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
September 9, 2008
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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 (EOF) 6
1.1.3 Sintering 8
1.1.4 Miscellaneous Combustion Sources 9
1.2 Coke Production 10
1.3 Taconite Iron Ore Processing16 14
1.4 Electric Arc Furnace (EAF) Steelmaking24 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 GHG Inventory 28 25
3.3 WRI/WBCSD Calculation Procedure 2925
3.4 European Union (EU) Emissions Trading Scheme 30 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 COi Emissions from Process Sources 31
6.2 Methane and Nitrous Oxide Emissions 33
6.3 COi 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 l
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 (MMTCC^e/yr) or just over 1 percent of total U.S. GHG
emissions. Emissions from both process units (47 million MMTCC^e/yr) and miscellaneous
combustion units (38 million MMTCC^e/yr) are significant.a Small amounts of N2O and CFLi
are also emitted during the combustion of different types of fuels. The primary process units that
emit GHG emissions are BF stoves (24 million MMTCC^e/yr), taconite indurating furnaces,
BOFs, EAFs (about 5 million MMTCC^e/yr each), coke oven battery combustion stacks (6
million MMTCC^e/yr), and sinter plants (3 million MMTCC^e/yr). Smaller amounts of GHG
emissions are produced by coke pushing (160,000 MMTCC^e/yr) and DRI furnaces (140,000
MMTCO2e/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 million MMTCO2e/yr for integrated iron and steel facilities, 18.6 million MMTCO2e/yr
for EAF steelmaking facilities, and 2.7 million MMTCO2e/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.
' 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.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Plants with Blast Furnaces (BF)
Mittal (formerly Ispat-Inland)
US Steel
Mittal (formerly ISO, Bethlehem)
Mittal (formerly LTV)
Severstal (formerly ISO, Bethlehem)
Mittal (formerly LTV)
US Steel (formerly National Steel)
Mittal (formerly Weirton Steel)
Severstal (formerly Rouge Steel)
US Steel Edgar Thomson Works
US Steel (formerly National Steel)
Republic Technologies
Wheeling Pittsburgh Steel
AK Steel
US Steel
AK Steel
WCI Steel
Location
East Chicago, IN
Gary, IN
Burns Harbor, IN
Cleveland, OH
Sparrows Point, MD
East Chicago, IN
Ecorse, MI
Weirton, WV
Dearborn, MI
Braddock, PA
Granite City, IL
Lorain, OH
Mingo Junction, OH
Middletown, OH
Fairfield, AL
Ashland, KY
Warren, OH
Total
Number of BFs
5
4
2
2
1
2
3
2
2
2
2
2
2
1
1
1
1
35
BF Capacity (tpy)c
6,500,000
5,560,000
5,100,000
4,100,000
3,500,000
3,100,000
2,781,000
2,700,000
2,700,000
2,500,000
2,400,000
2,300,000
2,300,000
2,200,000
2,000,000
1,900,000
1,400,000
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 Ibs), 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 Ibs) 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 Gas6'7
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 (62) 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 CC>2 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 CC>2, is
usually supplemented with natural gas, which is mostly CFLi, 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 MMTCC^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 CC>2 emissions from blast
furnace stoves would be about 24 million MMTCC^e/yr.
Table 2. Energy Consumption by Blast Furnace Stoves 8
Capacity (million short
tons per year)
5.5
4.0
2.5
1.6
2.0
3.4
2.7
1.2
1.0
1.4
1.3
1.6
0.9
Million Btu/hr
1,320
586
953
441
486
1,025
700
309.1
298.4
309.9
319.2
301.5
192.9
Average
Million Btu per short
ton of iron
2.10
1.28
3.34
2.41
2.13
2.64
2.27
2.31
2.68
1.97
2.12
1.68
1.88
2.22
1.1.2 Basic Oxygen Furnace (EOF)
As shown in Table 3, there are 18 plants that operate 46 BOFs at 21 EOF 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
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Plants with BOFs
Mittal (formerly Ispat-Inland)
US Steel
Mittal (formerly ISO, Bethlehem)
Severstal (formerly ISO, Bethlehem)
Mittal (formerly LTV)
Mittal (formerly LTV)
US Steel (formerly National Steel)
Severstal (formerly Rouge Steel)
Mittal (formerly Weirton Steel)
US Steel Edgar Thomson Works
US Steel (formerly National Steel)
AK Steel
Republic Technologies
Wheeling Pittsburgh Steel
US Steel
AK Steel
WCI Steel
Mittal (formerly Acme Steel)
Location
East Chicago, IN
Gary, IN
Burns Harbor, IN
Sparrows Point, MD
Cleveland, OH
East Chicago, IN
Ecorse, MI
Dearborn, MI
Weirton, WV
Braddock, PA
Granite City, IL
Middletown, OH
Lorain, OH
Mingo Junction, OH
Fairfield, AL
Ashland, KY
Warren, OH
Riverdale, IL
Total
Number of
BOFs
4
6
3
2
4
2
2
2
2
2
2
2
2
2
3
2
2
2
46
EOF Capacity (short
tons per year)
10,000,000
7,500,000
4,700,000
3,900,000
3,800,000
3,800,000
3,800,000
3,309,000
3,000,000
2,900,000
2,800,000
2,716,000
2,700,000
2,600,000
2,200,000
2,200,000
1,900,000
750,000
64,575,000
EOF 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 CC>2 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
CC>2 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 MMTCO2e/mt steel for carbon removed from the iron as CC>2.
