TECHNICAL SUPPORT DOCUMENT FOR THE
IRON AND STEEL SECTOR: PROPOSED RULE
FOR MANDATORY REPORTING OF
GREENHOUSE GASES
Office of Air and Radiation
U.S. Environmental Protection Agency
August 28, 2009
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CONTENTS
INTRODUCTION 2
1. INDUSTRY DESCRIPTION 3
1.1 Integrated Iron and Steel Facilities 4
1.1.1 Blast Furnaces 4
1.1.2 Basic Oxygen Furnace (BOF) 6
1.1.3 Sintering 8
1.1.4 Miscellaneous Combustion Sources 9
1.2 Coke Production 10
1.3 Taconite Iron Ore Processing 16 14
1.4 Electric Arc Furnace (EAF) Steelmaking 24 16
1.6 Other Steelmaking Processes 21
1.7 Miscellaneous Emissions Sources 22
2. TOTAL EMISSIONS 23
3. REVIEW OF EXISTING PROGRAMS AND METHODOLOGIES 24
3.1 2006 IPCC Guidelines 10 24
3.2 U.S. EPA GIIG Inventory 28 25
3.3 WRIAVBCSD Calculation Procedure 29 25
30
3.4 European Union (EU) Emissions Trading Scheme 26
3.5 DOE Technical Guidelines 31 27
3.6 AISI Methodology 32 27
3.7 Environment Canada Guidance Manual 33 27
3.8 Current Practices for Estimating Greenhouse Gas Emissions 28
5. OPTIONS FOR REPORTING THRESHOLDS 30
6. OPTIONS FOR MONITORING METHODS 31
6.1 CO2 Emissions from Process Sources 31
6.2 Methane and Nitrous Oxide Emissions 33
6.3 CO2 Emissions from Coke Pushing Operations 33
7. OPTIONS FOR ESTIMATING MISSING DATA 34
8. QA/QC REQUIREMENTS 35
9. REFERENCES 36
APPENDIX A. DEFINITIONS AND THEIR ORIGINS 39
APPENDIX B. EXAMPLES OF COMBUSTION UNITS 41
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
INTRODUCTION
The iron and steel industry in the United States is the third largest in the world (after
China and Japan), accounting for about 8 percent of the world's raw iron and steel production 1
and supplying several industrial sectors, such as construction (building and bridge skeletons and
supports), vehicle bodies, appliances, tools, and heavy equipment. Currently, there are 18
integrated iron and steel steelmaking facilities that make iron from iron ore and coke in a blast
furnace (BF) and refine the molten iron (and some ferrous scrap) in a basic oxygen furnace
(BOF) to make steel. In addition, there are over 90 electric arc furnace (EAF) steelmaking
facilities that produce steel primarily from recycled ferrous scrap. In 2007, integrated mills
produced 40 million metric tons (mt) of raw steel and minimills produced 58 million mt. 2 The
iron and steel source category also includes taconite (iron ore) processing facilities, cokemaking
facilities, and direct reduced ironmaking (DRI) facilities. There are eight taconite iron ore
processing facilities that produced 52 million mt of pellets in 20073, primarily for use in blast
furnaces to make iron. There are 18 cokemaking facilities that produced 15.8 million mt of coke
in 2007, 4 also primarily for use in blast furnaces, and 7 of these coke plants are co-located with
integrated iron and steel facilities. There is one operating DRI plant located at an EAF
steelmaking facility that produced 0.2 million mt of iron in 2007. 5
GHG emissions from the source category are estimated at about 85 million metric tons of
carbon dioxide equivalents per year (MMTC02e/yr) or just over 1 percent of total U.S. GHG
emissions. Emissions from both process units (47 MMTC02e/yr) and miscellaneous combustion
units (38 MMTC02e/yr) are significant.21 Small amounts of N2O and CH4 are also emitted during
the combustion of different types of fuels. The primary process units that emit GHG emissions
are BF stoves (24 MMTC02e/yr), taconite indurating furnaces, BOFs, EAFs (about 5
MMTC02e/yr each), coke oven battery combustion stacks (6 MMTC02e/yr), and sinter plants (3
MMTC02e/yr). Smaller amounts of GHG emissions are produced by coke pushing (0.16
MMTC02e/yr) and DRI furnaces (0.14 MMTC02e/yr).
In addition to the blast furnace stoves and byproduct coke battery underfiring systems,
the other combustion units where fuel is the only source of GHG emissions include boilers,
process heaters, reheat and annealing furnaces, flares, flame suppression systems, ladle reheaters,
and other miscellaneous sources. Emissions from these other combustion sources are estimated
at 16.8 MMTC02e/yr for integrated iron and steel facilities, 18.6 MMTC02e/yr for EAF
steelmaking facilities, and 2.7 MMTC02e/yr for coke facilities not located at integrated iron and
steel facilities.
This document describes the various processes in the iron and steel industry that generate
greenhouse gas emissions and provides information on the locations and sizes of facilities that
may be impacted by the proposed mandatory reporting rule. The impact of potential thresholds
on the number of facilities reporting and the emissions coverage is also discussed. Options for
monitoring greenhouse gases to determine the level of emissions are also presented and
discussed. Other sections of this document address procedures for estimating missing data,
quality assurance/quality control (QA/QC) requirements, and reporting procedures.
a These are preliminary estimates and are documented in the following sections of this Technical Support Document.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
1. INDUSTRY DESCRIPTION
This section summarizes the processes and major emission points of greenhouse gases for
taconite iron ore processing, coke plants, sinter plants, blast furnaces, basic oxygen furnaces,
electric arc furnaces, and plants producing iron by direct reduction. Other processes associated
with steelmaking, such as ladle metallurgy, argon-oxygen decarburization, and casting are also
discussed.
The focus of this document is on process sources of GHG emissions because the
methodologies for determining GHG emissions from combustion units are discussed in the
technical support document that applies to all types of general stationary fuel combustion
sources.b However, there are several types of combustion units unique to the iron and steel
industry, and they are important parts of the different processes. A description of these processes
is given in this section to provide background on combustion units at iron and steel facilities. In
addition, the information on combustion units at iron and steel facilities needs to be presented to
develop and describe preliminary estimates of total GHG emissions from all sources in the
source category, including estimates of both process emissions and combustion unit emissions.
The combustion units at iron and steel facilities where GHGs are formed solely from
burning fuels include:
Byproduct recovery coke oven battery combustion stacks,
Blast furnace stoves,
Boilers,
Process heaters,
Reheat furnaces,
Flame suppression systems,
Annealing furnaces,
Flares,
Ladle reheaters, and
Other miscellaneous combustion sources.
The major process units at iron and steel facilities where raw materials, usually in
combination with fuel combustion, contribute to the emission of GHGs include:
Taconite indurating furnaces,
Nonrecovery coke oven battery combustion stacks,
Coke pushing,
BOFs,
EAFs,
DRI furnaces, and
Sinter plants.
b Process emissions of GHGs include emissions from processes where raw materials, usually in addition to the
combustion of fuels, contribute to the formation of GHGs. Combustion units are those in which the GHGs are
generated solely from the combustion of fuel.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
1.1 Integrated Iron and Steel Facilities
This section discusses the processes at integrated iron and steel facilities that are the
major sources of GHG emissions: blast furnaces, BOFs, sinter plants, and miscellaneous
combustion units. A few integrated facilities also have co-located coke plants. However, coke
production is discussed in a separate section because there are many independent (stand-alone)
coke plants, and the complex production processes are best described in a separate section.
1.1.1 Blast Furnaces
There are 35 blast furnaces at 17 plant locations shown in Table 1.
Table 1. Blast Furnace (BF) Locations and Capacity 6
No.
Plants with Blast Furnaces (BF)
Location
Number of BFs
BF Capacity (tpy)c
1
Mittal (formerly Ispat-Inland)
East Chicago, IN
5
6,500,000
2
US Steel
Gary, IN
4
5,560,000
3
Mittal (formerly ISG, Bethlehem)
Burns Harbor, IN
2
5,100,000
4
Mittal (formerly LTV)
Cleveland, OH
2
4,100,000
5
Severstal (formerly ISG, Bethlehem)
Sparrows Point, MD
1
3,500,000
6
Mittal (formerly LTV)
East Chicago, IN
2
3,100,000
7
US Steel (formerly National Steel)
Ecorse, MI
3
2,781,000
8
Mittal (formerly Weirton Steel)
Weirton, WV
2
2,700,000
9
Severstal (formerly Rouge Steel)
Dearborn, MI
2
2,700,000
10
US Steel Edgar Thomson Works
Braddock, PA
2
2,500,000
11
US Steel (formerly National Steel)
Granite City, IL
2
2,400,000
12
Republic Engineered Products
Lorain, OH
2
2,300,000
13
Severstal (formerly Wheeling Pittsburgh)
Mingo Junction, OH
2
2,300,000
14
AK Steel
Middletown, OH
1
2,200,000
15
US Steel
Fairfield, AL
1
2,000,000
16
AK Steel
Ashland, KY
1
1,900,000
17
Severstal (formerly WCI Steel)
Warren, OH
1
1,400,000
Total
35
53,041,000
tpy = short tons per year
Iron Production 6'7
Iron is produced in blast furnaces by the reduction of iron-bearing materials with a hot
gas. The large, refractory-lined blast furnace is charged through its top with iron ore pellets,
sinter, flux (limestone and dolomite), and coke, which provides fuel and forms a reducing
atmosphere in the furnace. Many modern blast furnaces also inject pulverized coal or other
sources of carbon to reduce the quantity of coke required. Iron oxides, coke, coal, and fluxes
react with the heated blast air injected near the bottom of the furnace to form molten reduced
iron, carbon monoxide (CO), and slag (a molten liquid solution of silicates and oxides that
solidifies upon cooling). The molten iron and slag collect in the hearth at the base of the furnace.
The by-product gas is collected at the top of the furnace and is recovered for use as fuel.
The production of one ton of iron requires approximately 1.4 tons of ore or other iron-
bearing material; 0.5 to 0.65 ton of coke and coal; 0.25 ton of limestone or dolomite; and 1.8 to 2
0 Note: Throughout this document the terms "ton" and "tons per year (tpy)" refer to short tons (2,000 lbs), which is
consistent with the way the U.S. industry reports production and capacity. The abbreviation "mt" is used for metric
tons (also known as "tonne" or 2,205 lbs) and is used for emissions, which are conventionally expressed in metric
units.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
tons of air. By-products consist of 0.2 to 0.4 ton of slag and 2.5 to 3.5 tons of blast furnace gas
containing up to 100 pounds of dust.
The molten iron and slag are removed from the furnace periodically (this is called
"tapping" or "casting"). The casting process begins with drilling a taphole into the clay-filled
iron notch at the base of the hearth. During casting, molten iron flows into runners that lead to
transport ladles. Slag also flows from the furnace and is directed through separate runners to a
slag pit adjacent to the casthouse or into slag pots for transport to a remote slag pit. At the
conclusion of the cast, the taphole is replugged with clay. The area around the base of the
furnace, including all iron and slag runners, is enclosed by a casthouse. The molten iron is
transferred to a refractory-lined rail car (called a "torpedo" car because of it shape) and sent to
the BOF shop. The hot metal is then poured from the torpedo cars into the BOF shop ladle; this
is referred to as hot metal transfer (also known as "reladling"). Hot metal transfer generally takes
place under a hood to capture emissions of PM including kish (flakes of carbon), which is
formed during the process.
Blast Furnace Gas 6'7
The blast furnace by-product gas, which is collected from the furnace top, has a low
heating value (about 90 Btu/ft3) and is composed of nitrogen (about 60 percent), carbon
monoxide (28 percent) and carbon dioxide (12 percent). A portion of this gas is fired in the blast
furnace stoves to preheat the blast air, and the rest is used in other plant operations.
There are generally three to four stoves per blast furnace. Before the blast air is delivered
to the blast furnace, it is preheated by passing it through a regenerator (heat exchanger). In this
way, some of the energy of the off-gas that would otherwise have been lost is returned to the
process. The additional thermal energy returned to the blast furnace as heat decreases the
amount of fuel that has to be burned for each unit of hot metal and improves the efficiency of the
process. In many furnaces, the off-gas is enriched by the addition of a fuel with much higher
calorific value, such as natural gas or coke oven gas, to obtain even higher hot blast
temperatures. This decreases the fuel requirements and increases the hot metal production rate to
a greater extent than is possible when burning blast furnace gas alone to heat the stoves.
