Alpha Coal
Handbook
A reference guide for coal, ironmaking, electricity
generation, and emissions control technologies.
2012 Edition
Forward-Looking Statements
Statements in this document which are not statements of historical fact are “forward-looking statements” within the Safe
Harbor provision of the Private Securities Litigation Reform Act of 1995. Such statements are not guarantees of future performance. Many factors could cause our actual results, performance or achievements, or industry results to be materially
different from any future results, performance, or achievements expressed or implied by such forward-looking statements.
These factors are discussed in detail in our filings with the SEC. We make forward-looking statements based on currently
available information, and we assume no obligation to update the statements made herein due to changes in underlying
factors, new information, future developments, or otherwise, except as required by law.
Third Party Information
This document, including certain forward-looking statements herein, includes information obtained from third party
sources that we believe to be reliable. However, we have not independently verified this third party information and cannot
assure you of its accuracy or completeness. While we are not aware of any misstatements regarding any third party data
contained in this document, such data involve risks and uncertainties and are subject to change based on various factors,
including those discussed in detail in our filings with the SEC. We assume no obligation to revise or update this third party
information to reflect future events or circumstances.
Definitions and Descriptions
The definitions, descriptions, formulas and other data used in, or referenced by, this document are not binding for purposes of interpreting any other document, including without limitation agreements to which Alpha Natural Resources, Inc. or
any of its affiliates is a party. Neither Alpha Natural Resources, Inc. nor any of its affiliates is responsible for any liabilities
Who Is Alpha?
Alpha Natural Resources is one of the world’s premier coal suppliers
with coal production capacity of greater than 120 million tons a
year. Alpha is the United States’ leading supplier of metallurgical
coal used in the steelmaking process and third-largest in the world.
Alpha is also a major supplier of thermal coal to electric utilities
and manufacturing industries across the country. The Company,
through its affiliates, operates mines and coal preparation facilities
in Appalachia and the Powder River Basin. More information about
Alpha can be found on the Company’s website at www.alphanr.com.
arising from a reliance upon the data in this document.
Design: McKenna Daniels Design
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About Alpha
About Alpha
Our Purpose
What is RUNNING RIGHT ?
We fuel progress around the world.
Running Right is an important piece of our culture, a part of who we are and how
we operate. At Alpha, we believe every employee should have a seat at the table
and participate actively in all aspects of our business.
Our Values
We conduct our business safely, ethically, honestly and with integrity at all times.
We care. Caring for one another helps us all return to our families safe and
healthy.
We treat each other how we want to be treated.
We trust our people and work together as a team. All employees have an
opportunity to contribute their ideas and share in our success.
We communicate openly, build on what we know and learn, and make informed
decisions to keep us ahead of the competition.
We embrace change, continuously improving ourselves and our business.
Embedded within Running Right is a robust observation process that relies
on participation from each and every employee to conduct observations.
All employees are encouraged to cite safe behaviors, at-risk behaviors and
operational improvements every day in order to improve the safety, efficiency, and
productivity of all of our locations in Alpha.
Safe and at-risk behaviors are part of Alpha’s behavior-based safety approach.
The reason why we focus so much on at-risk behavior is that research has shown
that 88 percent of workplace accidents can be attributed to at-risk behavior. At-risk
behavior is often the precursor to workplace accidents.
Observations are reviewed daily. In many cases action can be taken right away
and employees are encouraged to take action when observations occur.
Running Right is a big part of who we are and what we do and employee
involvement and engagement are the keys to Running Right at Alpha. “We fuel
progress around the world...and we do this through the energy of our people.”
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About Alpha
About Alpha
History
Alpha was formed in 2002 by members of management and by affiliates of First
Reserve Corporation, a private equity firm.
We acquired the majority of the Virginia coal operations of Pittston Coal Company,
a subsidiary of The Brink’s Company, in December 2002.
On January 31, 2003, we acquired Coastal Coal Company, and on March 11, 2003,
we acquired the U.S. coal production and marketing operations of American
Metals and Coal International. In November of that year, we acquired Mears
Enterprises, Inc. and affiliated entities.
In April of the following year, we acquired substantially all of the assets of
Moravian Run Reclamation Co., Inc., including four active surface mines and two
additional surface mines under development, operating in close proximity to and
serving many of the same customers as our AMFIRE business unit located in
Pennsylvania. That May, we acquired a coal preparation plant and railroad loading
facility located in Portage, Pennsylvania and related equipment and coal inventory
from Cooney Bros. Coal Company and an adjacent coal refuse disposal site from a
Cooney family trust.