Applying the emission factor to the production of 40 million mt of steel in BOFs in 2007 2 yields
an estimate of 4.4 million MMTCO2e/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
No.
1
2
O
4
5
Plant
US Steel
Severstal (formerly ISO, Bethlehem)
Mittal (formerly ISO, Bethlehem)
Mittal (formerly LTV)
Mittal (formerly Ispat-Inland)
Location
Gary, IN
Sparrows Point, MD
Burns Harbor, IN
East Chicago, IN
East Chicago, IN
Total
Sinter Capacity
(short tons per year)
4,400,000
4,000,000
2,900,000
1,900,000
1,400,000
14,600,000
Sinter Process
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 ((CaO+MgO)/(SiO2+Al2O3)); 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 CC>2 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 MMTCO2e/mt of sinter 10
and the production of 13.3 million mt of sinter, 6 CC>2 emissions are estimated as 2.7 million
mt/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 CH/t) also emit a small amount of CH/t.
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
MMTCO2e/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 million MMTCO2e.
Table 5. Design Capacity of Combustion Units at Integrated Iron and Steel Facilities 8
Steel capacity (short
tons per year)
3,800,000
2,800,000
2,716,000
2,700,000
2,600,000
2,200,000
MM Btu/hr
1,088
1,113
844
1,055
1,033
952
Average
At 90%
MM Btu/short ton
2.51
3.48
2.72
3.42
3.48
3.79
3.23
2.91
Table 6. Development of an Emission Factor for Combustion Units
Fuel
Natural gas
Coke oven gas
Blast furnace gas
% of energy n
51
14
34
IPCC emission
factor
(mtCO2/TJ) 9
56.1
44
260
TJ/mt of steel"
0.0017
0.00047
0.0011
Total
mtCCVmt of
steel"
0.097
0.021
0.30
0.42
a (% of energy/100) * (0.00338 TJ/mt of steel)
b(IPCC emission factor in mtCO2/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.
10
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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.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Company
Indiana Harbor Cokea
Haverhill Cokea
US Steel
Jewell Coke and
Coaf
US Steel
Mittal Steel
Mountain State
Carbon
AK Steel
EES Coke
ABC Coke
US Steel
Mittal Steel
Shenango
Sloss Industries
AK Steel
Koppers
Tonawanda
Erie Coke
City
East Chicago
Haverhill
Clairton
Vansant
Gary
Burns Harbor
Follansbee
Ashland
Ecorse
Tarrant
Granite City
Warren
Neville Island
Birmingham
Middletown
Monessen
Tonawanda
Erie
State
IN
OH
PA
VA
IN
IN
WV
KY
MI
AL
IL
OH
PA
AL
OH
PA
NY
PA
Total
Number
of
batteries
4
4
12
6
4
2
4
2
1
O
2
1
1
3
1
2
1
2
55
Coke capacity
(short tons per
year)
1,300,000
1,100,000
5,573,185
649,000
2,249,860
1,877,000
1,247,000
1,000,000
1,000,000
699,967
601,862
550,000
514,779
451,948
429,901
372,581
268,964
214,951
20,099,998
12,13
a These are nonrecovery coke plants.
By-product Recovery Coke Oven Batteries
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 CC>2 (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 MMTCO2e/mt coal (
0.21 MMTCO2e/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 MMTCO2e/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
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Technical Support Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases
stacks based on the 2007 production rate are estimated as 3 million MMTCO2e from
nonrecovery battery stacks and 2.8 MMTCC^e/mt from byproduct recovery battery stacks.