Desulfurization 6'7
Desulfurization of the hot metal is accomplished by adding reagents such as soda ash,
lime, and magnesium. Injection of the reagents is accomplished pneumatically with either dry
air or nitrogen. Desulfurization may take place at various locations within the iron and steel
making facility; however, if the location is the BOF shop, then it is most often accomplished at
the hot metal transfer (reladling) station to take advantage of the fume collection system at that
location.
Emissions
The vast majority of GHGs (CO2) are emitted from the blast furnaces stove stacks where
the combustion gases from the stoves are discharged. A small amount of emissions may also
occur from flares, leaks in the ductwork for conveying the gas, and from blast furnace "slips." A
slip occurs when the burden material hangs or bridges in the furnace rather than continuing its
downward movement. When this happens, the solid material below the "hang" continues to
move downward and forms a void below the hang that is filled with hot gas at very high
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
pressure. When the hang finally collapses, the sudden downward thrust of the burden material
forces the hot gas upward with the force of an explosion. To prevent damage to the furnace, the
pressure is relieved through bleeder stacks on top of the furnace that discharge the particle-laden
gas directly to the atmosphere.
Emissions of CO2 are also generated from the combustion of natural gas using flame
suppression to reduce emissions of particulate matter. Flame suppression maintains a flame over
the surface of the molten metal (for example, during tapping) to consume oxygen and to inhibit
the formation of metal oxides that become airborne. Emissions also occur from the flaring of
blast furnace gas.
The IPCC guidelines also note that a small amount of CH4 may be emitted from blast
furnace stoves. The blast furnace gas, which is mostly nitrogen, carbon monoxide, and CO2, is
usually supplemented with natural gas, which is mostly CH4, and a small amount of methane
may be emitted because of incomplete combustion.
Title V operating permits were reviewed to obtain data on the design energy input of
blast furnace stoves and to relate the energy input to capacity.8 The results are given in Table 2
and show an average of 2.2 million Btu per short ton of iron (0.00255 TJ/mt of iron). The IPCC
guidelines provide an emission factor of 260 mtCC^e /TJ for the combustion of blast furnace
gas. 9 Based on the production of 36.1 million mt of pig iron on 2007,2 C02 emissions from blast
furnace stoves would be about 24 MMTC02e/yr.
Table 2. Energy Consumption by Blast Furnace Stoves 8
Capacity (million short
Million Btu/hr
Million Btu per short
tons per year)
ton of iron
5.5
1,320
2.10
4.0
586
1.28
2.5
953
3.34
1.6
441
2.41
2.0
486
2.13
3.4
1,025
2.64
2.7
700
2.27
1.2
309.1
2.31
1.0
298.4
2.68
1.4
309.9
1.97
1.3
319.2
2.12
1.6
301.5
1.68
0.9
192.9
1.88
Average
2.22
1.1.2 Basic Oxygen Furnace (BOF)
As shown in Table 3, there are 18 plants that operate 46 BOFs at 21 BOF shops. A
"shop" consists of at least two furnaces (sometimes three) that may be operated alternately or
together with each furnace in a different stage of the operating cycle.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
Table 3. Basic Oxygen Furnace Locations and Capacity 6
No.
Plants with BOFs
Location
Number of
BOFs
BOF Capacity (short
tons per year)
1
Mittal (formerly Ispat-Inland)
East Chicago, IN
4
10,000,000
2
US Steel
Gary, IN
6
7,500,000
3
Mittal (formerly ISG, Bethlehem)
Burns Harbor, IN
3
4,700,000
4
Severstal (formerly ISG, Bethlehem)
Sparrows Point, MD
2
3,900,000
5
Mittal (formerly LTV)
Cleveland, OH
4
3,800,000
6
Mittal (formerly LTV)
East Chicago, IN
2
3,800,000
7
US Steel (formerly National Steel)
Ecorse, MI
2
3,800,000
8
Severstal (formerly Rouge Steel)
Dearborn, MI
2
3,309,000
9
Mittal (formerly Weirton Steel)
Weirton, WV
2
3,000,000
10
US Steel Edgar Thomson Works
Braddock, PA
2
2,900,000
11
US Steel (formerly National Steel)
Granite City, IL
2
2,800,000
12
AK Steel
Middletown, OH
2
2,716,000
13
Republic Engineered Products
Lorain, OH
2
2,700,000
14
Severstal (formerly Wheeling Pittsburgh)
Mingo Junction, OH
2
2,600,000
15
US Steel
Fairfield, AL
3
2,200,000
16
AK Steel
Ashland, KY
2
2,200,000
17
Severstal (formerly WCI Steel)
Warren, OH
2
1,900,000
18
Mittal (formerly Acme Steel)
Riverdale, IL
2
750,000
Total
46
64,575,000
BOF Steelmaking 6'7
The BOF is a large, open-mouthed vessel lined with a basic refractory material (the term
"basic" refers to the chemical characteristic of the lining) that refines iron into steel. The BOF
receives a charge composed of molten iron from the blast furnace and ferrous scrap. A jet of
high-purity oxygen is injected into the BOF and oxidizes carbon and silicon in the molten iron in
order to remove these constituents and to provide heat for melting the scrap. After the oxygen jet
is started, lime is added to the top of the bath to provide a slag of the desired basicity. Fluorspar
and mill scale are also added in order to achieve the desired slag fluidity. The oxygen combines
with the unwanted elements (with the exception of sulfur) to form oxides, which leave the bath
as gases or enter the slag. As refining continues and the carbon content decreases, the melting
point of the bath increases. Sufficient heat must be generated from the oxidation reactions to
keep the bath molten.
There are currently three methods that are used to supply the oxidizing gas: (1) top
blown, (2) bottom blown, and (3) combination blowing. Most bottom blown furnaces use
tuyeres consisting of two concentric pipes, where oxygen is blown through the center of the inner
pipe and a hydrocarbon coolant (such as methane) is injected between the two pipes. The
hydrocarbon decomposes at the temperature of liquid steel, absorbing heat as it exits and
protecting the oxygen tuyere from overheating and burn back.
The distinct operations in the BOF process are the following:
Charging - the addition of molten iron and metal scrap to the furnace
Oxygen blow - introducing oxygen into the furnace to refine the iron
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
Turndown - tilting the vessel to obtain a sample and check temperature
Reblow - introducing additional oxygen, if needed
Tapping - pouring the molten steel into a ladle
Deslagging - pouring residual slag out of the vessel.
The basic oxygen steelmaking process is a thermochemical process; computations are
made to determine the necessary percentage of molten iron, scrap, flux materials, and alloy
additions. Various steelmaking fluxes are added during the refining process to reduce the sulfur
and phosphorus content of the metal to the prescribed level. The oxidation of silicon, carbon,
manganese, phosphorus, and iron provide the energy required to melt the scrap, form the slag,
and raise the temperature of the bath to the desired temperature.
Process Emissions
The major emission point for CO2 from the BOF is the furnace exhaust gas that is
discharged through a stack after gas cleaning. The carbon is removed as carbon monoxide and
CO2 during the oxygen blow. Carbon may also be introduced to a much smaller extent from
fluxing materials and other process additives that are charged to the furnace. Using the default
values in the IPCC guidelines for iron (0.04) and steel (0.01) for the fraction of carbon 10 gives
an emission factor of 0.11 mtCC^e/mt steel for carbon removed from the iron as CO2. Applying
the emission factor to the production of 40 million mt of steel in BOFs in 2007 2 yields an
estimate of 4.4 MMTC02e/yr.
1.1.3 Sintering
Sintering is a process that recovers the raw material value of many waste materials
generated at iron and steel plants that would otherwise be landfilled or stockpiled. An important
function of the sinter plant is to return waste iron-bearing materials to the blast furnace to
produce iron. Another function is to provide part or all of the flux material (e.g., limestone,
dolomite) for the ironmaking process. As shown in Table 4, there are currently 5 plants with
sintering operations, and all of the sinter plants are part of an integrated iron and steel plant.6
Table 4. Sinter Plants 6
No.
Plant
Location
Sinter Capacity
(short tons per year)
1
US Steel
Gary, IN
4,400,000
2
Severstal (formerly ISG, Bethlehem)
Sparrows Point, MD
4,000,000
3
Mittal (formerly ISG, Bethlehem)
Burns Harbor, IN
2,900,000
4
Mittal (formerly LTV)
East Chicago, IN
1,900,000
5
Mittal (formerly Ispat-Inland)
East Chicago, IN
1,400,000
Total
14,600,000
Sinter Process 6
Feed material to the sintering process includes ore fines, coke, reverts (including blast
furnace dust, mill scale, and other by-products of steelmaking), recycled hot and cold fines from
the sintering process, and trim materials (calcite fines, and other supplemental materials needed
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
to produce a sinter product with prescribed chemistry and tonnage). The materials are
proportioned and mixed to prepare a chemically uniform feed to the sinter strand, so that the
sinter will have qualities desired for satisfactory operation of the blast furnace. The chemical
quality of the sinter is often assessed in terms of its basicity, which is the percent total basic
oxides divided by the percent total acid oxides ((Ca0+Mg0)/(Si02+Al203)); sinter basicity is
generally 1.0 to 3.0. The relative amounts of each material are determined based on the desired
basicity, the rate of consumption of material at the sinter strand, the amount of sinter fines that
must be recycled, and the total carbon content needed for proper ignition of the feed material.
The sintering machine accepts feed material and conveys it down the length of the
moving strand. Near the feed end of the grate, the bed is ignited on the surface by gas burners
and, as the mixture moves along on the traveling grate, air is pulled down through the mixture to
burn the fuel by downdraft combustion; either coke oven gas or natural gas may be used for fuel
to ignite the undersize coke or coal in the feed.
Process Emissions
The primary emission point of interest for the sinter plant is the stack that discharges the
windbox exhaust gases after gas cleaning. The CO2 is formed from the fuel combustion (natural
gas or coke oven gas) and from carbon in the feed materials, including coke fines and other
carbonaceous materials. Based on the IPCC emission factor of 0.2 mtC02e/mt of sinter 10 and
the production of 13.3 million mt of sinter,6 C02 emissions are estimated as 2.7 MMTC02e/yr.
However, greenhouse gas emissions from sinter plants may vary widely over time as a
consequence of variations in the fuel inputs and other feedstock, especially in the types and
quantities of iron-bearing materials that are recycled. Both natural gas and coke oven gas
contain CH4, and when the gases are burned, a small amount of the CH4 is emitted with the
exhaust gases due to incomplete combustion. Consequently, sinter plants (and any other process
that burns fuels that contain CH4) also emit a small amount of CH4.
1.1.4 Miscellaneous Combustion Sources
There are many different types of combustion processes at iron and steel facilities not
directly related to the major production processes discussed in previous section. These include
boilers, process heaters, flares, dryout heaters, and several types of furnaces (more detailed
examples are given in Appendix B). For example, soaking pits and reheat furnaces are used to
raise the temperature of the steel until it is sufficiently hot to be plastic enough for economic
reduction by rolling of forging. Annealing furnaces are used to heat the steel to relieve cooling
stresses induced by cold or hot working and to soften the steel to improve machinability and
formability. Ladle reheating using natural gas to keep the ladle hot while waiting for molten
steel. Natural gas is the most commonly used fuel; however, coke oven gas and blast furnace gas
are also used in the combustion processes.
Table 5 provides the results from reviewing the operating permits of 6 integrated iron and
steel plants to extract information on the sizes of their combustion units. The facilities average
3.12 MM Btu/ton of steel for combustion units burning natural gas, coke oven gas, and blast
furnace gas. At 90 percent utilization of combustion capacity, the average is 2.91 MM Btu/ton
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
of steel (0.00338 TJ/mt steel). Table 6 illustrates the development of an emission factor of 0.42
mtC02e/mt of steel for combustion units based on the energy distribution of these gases for fuel,
90 percent utilization of combustion capacity, and the IPCC emission factors for the three gases.
For a production rate of steel of 40 million mt in 2007, emissions from combustion units at
integrated iron and steel plants would be 16.8 MMTC02e.