In July 2009, Alpha consummated its largest business venture to date by
completing a merger with Foundation Coal Holdings Inc. The Alpha-Foundation merger resulted in the third-largest coal company in America.
In June 2011, Alpha acquired Massey Energy Company in a $7.7 billion
transaction. The acquisition brought together highly complementary assets, which
included more than 150 mines and combined coal reserves of approximately 5
billion tons, including one of the world’s largest and highest-quality metallurgical
coal reserve bases.
U.S. Leader in Metallurgical Exports
Alpha Natural Resources is the largest exporter of metallurgical coal in the United
States. In 2011, metallurgical export shipments exceeded 14 million tons and we
expect to see growth going forward.
Alpha ships export coal on the East Coast through Norfolk Southern’s Lamberts
Point facility in Norfolk, VA; through Dominion Terminal Associates (DTA) in
Newport News, VA; through Pier IX Terminal in Newport News, VA; and through
CSX Chesapeake Bay piers located in Baltimore, MD. Coal is also moved through
United Bulk Terminal and International Marine Terminals, both located in New
Orleans, LA.
In October 2005 Alpha acquired the Nicewonder Coal Group including their three
surface mines and a road construction and coal recovery business in southwestern
Virginia and southern West Virginia.
International Sales and Development Offices
In May 2006, Alpha completed the acquisition of certain coal mining operations
in eastern Kentucky from Progress Fuels Corp. Collectively the acquired
businesses controlled 73 million tons of coal reserves. In December of that year,
an Alpha subsidiary, Palladian Lime LLC, acquired a 94% ownership interest in
Gallatin Materials LLC, a start-up lime manufacturing business in Verona, Ky. That
interest was subsequently sold in October 2008.
In 2010, Alpha opened a European sales office in Lugano, Switzerland. In early
2011, Alpha opened two international sales and development offices: one in New
Delhi, India and one in Sydney, Australia. Each office is focused on increasing
Alpha’s sales of coal to high-growth markets through our existing export platform,
as well as unique optimization opportunities. Both offices also serve to further
develop and enhance trading opportunities, market intelligence, and strategic
relationships in the Asian markets.
In June 2008, Alpha acquired the Mingo Logan-Ben Creek coal mining assets in
West Virginia from Arch Coal Inc. Mingo Logan consists of coal reserves, one deep
mine and a load-out and coal processing plant.
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About Alpha
About Alpha
Alpha Shipping and Chartering, LLC
Alpha Natural Resources U.S. Locations
Alpha Shipping and Chartering, LLC, a subsidiary of Alpha Natural Resources,
was formed in 2010 to provide ocean shipping services for overseas customers.
Alpha is the disponent owner of two Panamax Gearless Bulk Carriers available to
transport coal or other dry bulk commodities worldwide.
Alpha Coal West
2 Surface Mines
WY
Export Capacity
Pennsylvania
Services
2 Deep Mines
2 Plants & LOs
Alpha’s total export capacity from all U.S. terminals is approximately 25-30 million
tons per year via multiple ports and terminals that provide unique blending,
storage and transportation advantages.
Amfire
6 Deep Mines
10 Surface Mines
2 Plants & LOs
Through our subsidiary, Alpha Terminal Company, LLC, we hold a 41% interest
in Dominion Terminal Associates. The DTA facility consists of state-of-the art
blending and sampling systems along with ground storage capability, allowing us
to provide outstanding service to customers worldwide. We also have access to
additional export capacity at Chesapeake Bay piers, Gulf of Mexico/New Orleans,
and Great Lakes terminals.