A small amount of CC>2 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 MMTCO2e/mt coal (0.01 MMTCO2e/mt coke).13 Using the 2007 production rate
for coke (15.8 million mt),4 the emissions from pushing are estimated as 158,000 MMTCO2e/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 MMTCO2e/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 MMTCO2e/mt coke (0.56 - 0.21 MMTCO2e/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 million
MMTCO2e/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
17 1
Table 8. Taconite or Pellet Production Facilities '
No.
1
2
O
4
5
6
7
8
Facility
USS Keetac
USS Mintac
Empire
Tilden
United
Taconite
Hibbing
Northshore
Ispat-Inland
City
Kewatin
Mountain
Iron
Palmer
Ishpeming
Forbes
Hibbing
Silver Bay
Virginia
State
MN
MN
MI
MI
MN
MN
MN
MN
Totals
Number of
furnaces
2
O
2
1
2
2
2
2
16
Pellet
capacity
(tpy)
6,160,000
16,352,000
9,408,000
8,802,000
6,608,000
9,632,000
5,376,000
3,248,000
65,586,000
Coal
usage
(tpy)
146,000
105,833
191,067
166,589
97,100
706,589
Natural gas
(MMCF/yr)
292
7,231
2,781
2,120
476
3,000
3,591
1,540
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 CC>2 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 CC>2 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 CC>2 emissions were 0.11
MMTCO2e/mt pellet when burning coal and 0.072 MMTCO2e/mt pellet when burning natural
gas. The IPCC default emission factor is 0.03 MMTCO2e/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 CC>2 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 million MMTCC^e for
2007.
Although the indurating furnace is by far the primary source of CC>2 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
pellets (tph)
natural gas (MCF/hr)
CC>2 emissions (tph)
CC>2 emissions (ton/ton pellets)
CC>2 emissions (ton/MCF)
779
289.5
56.3
0.072
0.194
Tilden - coal as fuel (July 13, 2000)20
pellets (tph)
coal (tph)
CC>2 emissions (tph)
CC>2 emissions (ton/ton pellets)
CC>2 (ton/ton coal)
609
15.85
65.8
0.11
4.15
tph = short tons per hour
MCF/hr = thousands of cubic feet per hour
24
1.4 Electric Arc Furnace (EAF) Steelmaking
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 92 EAF minimills, their location, and capacity.
Table 10. Electric Arc Furnace Locations and Capacity
22,23
No.
1
2
o
5
4
5
6
7
8
9
10
11
12
13
Company
Nucor Corporation
Nucor-Yamato Steel
Nucor Corporation
Steel Dynamics Inc.
Northwestern Steel & Wire Co.
Nucor Corporation
TXI Chaparral Steel
Nucor Corporation
CMC Steel/SMI Steel.
North Star Steel - Blue Scope
Steel
Steel Dynamics Inc.
Gerdau Ameristeel (Gallatin
Steel)
Oregon Steel Mills
City
Berkeley Co.
Blytheville
Hickman
Butler
Sterling
Decatur
Midlothian
Crawfordsville
Birmingham
Delta
Whitley Co.
Ghent
Pueblo
State
SC
AR
AR
IN
IL
AL
TX
IN
AL
OH
IN
KY
CO
Capacity (short
tons per year)
3,300,000
3,277,000
2,400,000
2,200,000
2,070,000
2,000,000
2,000,000
1,900,000
1,855,000
1,800,000
1,600,000
1,500,000
1,200,000
Cumulative percent
of capacity
4.6
9.1
12.4
15.4
18.3
21.0
23.8
26.4
29.0
31.5
33.7
35.7
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.
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
Company
TXI Chaparral Steel
Nucor Corporation
Nucor Corporation
Ipsco Inc.
Ipsco Inc.
Mittal Steel
CMC Steel Group/SMI Steel
Republic Engineered Steels, Inc.
Gerdau Ameristeel
Keystone Steel & Wire
Mittal Steel
Nucor Corporation
AK Steel Corporation
Gerdau Ameristeel
CMC Steel Group/SMI Steel.
Gerdau Ameristeel
Mittal Steel
Nucor Corporation
Coras Tuscaloosa
Timken Co.
Gerdau Ameristeel
Nucor Corporation
Gerdau Ameristeel
North American Stainless
Nucor Corporation
Gerdau Ameristeel
TAMCO
MACSTEEL. (Quanex)
Nucor Corporation
Roanoke Electric Steel Corp.