Table 5. Design Capacity of Combustion Units at Integrated Iron and Steel Facilities 8
Steel capacity (short
MM Btu/hr
MM Btu/short ton
tons per year)
3,800,000
1,088
2.51
2,800,000
1,113
3.48
2,716,000
844
2.72
2,700,000
1,055
3.42
2,600,000
1,033
3.48
2,200,000
952
3.79
Average
3.23
At 90%
2.91
Table 6. Development of an Emission Factor for Combustion Units
Fuel
% of energy 11
IPCC emission
factor
(mtC02/TJ) 9
TJ/mt of steel3
mtCCVmt of
steelb
Natural gas
51
56.1
0.0017
0.097
Coke oven gas
14
44
0.00047
0.021
Blast furnace gas
34
260
0.0011
0.30
Total
0.42
a (% of energy/100) * (0.00338 TJ/mt of steel)
b (IPCC emission factor in mtC02/TJ)*(TJ/mt of steel)
1.2 Coke Production
As shown in Table 7, there are 18 coke plants in the U.S. that produce coke from coal
primarily for use in blast furnaces to make iron, but also for use at iron foundries and other
industrial processes. In 2007, coke plants produced 15.8 million mt of coke and coke breeze
(undersize coke).4 Most coke is produced in by-product recovery coke oven batteries. However,
there are three non-recovery coke oven batteries, including the two newest coke plants, and both
of the newest nonrecovery plants use the waste heat from combustion to generate electricity.
The recovery of waste heat to generate electricity reduces the purchase of electricity, the need to
purchase additional fuel to generate electricity onsite, or when supplied to the grid, reduces the
amount of electricity that must be produced from fossil fuel combustion.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
Table 7. U.S. Coke Plants12'14
No.
Company
City
State
Number
of
batteries
Coke capacity
(short tons per
year)
1
Indiana Harbor Cokea
East Chicago
IN
4
1,300,000
2
Haverhill Cokea
Haverhill
OH
4
1,100,000
3
US Steel
Clairton
PA
12
5,573,185
4
Jewell Coke and
Coala
Vansant
VA
6
649,000
5
US Steel
Gary
IN
4
2,249,860
6
Mittal Steel
Burns Harbor
IN
2
1,877,000
7
Mountain State
Carbon
Follansbee
WV
4
1,247,000
8
AK Steel
Ashland
KY
2
1,000,000
9
EES Coke
Ecorse
MI
1
1,000,000
10
ABC Coke
Tarrant
AL
3
699,967
11
US Steel
Granite City
IL
2
601,862
12
Mittal Steel
Warren
OH
1
550,000
13
Shenango
Neville Island
PA
1
514,779
14
Sloss Industries
Birmingham
AL
3
451,948
15
AK Steel
Middletown
OH
1
429,901
16
Koppers
Monessen
PA
2
372,581
17
Tonawanda
Tonawanda
NY
1
268,964
18
Erie Coke
Erie
PA
2
214,951
Total
55
20,099,998
a These are nonrecovery coke plants.
By-product Recovery Coke Oven Batteries 12'13
Coke ovens use thermal distillation to remove volatile non-carbon elements from coal to
produce coke. Thermal distillation takes place in groups of ovens called batteries. A by-product
coke oven battery consists of 20 to 100 adjacent ovens with common side walls made of high
quality silica and other types of refractory brick. The wall separating adjacent ovens, as well as
each end wall, is made up of a series of heating flues. At any one time, half of the flues in a
given wall will be burning gas while the other half will be conveying waste heat from the
combustion flues to a heat exchanger and then to the combustion stack. Every 20 to 30 minutes
the battery "reverses," and the former waste heat flues become combustion flues while the former
combustion flues become waste heat flues. This process avoids melting the battery brick work
(the flame temperature is above the melting point of the brick) and provides more uniform
heating of the coal mass. Process heat comes from the combustion of coke oven gas, sometimes
supplemented with blast furnace gas. The flue gas is introduced from piping in the basement of
the battery and combusted in flues. The gas flow to each flue is metered and controlled. Waste
gases from combustion, including GHGs, exit through the battery stack.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
Each oven holds between 15 and 25 short tons of coal. Offtake flues remove gases
evolved from the destructive distillation process. Process heat comes from the combustion of
gases between or beneath the coking chambers. The operation of each oven in the battery is
cyclic, but the batteries usually contain a sufficiently large number of ovens so that the yield of
by-products is essentially continuous. Coking continues for 15 to 18 hours to produce blast
furnace coke and 25 to 30 hours to produce foundry coke. The coking time is determined by the
coal mixture, moisture content, rate of underfiring, and the desired properties of the coke.
Coking temperatures generally range from 900 to 1,100°C and are kept on the higher side of the
range to produce blast furnace coke.
Pulverized coal is mixed and blended, and sometimes water and oil are added to control
the bulk density of the mixture. The prepared coal mixture is transported to the coal storage
bunkers on the coke oven battery. A specific volume of coal is discharged from the bunker into a
larry cara charging vehicle that moves along the top of the battery. The larry car is positioned
over an empty, hot oven; the lids on the charging ports are removed; and the coal is discharged
from the hoppers of the larry car into the oven. To minimize the escape of gases from the oven
during charging, steam aspiration is used to draw gases from the space above the charged coal
into a collecting main. After charging, the aspiration is turned off, and the gases are directed
through an offtake system into a gas collecting main.
The maximum temperature attained at the center of the coke mass is usually 1100°C to
1500°C. At this temperature, almost all volatile matter from the coal mass volatilizes and leaves
a high quality metallurgical coke. Air is prevented from leaking into the ovens by maintaining a
positive back pressure of about 10 mm of water. The gases and hydrocarbons, including GHGs,
that evolve during thermal distillation are removed through the offtake system and sent to the by-
product plant for recovery.
Near the end of the coking cycle, each oven is dampered off the collection main. Once an
oven is dampered off, the standpipe cap is opened to relieve pressure. Volatile gases exiting
through the open standpipe are ignited if they fail to self-ignite and are allowed to burn until the
oven has been pushed. At the end of the coking cycle, doors at both ends of the oven are
removed, and the hot coke is pushed out the coke side of the oven by a ram that is extended from
a pusher machine. The coke is pushed through a coke guide into a special rail car, called a
quench car, which traverses the coke side of the battery. The quench car carries the coke to a
quench tower where the hot coke is deluged with water. The quenched coke is discharged onto
an inclined "coke wharf' to allow excess water to drain and to cool the coke to a reasonable
temperature. Gates along the lower edge of the wharf control the rate that the coke falls on the
conveyor belt that carries it to a crushing and screening system.
Gases evolved during coking leave the coke oven through standpipes, pass into
goosenecks, and travel through a damper valve to the gas collection main that directs the gases to
the by-product plant. These gases account for 20 to 35 percent by weight of the initial coal
charge and are composed of water vapor, tar, light oils, heavy hydrocarbons, and other chemical
compounds.
At the by-product recovery plant, tar and tar derivatives, ammonia, and light oil are
extracted from the raw coke oven gas. After tar, ammonia, and light oil removal, the gas
undergoes a final desulfurization process at most coke plants to remove hydrogen sulfide before
being used as fuel. Approximately 35 to 40 percent of cleaned coke oven gas (after the removal
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
of economically valuable by-products) is used to heat the coke ovens, and the remainder is used
in other operations related to steel production, in boilers, or is flared. Coke oven gas has a
heating value of 500 to 600 Btu/ft3 and is composed of hydrogen (about 47 percent), methane (32
percent), carbon monoxide (6 percent), and C02 (2 percent).
Nonrecovery Coke Oven Batteries12'13
As the name implies, the nonrecovery cokemaking process does not recover the
numerous chemical by-products as discussed above. All of the coke oven gas is burned, and
instead of recovery of chemicals, this process offers the potential for heat recovery and
cogeneration of electricity. Non-recovery ovens are of a horizontal design (as opposed to the
vertical slot oven used in the by-product process) with a typical range of 30 to 60 ovens per
battery. The oven is generally between 9 and 14 m (30 and 45 ft) long and 1.8 to 3.7 m (6 to 12
ft) wide. The internal oven chamber is usually semicylindrical in shape with the apex of the arch
1.5 to 3.7 m (5 to 12 ft) above the oven floor. Each oven is equipped with two doors, one on
each side of the horizontal oven, but there are no lids or offtakes as found on by-product ovens.
The oven is charged through the oven doorway with a coal conveyor rather than from the top
through charging ports.
After an oven is charged with coal, carbonization begins as a result of the hot oven brick
work from the previous charge. Combustion products and volatiles that evolve from the coal
mass are burned in the chamber above the coal, in the gas pathway through the walls, and
beneath the oven in sole flues. Each oven chamber has two to six downcomers in each oven
wall, and the sole flue may be subdivided into separate flues that are supplied by the
downcomers. The sole flue is designed to heat the bottom of the coal charge by conduction
while radiant and convective heat flow is produced above the coal charge.
Primary combustion air is introduced into the oven chamber above the coal through one
of several dampered ports in the door. The dampers are adjusted to maintain the proper
temperature in the oven crown. Outside air may also be introduced into the sole flues; however,
additional air usually is required in the sole flue only for the first hour or two after charging. All
of the ovens are maintained under a negative pressure. Consequently, the ovens do not leak
under normal operating conditions as do the by-product ovens which are maintained under a
positive pressure. The combustion gases are removed from the ovens and directed to the stack
through a waste heat tunnel that is located on top of the battery centerline and extends the length
of the battery.
Emissions
The primary emission point of gases is the battery's combustion stack. Test data were
obtained for 53 emission tests (generally 3 runs per tests) for CO2 emissions from the
combustion stacks at by-product recovery coke plants for development of an emission factor for
EPA's 2008 revision to AP-42. 13 These tests averaged 0.143 mtC02e/mt coal (0.21 mtC02e/mt
coke). Test results for a nonrecovery battery were obtained and analyzed. The average of three
runs at Haverhill Coke resulted in an emission factor of 1.23 mtC02e/mt coke, 15 approximately
six times higher than the factor for the combustion stack at by-product recovery batteries. The
emission factor for nonrecovery combustion stacks is much higher because all of the coke oven
gas and all of the by-products are burned. In comparison, organic liquids (such as tar and light
oil) are recovered at by-product recovery coke plants, and only about one third of the gas is
consumed in underfiring the ovens. Emissions from combustion stacks based on the 2007
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
production rate are estimated as 3 MMTC02e from nonrecovery battery stacks and 2.8
MMTC02e/mt from byproduct recovery battery stacks.
A small amount of CO2 is emitted from the pushing operation when the incandescent
coke is pushed from the oven and transported to the quench tower where it is quenched with
water. The 2008 revisions to EPA's AP-42 compilation of emission factors provides an emission
factor of 0.008 mtC02e/mt coal (0.01 mtC02e/mt coke).13 Using the 2007 production rate for
coke (15.8 million mt),4 the emissions from pushing are estimated as 0.16 MMTC02e/yr.
Fugitive emissions occur during the coking process from leaks of raw coke oven gas that
contains methane. The leaks occur from doors, lids, offtakes, and collecting mains and are
almost impossible to quantify because they change in location, frequency, and duration during
the coking cycle, and they are not captured in a conveyance. However, the number, size, and
frequency of these leaks have decreased significantly over the past 20 years as a result of
stringent regulations, including national standards, consent decrees, and State regulations.
Many by-product recovery coke plants also have other combustion sources, primarily
boilers and flares. These units use excess coke oven gas that is not used for underfiring the
battery or shipped offsite for use as fuel in other processes. The IPCC guidelines 10 provide an
emission factor of 0.56 mtCC^e/mt coke (assuming all of the coke oven gas is burned).
Emissions from the combustion of coke oven gas in units other than the coke battery underfiring
system are estimated as 0.35 mtC02e/mt coke (0.56 - 0.21 mtC02e/mt coke). For the production
of 7.6 million mt of coke in stand alone byproduct coke plants (i.e., coke plants not located at
iron and steel facilities), emissions from other combustion units would be 2.7 MMTC02e/yr.
(Emissions from the combustion of coke oven gas from coke plants co-located with integrated
iron and steel facilities are included in the estimates for integrated iron and steel facilities.)
