subpart D, Standards of
Performance for Fossil-Fuel-Fired Steam Generators, for sources whose initial compliance test
indicates the unit emits at 70% or less of the applicable standard.

68


-------
EPA is proposing to require that the initial compliance test be conducted no later than 90
days after the installation of control applied to meet the proposed emission standards, and
performed as described under 40 CFR Part 60.8 using the continuous system for monitoring NOx
specified by EPA Test Method 7E - Determination of Nitrogen Oxide Emissions from Stationary
Sources (Instrumental Analyzer Procedure), as described at 40 CFR Part 60, Appendix A-4. EPA
is also proposing to require that, in lieu of the timing of the compliance test described under 40
CFR § 60.8(a), the test shall be conducted within 90 days from the installation of the pollution
control equipment used to comply with the NOx emission limits of this section.

Table 7 - Excerpt from Menu of Control Measures Applicable to Industrial Boilers

Source Category

Emission

Reduction

Measure

Control
Efficiency
(%)

Description/Notes/Caveats

References

Industrial/
Commercial/
Institutional
Boilers - Coal

Selective
Catalytic
Reduction

80

This control is the selective catalytic
reduction of NOx through add-on
controls. SCR controls are post-
combustion control technologies based
on the chemical reduction of nitrogen
oxides (NOx) into molecular nitrogen
(N2) and water vapor (H20). The SCR
utilizes a catalyst to increase the NOx
removal efficiency, which allows the
process to occur at lower temperatures.
This control applies to coal ICI boilers
with NOx emissions greater than 10
tons per year.

EPA 2003b,
EPA 1998e

Industrial/
Commercial/
Institutional
Boilers - Coal

Selective
Non-
Catalytic
Reduction

40

This control is the reduction of NOx
emission through selective non-
catalytic reduction add-on controls.
SNCR controls are post-combustion
control technologies based on the
chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2)
and water vapor (H20). This control
applies to coal ICI boilers with
uncontrolled NOx emissions greater
than 10 tons per year.

EPA 2003b,
Pechan 2006

Industrial/
Commercial/
Institutional
Boilers - Coal or
Petroleum Coke

Low NOx
Burner

50

This control is the use of low NOx
burner (LNB) technology to reduce
NOx emissions. LNBs reduce the
amount of NOx created from reaction
between fuel nitrogen and oxygen by
lowering the temperature of one
combustion zone and reducing the

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994g,
OTC/LADCO
2010

69


-------






amount of oxygen available in another.
This control is applicable to coal/wall
fired ICI boilers and Petroleum coke
fired ICI boilers with uncontrolled
NOx emissions greater than 10 tons per
year. Cost estimates are from the OTC
/ LADCO Workgroup (OTC / LADCO
Control Cost Subgroup), for a single
burner (for a 66% capacity factor at
8760 hours/year), and are based on a
methodology similar to EPA's
methodology provided in EPA
document "Alternative Control
Techniques Document - NOx
Emissions from

Industrial/Commercial/Institutional
(ICI) Boilers".



Industrial/
Commercial/
Institutional
Boilers - Coal or
Petroleum Coke -
Wall Fired

Selective
Non-
Catalytic
Reduction

40

This control is the reduction of NOx
emission through selective non-
catalytic reduction add-on controls to
wall fired (coal) IC boilers. SNCR
controls are post-combustion control
technologies based on the chemical
reduction of nitrogen oxides (NOx)
into molecular nitrogen (N2) and water
vapor (H20). This control applies to
coal-fired and petroleum coke-fired IC
boilers with uncontrolled NOx
emissions greater than 10 tons per
year. Cost estimates are from the OTC
/ LADCO Workgroup (OTC / LADCO
Control Cost Subgroup), for a single
burner (for a 66% capacity factor at
8760 hours/year), and are based on a
methodology similar to EPA's
methodology provided in EPA
document "Alternative Control
Techniques Document - NOx
Emissions from

Industrial/Commercial/Institutional
(ICI) Boilers".

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994g,
OTC/LADCO
2010

Industrial/
Commercial/
Institutional
Boilers - Coal/
Bituminous

Low NOx
Burner and
Over Fire
Air

51

This control is the use of low NOx
burner (LNB) technology and Over
Fire Air (OF A) to reduce NOx
emissions. LNBs reduce the amount of
NOx created from reaction between

EPA 2003b,
Pechan 2006

70


-------






fuel nitrogen and oxygen by lowering
the temperature of one combustion
zone and reducing the amount of
oxygen available in another. This
control applies to bituminous coal
Industrial/Commercial/Institutional
(ICI) boilers.



Industrial/
Commercial/
Institutional
Boilers - Coal/
Subbituminous

Low NOx
Burner

51

This control is the use of low NOx
burner (LNB) technology to reduce
NOx emissions. LNBs reduce the
amount of NOx created from reaction
between fuel nitrogen and oxygen by
lowering the temperature of one
combustion zone and reducing the
amount of oxygen available in another.
This control is applicable to
subbituminous coal
industrial/commercial/institutional
boilers. Cost estimates are from the
OTC / LADCO Workgroup (OTC /
LADCO Control Cost Subgroup), for a
single burner (for a 66% capacity
factor at 8760 hours/year), and are
based on a methodology similar to
EPA's methodology provided in EPA
document "Alternative Control
Techniques Document - NOx
Emissions from

Industrial/Commercial/Institutional
(ICI) Boilers".

EPA 2003b,
Pechan 2006,
OTC/LADCO
2010

Industrial/
Commercial/
Institutional
Boilers - Coal/
Cyclone

Coal Reburn

50

This control reduces NOx emissions
through coal reburn. This control is
applicable to coal/cyclone ICI boilers.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 1994g,
Cadmus 1995

Industrial/
Commercial/
Institutional
Boilers - Coal/
Cyclone

Natural Gas
Reburn

55

Natural gas reburning (NGR) involves
add-on controls to reduce NOx
emissions. NGR is a combustion
control technology in which part of the
main fuel heat input is diverted to
locations above the main burners,
called the reburn zone. As flue gas
passes through the reburn zone, a
portion of the NOx formed in the main
combustion zone is reduced by
hydrocarbon radicals and converted to

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
ERG 2000,
EPA 1994g

71


-------






molecular nitrogen (N2). This control
applies to coal/cyclone ICI boilers with
uncontrolled NOx emissions greater
than 10 tons per year.