Brooks Run West
5 Deep Mines
6 Surface Mines
4 Plants & LOs
Coal River West
1 Deep Mine
1 Surface Mine
2 Plants & LOs
PA
Coal River East
11 Deep Mines
1 Surface Mine
3 Plants & LOs
Brooks Run North
9 Deep Mines
3 Surface Mines
4 Plants & LOs
WV
VA
KY
Corporate
Office
Northern Kentucky
7 Deep Mines
1 Surface Mines
3 Plants & LOs
Southern Kentucky
12 Deep Mines
2 Surface Mines
2 Plants & LOs
Total Mines: 132*
Virginia
20 Deep Mines
6 Surface Mines
4 Plants & LOs
Underground: 87
Western Coal Operations – 2011
49.9 million tons thermal
*As of March 31, 2012 **Includes Massey
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Brooks Run South
14 Deep Mines
6 Surface Mines
4 Plants & LOs
Surface: 45
Coal River Surface
7 Surface Mines
4 Plants & LOs
Prep Plants: 34
Eastern Coal Operations – 2011**
37.2 million tons thermal
19.2 million tons met
LO = Loadout
About Alpha
About Alpha
Alpha Natural Coal Loading Facilities, 2011
Alpha Natural Resources Coal Exports, 2011
Northern KY
Southern KY
AMFIRE
PA Services
Brooks Run South
Virginia
Brooks Run North
Brooks Run South
Brooks Run West
Coal River East
Coal River Surface
Coal River West
Alpha Coal West
Railroad
Long Fork Prep Plant
Martin County Prep Plant
Sidney Prep Plant
Cave Branch Prep Plant
Roxana Plant
Clearfield
Clymer Plant
Homer City
Portage Plant
Cumberland Plant
Emerald Plant
Virginia Energy
Knox Creek Prep Plant
Mcclure Plant
Pigeon Creek Prep Plant
Toms Creek Plant
Erbacon Plant
Green Valley Prep Plant
Mammoth Prep Plant
Power Mountain Prep Plant
Ben Creek (Black Bear Plant)
Kepler Plant
Litwar Plant
Stirrat Prep Plant
Bandmill Prep Plant
Delbarton Prep Plant
Holden 29 Loadout
Rockspring Plant
Elk Run Prep Plant
Goals Prep Plant
Kingston Plant
Marfork Prep Plant
Pax (Hopkins) Loadout
Homer Iii Loadout
Liberty Prep Plant
Omar Loadout
Belle Ayr Loadout
Eagle Butte Loadout
KY
KY
KY
KY
KY
PA
PA
PA
PA
PA
PA
VA
VA
VA
VA
VA
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WY
WY
NS
NS
NS
CSX
CSX
Truck
NS
Truck
NS
NS/Mon River
CSX
NS
NS
CSX
NS
NS
CSX
CSX
NS
NS
NS
NS
NS
CSX
CSX
NS
CSX
NS
CSX
CSX
CSX
CSX
CSX
CSX
CSX
CSX
UPR
UPR
Stockpiling
Wheelersburg*
*
State
Rivereagle
Loadout
Marmet*
Business Unit
KRT
Barge Terminal Access***
Europe
7.1mm tons
Asia
3.5mm tons
Canada/Mexico
2.0mm tons
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
South America
1.7mm tons
X
X
X
X
X
X
2011 Export Shipments
14.2mm tons met exports
2.1mm tons steam exports
16.3mm tons total exports
X
X
X
X
X
X
* Marmet is owned by Alpha
** Wheelersburg is run by NS and rails in/out for Alpha stockpiles. Coal is typically used for our Great Lakes business
serviced by Sandusky/Toledo terminals.
*** We ship barges direct to customers, or down to the Gulf for export all over the globe.
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Africa
2.0mm tons
About Alpha
Table of Contents
Coal Supply & Demand
3
Electricity
53
World Coal Overview . . . . . . . . . . . . 4
Coal . . . . . . . . . . . . . . . . . . . . 54
U.S. Coal Overview . . . . . . . . . . . . 12
Natural Gas . . . . . . . . . . . . . . . . 60
Nuclear . . . . . . . . . . . . . . . . . . 64
Coal
19
Renewables . . . . . . . . . . . . . . . 70
Cooling Systems . . . . . . . . . . . . . 84
Formation of Coal . . . . . . . . . . . . 20
Turbines and Generators . . . . . . . . . 86
Mining . . . . . . . . . . . . . . . . . . 22
Transmission and the Grid . . . . . . . . 88
Mining Laws and Regulations . . . . . . 30
Energy Storage . . . . . . . . . . . . . . 92
Mine Reclamation . . . . . . . . . . . . 32
Preparation and Processing . . . . . . . 34
Transportation . . . . . . . . . . . . . . 36
Emissions Control Technology
95
Emissions Control . . . . . . . . . . . . 96
Metallurgical Coal
39
Metallurgical Coal . . . . . . . . . . . . 40
Coke . . . . . . . . . . . . . . . . . . . 46
Iron Making . . . . . . . . . . . . . . . . 48
Particulate Emissions . . . . . . . . . . . 98
SO2 & NOx . . . . . . . . . . . . . . . . 100
Carbon Dioxide (CO2) . . . . . . . . . . 104
Mercury (Hg) . . . . . . . . . . . . . . 106
Coal Combustion Laws and Regulations . 108
Finished Steelmaking . . . . . . . . . . . 50
Additional Information
111
Definitions . . . . . . . . . . . . . . . . 112
Abbreviations . . . . . . . . . . . . . . 126
OTC Specifications . . . . . . . . . . . 131
Conversions and Formulas . . . . . . . 132
Useful Websites . . . . . . . . . . . . 141
Coal Supply
& Demand
World Coal Overview
4
U.S. Coal Overview
12
Coal Supply & Demand
World Coal Overview
World Coal Overview
2011 Global Coal Top 10
World recoverable coal reserves are currently estimated at 948 billion tons,
according to the U.S. Energy Information Agency (EIA), which at current
consumption rates is enough coal to last 118 years. Recoverable coal reserves
represent coal that can be economically extracted at today’s prices using
current technology. The U.S. has more coal reserves than all other countries
(29%), followed by Russia (19%), China (14%), and Australia (9%). Anthracite
and bituminous coal represent half of the world’s recoverable reserves,
subbituminous is 32%, and lignite is 18%.