1.3 Taconite Iron Ore Processing16
There are eight taconite or pellet production facilities that mine taconite ore from the
Mesabi Iron Ore Range with six facilties in Minnesota and two in Michigan (Table 8). Taconite
ore is transported from the mine to primary crushers, and after crushing, the ore is conveyed to
large storage bins at the concentrator building. In the concentrator building, water is typically
added to the ore as it is conveyed into rod and ball mills, which further grind the taconite ore to
the consistency of coarse beach sand. In a subsequent process step, taconite ore in the slurry is
separated from the waste rock material using a magnetic separation process. The concentrated
taconite slurry then enters the agglomerating process where water is removed from the taconite
slurry using vacuum disk filters or similar equipment. Next, the taconite is mixed with various
binding agents such as bentonite and dolomite in a balling drum that tumbles and rolls the
taconite into unfired pellets. When the unfired pellets exit the balling drum, they are transferred
to a metal grate that conveys them to the indurating furnace. During the indurating process, the
unfired taconite pellets are hardened and oxidized in the indurating furnace at a fusion
temperature between 2,290° to 2,550°F.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
Table 8. Taconite or Pellet Production Facilities 17'18
No.
Facility
City
State
Number of
furnaces
Pellet
capacity
(tpy)
Coal
usage
(tpy)
Natural gas
(MMCF/yr)
1
USS Keetac
Kewatin
MN
2
6,160,000
146,000
292
2
USS Mintac
Mountain
Iron
MN
3
16,352,000
105,833
7,231
3
Empire
Palmer
MI
2
9,408,000
191,067
2,781
4
Tilden
Ishpeming
MI
1
8,802,000
166,589
2,120
5
United
Taconite
Forbes
MN
2
6,608,000
97,100
476
6
Hibbing
Hibbing
MN
2
9,632,000
3,000
7
Northshore
Silver Bay
MN
2
5,376,000
3,591
8
Ispat-Inland
Virginia
MN
2
3,248,000
1,540
Totals
16
65,586,000
706,589
21,031
tpy = short tons per year
MMCF/yr = millions of cubic feet per year
Process Emissions
The primary source of greenhouse gas emissions is the exhaust from the indurating
furnaces. These furnaces are considered to be process sources of GHG emissions rather than
exclusively combustion sources because a significant amount of the CO2 emissions originate
from carbon in the raw materials (dolomite, bentonite, iron ore). The indurating furnaces have
historically been fired with natural gas; however, several plants converted to coal after natural
gas prices surged over the past several years. None of the plants can burn 100 percent coal, and
three of the plants are not permitted to burn coal. Data on fuel type and consumption along with
pellet production rates were obtained for the 2004 to 2005 time period from personal
communications with plant representatives and are shown in Table 9. The fuel consumption data
were scaled up from production rates to capacity to estimate fuel consumption when operating at
capacity.
Test data for CO2 were obtained from a plant burning coal as fuel and from the same
plant when burning natural gas as fuel. 19'20 As shown in Table 9, the CO2 emissions were 0.11
mtC02e/mt pellet when burning coal and 0.072 mtC02e/mt pellet when burning natural gas. The
IPCC default emission factor is 0.03 mtC02e/mt pellet; however, this is apparently based on
carbon in the fuel (natural gas) and does not include the carbon in the feed materials or the use of
coal as fuel. For the CO2 emission estimate, the emission factors from the tests were used for
coal and natural gas, and coal and natural gas consumption was scaled to the 2007 production
rate of 52 million mt of pellets to provide an estimate of 5.6 MMTCC^e for 2007.
Although the indurating furnace is by far the primary source of CO2 emissions, the
taconite facilities also have other combustion units. A review of operating permits indicated that
most of the plants have boilers. Other combustion devices reported include space heaters and
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
emergency diesel generators. One company also operates a power plant at the site to supply
electricity for taconite processing and to supply the electricity grid. 8
Table 9. Test Results for a Taconite Plant
Tilden - natural gas as fuel (March 13,1995)19
Tilden - coal as fuel (July 13, 20
DO)20
pellets (tph)
779
pellets (tph)
609
natural gas (MCF/hr)
289.5
coal (tph)
15.85
CO2 emissions (tph)
56.3
CO2 emissions (tph)
65.8
CO2 emissions (ton/ton pellets)
0.072
CO2 emissions (ton/ton pellets)
0.11
C02 emissions (ton/MCF)
0.194
C02 (ton/ton coal)
4.15
tph = short tons per hour
MCF/hr = thousands of cubic feet per hour
1.4 Electric Arc Furnace (EAF) Steelmaking24
The production of steel in EAFs (minimills) has increased dramatically over the past 30
years. Minimills accounted for 10 percent of the national steel production in 1970, 30 to 40
percent in the 1980s, 40 to 50 percent in the 1990s, and 59 percent in 2007. The growth has been
attributed in part to an expansion in the types and quality of steel products that minimills can
produce, including heavy structurals, rail, plate, specialty bar, hot rolled, cold rolled, galvanized,
and stainless flat rolled products. Most of the steel produced in EAFs is carbon steel used in the
manufacture of construction materials, automobiles, appliances, and other applications.
Approximately 4 percent (about 2 million tons) is specialty and stainless steel, which are high
value steel products. The types of steel are defined by their composition of alloying elements.
Stainless and alloy steels contain less carbon and zinc and more chromium, manganese, and
nickel than carbon steels. Some stainless steel grades contain 12 to 28 percent chromium and 4
to 25 percent nickel. Table 10 lists 91 EAF minimills, their location, and capacity.
Table 10. Electric Arc Furnace Locations and Capacity 22,23
No.
Company
City
State
Capacity (short tons
per year)
Cumulative percent
of capacity
1
Nucor Corporation
Berkeley Co.
SC
3,300,000
4.6
2
Nucor-Yamato Steel
Blytheville
AR
3,277,000
9.1
3
Nucor Corporation
Hickman
AR
2,400,000
12.4
4
Steel Dynamics Inc.
Butler
IN
2,200,000
15.4
5
Sterling Steel
Sterling
IL
2,070,000
18.3
6
Nucor Corporation
Decatur
AL
2,000,000
21.0
7
TXI Chaparral Steel
Midlothian
TX
2,000,000
23.8
8
Nucor Corporation
Crawfordsville
IN
1,900,000
26.4
9
CMC Steel/SMI Steel.
Birmingham
AL
1,855,000
29.0
10
North Star Steel - Blue Scope
Steel
Delta
OH
1,800,000
31.5
11
Steel Dynamics Inc.
Whitley Co.
IN
1,600,000
33.7
12
Gerdau Ameristeel (Gallatin
Steel)
Ghent
KY
1,500,000
35.7
13
Evraz Rocky Mountain Steel
Pueblo
CO
1,200,000
37.4
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
Table 10. Electric Arc Furnace Locations and Capacity 22,23
No.
Company
City
State
Capacity (short tons
per year)
Cumulative percent
of capacity
14
TXI Chaparral Steel
Dinwiddie
VA
1,200,000
39.0
15
Nucor Corporation
Plymouth
UT
1,111,000
40.6
16
Nucor Corporation
Norfolk
NE
1,103,000
42.1
17
Ipsco Inc.
Axis
AL
1,100,000
43.6
18
Ipsco Inc.
Muscatine
IA
1,100,000
45.1
19
Mittal Steel
Steelton
PA
1,100,000
46.7
20
CMC Steel Group/SMI Steel
Cayce
SC
1,089,000
48.2
21
Republic Engineered Steels,
Inc.
Canton
OH
1,050,000
49.6
22
Gerdau Ameristeel
Beaumont
TX
1,002,000
51.0
23
Keystone Steel & Wire
Peoria
IL
1,000,000
52.4
24
Mittal Steel
Georgetown
SC
1,000,000
53.7
25
Nucor Corporation
Cofield
NC
1,000,000
55.1
26
AK Steel Corporation
Butler
PA
960,000
56.4
27
Gerdau Ameristeel
Wilton
IA
917,000
57.7
28
CMC Steel Group/SMI Steel.
Seguin
TX
900,000
59.0
29
Gerdau Ameristeel
Jackson
TN
892,000
60.2
30
Mittal Steel
Coatsville
PA
880,000
61.4
31
Nucor Corporation
Darlington
SC
872,000
62.6
32
Coras Tuscaloosa
Tuscaloosa
AL
870,000
63.8
33
Timken Co.
Canton
OH
870,000
65.0
34
Gerdau Ameristeel
St. Paul
MN
843,000
66.2
35
Nucor Corporation
Seattle
WA
840,000
67.3
36
Gerdau Ameristeel
Perth Amboy
NJ
800,000
68.4
37
North American Stainless
Ghent
KY
800,000
69.5
38
Nucor Corporation
Kankakee
IL
800,000
70.6
39
Gerdau Ameristeel
Sayreville
NJ
750,000
71.7
40
TAMCO
Rancho
Cucamonga
CA
750,000
72.7
41
Gerdau Macsteel
Jackson
MI
725,000
73.7
42
Nucor Corporation
Jewett
TX
725,000
74.7
43
Steel Dynamics
Roanoke
VA
710,000
75.7
44
AK Steel Corporation
Mansfield
OH
700,000
76.6
45
Cascade Steel Rolling Mills,
Inc
McMinnville
OR
700,000
77.6
46
Bayou Steel Corp
LaPlace
LA
683,000
78.6
47
Gerdau Ameristeel
Cartersville
GA
658,000
79.5
48
V&M Star
Youngstown
OH
650,000
80.4
49
Gerdau Ameristeel
Charlotte
NC
622,000
81.2
50
Gerdau Ameristeel
Baldwin
FL
607,000
82.1
51
Gerdau Macsteel
Fort Smith
AR
607,000
82.9
52
Gerdau Ameristeel (formerly
Sheffield Steel)
Sand Springs
OK
600,000
83.7
53
Gerdau Macsteel
Monroe
MI
600,000
84.5
54
NS Group Inc./Koppel Steel
Corp.
Beaver Falls
PA
550,000
85.3
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
Table 10. Electric Arc Furnace Locations and Capacity 22,23
No.
Company
City
State
Capacity (short tons
per year)
Cumulative percent
of capacity
55
Nucor Corporation
Auburn
NY
550,000
86.1
56
Charter Manufacturing
Saukville
WI
515,000
86.8
57
Gerdau Ameristeel
Knoxville
TN
515,000
87.5
58
BetaSteel Corporation
Portage
IN
500,000
88.2
59
Hoeganeas Corp.
Gallatin
TN
500,000
88.9
60
Mittal Steel (Ispat Inland)
East Chicago
IN
500,000
89.6
61
Nucor Corporation
Birmingham
AL
500,000
90.2
62
Nucor Corporation
Jackson
MS
500,000
90.9
63
Severstal
Mingo Junction
OH
500,000
91.6
64
Oregon Steel Mills, Inc.
Portland
OR
499,000
92.3
65
Allegheny Technologies Inc.
Brackenridge
PA
496,000
93.0
66
Carpenter Technology
Reading
PA
450,000
93.6
67
Ellwood Quality Steels
New Castle
PA
410,000
94.2
68
Allegheny Technologies Inc.
Midland
PA
400,000
94.7
69
Evraz Claymont
Claymont
DE
400,000
95.3
70
Marion Steel Co.
Marion
OH
400,000
95.8
71
Mittal Steel
Cleveland
OH
396,000
96.4
72
Erie Forge and Steel
Erie
PA
385,000
96.9
73
Timken Co.
Canton
OH
358,000
97.4
74
Lone Star Steel Inc.
Lone Star
TX
265,000
97.8
75
Border Steel Mills, Inc.
El Paso
TX
250,000
98.1
76
Standard Steel
Burnham
PA
231,000
98.4
77
Arkansas Steel
Newport
AR
130,000
98.6
78
LeTourneau Inc.
Longview
TX
124,000
98.8
79
Hoeganeas Corp.
Riverton
NJ
112,000
98.9
80
Universal Stainless & Alloy
Products, Inc.
Bridgeville
PA
105,000
99.1
81
Steel of West Virginia
Huntington
WV
100,000
99.2
82
Electralloy
Oil City
PA
90,000
99.4
83
Finkl, A., & Sons
Chicago
IL
90,000
99.5
84
Kobelco Metal Powder of
America
Seymore
IN
63,000
99.6
85
Timken Co.
Latrobe
PA
60,000
99.6
86
Standard Steel
Latrobe
PA
59,000
99.7
87
National Forge Co.
Irvine
PA
58,000
99.8
88
Crucible Materials
Syracuse
NY
50,000
99.9
89
Union Electric Steel
Carnegie
PA
35,000
99.9
90
Haynes International
Kokomo
IN
20,000
99.99
91
Champion Steel Co.