Industrial/
Commercial/
Institutional
Boilers - Coal/
Cyclone

Selective
Catalytic
Reduction

90

This control is the selective catalytic
reduction of NOx through add-on
controls. SCR controls are post-
combustion control technologies based
on the chemical reduction of nitrogen
oxides (NOx) into molecular nitrogen
(N2) and water vapor (H20). The SCR
utilizes a catalyst to increase the NOx
removal efficiency, which allows the
process to occur at lower temperatures.
This control applies to coal/cyclone
ICI boilers with nameplate capacity
greater than 25 MW (250 mmBTU/hr).

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994g,
EPA 2010a

Industrial/
Commercial/
Institutional
Boilers - Coal/
Cyclone

Selective
Non-
Catalytic
Reduction

35

This control is the reduction of NOx
emission through selective non-
catalytic reduction add-on controls.
SNCR controls are post-combustion
control technologies based on the
chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2)
and water vapor (H20). This control
applies to coal/cyclone IC boilers with
uncontrolled NOx emissions greater
than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994g

Industrial/
Commercial/
Institutional
Boilers - Coal/
Fluidized Bed
Combustion

Selective
Catalytic
Reduction

90

This control is the selective catalytic
reduction of NOx through add-on
controls. SCR controls are post-
combustion control technologies based
on the chemical reduction of nitrogen
oxides (NOx) into molecular nitrogen
(N2) and water vapor (H20). The SCR
utilizes a catalyst to increase the NOx
removal efficiency, which allows the
process to occur at lower temperatures.
This control applies to fluidized bed
combustion coal ICI boilers.

EPA 2007b

Industrial/
Commercial/
Institutional
Boilers - Coal/
Fluidized Bed
Combustion

Selective
Non-
Catalytic
Reduction -
Urea

75

This control is the reduction of NOx
emission through urea based selective
non-catalytic reduction add-on
controls. SNCR controls are post-
combustion control technologies based
on the chemical reduction of nitrogen

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994g

72


-------






oxides (NOx) into molecular nitrogen
(N2) and water vapor (H20). This
control applies to coal-fired/fluidized
bed combustion IC boilers with
uncontrolled NOx emissions greater
than 10 tons per year.



Industrial/
Commercial/
Institutional
Boilers - Coal/
Stoker

Selective
Catalytic
Reduction

90

This control is the selective catalytic
reduction of NOx through add-on
controls. SCR controls are post-
combustion control technologies based
on the chemical reduction of nitrogen
oxides (NOx) into molecular nitrogen
(N2) and water vapor (H20). The SCR
utilizes a catalyst to increase the NOx
removal efficiency, which allows the
process to occur at lower temperatures.
This control applies to coal/stoker IC
boilers with uncontrolled NOx
emissions greater than 10 tons per
year.

EPA 2007b

Industrial/
Commercial/
Institutional
Boilers - Coal/
Stoker

Selective
Non-
Catalytic
Reduction

40

This control is the reduction of NOx
emission through selective non-
catalytic reduction add-on controls to
coal/stoker IC boilers. SNCR controls
are post-combustion control
technologies based on the chemical
reduction of nitrogen oxides (NOx)
into molecular nitrogen (N2) and water
vapor (H20). This control applies to
coal/stoker IC boilers with
uncontrolled NOx emissions greater
than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994g

Industrial/
Commercial/
Institutional
Boilers - Coal/
Subbituminous

Low NOx
Burner and
Over Fire
Air

65

This control is the use of low NOx
burner (LNB) technology and Over
Fire Air (OF A) to reduce NOx
emissions. LNBs reduce the amount of
NOx created from reaction between
fuel nitrogen and oxygen by lowering
the temperature of one combustion
zone and reducing the amount of
oxygen available in another. This
control applies to subbituminous coal
Industrial/Commercial/Institutional
(ICI) boilers.

EPA 2003b,
Pechan 2006

73


-------
Industrial/
Commercial/
Institutional
Boilers - Coal/
Wall

Selective
Catalytic
Reduction

90

This control is the selective catalytic
reduction of NOx through add-on
controls. SCR controls are post-
combustion control technologies based
on the chemical reduction of nitrogen
oxides (NOx) into molecular nitrogen
(N2) and water vapor (H20). The SCR
utilizes a catalyst to increase the NOx
removal efficiency, which allows the
process to occur at lower temperatures.
This control applies to coal/wall IC
boilers with nameplate capacity greater
than 25 MW.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994g,
EPA 2010a

Industrial/
Commercial/
Institutional
Boilers -
Distillate Oil

Selective
Catalytic
Reduction

80

This control is the selective catalytic
reduction of NOx through add-on
controls. SCR controls are post-
combustion control technologies based
on the chemical reduction of nitrogen
oxides (NOx) into molecular nitrogen
(N2) and water vapor (H20). The SCR
utilizes a catalyst to increase the NOx
removal efficiency, which allows the
process to occur at lower temperatures.
This control applies to distillate oil-
fired ICI boilers with nameplate
capacity greater than 25 MW.

EPA 2006b,
EPA 1998e,
EPA 2002a,
EPA 2007d,
Sorrels 2007,
EPA 2010a

Industrial/
Commercial/
Institutional
Boilers -
Distillate Oil or
LPG

Low NOx
Burner

50

This control is the use of low NOx
burner (LNB) technology to reduce
NOx emissions. LNBs reduce the
amount of NOx created from reaction
between fuel nitrogen and oxygen by
lowering the temperature of one
combustion zone and reducing the
amount of oxygen available in another.
This control is applicable to Oil and
LPG ICI boilers with uncontrolled
NOx emissions greater than 10 tons per
year. Cost estimates are from the OTC
/ LADCO Workgroup (OTC / LADCO
Control Cost Subgroup), for a single
burner (for a 66% capacity factor at
8760 hours/year), and are based on a
methodology similar to EPA's
methodology provided in EPA
document "Alternative Control
Techniques Document - NOx

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994g,
OTC/LADCO
2010

74


-------






Emissions from

Industrial/Commercial/Institutional

(ICI) Boilers".