AK Steel Corporation
Cascade Steel Rolling Mills, Inc
Bayou Steel Corp
Gerdau Ameristeel
V&M Star
Gerdau Ameristeel
Gerdau Ameristeel
MACSTEEL (Quanex)
Gerdau Ameristeel (formerly
Sheffield Steel)
MACSTEEL. (Quanex)
NS Group Inc./Koppel Steel
Corp.
Nucor Corporation
City
Dinwiddie
Plymouth
Norfolk
Axis
Muscatine
Steelton
Cayce
Canton
Beaumont
Peoria
Georgetown
Cofield
Butler
Wilton
Seguin
Jackson
Coatsville
Darlington
Tuscaloosa
Canton
St. Paul
Seattle
Perth Amboy
Ghent
Kankakee
Sayreville
Rancho
Cucamonga
Jackson
Jewett
Roanoke
Mansfield
McMinnville
LaPlace
Cartersville
Youngstown
Charlotte
Baldwin
Fort Smith
Sand Springs
Monroe
Beaver Falls
Auburn
State
VA
UT
NE
AL
IA
PA
SC
OH
TX
IL
SC
NC
PA
IA
TX
TN
PA
SC
AL
OH
MN
WA
NJ
KY
IL
NJ
CA
MI
TX
VA
OH
OR
LA
GA
OH
NC
FL
AR
OK
MI
PA
NY
Capacity (short
tons per year)
1,200,000
1,111,000
1,103,000
1,100,000
1,100,000
1,100,000
1,089,000
1,050,000
1,002,000
1,000,000
1,000,000
1,000,000
960,000
917,000
900,000
892,000
880,000
872,000
870,000
870,000
843,000
840,000
800,000
800,000
800,000
750,000
750,000
725,000
725,000
710,000
700,000
700,000
683,000
658,000
650,000
622,000
607,000
607,000
600,000
600,000
550,000
550,000
Cumulative percent
of capacity
39.0
40.6
42.1
43.6
45.1
46.7
48.2
49.6
51.0
52.4
53.7
55.1
56.4
57.7
59.0
60.2
61.4
62.6
63.8
65.0
66.2
67.3
68.4
69.5
70.6
71.7
72.7
73.7
74.7
75.7
76.6
77.6
78.6
79.5
80.4
81.2
82.1
82.9
83.7
84.5
85.3
86.1
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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.
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
Company
Charter Manufacturing
Gerdau Ameristeel
BetaSteel Corporation
Hoeganeas Corp.
Mittal Steel (Ispat Inland)
Nucor Corporation
Nucor Corporation
Wheeling-Pittsburgh Steel
Oregon Steel Mills, Inc.
Allegheny Technologies Inc.
Carpenter Technology
Ellwood Quality Steels
Allegheny Technologies Inc.
CitiSteel USA Inc.
Marion Steel Co.
Mittal Steel
Erie Forge and Steel
Timken Co.
Lone Star Steel Inc.
Border Steel Mills, Inc.
Standard Steel
Arkansas Steel
LeTourneau Inc.
Hoeganeas Corp.
Universal Stainless & Alloy
Products, Inc.
Steel of West Virginia
Electralloy
Finkl, A., & Sons
Kobelco Metal Powder of
America
Timken Co.
Standard Steel
National Forge Co.
Crucible Materials
Union Electric Steel
Inmetco
Haynes International
Champion Steel Co.
City
Saukville
Knoxville
Portage
Gallatin
East Chicago
Birmingham
Jackson
Mingo Junction
Portland
Brackenridge
Reading
New Castle
Midland
Claymont
Marion
Cleveland
Erie
Canton
Lone Star
El Paso
Burnham
Newport
Longview
Riverton
Bridgeville
Huntington
Oil City
Chicago
Seymore
Latrobe
Latrobe
Irvine
Syracuse
Carnegie
Ellwood City
Kokomo
Orwell
State
WI
TN
IN
TN
IN
AL
MS
OH
OR
PA
PA
PA
PA
DE
OH
OH
PA
OH
TX
TX
PA
AR
TX
NJ
PA
WV
PA
IL
IN
PA
PA
PA
NY
PA
PA
IN
OH
Total
Capacity (short
tons per year)
515,000
515,000
500,000
500,000
500,000
500,000
500,000
500,000
499,000
496,000
450,000
410,000
400,000
400,000
400,000
396,000
385,000
358,000
265,000
250,000
231,000
130,000
124,000
112,000
105,000
100,000
90,000
90,000
63,000
60,000
59,000
58,000
50,000
35,000
28,000
20,000
6,000
72,488,000
Cumulative percent
of capacity
86.8
87.5
88.2
88.9
89.6
90.2
90.9
91.6
92.3
93.0
93.6
94.2
94.7
95.3
95.8
96.4
96.9
97.4
97.8
98.1
98.4
98.6
98.8
98.9
99.1
99.2
99.4
99.5
99.6
99.6
99.7
99.8
99.9
99.9
99.96
99.99
100.0
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
EAFSteelmaking21'24
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 CC>2. 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 million MMTCC^e for EAFs is based on
the IPCC emission factor of 0.08 MMTCO2e/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, dry out 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. CC>2 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 MT CO2/TJ. 9 The calculation is shown below and results in an
emission factor of 0.32 MMTCO2e/mt steel from combustion units at EAF facilities:
(5,400 CF/ton)* (0.9)*(56.1 mtCO2/TJ)*(l,000 Btu/CF)*( 1.1 ton/mt)/(947.8 E6 Btu/TJ)= 0.32 MMTCO2e/mt steel.