Orwell
OH
6,000
100.0
Total
72,460,000
U.S. minimills are the largest recyclers of metal scrap in the world. Recycled iron and
steel scrap nationwide includes approximately 25 percent "home scrap" (from current operations
at the plant), 26 percent "prompt scrap" (from plants manufacturing steel products), and 49
percent post-consumer scrap. The primary source of post-consumer scrap is the automobile, and
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
in 2004, the steel industry recycled 14.2 million tons of iron and steel scrap from 14 million
vehicles.21
EAF Steelmaking 21,24
EAFs are operated as a batch process that includes charging scrap and other raw materials
(loading these materials into the EAF), melting, slagging (removing slag), and tapping (pouring
the molten steel into a ladle). The length of the operating cycle is referred to as the tap-to-tap
time, and each batch of steel produced is known as a "heat." Tap-to-tap times range from 35 to
over 200 minutes with generally higher tap-to-tap times for stainless and specialty steel. Newer
EAFs are designed to achieve a tap-to-tap time of less than 60 minutes.
After ferrous scrap is charged to the EAF, the melting phase begins when electrical
energy is supplied to the carbon electrodes. Oxy-fuel burners and oxygen lances may also be
used to supply chemical energy. Oxy-fuel burners, which burn natural gas and oxygen, use
convection and flame radiation to transfer heat to the scrap metal. During oxygen lancing,
oxygen is injected directly into the molten steel; exothermic reactions with the iron and other
components provide additional energy to assist in the melting of the scrap and removal of excess
carbon. Alloying elements may be added to achieve the desired composition.
Refining of the molten steel can occur simultaneously with melting, especially in EAF
operations where oxygen is introduced throughout the batch. During the refining process,
substances that are incompatible with iron and steel are separated out by forming a layer of slag
on top of the molten metal. After completion of the melting and refining steps, the slag door is
opened, and the furnace is tipped backward so the slag pours out ("slagging"). The furnace is
righted, and the tap hole is opened. The furnace is then tipped forward and the steel is poured
("tapped") into a ladle (a refractory-lined vessel designed to hold the molten steel) for transfer to
the ladle metallurgy station. Bulk alloy additions are made during or after tapping based on the
desired steel grade.
Process Emissions
CO2 emissions are generated during the melting and refining process when carbon is
removed from the charge material and carbon electrodes as carbon monoxide and CO2. These
emissions are captured and sent to a baghouse for removal of particulate matter before discharge
to the atmosphere. The CO2 emission estimate of 4.6 MMTCC^e for EAFs is based on the IPCC
emission factor of 0.08 mtC02e/mt of steel 7 and the production of 58 million mt of steel in 2007.
2
Combustion Emissions
EAF facilities have the same miscellaneous combustion units found at integrated iron and
steel facilities: boilers, process heaters, flares, dryout heaters, soaking pits, reheat furnaces,
annealing furnaces, and ladle reheating. A difference is that the EAF facilities burn natural gas
exclusively in these unit, and integrated facilities burn a combination of fuels (natural gas, coke
oven gas, and blast furnace gas).
Operating permits were reviewed for several EAF facilities, including both small
stainless and specialty steel producers as well as large carbon steel producers, to obtain
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
information on combustion units. As shown in Table 11, the average capacity of the combustion
processes was 5,400 CF of natural gas per ton of steel. C02 emissions were estimated based on
the processes operating at 90 percent of their rated capacity, 1,000 Btu/CF for natural gas, and an
IPCC emission factor of 56.1 mtC02/TJ. 9 The calculation is shown below and results in an
emission factor of 0.32 mtC02e/mt steel from combustion units at EAF facilities:
(5,400 CF/ton)* (0.9)*(56.1 mtC02/TJ)*( 1,000 Btu/CF)*(1.1 ton/mt)/(947.8 E6 Btu/TJ)= 0.32 mtC02e/mt steel.
The production of 58 million mt of steel in EAFs in 2007 results in an emission estimate of 18.6
MMTC02e from combustion units burning natural gas
Table 11. Natural Gas Usage from EAF Operating Permits 8
EAF steel capacity
(short tons per year)
Capacity of combustion
units (MMCF/yr)
Natural gas per
short ton of steel
(CF/short ton)
105,000
584
5,562
385,000
1,839
4,777
410,000
1,564
3,815
500,000
5,600
11,200
607,000
2,847
4,690
960,000
5,718
5,956
3,300,000
6,079
1,842
Average
5,406
1.5 Direct reduced iron (DRI) production
As of December 2006, there were two DRI plants in the U.S., one operating and one shut
down.25 Both are located at EAF steelmaking facilities. The DRI process operates below the
melting point of iron; consequently, the iron from the furnace is in solid form whereas blast
furnaces produce molten iron. The operating plant is owned by Steel Dynamics in Butler, IN and
began operation in 1998. The process feeds iron ore and coal to a rotary hearth furnace fired by
natural gas at 376 million (MM) Btu/hr. 26 The non-operating DRI plant is located at Mittal
Steel's EAF shop in Georgetown, SC. It was built in 1971 with a capacity of 500,000 mt/yr and
was subsequently idled.25
Emission of C02 are generated in the DRI furnace from the combustion of natural gas in
the furnace and from the carbonaceous materials (coal, coke) used to reduce the iron ore into
iron. The IPCC guidelines also note that a small amount of CH4 is emitted from the DRI
process. 10 The CH4 is the primary component of the natural gas used as fuel, and for any type of
process or combustion unit burning natural gas, a small amount of CH4 may be emitted because
of incomplete combustion.
The plant produced about 200,000 mt of iron in 2006 (less than 0.5 percent of the U.S.
total), and this represents about 50 percent of the plant's capacity. Using the IPCC emission
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
factor of 0.7 mtC02e/mt iron for DRI, 10 CO2 emissions are about 0.14 MMTCC^e /yr based on
actual production and about twice that operating at capacity.
1.6 Other Steelmaking Processes
This section discusses miscellaneous processes at iron and steel facilities, and in general,
these processes are not significant emitters of GHGs based on review of test reports that show
C02 levels that are not distinguishable from background. An exception discussed below is
argon-oxygen decarburization, which uses oxygen to remove carbon from steel to make low-
carbon and specialty steels.
Ladle Metallurgy
The molten steel from BOFs and EAFs is transferred to a ladle metallurgy facility (LMF)
for further alloy additions to achieve the desired specifications. The purpose of ladle metallurgy
(also referred to as secondary steelmaking) is to produce steel that satisfies stringent
requirements of surface, internal, and microcleanliness quality and mechanical properties. Ladle
metallurgy is a secondary step of the steelmaking process and is performed in a ladle after the
initial refining process in the primary BOF or EAF is completed. This secondary step enables
plants to exercise control over many processing conditions contributing to a higher quality of
steel including the following:
Temperature, especially for continuous casting operations
Deoxidation
Decarburization (ease of producing steels to carbon levels of less than 0.03 percent)
Addition of alloys to adjust chemical composition.
This step also increases production rates by decreasing refining times in the furnace. Several
LMF processes are commonly used, including vacuum degassing, ladle refining, and lance
powder injection.
Argon Oxygen Decarburization 6,24
Argon oxygen decarburization (AOD) is a process used to further refine the steel outside
the EAF during the production of certain stainless and specialty steels. In the AOD process, steel
from the EAF is transferred into an AOD vessel and gaseous mixtures containing argon and
oxygen or nitrogen are blown into the vessel to reduce the carbon content of the steel. Argon
assists the carbon removal by increasing the affinity of carbon for oxygen. The carbon is
removed from the steel and emitted as CO and CO2, which makes AODs a source of GHG
emissions.
Casting 6
At most plants, the molten steel is transferred from ladle metallurgy to the continuous
caster, which casts the steel into semi-finished shapes (slabs, blooms, billets, rounds, and other
special sections). Although continuous casting is a relatively recent development, it has
essentially replaced the ingot casting method because it increases process yield from 80 percent
to over 95 percent, and it offers significant quality benefits.
Another finishing route, which is not used as frequently as continuous casting, is ingot
casting. Molten steel is poured from the ladle into an ingot mold, where it cools and begins to
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
solidify. The molds are stripped away, and the ingots are transported to a soaking pit or reheat
furnace where they are heated to a uniform temperature. The ingots are shaped by rolling into
semi-finished products, usually blooms, billets, slabs, or by forging. Ingot casting is typically
used for small specialty batches and certain applications for producing steel plates.
Rolling Mills 6
Steel from the continuous caster is processed in rolling mills to produce steel shapes that
are classified according to general appearance, overall size, proportions of the three dimensions,
and intended use. Slabs are always oblong and are mostly 2 to 9 inches thick and 24 to 60 inches
wide. Blooms are square or slightly oblong and mostly in the range of 6 inches by 6 inches to 12
inches by 12 inches. Billets are mostly square and range from 2 inches by 2 inches to 5 inches
by 5 inches. Rolling mills are used to produce the final steel shapes that are sold by the steel
mill, including coiled strips, rails and other structural shapes, sheets, bars, etc.
Other Steel Finishing Processes 6
The semi-finished products may be further processed by a number of different steps, such
as annealing, hot forming, cold rolling, pickling, galvanizing, coating, or painting. Some of these
steps require additional heating or reheating. The additional heating or reheating is accomplished
using furnaces usually fired with natural gas. The furnaces are custom designed for the type of
steel, the dimensions of the semi-finished steel pieces, and the desired temperature.
1.7 Miscellaneous Emissions Sources
There are dozens of emission points and various types of fugitive emissions at integrated
iron and steel facilities. These emissions from iron and steel plants have been of environmental
interest primarily because of the particulate matter in the emissions. Examples include ladle
metallurgy operations, desulfurization, hot metal transfer, sinter coolers, and the charging and
tapping of furnaces. The information EPA has examined to date indicates that fugitive emissions
contribute very little to the overall GHG emissions from the iron and steel sector (probably on
the order of one percent or less). For example, fugitive emissions of blast furnace gas may be
emitted during infrequent process upsets (called "slips") when gas is vented for a short period or
from leaks in the ductwork that handles the gas. However, the mass of GHG emissions is
expected to be small because most of the carbon in blast furnace gas is from carbon monoxide,
which is not a greenhouse gas.27
Fugitive emissions and emissions from control device stacks may also occur from blast
furnace tapping, the charging and tapping of BOFs and EAFs, ladle metallurgy, desulfurization,
etc. However, EPA has no information that indicates CO2 is generated from these operations,
and a review of test reports from systems that capture these emissions show that CO2
concentrations are very low (at ambient air levels).
Fugitive emissions containing methane may occur from leaks of raw coke oven gas from
the coke oven battery during the coking cycle. However, the mass of these emissions is expected
to be small based on the small number of leaks that are now allowed under existing Federal and
State standards that regulate these emissions. In addition, since these emissions are not captured
in a conveyance, there is no practical way to measure them.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
2. TOTAL EMISSIONS
Table 12 summarizes the emission estimates developed in the previous section for each
type of plant and for the major GHG emitting units.
Table 12. Summary of Emission Estimates
Type of facility
Number of
facilities
Emissions (mtC02e/yr)a
Process units
Miscellaneous
combustion
units
Total
Taconite indurating furnaces
8
5,600,000
(b)
5,600,000
Byproduct coke stand alone:
9
l,592,640c
2,654,400
4,247,040
Nonrecovery coke
3
2,953,968c
(b)
2,953,968
EAF facilities
92
4,780,000
18,560,000
23,340,000
Integrated plants:
Byproduct coke co-located
6
1,221,024
1,221,024
Blast furnaces
17
23,934,300d
23,934,300
BOFs
18
4,400,000
4,400,000
Sinter plants
5
2,654,545
2,654,545
Total integrated
18
32,209,869
16,800,000
49,009,869
Total for all facilities
130
47,136,477
38,014,400
85,150,877
a Emission estimates are provided for the predominant GHG (C02). Small amounts of methane (CH4) may also be
emitted because combustion is not complete (i.e., some of the CH4 in fuel may not be combusted), and some CH4
may be emitted from leaks in the equipment that handles the fuels (compressors, valves, flanges). Small amounts of
N20 may be emitted as a by-product of combustion. There is not enough data available to develop a credible
estimate of the emissions of CH4 and N20 for this preliminary analysis.
b No information on combustion units at these plants, but emissions are expected to be small compared to those from
the production processes.