Industrial/
Commercial/
Institutional
Boilers -
Distillate Oil or
LPG

Low NOx
Burner and
Flue Gas
Recirculation

60

This control is the use of low NOx
burner (LNB) technology and flue gas
recirculation (FGR) to reduce NOx
emissions. LNBs reduce the amount of
NOx created from reaction between
fuel nitrogen and oxygen by lowering
the temperature of one combustion
zone and reducing the amount of
oxygen available in another. This
control is applicable to distillate oil-
fired ICI boilers and LPG-fired ICI
Boilers with uncontrolled NOx
emissions greater than 10 tons per
year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1993 c

Industrial/
Commercial/
Institutional
Boilers -
Distillate Oil or
LPG

Selective
Non-
Catalytic
Reduction

50

This control is the reduction of NOx
emission through selective non-
catalytic reduction add-on controls.
SNCR controls are post-combustion
control technologies based on the
chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2)
and water vapor (H20). This control
applies to distillate oil and LPG-fired
IC boilers with uncontrolled NOx
emissions greater than 10 tons per
year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994g

Industrial/
Commercial/
Institutional
Boilers - Gas

Low NOx
Burner and
Flue Gas
Recirculation
+ Over Fire
Air

80

This control is the use of low NOx
burner (LNB) technology, flue gas
recirculation (FGR), and over fire air
(OFA) to reduce NOx emissions.
LNBs reduce the amount of NOx
created from reaction between fuel
nitrogen and oxygen by lowering the
temperature of one combustion zone
and reducing the amount of oxygen
available in another. This control
applies to gas

Industrial/Commercial/Institutional
(ICI) boilers.

EPA 2003b,
EPA 1998e

Industrial/
Commercial/
Institutional
Boilers - Gas

Low NOx
Burner and
Over Fire
Air

60

This control is the use of low NOx
burner (LNB) technology and Over
Fire Air (OF A) to reduce NOx
emissions. LNBs reduce the amount of

EPA 2003b,
Pechan 2006

75


-------






NOx created from reaction between
fuel nitrogen and oxygen by lowering
the temperature of one combustion
zone and reducing the amount of
oxygen available in another. This
control applies to gas
Industrial/Commercial/Institutional
(ICI) boilers.



Industrial/
Commercial/
Institutional
Boilers - Gas

Selective
Catalytic
Reduction

80

This control is the selective catalytic
reduction of NOx through add-on
controls. SCR controls are post-
combustion control technologies based
on the chemical reduction of nitrogen
oxides (NOx) into molecular nitrogen
(N2) and water vapor (H20). The SCR
utilizes a catalyst to increase the NOx
removal efficiency, which allows the
process to occur at lower temperatures.
This control applies to gas-fired ICI
boilers with uncontrolled NOx
emissions greater than 10 tons per
year.

EPA 2003b,
EPA 1998e

Industrial/
Commercial/
Institutional
Boilers - Gas

Selective
Non-
Catalytic
Reduction

40

This control is the reduction of NOx
emission through selective non-
catalytic reduction add-on controls.
SNCR controls are post-combustion
control technologies based on the
chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2)
and water vapor (H20). This control
applies to natural gas fired IC boilers
with uncontrolled NOx emissions
greater than 10 tons per year.

EPA 2003b,
Pechan 2006

Industrial/
Commercial/
Institutional
Boilers - Natural
Gas

Selective
Non-
Catalytic
Reduction

50

This control is the reduction of NOx
emission through selective non-
catalytic reduction add-on controls.
SNCR controls are post-combustion
control technologies based on the
chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2)
and water vapor (H20). This control
applies to natural gas fired IC boilers
with uncontrolled NOx emissions
greater than 10 tons per year.

EPA 2006b

Industrial/
Commercial/

Low NOx
Burner

50

This control is the use of low NOx
burner (LNB) technology to reduce

EPA 2006b,
Pechan 2001,

76


-------
Institutional
Boilers - Natural
Gas or Process
Gas





NOx emissions. LNBs reduce the
amount of NOx created from reaction
between fuel nitrogen and oxygen by
lowering the temperature of one
combustion zone and reducing the
amount of oxygen available in another.
This control is applicable to natural gas
and process gas fired ICI boilers with
uncontrolled NOx emissions greater
than 10 tons per year. Cost estimates
are from the OTC / LADCO
Workgroup (OTC / LADCO Control
Cost Subgroup), for a single burner
(for a 66% capacity factor at 8760
hours/year), and are based on a
methodology similar to EPA's
methodology provided in EPA
document "Alternative Control
Techniques Document - NOx
Emissions from

Industrial/Commercial/Institutional
(ICI) Boilers".

EPA 1998e,
EPA 2002a,
EPA 1994g,
OTC/LADCO
2010

Industrial/
Commercial/
Institutional
Boilers - Natural
Gas or Process
Gas

Low NOx
Burner and
Flue Gas
Recirculation

60

This control is the use of low NOx
burner (LNB) technology and flue gas
recirculation (FGR) to reduce NOx
emissions. LNBs reduce the amount of
NOx created from reaction between
fuel nitrogen and oxygen by lowering
the temperature of one combustion
zone and reducing the amount of
oxygen available in another. This
control is applicable to natural gas-
fired and process gas-fired ICI boilers
with uncontrolled NOx emissions
greater than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1993 c

Industrial/
Commercial/
Institutional
Boilers - Natural
Gas or Process
Gas

Oxygen
Trim and
Water
Injection

65

This control is the use of Oxygen Trim
and Water Injection to reduce NOx
emissions. Water is injected into the
gas turbine, reducing the temperatures
in the NOx-forming regions. The water
can be injected into the fuel, the
combustion air or directly into the
combustion chamber. This control
applies to natural gas-fired and process
gas-fired ICI boilers with uncontrolled

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
ERG 2000,
EPA 1994g

77


-------






NOx emissions greater than 10 tons per
year.



Industrial/
Commercial/
Institutional
Boilers - Natural
Gas or Process
Gas

Selective
Catalytic
Reduction

80

This control is the selective catalytic
reduction of NOx through add-on
controls. SCR controls are post-
combustion control technologies based
on the chemical reduction of nitrogen
oxides (NOx) into molecular nitrogen
(N2) and water vapor (H20). The SCR
utilizes a catalyst to increase the NOx
removal efficiency, which allows the
process to occur at lower temperatures.
This control applies to natural gas fired
and process gas-fired ICI boilers
nameplate capacity greater than 25
MW.