The production of 58 million mt of steel in EAFs in 2007 results in an emission estimate of 18.6
million MMTCC^e from combustion units burning natural gas
Table 11. Natural Gas Usage from EAF Operating Permits 8
EAF steel capacity
(short tons per year)
105,000
385,000
410,000
500,000
607,000
960,000
3,300,000
Capacity of combustion
units (MMCF/yr)
584
1,839
1,564
5,600
2,847
5,718
6,079
Average
Natural gas per
short ton of steel
(CF/short ton)
5,562
4,777
3,815
11,200
4,690
5,956
1,842
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 CC>2 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 CFLt is emitted from the DRI
process. 10 The CFLi 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 MMTCO2e/mt iron for DRI, 10 CO2 emissions are about 140,000 MMTCO2e /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
CC>2 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 CC>2 is generated from these operations,
and a review of test reports from systems that capture these emissions show that CC>2
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
Taconite indurating furnaces
Byproduct coke stand alone:
Nonrecovery coke
EAF facilities
Integrated plants:
Byproduct coke co-located
Blast furnaces
BOFs
Sinter plants
Total integrated
Total for all facilities
Number of
facilities
8
9
3
92
6
17
18
5
18
130
Emissions (MMTCO2e/yr)a
Process units
5,600,000
1,592,640C
2,953,968C
4,780,000
1,221,024
23,934,300d
4,400,000
2,654,545
32,209,869
47,136,477
Miscellaneous
combustion
units
(b)
2,654,400
(b)
18,560,000
16,800,000
38,014,400
Total
5,600,000
4,247,040
2,953,968
23,340,000
1,221,024
23,934,300
4,400,000
2,654,545
49,009,869
85,150,877
a Emission estimates are provided for the predominant GHG (CO2). 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
N2O 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 N2O 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:
http://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 I.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.
1. 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 CC>2 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 CC>2. 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 CC>2 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 (CFLi) 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 CC>2 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 CC>2 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 WRI/WBCSD protocol presents two procedures for estimating CC>2 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. CC>2 emissions from flaring are based on the volume of gas flared, the carbon content
of the gas, and a combustion efficiency of 98 percent. CIHLt emissions from flaring are estimated
by assuming 2 percent of the CR4 in the gas is not burned. The WRI/WBCSD provides equations
for estimating CR4 emissions from the production of coke, sinter, pig iron, and DRI; CR4
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 CR4 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 CO2/yr 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 CCVyr 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
1
2
3
4
Uncertainty in mass flow of inputs and outputs
must be less than
±7.5%
±5.0%
±2.5%
±1.5%
Carbon content
Default (typical) values
Country-specific values
Analysis of representative samples
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 CO2/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 accounted for 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, blastfurnace stoves, flares,
boilers, EOF 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 blastfurnace 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 Ib CO2/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
MMTCO2e/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 CC>2. However, CIHLt 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 CC>2 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 MMTCO2e, 10,000 MMTCO2e, 25,000 MMTCO2e, and
100,000 MMTCO2e. 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 MMTCO2e
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 MMTCO2e/mt steel) and combustion sources (0.32
MMTCO2e/mt steel).