0 From the battery combustion stack.
d From the blast furnace stoves.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
3. REVIEW OF EXISTING PROGRAMS AND METHODOLOGIES
This section presents a review and summary of methodologies for measuring or
estimating greenhouse gas emissions for the iron and steel sector that have been developed by
different international groups, U.S. agencies, and others. The following resources are examined
and their approaches are summarized:
1. 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for National
Greenhouse Gas Inventories. Chapter 4.2 Iron & Steel and Metallurgical Coke
Production.
2. U.S. Environmental Protection Agency (EPA). Inventory of U.S. Greenhouse Gas
Emissions and Sinks: 1990-2006. USEPA #430-R-08-005. April 2008.
http://www.epa.gov/climatechange/emissions/usinventoryreport.html.
3. World Resources Institute (WRI) and World Business Council for Sustainable
Development (WBCSD). Calculating Greenhouse Gas Emissions from Iron and Steel
Production. January 2008. Available at: http://www.ghgprotocol.org/calculation-
tools/iron-and-steel-sector.
4. European Union (EU) Emissions Trading System. 2007/589/EC: Commission Decision
of 18 July 2007 Establishing Guidelines for the Monitoring and Reporting of Greenhouse
Gas Emissions Pursuant to Directive 2003/87/EC of the European Parliament and of the
Council. Available at:
htto://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32007D0589:EN:NOT. July
2007.
5. U.S. Department of Energy (DOE). Technical Guidelines: Voluntary Reporting Of
Greenhouse Gases (1605(B)) Program. Section l.E.4.1.6. Iron and Steel Production.
January 2007.
6. American Iron and Steel Institute (AISI) protocol presented through the Climate Vision
Program. Principles for a Steel Industry Methodology for Reporting Carbon-Related
Energy Sources and Raw Materials.
7. Environment Canada. Guidance Manual for Estimating Greenhouse Gas Emissions.
Primary Iron and Steel Production, http://www.ec.gc.ca/pdb/ghg/guidance e.cfm. 2008.
3.1 2006 IPCC Guidelines 10
The IPCC Guidelines present three tiers for estimating CO2 emissions. The Tier 1 method
uses production-based emission factors in which default emission factors are multiplied by the
quantity of material produced (coke, iron, steel iron ore pellets). For Tier 1, the only site-specific
input that is needed for the emission estimate is the production for the year of interest for coke,
steel, pig iron, direct reduced iron (DRI), sinter, and iron ore pellets.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
The Tier 2 approach for estimating CO2 emissions uses a carbon balance in which carbon
in the process outputs inputs is subtracted from carbon in process inputs, and the difference is
assumed to be converted to CO2. The guidelines provide typical or default values of the carbon
content of process inputs and outputs (e.g., blast furnace gas, coke oven gas, limestone, dolomite,
iron, ferrous scrap, steel). For Tier 2, the site-specific information is needed for the quantity of
process inputs and outputs for each process for the year of interest. The carbon balances are
performed around each process: the coke plant, sinter plant, iron and steel processes combined,
DRI plant, and pellet production.
The Tier 3 approach for C02 emissions uses plant-specific emissions data to estimate
national emissions and describes actual site-specific emission measurements as the preference.
If emission measurements are not available, the next choice is to use site-specific data in the Tier
2 approach and then sum the results across plants to determine national totals.
The Guidelines provide two Tiers for estimating methane (CH4) emissions for coke, iron,
and sinter production. The Tier 1 approach uses a default emission factor, and Tier 3 is based on
plant-specific emissions data. There is no Tier 2 approach for methane.
3.2 U.S. EPA GHG Inventory 28
The current U.S. Inventory methodology for iron and steel and metallurgical coke
production uses a mass balance approach based on an estimate of the amount of carbon
contained in the steel produced, metallurgical coke oven byproducts produced, and pig iron
produced and used for non-steel purposes. This amount of carbon is deducted from the carbon
introduced into the iron and steel production process from metallurgical coke produced from
coking coal, metallurgical coke consumed for pig iron production, and scrap steel consumed at
steel plants. In addition, the amount of carbon generated from carbon anode consumption for
steel produced in an electric arc furnace is estimated. The difference between the carbon inputs
to metallurgical coke and iron and steel production and carbon outputs from these processes
constitutes the CO2 emissions from these processes.
The U.S. Inventory methodology does not account for certain other carbon inputs to the
process including natural gas, limestone, etc. The GHG emissions from these other carbon
inputs are included (but not separately identified) elsewhere in the U.S. Inventory (e.g., Energy,
Lime, Limestone, and Dolomite use, etc.). The U.S. Inventory methodology also does not
include consumption of raw materials for sinter, pellet, and direct reduced iron production; the
GHG emissions from these other processes are included (but not separately identified) in the
"Energy" section of the Inventory. Methane emissions from metallurgical coke production and
pig iron production are estimated using emission factors and activity data. Emissions of CO2 and
CH4 associated with metallurgical coke production and iron and steel production are attributed to
the Industrial Processes chapter of the U.S. Inventory.
3.3 WRI/WBCSD Calculation Procedure 29
The WRIAVBCSD protocol presents two procedures for estimating CO2 emissions from
the production of coke, sinter, DRI, and iron and steel, and both use a carbon balance approach.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
The preferred approach is Tier 3, which uses facility-specific data for carbon content of all
process inputs and outputs and the mass rate of all process inputs and outputs. In the absence of
facility-specific data, Tier 1 default factors for carbon contents of inputs and outputs are
provided. C02 emissions from flaring are based on the volume of gas flared, the carbon content
of the gas, and a combustion efficiency of 98 percent. CH4 emissions from flaring are estimated
by assuming 2 percent of the CH4 in the gas is not burned. The WRI/WBCSD provides equations
for estimating CH4 emissions from the production of coke, sinter, pig iron, and DRI; CH4
emissions from steelmaking are assumed to be negligible. In the absence of facility-specific data
that would allow the derivation of Tier 3 emission factors, equations and default emission factors
(Tier 1) are provided for CH4 emissions for all of these processes except for pig iron production.
3.4 European Union (EU) Emissions Trading System 30
Source streams are defined as: (1) "de-minimus" sources that collectively contribute less
than 1,000 mt CCVyr or that contribute less than 2% of total emissions up to 20,000 mt/yr); (2)
"minor" sources that collectively contribute less than 5,000 mt C02/yr or that contribute less than
10% of total emissions up to 100,000 mt/yr); and (3) "major" sources that include all other
streams. The highest tier must be used for major source streams unless it is not technically
feasible. Tier 1 can be used for minor source streams, and a facility may use their own no-tier
method for de-minimius streams.
Annex V addresses sinter and iron ore pellets plants, and Annex VI addresses pig iron
and steel manufacture, including continuous casting. If the process is part of a larger integrated
iron and steel plant, the operator is given the choice of a carbon balance approach around either
the entire plant or around each process. The tiers relate to the quality of the input data:
Tier
Uncertainty in mass flow of inputs and outputs
must be less than
Carbon content
1
±7.5%
Default (typical) values
2
±5.0%
Country-specific values
3
±2.5%
Analysis of representative samples
4
±1.5%
This approach is similar to the IPCC Tier 2/3 methods.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
3.5 DOE Technical Guidelines 31
The DOE guidelines provide 3 general approaches for the production of iron and steel
that are given a rating of A, B, or C. A rating of "A" is for approaches that use a carbon balance
around the process with site-specific data for process inputs, outputs, and carbon content.
Default values are given for carbon content, and if the default values are used, the approach is
given a rating of "B". The "C" rating is assigned when emissions are simply estimated as 1.75
MT C02/ton of steel. The approach focuses on the streams that contain the most carbon:
limestone, dolomite, coke/coal, iron, steel, and graphite electrodes. The approach does not
consider slag or air pollution control residues (dusts and sludges) that are not likely to contain
much carbon.
3.6 AISI Methodology 32
The AISI methodology is based on a net carbon balance within the fence line of the facility.
Their approach states that:
...if all of the carbon in metallurgical coal is accountedfor by the total quantity of
coal entering a plant, it is not necessary to determine if that carbon is ultimately
emitted as CO 2 emissions from coke battery stacks, blast furnace stoves, flares,
boilers, BOF off-gas, or other sources of byproduct fuel combustion. It is only
important to make adjustments for carbon that may leave the plant boundary in a
form other than CO2 (e.g., sold or transferred coke, tar, byproducts, or byproduct
fuels such as blast furnace gas or coke oven gas). Adjustments can also be made for
carbon contained in steel products if deemed to be significant.
The carbon balance focuses on the streams contributing the most carbon and do not
include minor contributors, such as iron ore, scrap, semi-finished steel, or ferroalloys.
However, raw materials with intrinsic carbon content (e.g., iron carbide, carbon
electrodes, charge carbon, limestone) should be reported if they are significant. In
addition, adjustment (subtraction) should be made for offsite transfer of process gases,
slag, scrap, or coke by-products if they are significant. They suggest emissions less than
1% of the facility's total should be considered de minimus.
The methodology includes a simple reporting form that requests the quantity of all
fuels by type, all carbon-containing materials consumed onsite, and the amount of steel
produced by BOFs and by EAFs. The form also requests information on the amount of
electricity and steam that was purchased. The methodology also provides factors that
convert fuel and raw material quantities to CO2 emissions (e.g., 5,540 lb CO^ton of
coking coal).
3.7 Environment Canada Guidance Manual 33
The guidance for mandatory reporting in Canada primarily references the IPCC
guidelines. However, the guidance also contains a section on developing a site-specific
emission factor rather than using default emissions factors with these observations:
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
A facility-specific emission factor is preferred over general or industry-averaged
factors because they provide a better representation of emissions from a facility's
specific operations. It may be necessary to update facility-specific emission
factors on a periodic basis to account for changes in facility conditions.
Obtaining emissions data by continuous emissions monitoring system (CEMS) is
the preferred method when data on emissions are needed over an extended period.
There are various types of monitoring systems available for installation, which
use different instrumentation equipment. It is necessary for the facility to ensure
the proper operation and calibration of the monitoring equipment used.
Stack sampling and analysis can be used to obtain direct data on emissions over a
short period (during the period of the test). Details on the sampling method and
lab techniques used should be provided if you choose to collect facility data
through this method. Standardized sampling and lab analysis protocols should be
used when available.
3.8 Current Practices for Estimating Greenhouse Gas Emissions
The current practice of many U.S. iron and steel companies as well as international iron
and steel facilities is to voluntarily report GHG emission intensity (e.g., in terms of
MMTC02e/mt steel produced). Many of these facilities are using the methodologies described
in the WRI/WBCSD protocol.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
4. TYPES OF INFORMATION TO BE REPORTED
Based on the review of existing programs and the emission sources at iron and
steel facilities, the major GHG (by far) to be reported is C02. However, CH4 is emitted
due to incomplete combustion, and N2O is emitted as a byproduct of combustion. These
are the three major GHGs to be reported for the iron and steel industry.
The type of information to be reported will depend in large part on the option
chosen for determining GHG emissions. However, in order to check the reported GHG
emissions for reasonableness and for other data quality considerations, certain types of
typical information about the emission sources is needed. The following items are
recommended for reporting to assist in checks for reasonableness and for other data
quality considerations:
1. Annual emission estimates for CO2 presented by calendar quarters for coke oven battery
combustion stacks, coke pushing, blast furnace stoves, taconite indurating furnaces,
BOFs, EAFs, DRI furnaces, and sinter plants;
2. Annual emission estimates for CH4 and N2O presented by calendar quarters for each type
of fuel that is burned;
3. Total for all process inputs and outputs when the carbon balance is used for specific
processes by calendar quarters;
4. Site-specific emission factor for all processes for which the site-specific emission factor
approach is used;
5. Annual production quantity for taconite pellets, coke, sinter, iron, raw steel by calendar
quarters (in metric tons);
6. Annual production capacity for taconite pellets, coke, sinter, iron, raw steel; and
7. Annual operating hours for taconite furnaces, coke oven batteries, sinter production, blast
furnaces, DRI furnaces, EAFs, and BOFs.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
5. OPTIONS FOR REPORTING THRESHOLDS
In evaluating potential thresholds for iron and steel production, EPA considered
emissions-based thresholds of 1,000 mtC02e, 10,000 mtC02e, 25,000 mtC02e, and 100,000
mtC02e. Table 14 summarizes the emission estimates developed in the previous sections and
shows that the average emission level for each type of plant is well above the thresholds.
However, there are several small EAF facilities that would fall below some of the thresholds.