EPA 2006b,
EPA 1998e,
EPA 2002a,
EPA 2007d,
Sorrels 2007,
EPA 2010a

Industrial/
Commercial/
Institutional
Boilers - Oil

Low NOx
Burner and
Over Fire
Air

50

This control is the use of low NOx
burner (LNB) technology and Over
Fire Air (OF A) to reduce NOx
emissions. LNBs reduce the amount of
NOx created from reaction between
fuel nitrogen and oxygen by lowering
the temperature of one combustion
zone and reducing the amount of
oxygen available in another. This
control applies to oil
Industrial/Commercial/Institutional
(ICI) boilers.

EPA 2003b,
Pechan 2006

Industrial/
Commercial/
Institutional
Boilers - Oil

Selective
Catalytic
Reduction

80

This control is the selective catalytic
reduction of NOx through add-on
controls. SCR controls are post-
combustion control technologies based
on the chemical reduction of nitrogen
oxides (NOx) into molecular nitrogen
(N2) and water vapor (H20). The SCR
utilizes a catalyst to increase the NOx
removal efficiency, which allows the
process to occur at lower temperatures.
This control applies to oil-fired ICI
boilers with uncontrolled NOx
emissions greater than 10 tons per
year.

EPA 2003b,
EPA 1998e

Industrial/
Commercial/
Institutional
Boilers - Oil

Selective
Non-
Catalytic
Reduction

40

This control is the reduction of NOx
emission through selective non-
catalytic reduction add-on controls.
SNCR controls are post-combustion

EPA 2003b,
Pechan 2006

78


-------






control technologies based on the
chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2)
and water vapor (H20). This control
applies to oil IC boilers with
uncontrolled NOx emissions greater
than 10 tons per year.



Industrial/
Commercial/
Institutional
Boilers - Residual
Oil or Liquid
Waste

Low NOx
Burner

50

This control is the use of low NOx
burner (LNB) technology to reduce
NOx emissions. LNBs reduce the
amount of NOx created from reaction
between fuel nitrogen and oxygen by
lowering the temperature of one
combustion zone and reducing the
amount of oxygen available in another.
This control is applicable to residual
oil-fired ICI boilers and liquid waste
fired ICI boilers with uncontrolled
NOx emissions greater than 10 tons per
year. Cost estimates are from the OTC
/ LADCO Workgroup (OTC / LADCO
Control Cost Subgroup), for a single
burner (for a 66% capacity factor at
8760 hours/year), and are based on a
methodology similar to EPA's
methodology provided in EPA
document "Alternative Control
Techniques Document - NOx
Emissions from

Industrial/Commercial/Institutional
(ICI) Boilers".

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1994g,
OTC/LADCO
2010

Industrial/
Commercial/
Institutional
Boilers - Residual
Oil or Liquid
Waste

Low NOx
Burner and
Flue Gas
Recirculation

60

This control is the use of low NOx
burner (LNB) technology and flue gas
recirculation (FGR) to reduce NOx
emissions. LNBs reduce the amount of
NOx created from reaction between
fuel nitrogen and oxygen by lowering
the temperature of one combustion
zone and reducing the amount of
oxygen available in another. This
control is applicable to residual oil-
fired and liquid waste-fired ICI boilers
with uncontrolled NOx emissions
greater than 10 tons per year.

EPA 2006b,
Pechan 2001,
EPA 1998e,
EPA 2002a,
EPA 1993 c

Industrial/
Commercial/

Selective
Non-

50

This control is the reduction of NOx
emission through selective non-

EPA 2006b,
Pechan 2001,

79


-------
Institutional
Boilers - Residual
Oil or Liquid
Waste

Catalytic
Reduction



catalytic reduction add-on controls.
SNCR controls are post-combustion
control technologies based on the
chemical reduction of nitrogen oxides
(NOx) into molecular nitrogen (N2)
and water vapor (H20). This control
applies to residual oil and liquid waste-
fired IC boilers with uncontrolled NOx
emissions greater than 10 tons per
year.

EPA 1998e,
EPA 2002a,
EPA 1994g

The information in the table above is an excerpt from EPA's Menu of Control Measures.

80


-------
7 Municipal Waste Combustors

MWCs emit substantial amounts of NOx, and some states have required emission limits
for these facilities that are more stringent than the federal requirements contained within EPA's
NSPS for this industry. These more stringent limits, if implemented within the final FIP, would
create an additional means of reducing NOx emissions across many of the states affected by the
FIP. EPA has received comments in past transport rulemakings that emission reductions should
be sought from MWCs, as noted within the RCU proposed rule (85 FR 68993). While EPA is not
currently proposing any emission limits for MWCs, EPA is soliciting comment on whether the
final FIP should establish NOx emissions limits for new and existing MWCs located in the states
affected by the proposed FIP.

Summary ofMWC Industry and Emissions

MWCs burn garbage and other non-hazardous solid material using a variety of
combustion techniques. Section 2.1, Refuse Combustion, of EPA emission factor reference
document AP-42 contains a description of the seven different combustion process technologies
most commonly used in the industry. These seven combustion processes are as follows: Mass
burn waterwall, mass burn rotary waterwall, mass burn refractory wall, refuse-derived fuel-fired,
fluidized bed, modular starved air, and modular excess air. Section 2.1 of AP-42 contains
detailed process descriptions of each of these MWC processes. During the combustion process, a
number of pollutants are produced, including NOx, which forms through oxidation of nitrogen in
the waste and from fixation of nitrogen in the air used to burn the waste. NOx emissions from
MWCs are typically released through tall stacks which enables the emissions to be transported
long distances.

Most MWCs are co-generation facilities in that they recover heat from the combustion
process to power a turbine to produce electricity. According to a 2018 report from the Energy
Recovery Council,84 72 of the 75 operating MWC facilities in the U.S. produce electricity from
heat captured from the combustion process. The electrical output of MWCs is relatively small
compared to the EGUs that will be regulated per the requirements of the proposed FIP, with most
MWCs having an electrical output capacity of less than 25 MW. Appendix 1 of this TSD
contains a Microsoft Excel spreadsheet listing all of the MWC units in the U.S. and includes
each unit's electrical output capacity as reflected in EPA's most recent version of the NEEDS
database (June 2021). All MWCs in the states included in the proposed FIP have an electrical
output capacity of less than 25 MW. The average electrical output capacity is 12.8 MW.