Table 14. Summary of Emission Estimates
Facility
Taconite
Byproduct coke stand alone
Nonrecovery coke
Integrated plants
EAF
Total facilities
Number
of plants
8
9
3
18
92
130
Production
(mt/yr)
52,000,000
7,056,000
2,234,400
40,000,000
58,000,000
159,290,400
Type of
production
pellets
coke
coke
steel
steel
products
Total
emissions
(mt of
CO2e)
5,600,000
4,247,040
2,953,968
49,009,869
23,340,000
85,150,877
Average per
plant
(MMTCO2e)
700,000
471,893
984,656
2,722,771
253,696
655,007
Table 15. Reporting Thresholds
Threshold
level
MMTCO2e
all in
1,000
10,000
25,000
100,000
Production
threshold
(mt/yr)
0
2,500
25,000
62,500
250,000
Total national
emissions
(MMTCO2e)
85,150,877
85,150,877
85,150,877
85,150,877
85,150,877
Total
number of
U.S.
facilities
130
130
130
130
130
Emissions covered
MMTCO2e/yr
85,150,877
85,150,877
85,141,423
85,013,059
84,468,696
Percent
100.0
100.0
99.99
99.8
99.2
Facilities covered
Number
130
130
128
121
111
Percent
100
100
98
93
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 COi 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 CC>2 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 CC>2 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 CC>2 emissions using a continuous
emission monitoring system (CEMS) for CC>2 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 CO2 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 N2O 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 CFLt and N2O 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 COi 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 CC>2 emissions developed from 26 tests for particulate matter from pushing operations.13 The
emissions factor (0.008 MMTCO2e 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 CC>2
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/mcs2008.pdf. January 2008.
3. Jorgeson, John. USGS Mineral Commodity Summary 2008. Iron Ore. Available at
http://minerals.usgs.gov/minerals/pubs/mcs/2008/mcs2008.pdf. January 2008.
4. Energy Information Administration (EIA), Quarterly Coal Report. Available at
http://www.eia.doe.gov/cneaf/coal/quarterly/html/t3pO 1 p 1 .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://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.jp/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.jp/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/ch 12/fmal/c 12s02_may08.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 I.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.13
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.0
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.0
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
material s.d
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.0
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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.0
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.
b40 CFR Part 63, Subpart FFFFF. National Emission Standards for Integrated Iron and Steel
Manufacturing.
C40 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.
e40 CFR Part 63, Subpart RRRRR. National Emission Standards for Taconite Iron Ore
Processing.
f 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'
Plant Name
Universal Stainless and Alloy Products
Erie Forge and Steel
Ellwood Quality Steels Company
AK Steel Corporation
Electroalloy
Nucor Steel
City
Bridgeville
Erie
New Castle
Butler
Oil City
Blytheville
State
PA
PA
PA
PA
PA
AR
CO2 source
Ladle Reheat Furnace
Vessel Reheat Furnace
Electro-Slag Remelt Holding Furnace
Annealing Furnaces
Plate Warming Furnace
Miscellaneous space heating units (75)
North American Steam Boiler
Ladle preheaters
Ladle refining furnace
Heat treat furnaces
Hood furnace
Boilers (4)
Oxy-fuel burner (for EAF)
Anneal furnaces
Scrap torching
Ladle preheaters
EAF pre-heater
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
Miscellaneous NG (<2.5 MMBtu/hr)
Anneal furnaces
Granular metal process
Ladle preheaters for melt shop
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'
Plant Name
Oregon Steel Mills Rivergate Plant
Quanex Corporation - MacSteel Division
City
Portland
Fort Smith
State
OR
AR
CO2 source
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
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
No. 2 Boilerhouse
D blast furnace stove
B blast furnace stove
Blast furnace flares
No. 1 Boilerhouse
Mill furnace heaters
Mill furnace heaters
No. 2 Boilerhouse
No. 1 Boilerhouse
No. 1 Boiler
Heaters
Dryout Heaters
Heaters
Process Heaters
Boiler
Annealing Heaters
No. 2 Boilerhouse
No. 1 Boiler
B blast furnace stove
Annealing Heaters
BOF operation
No. 3 Boilerhouse
Fuel
Blast furnace gas
Blast furnace gas
Blast furnace gas
Blast furnace gas
Blast furnace gas
Coke oven gas
Natural Gas
Coke oven gas
Coke oven gas
Coke oven gas
Natural Gas
Natural Gas
Natural Gas
Natural Gas
Natural Gas
Natural Gas
Natural Gas
Natural Gas
Natural Gas
Natural Gas
Natural Gas
Natural Gas
MMCF/yr
30,711
30,397
28,145
28,059
21,290
4,647
3,163
2,773
1,917
987
590
580
428
393
268
228
208
135
126
122
121
107
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