Table 15 illustrates the various thresholds and their estimated effect on the amount of
emissions that would be covered (reported). All integrated iron and steel facilities and taconite
facilities exceed the highest emissions threshold considered. Most EAF facilities (with the
possible exception of about 11 facilities) are estimated to exceed the 25,000 mtC02e emissions
threshold. Table 15 also provides an estimate of the production level that corresponds to the
emission thresholds. The production thresholds are estimated from the emission factors
developed earlier for EAF processes (0.08 mtC02e/mt steel) and combustion sources (0.32
mtC02e/mt steel).
Table 14. Summary of Emission Estimates
Facility
Number
of plants
Production
(mt/yr)
Type of
production
Total
emissions
(mtC02e)
Average per
plant
(mtC02e)
Taconite
8
52,000,000
pellets
5,600,000
700,000
Byproduct coke stand alone
9
7,056,000
coke
4,247,040
471,893
Nonrecovery coke
3
2,234,400
coke
2,953,968
984,656
Integrated plants
18
40,000,000
steel
49,009,869
2,722,771
EAF
92
58,000,000
steel
23,340,000
253,696
Total facilities
130
159,290,400
products
85,150,877
655,007
Table 15. Reporting Thresholds
Production
Total national
Total
Emissions covered
Facilities covered
Threshold
threshold
emissions
number of
level mtC02e
(mt/yr)
(mtC02e)
U.S. facilities
mtC02e/yr
Percent
Number
Percent
all in
0
85,150,877
130
85,150,877
100.0
130
100
1,000
2,500
85,150,877
130
85,150,877
100.0
130
100
10,000
25,000
85,150,877
130
85,141,423
99.99
128
98
25,000
62,500
85,150,877
130
85,013,059
99.8
121
93
100,000
250,000
85,150,877
130
84,468,696
99.2
111
85
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
6. OPTIONS FOR MONITORING METHODS
6.1 C02 Emissions from Process Sources
The monitoring methods for the iron and steel sector include emissions from stationary
combustion sources and from process sources. The methods for combustion sources, where the
only source of CO2 emissions is the carbon in the fuel, are addressed separately for stationary
combustion sources in general. (See the technical support document for general stationary fuel
combustion sources for more details EPA-HQ-OAR-2008-0508-004.) This section summarizes
the monitoring methods for process sources, which are defined as sources in which the process
feed materials, usually in addition to the fuel, contribute the carbon for CO2 emissions. The
affected processes are each indurating furnace, BOF, nonrecovery coke oven battery, coke
pushing operation, sinter plant, direct reduction furnace, and EAF.
The approach to develop the monitoring options was to consider accuracy, uncertainty,
completeness, and comparability in the estimates; whether they were technically feasible,
reasonably easy to implement, and cost effective; and if they provided adequate flexibility to the
owner or operator. The five options that were developed from the review of existing methods for
monitoring CO2 emissions from the process sources are described below:
1. Option 1: Apply a default emission factor based on the type of process and an
annual activity rate (e.g. quantity of raw steel, sinter, or direct reduced iron
produced). This option is the same as the IPCC Tier 1 approach.
2. Option 2: Perform a carbon balance of all inputs and outputs using default or
typical values for the carbon content of inputs and outputs. Use facility
production and other records to determine the annual quantity of process inputs
and outputs. Calculate CO2 emissions from the difference of carbon-in minus
carbon-out assuming all is converted to CO2. This option is the same as the IPCC
Tier 2 approach, the WRI default approach, and the DOE 1605(b) approach that is
rated "B." It is similar to the approach recommended by AISI except that the
carbon balance for Option 2 is based on the individual processes rather than the
entire plant.
3. Option 3: Perform a monthly carbon balance of all inputs and outputs using
measurements of the carbon content of specific process inputs and process outputs and
measure the mass rate of process inputs and process outputs. Calculate CO2 emissions
from the difference of carbon-in minus carbon-out assuming all is converted to CO2.
This is the IPCC Tier 3 approach (if direct measurements are not available), the WRI
preferred approach, the approach used in the EU Emissions Trading Scheme, and the
DOE 1605(b) approach that is rated "A."
4. Option 4: Develop a site-specific emission factor based on simultaneous and accurate
measurements of CO2 emissions and production rate or process input rate during
representative operating conditions. Multiply the site-specific factor by the annual
production rate or appropriate periodic production rate (or process input rate, as
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
appropriate). This approach is included in Environment Canada's methodologies and
might be considered a form of direct measurement as in the IPCC's Tier 3 approach.
5. Option 5: Direct and continuous measurement of C02 emissions using a continuous
emission monitoring system (CEMS) for CO2 concentration and stack gas volumetric
flow rate based on the requirements in 40 CFR part 75. This is the IPCC Tier 3 approach
(direct measurement).
Two characteristics of Options 1 and 2 are the use of default values and lack of
direct measurements, which results in a very high level of uncertainty in the emission
estimates. These default approaches will not provide site-specific estimates of emissions
that will reflect differences in feedstocks, operating conditions, fuel combustion
efficiency, variability in fuels and other differences among facilities. Methodologies
based on default values have commonly been used more for sector wide or national total
estimates from aggregated activity data than for determining emissions from a specific
facility.
Options 3, 4, and 5 use approaches that provide good site-specific estimates of emissions
that reflect differences in feedstocks, operating conditions, fuel combustion efficiency, and other
differences among plants. These three options span the range of types of methodologies
currently used that do not apply default or typical values. The options also provide flexibility.
For example, a C02 CEM may be the most accurate measurement method: however, it may
expensive except for the largest emission sources, it would certainly be expensive for sources
with multiple stacks, and it is not feasible for certain sources, such as flares and other emission
points where emissions are not captured in a conveyance (e.g., a stack). In those cases, one of
the other two options would be more appropriate.
Several iron and steel companies in the U.S. and abroad have recommended and are using
a carbon balance approach similar to or a variation of the one described in Option 3. Many of
the measurements required for that approach, such as the amount of specific feedstocks
consumed, production rates from each process, process gas (coke oven gas, blast furnace gas)
production and consumption, and purchased fuel consumption, are already routinely measured
and used for accounting purposes (e.g., determining the cost of production), process control, and
yield calculations. In addition, most plants monitor the composition of blast furnace gas and
coke oven gas for process control and to ensure gas quality for combustion, and the carbon
content of steel is routinely determined because it is a quality specification. Consequently,
Option 3 offers an advantage in that it would use a significant amount of information that is
already readily available.
According to the IPCC's 2006 guidelines, the uncertainty associated with default
emission factors for Options 1 and 2 is ±25 percent, and the uncertainty in the production data
used with the default emission factor is ±10 percent,10 which results in a combined overall
uncertainty greater than ±25 percent. If process-specific carbon contents and actual mass rate
data for the process inputs and outputs are used (i.e., Option 3) or if direct measurements are
used (i.e., Options 4 and 5), the guidelines state that the uncertainty associated with the emission
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
estimates would be reduced. Options 3, 4, and 5 meet the requirements of the IPCC's highest
tier methodology (Tier 3).10
6.2 Methane and Nitrous Oxide Emissions
A small amount of CH4 is emitted when any fuel that contains CH4 is burned, in either
process units or combustion units, because combustion is not complete (i.e., a small amount of
methane escapes unburned). A small amount of N20 is produced as a combustion byproduct
when fuel is burned. For coke oven gas and blast furnace gas that are used as fuels, the
recommended approach for estimating emissions of CH4 and N20 is to use the same
methodology as that used for combustion units and to apply the default emission factor presented
for natural gas, which is the procedure used in the IPCC Guidelines for coke oven gas and blast
furnace gas,9 and the measured high heating value.
6.3 C02 Emissions from Coke Pushing Operations
Emissions may also occur when the incandescent coke is pushed from the coke oven and
transported to the quench tower where it is cooled (quenched) with water. A small portion of the
coke burns during this process prior to quenching. EPA updated the coke oven section of the
AP-42 compilation of emission factors in May 2008, and the update included an emission factor
for C02 emissions developed from 26 tests for particulate matter from pushing operations.13 The
emissions factor (0.008 mtC02e per metric ton of coal charged) was derived to account for
emissions from the pushing emission control device and those escaping the capture system. The
recommended approach is for coke facilities to use the AP-42 emission factor to estimate C02
emissions from coke pushing operations.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
7. OPTIONS FOR ESTIMATING MISSING DATA
For process sources that use Option 3 (carbon balance) or Option 4 (site-specific
emission factor), no missing data procedures are appropriate because 100 percent data
availability would be required. (There are no valid reasons for missing data for these options
because re-testing for the site-specific emission factor can be performed at any time, and for the
carbon balance, only a weekly sample would be necessary). For process sources that use Option
5 (direct measurement by CEMS), the missing data procedures that are appropriate are the same
as for units using Tier 4 in the general stationary fuel combustion source category.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
8. QA/QC REQUIREMENTS
For the carbon balance approach, the following QA/QC procedures would better ensure
the quality of the reported emissions:
For each process input and output other than fuels, the carbon content could be analyzed
by a third-party certified laboratory using the test methods (and their QA/QC procedures)
in the General Provisions (subpart A) of the proposed rule.
Facilities could keep records that include a detailed explanation of how company records
of measurements are used to estimate all sources of carbon input and output. The owner
or operator also could document the procedures used to ensure the accuracy of the
measurements of fuel usage including, but not limited to, calibration of weighing
equipment, fuel flow meters, and other measurement devices. The estimated accuracy of
measurements made with these devices could also be recorded, and the technical basis for
these estimates provided. The procedures and equations used to convert the fuel feed
rates to units of mass also could be documented.
Records could be made available for verification of the records and measurements upon
request.
For the site-specific emission factor approach, the following QA/QC elements were identified:
The QA/QC procedures in the EPA reference test methods could be followed.
The results of a performance test could include the analysis of samples, determination of
emissions, and raw data. The performance test report could contain all information and
data used to derive the emission factor.
For each of the options, all QA/QC data from each facility in the iron and steel
production source category should be available for inspection upon request.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
9. REFERENCES
1. International Iron and Steel Institute. World Steel in Figures 2007. Available at
http://www.worldsteel.org/?action=programs&id=52.
2. Fenton, Michael. USGS Mineral Commodity Summary 2008. Iron and Steel. Available
at http://minerals.usgs.gov/minerals/pubs/mcs/2008/mcs20Q8.pdf. January 2008.
3. Jorgeson, John. USGS Mineral Commodity Summary 2008. Iron Ore. Available at
http://minerals.usgs.gov/minerals/pubs/mcs/2008/mcs20Q8.pdf. January 2008.
4. Energy Information Administration (EIA), Quarterly Coal Report. Available at
http://www.eia.doe.gov/cneaf/coal/quarterlv/html/t3p01pl.pdf. 2008.
5. International Iron and Steel Institute. Direct reduced iron production, 2001 to 2006.
Available at http://www.worldsteel.org/?action=storypages&id=204.
6. U.S. EPA. National Emission Standards for Hazardous Air Pollutants (NESHAP) for
Integrated Iron and Steel PlantsBackground Information for Proposed Standards. EPA-
453/R-01-005. January 2001.
7. United States Steel. The Making, Shaping, and Treating of Steel. Published by the
Association of Iron and Steel Engineers (AISE). Available from AISE at Suite 2350,
Three Gateway Center, Pittsburgh, PA.
8. Compiled from operating permits posted on state agency websites, including
http://www.dep.state.wv.us/item.cfm?ssid=8; http://www.air.ky.gov/permitting/:
http://www.epa.gov/ARD-R5/permits/epermits.htm:
http://www.in.gov/idem/permits/air/pending.html: http J/www, epa. gov/ARD-
R5/permits/epermits.htm; http://www.deq.state.mi.us/aps/: http://www.epa.gov/ARD-
R5/permits/epermits.htm; http://www.epa.state.oh.us/dapc/title v/permits/tvpermit.html.
9. 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for National
Greenhouse Gas Inventories. Volume 2: Energy, Chapter 2 Stationary Combustion.
Available at: http://www.ipcc-nggip.iges.or.ip/public/2006gl/vol2.html.
10. 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for National
Greenhouse Gas Inventories. Volume 3: Industrial Processes and Product Use,
Chapter 4.2 Iron & Steel and Metallurgical Coke Production. Available at:
http://www.ipcc-nggip.iges.or.ip/public/2006gl/vol3.html.