NOx emissions from MWCs located in the transport states identified in this proposal are
substantial. According to EPA's National Emission Inventory (NEI) database, in 201785 20,344
tons of NOx were emitted from MWCs in the ten transport states containing them. Table 8
contains a list ofMWC facilities located within a transport state along with their NOx emissions
as reported to the 2017 NEI. Data reported to the 2017 NEI indicates that NOx emissions from

84	"2018 Directory of Waste to Energy Facilities"; Energy Recovery Council.

85	Emissions data for Indiana's Covanta facility located in Indianapolis was taken from the 2019 NEI because
emissions for that facility were not reported to EPA by the state for that year. Data for all other facilities was taken
from the 2017 NEI.

81


-------
29 MWC facilities located in non-transport states (states not affected by the proposed FIP)
equaled 17,968 tons in 2017.

Table 8: NOx Emissions from MWC Facilities Located in States Affected by Proposed FIP

Units = Tons/Year for 2017

STATE

FACILITY

CITY

EMISSIONS

CA

COVANTA STANISLAUS, INC

CROWS
LANDING

290.1

CA

LONG BEACH CITY, SERRF PROJECT

LONG BEACH

268.7

CA

COMMERCE REFUSE TO ENERGY
FACILITY

COMMERCE

95.7

IN

COVANTA INDIANAPOLIS INC

INDIANAPOLIS

1,122.0

MD

Wheelabrator Baltimore, LP

Baltimore

1,101.2

MD

Montgomery County RRF

Dickerson

441.7

MI

DETROIT RENEWABLE POWER, LLC

DETROIT

1,212.4

MI

Kent County Waste to Energy Facility

GRAND RAPIDS

342.0

MN

Xcel Energy - Red Wing Generating Plant

Red Wing

593.3

MN

Xcel Energy - Key City/Wilmarth

Mankato

498.4

MN

Hennepin Energy Recovery Center

Minneapolis

411.7

MN

Great River Energy

Elk River

391.7

MN

Olmsted Waste-to-Energy Facility

Rochester

140.7

MN

Pope/Douglas Solid Waste Management

Alexandria

138.2

MN

Perham Resource Recovery Facility

Perham

74.3

MN

Polk County Solid Waste Facility

Fosston

31.4

NJ

Covanta Essex Company

NEWARK

762.7

NJ

Union County Resource Recovery Facility

RAHWAY

613.3

NJ

Camden County Energy Recovery
Associates L.P.

CAMDEN

375.8

NJ

WHEELABRATOR GLOUCESTER
COMPANY L P

WESTVILLE

240.3

NJ

Covanta Warren Energy Resource Co. L.P.

OXFORD

170.0

NY

HEMPSTEAD RESOURCE RECOVERY
FACILITY

WESTBURY

1,111.0

NY

WHEELABRATOR WESTCHESTER LP

PEEKSKILL

1,046.7

NY

COVANTA NIAGARA LP

NIAGARA FALLS

748.2

NY

ONONDAGA CO RESOURCE
RECOVERY FACILITY

JAMESVILLE

541.0

NY

HUNTINGTON RESOURCE RECOVERY
FACILITY

E NORTHPORT

357.3

NY

WHEELABRATOR HUDSON FALLS

HUDSON FALLS

237.6

NY

BABYLON RESOURCE RECOVERY
FACILITY

WEST BABYLON

183.7

NY

ISLIP MCARTHUR RESOURCE
RECOVERY FACIL

RONKONKOMA

157.4

82


-------
NY

DUTCHESS CO RESOURCE
RECOVERY FACILITY

POUGHKEEPSIE

148.5

NY

OSWEGO CO ENERGY RECOVERY
FAC

FULTON

148.0

OK

WALTER B HALL RESOURCE
RECOVERY FACLTY

TULSA

518.5

PA

COVANTA DELAWARE VALLEY
LP/DELAWARE VALLEY RES REC

CHESTER

1,236.6

PA

WHEELABRATOR FALLS INC/FALLS
TWP

MORRIS VILLE

688.1

PA

COVANTA PLYMOUTH RENEWABLE
ENERGY/ PLYMOUTH

CONSHOHOCKEN

660.5

PA

LANCASTER CNTY RRF/ LANCASTER

BAINBRIDGE

517.1

PA

YORK CNTY SOLID WASTE/YORK
CNTY RESOURCE RECOVERY

YORK

449.0

PA

LANCASTER CNTY SWMA/SUSQ
RESOURCE MGMT COMPLEX

HARRISBURG

196.3

PA

SCRANTON ARMY AMMUNITION
PLT/SCRANTON CITY

SCRANTON

11.4

VA

Wheelabrator Portsmouth Inc, RDF Facility

Portsmouth

1,324.5

VA

Covanta Alexandria/Arlington Inc

Alexandria

461.5

VA

Covanta Fairfax Inc

Lorton

174.2

VA

Hampton/NASA Steam Plant

Hampton

111.5





Total

20,344.1

Summary of Federal NSPS and Emission Guideline NOx limits.

EPA has promulgated NOx emission limits for large MWCs, defined as those that
process 250 tons of municipal solid waste per day or more at 40 CFR Part 60, Subpart Cb and 40
CFR Part 60, Subpart Eb. Subpart Cb is applicable to MWCs that commenced construction on or
before September 20, 1994, while Subpart Eb is applicable to MWCs that commenced
construction, modification, or reconstruction after September 20, 1994. The NOx limits for
Subpart Cb are found within Tables 1 and 2 of 40 CFR 60.39b and range from 165 to 250 ppm
depending on the combustor design type. The NOx limits for Subpart Eb are found at 40 CFR
60.52b(d) and are 180 ppm during a unit's first year of operation and drop to 150 ppm
afterwards, applicable across all combustor types.

NOx limits adopted by states for MWCs.