11. American Iron and Steel Institute (AISI). Annual Statistics 2005. Consumption of Fuels.
2006.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
12. U.S. EPA. National Emission Standards for Hazardous Air Pollutants (NESHAP) for
Coke Ovens: Pushing, Quenching, and Battery Stacks Background Information for
Proposed Standards. EPA-453/R-01-006. February 2001.
13. U.S. Environmental Protection Agency. AP-42 Section 12.2: Coke Production.
Available at http://www.epa.gov/ttn/chief/ap42/chl2/final/cl2s02 mav08.pdf. May
2008.
14. Memorandum with attachments, S. Burns, RTI, to the docket, enclosing data compiled
from EPA Section 114 survey responses of coke plants, July 1998. Docket Item II-I-45
in Docket Number A-2000-34.
15. URS Corporation. Compliance Test Report for Haverhill Coke Company, Franklin
Furnace, Ohio. March 2006.
16. Federal Register (67 FR 77565). Preamble for National Emission Standards for
Hazardous Air Pollutants for Taconite Iron Ore Processing; Proposed Rule. December
18, 2002.
17. U.S. Environmental Protection Agency (EPA). National Emissions Standard for
Hazardous Air Pollutants (NESHAPs) for Taconite Iron Ore Processing Plants-
Background Information for Proposed Standards. Table 2.1-3 on page 2-6: Taconite
Pellet Plants, Capacity, and Production. In EPA Docket ID No. OAR-2002-0039. 2001.
18. Minnesota Pollution Control Agency. Taconite Iron Ore Industry in the United States.
Submitted to the US EPA. Docket Item IV-D-05 in Docket No. OAR-2002-0039.
December 30, 1999.
19. Network Environmental, Inc. Emission Study Performed for the Tilden Magnetitie
Partnership. Unit #2 at Tilden Mine, National Mine, Michigan. March 13, 1995.
20. Network Environmental, Inc. Tilden Mining Company L.C. Particulate and Hg Emission
Study. July 13, 2000.
21. Federal Register (72 FR 53818). Preamble for National Emission Standards for
Hazardous Air Pollutants for Electric Arc Furnace Steelmaking Facilities; Proposed Rule.
September 20, 2007.
22. U.S. Environmental Protection Agency. Summary of EAF Survey Responses from
Section 114 Questionnaire for 27 EAF Steelmaking Facilities. May 2004. Available in
EPA Docket No. EPA-HQ-OAR-2004-0083.
23. Iron & Steel Society. Iron and Steelmaker Electric Arc Furnace Roundup. May 2003.
pp. 38-49.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
24. U.S. Environmental Protection Agency. Electric Arc Furnaces andArgon-
Decarburization Vessels in the Steel Industry - Background Information for Proposed
Revisions to the Standard. EPA-450/3-82-020a. July 1983.
25. Midrex Technologies, Inc. 2006 World Direct Reduction Statistics. Available at
http://www.midrex.com. 2007.
26. Title V Operating Permit issues to Iron Dynamics, Inc., Butler, Indiana by the Indiana
Department Of Environmental Management. October 4, 2006.
27. Branscome, M., and S. Burns. 2006. Evaluation of PM2.5 Emissions and Controls at Two
Michigan Steel Mills and a Coke Oven Battery. Prepared for the Air Quality Strategies
and Standards Division, Office of Air Quality Planning and Standards, U.S.
Environmental Protection Agency, Research Triangle Park, NC. Available at
http://epa.gov/air/caaac/aqm/detroit steel report final 20060207.pdf.
28. U.S. Environmental Protection Agency (EPA). Inventory of U.S. Greenhouse Gas
Emissions and Sinks: 1990-2006. USEPA #430-R-08-005. April 2008.
http://www.epa.gov/climatechange/emissions/usinventoryreport.html.
29. World Resources Institute (WRI) and World Business Council for Sustainable
Development (WBCSD). Calculating Greenhouse Gas Emissions from Iron and Steel
Production. January 2008. Available at: http://www.ghgprotocol.org/calculation-
tools/iron-and-steel-sector.
30. European Union (EU) Emissions Trading Scheme. 2007/589/EC: Commission Decision
of 18 July 2007 Establishing Guidelines for the Monitoring and Reporting of Greenhouse
Gas Emissions Pursuant to Directive 2003/87/EC of the European Parliament and of the
Council. Available at:
http://eurex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32007D0589:EN:NOT. July
2007.
31. U.S. Department of Energy (DOE). Technical Guidelines: Voluntary Reporting Of
Greenhouse Gases (1605(B)) Program. Section l.E.4.1.6. Iron and Steel Production.
January 2007.
32. American Iron and Steel Institute (AISI) protocol presented through the Climate Vision
Program. Principles for a Steel Industry Methodology for Reporting Carbon-Related
Energy Sources and Raw Materials.
33. Environment Canada. Guidance Manual for Estimating Greenhouse Gas Emissions.
Primary Iron and Steel Production, http://www.ec.gc.ca/pdb/ghg/guidance e.cfm. 2008.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
APPENDIX A. DEFINITIONS AND THEIR ORIGINS
Argon-oxygen decarburization vessel means any closed-bottom, refractory-lined
converter vessel with submerged tuyeres through which gaseous mixtures containing argon and
oxygen or nitrogen may be blown into molten steel for further refining to reduce the carbon
content of the steel.a
Basic oxygen furnace means any refractory-lined vessel in which high-purity oxygen is
blown under pressure through a bath of molten iron, scrap metal, and fluxes to produce steel.b
Blast furnace means a furnace that is located at an integrated iron and steel facility and is
used for the production of molten iron from iron ore pellets and other iron bearing materials.11
By-product coke oven battery means a group of ovens connected by common walls,
where coal undergoes destructive distillation under positive pressure to produce coke and coke
oven gas from which by-products are recovered.c
Cokemaking facility means a facility that produces coke from coal in either a by-product
coke oven battery or a non-recovery coke oven battery.c
Direct reduction furnace means a high temperature furnace typically fired with natural
gas to produce solid iron from iron ore or iron ore pellets and coke, coal, or other carbonaceous
materials.11
Electric arc furnace (EAF) means a furnace that produces molten steel and heats the
charge materials with electric arcs from carbon electrodes. The charge materials in the electric
arc furnace is primarily recycled ferrous scrap but also may include direct reduced iron or molten
iron from the blast furnace.a
Electric arc furnace (EAF) steelmaking facility means a facility that produces carbon,
alloy, or specialty steels using an EAF. This definition excludes EAFs at steel foundries and
EAFs used to produce nonferrous metals.a
Indurating furnace means a furnace where unfired taconite pellets, called green balls, are
hardened at high temperatures to produce fired pellets for use in a blast furnace. Types of
indurating furnaces include straight gate and grate kiln furnaces.6
Integrated iron and steel manufacturing facility means a facility engaged in the
production of steel from iron ore or iron ore pellets. At a minimum, an integrated iron and steel
facility has a basic oxygen furnace for refining molten iron into steel.b'f
Non-recovery coke oven battery means a group of ovens connected by common walls
and operated as a unit, where coal undergoes destructive distillation under negative pressure to
produce coke, and which is designed for the combustion of the coke oven gas from which by-
products are not recovered.6
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
Pushing means the process of removing the coke from the coke oven at the end of the
coking cycle. Pushing begins when coke first begins to fall from the oven into the quench car
and ends when the quench car enters the quench tower.c
Sinter process means a process that produces a fused aggregate of fine iron-bearing
materials suited for use in a blast furnace. The sinter machine is composed of a continuous
traveling grate that conveys a bed of ore fines and other finely divided iron-bearing material and
fuel (typically coke breeze), a burner at the feed end of the grate for ignition, and a series of
downdraft windboxes along the length of the strand to support downdraft combustion and heat
sufficient to produce a fused sinter product.b
Taconite iron ore processing facility means a facility that separates and concentrates iron
ore from taconite, a low grade iron ore, and heats the taconite in an indurating furnace to produce
taconite pellets that are used as the primary feed material for the production of iron in blast
furnaces at integrated iron and steel facilities.6
Origins:
a40 CFR Part 63, Subpart YYYYY. National Emission Standards for Hazardous Air Pollutants
for Area Sources: Electric Arc Furnace Steelmaking Facilities.
b 40 CFR Part 63, Subpart FFFFF. National Emission Standards for Integrated Iron and Steel
Manufacturing.
c 40 CFR Part 63, Subpart CCCCC. National Emission Standards for Hazardous Air Pollutants
for Coke Ovens: Pushing, Quenching, and Battery Stacks.
d The definition of "direct reduction furnace" was developed from the process description in The
Making, Shaping, and Treating of Steel (Reference 7) because there is no definition codified in
40 CFR.
e 40 CFR Part 63, Subpart RRRRR. National Emission Standards for Taconite Iron Ore
Processing.
This definition in 40 CFR was modified by adding "and iron ore pellets" because most
integrated plants use pellets in the blast furnace rather than iron ore. Also added "At a minimum,
an integrated iron and steel facility has a basic oxygen furnace for refining molten iron into steel"
because one integrated plant recently shut down the onsite blast furnace, but continues to operate
the BOFs with molten iron supplied by a nearby plant.
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
APPENDIX B. EXAMPLES OF COMBUSTION UNITS
Table B-l. Examples of Combustion Unit at Minimills 8
Plant Name
City
State
C02 source
Universal Stainless and Alloy Products
Bridgeville
PA
Ladle Reheat Furnace
Vessel Reheat Furnace
Electro-Slag Remelt Holding Furnace
Annealing Furnaces
Plate Warming Furnace
Miscellaneous space heating units (75)
Erie Forge and Steel
Erie
PA
North American Steam Boiler
Ladle preheaters
Ladle refining furnace
Heat treat furnaces
Hood furnace
Ellwood Quality Steels Company
New Castle
PA
Boilers (4)
Oxy-fuel burner (for EAF)
Anneal furnaces
Scrap torching
Ladle preheaters
EAF pre-heater
AK Steel Corporation
Butler
PA
Boilers
Spaceheaters >2.5 MMBtu/hr
Electric furnace
Slab heating furnaces
Decarb furnace
Silicon drying furnace
AOD reactor
Continuous caster
Vacuum degas
Anneal furnaces
Drying furnace
Carlite line dry furnace
Ladle preheaters
Electroalloy
Oil City
PA
Miscellaneous NG (<2.5 MMBtu/hr)
Anneal furnaces
Granular metal process
Ladle preheaters for melt shop
Nucor Steel
Blytheville
AR
Pickle line boilers
Galvanizing line
Alkali wash burners
Chromate spray dryer
Annealing furnaces
Tunnel furnace
Ladle preheaters
Ladle dryouts
Vertical holding stations
Tundish preheaters
Tundish dryers
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
Table B-l. Examples of Combustion Unit at Minimills 8
Plant Name
City
State
C02 source
Oregon Steel Mills Rivergate Plant
Portland
OR
Oxide reformer furnace
Vacuum Degasser Boiler
Degasser stack flare
Other natural gas sources
Glass frit rotary dryer
Low NOx natural gas sources
Heat treat facility
Quanex Corporation - MacSteel Division
Fort Smith
AR
Natural gas-fired boiler
Tundish preheaters
Three ladle preheaters
One ladle dryout, six refractory dryers
Reheat furnace
Boiler
Heat treating furnaces
Car bottom furnace
Table B-2. Reported Fuel Usage at U.S. Steel's Integrated Plant in Michigan (2004)28
Source
Fuel
MMCF/yr
No. 2 Boilerhouse
Blast furnace gas
30,711
D blast furnace stove
Blast furnace gas
30,397
B blast furnace stove
Blast furnace gas
28,145
Blast furnace flares
Blast furnace gas
28,059
No. 1 Boilerhouse
Blast furnace gas
21,290
Mill furnace heaters
Coke oven gas
4,647
Mill furnace heaters
Natural Gas
3,163
No. 2 Boilerhouse
Coke oven gas
2,773
No. 1 Boilerhouse
Coke oven gas
1,917
No. 1 Boiler
Coke oven gas
987
Heaters
Natural Gas
590
Dryout Heaters
Natural Gas
580
Heaters
Natural Gas
428
Process Heaters
Natural Gas
393
Boiler
Natural Gas
268
Annealing Heaters
Natural Gas
228
No. 2 Boilerhouse
Natural Gas
208
No. 1 Boiler
Natural Gas
135
B blast furnace stove
Natural Gas
126
Annealing Heaters
Natural Gas
122
BOF operation
Natural Gas
121
No. 3 Boilerhouse
Natural Gas
107
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