Section 182(b)(2) and (f) of the CAA requires states containing moderate or above ozone
nonattainment areas to adopt regulations with control requirements representing reasonably
available control technology (RACT) for major sources of volatile organic compounds (VOCs)
and NOx, and sections 184(b)(1)(B) and 182(f) of the Act require RACT control requirements be
adopted in all areas included within an Ozone Transport Region (OTR). Due primarily to the
NOx RACT requirement, many states within the Northeast located within the OTR have adopted

83


-------
NOx emission limits for MWCs that are more stringent than what would otherwise be required
by EPA's NSPS or emissions guideline for these units. For example, the Montgomery County
Resource Recovery Facility in Maryland is required to meet a NOx RACT limit of 140 ppm (@
7% oxygen) on a 24-hour block average. Additionally, MWC facilities located in Virginia
operated by Covanta, Inc., are required to meet a NOx RACT limit of 110 ppm (@ 7% oxygen)
on a 24-hour basis, and a limit of 90 ppm (@ 7% oxygen) on an annual average basis.86

Emissions and control options outlined within a June 2021 report from the OTC

The OTC issued a report entitled "Municipal Waste Combustor Workgroup Report" in
June of 2021. The report is included within the Docket for this proposal. The report notes that
MWCs are a significant source of NOx emissions in the OTR, releasing approximately 22,000
tons of NOx from facilities within 9 OTR states in 2018. The report summarizes the results of a
literature review of state-of-the-art NOx controls that have been successfully installed on MWCs
and concludes that significant reductions could be achieved using several different technologies
described in the report, primarily via combustion modifications made to MWC units already
equipped with SNCR. The MWC workgroup evaluated the emission reduction potential from
two different control levels, one based on a NOx concentration in the effluent of 105 to 110 ppm,
and another based on a limit of 130 ppm. The workgroup's findings were that a control level of
105 ppmvd on a 30-day average basis and a 110 ppmvd on a 24-hour averaging period would
reduce NOx emissions from MWCs by approximately 7,300 tons annually, and that a limit of
130 ppmvd on a 30 day-average could achieve a 4,000 tons reduction. The report notes that 8
MWC units exist that are already subject to permit limits of 110 ppm, 7 in Virginia, and one in
Florida. Studies evaluating MWCs similar in design to the large MWCs in the OTR found NOx
reductions could be achieved at costs ranging from $2,900 to $6,600 per ton of NOx reduced.
Based on the findings of this report, the Commissioners of the states within the OTR adopted a
resolution to develop a recommendation for emission reductions from MWCs during their June
15, 2021 annual public meeting.87

The OTC's MWC workgroup report describes a literature review to identify additional
control technologies to reduce NOx emissions from large MWCs. Based on that review, two
control technologies emerged as potentially technically and economically feasible options to
achieve the control levels of 105 ppm on a 30-day average basis and a 110 ppm on a 24-hour
averaging period: Covanta's "Low-NOx (LN™) technology" and advanced selective non-
catalytic reduction (ASNCR).

Covanta's LN™ Process

Covanta's LN™ process is a trademarked system which modifies the secondary air (also
called overfire air) stream. To complete the combustion process in the MWC furnace, the
secondary air is injected through nozzles located in the furnace side walls above the grate to
allow turbulent mixing. With the LN™ process, a tertiary air stream is introduced by diverting a

86	The NOx permit limits for the Montgomery County facility and the Virginia facilities can be found within the
OTC's Municipal Waste Combustor Workgroup Report included within the Docket for this action.

87	See "Notice of Actions Taken by Ozone Transport Commission At Annual Public Meeting, June 15, 2021"
included in the Docket for this action.

84


-------
portion of secondary air through a new series of air nozzles located higher in the furnace. By
controlling the distribution of air between the primary, secondary, and tertiary streams, the
optimal gas composition and temperature is achieved to minimize NOx formation. With
complete coverage of the furnace cross-section, the tertiary air stream ensures good mixing with
the combustion gases. During the LN™ process, only the distribution of air is altered. The total
air flow to the MWC is left unchanged.

Approximately 20 units have installed or been retrofitted with the LN™ process,
including the two Covanta facilities located in Virginia. However, since the LN™ technology is
proprietary, it is available only to Covanta facilities.

Advanced Selective Non-Catalytic Reduction (ASNCR)

The OTC's MWC report describes a report conducted by Babcock Power for the
Wheelabrator Baltimore facility that evaluated several potential NOx control technologies,
including ASNCR. ASNCR, like SNCR, involves the injection of reagents (typically ammonia or
urea) into the proper temperature zone of the furnace to reduce the NOx concentration within the
flue gas. ASNCR also utilizes Computational Fluid Dynamics (CFD) modeling and Chemical
Kinetic Modeling (CKM) technology along with real-time furnace temperature maps to modulate
which injectors are in operation and the reagent flow rates. This not only significantly decreases
NOx emissions but ensures a low ammonia slip (around 5 ppm). ASNCR is currently being
installed at Wheelabrator Baltimore and is available to non-Covanta facilities. In addition to the
two NOx control technologies described above, the Babcock report also reviewed other NOx
control options including optimized SNCR, flue gas recirculation SNCR (FGR-SNCR), and
FGR-ASNCR.

OTC Report's Evaluation of Control Costs

The OTC's MWC report also evaluated the cost for the installation and operation of the
control technologies. The cost effectiveness for LN™ technology were based off of two RACT
analyses by Trinity Consultants for the Covanta Alexandria/Arlington and Covanta Fairfax
facilities in Virginia. These reports assessed the total capital investment expenditures for the
LN™ technology, which includes direct cost (purchasing the equipment) and indirect costs
(installation and lost production resulting from extended downtime due to installation). The costs
from the installation of the LN™ technology at the Covanta facility in Montgomery County, MD
were used to estimate the costs for Covanta Alexandria/Arlington and Covanta Fairfax. Capital
cost were annualized, based on projected lifetime of 20 years and a 7% interest rate, and added to
the annual operating cost to determine the total yearly costs.88

Although the Trinity Consultants reports assumed a controlled NOx value of 90 ppm (the
new annual NOx limit at the two Virginia facilities), the OTC's MWC workgroup estimated the
cost reduction for a 110 ppm 24-hour limit. This was done because the amount of reagent used
and operations and maintenance costs are likely to be higher to achieve a 90 ppm limit, as
compared to a 110 ppm 24-hour limit. This resulted in a price decrease of $0.89 per pound of

88 We note that the OTC white paper did not provide a year dollars for the total yearly costs, nor for the cost per
NOx reduced estimates quoted from the white paper.

85


-------
NOx reduced, per information contained in the Babcock report for the Wheelabrator Baltimore
facility.

The OTC's MWC workgroup then calculated the projected NOx emission reduction
based on a 110 ppm limit. To determine the cost effectiveness, the total yearly costs were divided
by the NOx emission reduction. Overall, the 110 ppm 24-hour NOx limit cost effectiveness for
LN™ technology ranged from $2,900 to $4,639 per ton of NOx reduced.

The OTC's MWC report also evaluated the cost effectiveness of ASNCR to control NOx
emissions at MWCs. Cost effectiveness calculations for ASNCR were based off the Babcock
report. To evaluate the annualized capital cost, the workgroup utilized a formula from EPA Air
Pollution Control Cost Manual and its Chapter 2 - Cost Estimation: Concepts and Methodology
(US EPA, 2017). Like the Trinity Consultants RACT analyses, a projected lifetime of 20 years
and a 7% interest rate were assumed to estimate the annualized capital cost. Also, as with the
LN™ technology, the NOx emission reduction for ASNCR was based on a 110 ppm 24-hour
limit. For ASNCR, the 110 ppm 24-hour NOx limit cost effectiveness was $6,159 per ton of
NOx reduced.

86


-------
8 Feasibility and Installation Timing

EPA proposes to require that the non-EGU controls discussed in this TSD be installed
and operational by the 2026 ozone season and to find that any earlier date is not possible. EPA
previously examined the time necessary to install the controls identified for several non-EGU
industries. Although the information on installation times for most NOx controls applied to glass
and cement manufacturing was uncertain, EPA identified minimum estimated installation times
for a number of other non-EGU source categories that ranged from several weeks to slightly over
a year. This included timeframes of 42-51 weeks for SNCR applied to dry cement
manufacturing facilities and cement kilns/dryers burning bituminous coal, 28-58 weeks for SCR
applied to boilers and process heaters, 28-58 weeks for SCR applied to iron and steel in-process
combustion, and 6-8 months for low NOx burners and flue gas recirculation at iron and steel
mills.89 Taking into account necessary scale-up of construction services for multiple control
installations at several emissions units, the time needed to have NOx monitoring installed and
operating, and other necessary steps in the permitting and construction processes (e.g., review of
vendor bids), EPA estimates an additional period of 6 to 18 months may be necessary for
existing non-EGU sources to install the necessary controls, depending on the number of control
installations at a facility.90

Additionally, EPA previously considered the installation timing needs for NOx controls
(including SCR, SNCR, and combustion controls) at both EGU and non-EGU sources as part of
the 1998 NOx SIP Call.91 With respect to combustion controls (e.g., low-NOx burners, overfire
air, etc.), EPA found that sources should be able to complete control technology installations and
obtain relevant permits in relatively short timeframes given considerable experience at that time
among sources and permitting agencies with the implementation of such controls, the fact that
combustion controls are constructed of commonly available materials (steel, piping, etc.) and do
not require reagent during operation, and the then availability of many vendors of combustion
control technology.92

With respect to post-combustion controls (primarily SCR and SNCR), EPA considered
three basic factors in assessing installation timing needs: (1) availability of materials and labor,
(2) the time needed to implement controls at plants with single or multiple retrofit requirements,
and (3) the potential for interruptions in power supply resulting from outages needed to complete
installations on EGUs.93 Assuming adequate supplies of both off-the-shelf hardware (such as
steel, piping, nozzles, pumps, and related equipment) and the catalyst used in the SCR process,
as well as sufficient vendor capacity to supply retrofit SCR catalyst to sources, and taking into
account the additional time needed for facility engineering review, developing control

89	Final Technical Support Document (TSD) for the Final Cross-State Air Pollution Rule for the 2008 Ozone
NAAQS, Assessment of Non-EGU NOx Emissions Controls, Cost of Controls, and Time for Compliance Final TSD
("CSAPR Update Non-EGU TSD"), August 2016 (Table 3), available at https://www.epa.gov/csapr/assessment-
non-egu-NOx-emission-controls-cost-controls-and-time-compliance-final-tsd. See also Institute of Clean Air
Companies, SNCR Committee, "White Paper, Selective Non-Catalytic Reduction (SNCR) For Controlling NOx
Emissions," at 5 (noting that "SNCR retrofits typically do not require extended source shutdowns").

90	63 FR 57356, 57448 (October 27, 1998).

91	Id. at 57447-57449.

92	Id. at 57447, 57449.

93	Id. at 57448.

87


-------
technology specifications, awarding a procurement contract, obtaining a construction permit,
completing control technology design, installation, and testing, and obtaining an operating
permit, EPA found that (a) about 21 months would be needed to implement an SCR retrofit on a
single unit and (b) about 19 months would be needed to implement an SNCR retrofit on a single
unit.94 EPA also examined several particularly complicated implementation efforts and found
that 34 months would be needed for a plant to install a maximum of 6 SCRs while 24 months
would be needed for a plant to install a maximum of 10 SNCRs.95 Finally, EPA found that the
necessary controls could be installed on EGUs without any disruptions in the supply of
electricity because connections between a NOx control system and a boiler can generally be
completed in 5 weeks or less and thus could occur during the 5-week planned outage that each
EGU typically has each year.96

Thus, for both EGUs and non-EGUs, EPA's technical analysis for the 1998 NOx SIP Call
indicated that a three-year period would be sufficient for installation of both combustion and
post-combustion controls, from the planning and specification of controls to completion of
control technology implementation.97 EPA's evaluation of the timeframes for post-combustion
controls was based on the Agency's projection that 639 retrofit installations at EGU sources and
235 retrofit installations at non-EGU industrial sources would be necessary for existing sources
in the covered states to comply with the NOx SIP Call.98 Although the scope of non-EGU
sources covered by this proposed FIP is broader, and the number of emissions units is greater,
than the scope and number of non-EGU sources evaluated in the 1998 NOx SIP Call, and
although a later analysis of timeframes for installation of post-combustion controls at EGUs
produced a more refined estimate for that sector only,99 EPA's prior analyses nonetheless inform
the evaluation in this proposal of the necessary implementation schedule for non-EGU sources
given they generally address NOx control technologies similar to those that EPA anticipates non-
EGU sources may install to comply with the provisions of the proposed FIP (e.g., SCR, SNCR,
low-NOx burners and ultra-low NOx burners).

Additionally, as part of EPA's evaluation of installation timing needs in the proposed
CAIR (69 FR 4566), EPA projected that it would take on average 21 months to install an SCR on
one EGU unit, 27 months to install a scrubber on one EGU unit, and three years to install seven
SCRs at a single EGU.100 EPA also noted that some EGUs could install SCR controls in as short
of a period as 13 months.101 This information and EPA's general experience indicate that a two-
year installation timeframe for a rule requiring installation of new control technologies across a
variety of emissions sources in several industries on a regional basis is a relatively fast
installation timeframe, but that a three-year installation timeframe should be feasible for most if

94	Id.

95	Id.

96	Id.

97	Id. at 57449.

98	Id. at 57448 (Table V-l and Table V-2).

99	See Final Report, "Engineering and Economic Factors Affecting the Installation of Control Technologies for
Multipollutant Strategies," EPA-600/R-02/073 (October 2002).

100	69 FR 4566, 4617 (January 30, 2004) (citing Final Report, "Engineering and Economic Factors Affecting the
Installation of Control Technologies for Multipollutant Strategies," EPA-600/R-02/073 (October 2002)).

101	Final Report, "Engineering and Economic Factors Affecting the Installation of Control Technologies for
Multipollutant Strategies," EPA-600/R-02/073 (October 2002), at 21.

88


-------
not all of the identified industries. A shorter installation timeframe of approximately one year
would likely raise significant challenges for sources, suppliers, contractors, and other economic
actors, potentially including customers relying on the products or services supplied by the
regulated sources. Thus, if EPA finalizes this proposed rule in 2023, implementation of the
necessary emissions controls across all of the affected non-EGU sources by the August 3, 2024
Moderate area attainment date would not be possible.

For purposes of this proposed rule, EPA estimates that the required controls for non-EGU
source categories would take up to three years to install across the affected industries in the 23
states that remain linked in 2026. Therefore, based on the available information, EPA proposes
to require compliance with these non-EGU control requirements by the beginning of the 2026
ozone season.

EPA requests comment on the time needed to install the various control technologies
across all of the emissions units in the Tier 1 and Tier 2 industries. In particular, EPA solicits
comment on the time needed to obtain permits, the availability of vendors and materials, design,
construction, and the earliest possible installation times for SCR on glass furnaces; SNCR or
SCR on cement kilns; ultra-low NOx burners, low NOx burners, and SCR on ICI boilers (coal-
fired, gas-fired, or oil-fired); low NOx burners on large non-EGU ICI boilers; and low emissions
combustion, layered emissions combustion, NSCR, and SCR on reciprocating rich-burn or lean-
burn IC engines.

With respect to emissions monitoring requirements, EPA requests comment on the costs
of installing and operating CEMS at non-EGU sources without NOx emissions monitors; the
time needed to program and install CEMS at non-EGU sources; whether monitoring techniques
other than CEMS, such as predictive emissions monitoring systems (PEMS), may be sufficient
for certain non-EGU facilities, and the types of non-EGU facilities for which such PEMS may be
sufficient; and the costs of installing and operating monitoring techniques other than CEMS.

EPA also requests comment on whether the FIP should provide a limited amount of time
beyond the 2026 ozone season for individual non-EGU sources to meet the emissions limitations
and associated compliance requirements, based on a facility-specific demonstration of necessity.
As the D.C. Circuit stated in Wisconsin, the good neighbor provision may be read to allow for
some deviation from the mandate to eliminate prohibited transport by downwind attainment
deadlines, "under particular circumstances and upon a sufficient showing of necessity," provided
such deviation is "rooted in Title I's framework [and] provide[s] a sufficient level of protection
to downwind States."102 Consistent with this directive, and recognizing that in general, EPA
aligns good neighbor obligations in the first instance with the last full ozone season before the
downwind attainment date, EPA requests comment on whether individual non-EGU sources
should be allowed to request an extension of the May 1, 2026 compliance deadline by no more
than 1 year (i.e., to May 1, 2027) based on a sufficient showing of necessity. Any such comments
should be supported by a detailed discussion of the facility-specific economic, technological, and
other circumstances that may justify such an extension. EPA notes that claims about infeasibility
of controls are generally insufficient to justify an extension of time to comply, given the

102 Wisconsin, 938 F. 3d at 320 (citing CAA section 181(a) (allowing one-year extension of attainment deadlines in
particular circumstances) and North Carolina, 531 F.3d at 912).

89


-------
Wisconsin court's holding that the good neighbor provision requires upwind states to eliminate
their significant contribution in accordance with the downwind states' attainment deadlines,
without regard to questions of feasibility.103

EPA further solicits comment on the specific criteria that EPA should apply in evaluating
requests for extension of the 2026 compliance deadline for non-EGU sources. Such criteria could
include documentation of inability, despite best efforts, to procure necessary materials or
equipment (e.g., equipment manufacturers are not able to deliver equipment before a specific
date) or hire labor as needed to install the emissions control technology by 2026; documentation
of installation costs well in excess of the highest representative cost-per ton threshold identified
for any source (including EGUs) discussed in Section VI (e.g., vendor estimate showing
equipment cost); documentation of a source owner or operator's inability to secure necessary
financing, due to circumstances beyond the owner/operator's control, in time to complete the
installation of controls by 2026; or documentation of extreme financial or technological
constraints that would require the subject non-EGU emissions unit or facility to significantly
curtail its operations or shut down before it could comply with the requirements of this proposed
rule by 2026. Finally, EPA requests comment on the process through which EPA should review
and act on an extension request—e.g., the appropriate deadline for submitting a request, and
whether EPA should provide an opportunity for public comment before granting or denying a
request.

EPA anticipates that the owner or operator of the facility would bear the burden of
establishing the necessity of an extension of time to comply, based on particular circumstances
described and sufficiently documented in the submitted request. Claims of generalized financial
or economic hardship or any claim that controls are not necessary to eliminate significant
contribution would not suffice to justify an extension. If EPA finalizes a provision allowing
sources to request limited extensions of time to comply, the Agency would review each request
on a case-by-case basis as necessary to ensure consistency with the provisions of title I of the
CAA.

103 Wisconsin, 938 F.3d at 313-314, 319 ("When an agency faces a statutory mandate, a decision to disregard it
cannot be grounded in mere infeasibility"). We note also that in the CSAPR Close-Out Rule (83 FR 65878,
December 21, 2018), EPA required no further reductions from upwind states beyond those set forth in the prior
CSAPR Update based, in part, on the Agency's conclusion that it was not feasible to implement cost-effective
emissions controls before 2023, two years after the 2021 attainment deadline for the downwind serious areas. The
D.C. Circuit vacated the Close-Out Rule for its reliance on the same interpretation of the Good Neighbor Provision
that the court had rejected in Wisconsin. New York v. EPA, 781 F. App'x 4 (D.C. Cir. 2019) (unpublished opinion).

90


-------