Total Recoverable World Coal Reserves, 2008
948 Billion Short Tons
Reserves (M tons)
Production (M tons)
Consumption (M tons)
United States
260,551
China
3,523
China
3,695
Russia
173,074
United States
1,085
United States
1,048
China
126,215
India
623
India
721
Australia
84,217
Australia
463
Russia
257
India
66,800
Indonesia
370
Germany
256
Germany
44,863
Russia
357
South Africa
206
Ukraine
37,339
South Africa
281
Japan
206
Kazakhstan
37,038
Germany
201
Poland
149
South Africa
33,241
Poland
146
Australia
145
Serbia
15,179
Kazakhstan
122
South Korea
126
Total
948,000
Total
7,985
Total
7,995
Source: EIA (Reserves, 2008; Production & Consumption,
Source: 2010)
EIA
Source: EIA (Reserves, 2008; Production & Consumption, 2010)
World coal consumption is expected to increase 39% by 2035 according to the
2011 EIA International Energy Outlook. Almost all of the future growth in world
coal demand is from non-OECD (Organisation for Economic Co-operation and
Development) countries, led by Brazil.
B
World Coal Demand (Millions of Tons)
Source: EIA
Source: EIA
Most of the international trade in coal is in steam coal (70%) imported by Asian
countries (58%). Asia also represents 70% of the global coking coal trade market.
India and China’s growing economies are driving demand for imported coal.
4
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5
Coal Supply & Demand
World Coal Overview
Major Seaborne Coal
Trade (2010)
Major Seaborne Coal Trade (2011)
Major International Coal Ports
Major International Coal Ports
Source: EIA, IEA, McCloskey, Velocity Suite
Source: EIA, IEA, McCloskey, Velocity Suite
56M
88M
63M
341M
2M
283M
17M
Export
Import
60M
27M
Net Exports
Importer
Exporter
Primary Purpose
Source: EIA, IEA, McCloskey, Velocity Suite
Australia
Dalrymple Bay
Hay Point
Abbot Point
Gladstone
Newcastle
Port Kembia
China
Qinhuangdao
Rizhao
Qingdao
Jingtang
Tianjin
Guangzhou
6
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Colombia
Puerto Bolivar
Indonesia
Kalimantan
Banjarmasin
India East
Chennai
Ennore
Gangavaram
Haldia
Karaikal
Krishnapatnam
Paradip
Vizag
India West
Kandia
Mumbai
Mormugao
Mundra
New Mangalore
Navlakhi
Pipavav
Italy
Piombino
Tananto
NW Europe
Antwerp
Rotterdam
Amsterdam
Immingham
Poland
Gdansk
Swinoujscie
U.S. East Coast
Baltimore
Hampton Roads
Russia (Baltic)
Murmansk
U.S. Gulf Coast
New Orleans
Mobile
Russia (Pacific)
Vostochnyy
South Africa
Richards Bay
Western Canada
Prince Ruppert
Vancouver
7
Coal Supply & Demand
World Coal Overview
World Generation Capacity & Demand
International Steel Intensity
Total world electricity generation
was 20.6 trillion kilowatt hours
in 2011 according to the EIA,
with coal responsible for the
most generation. Through 2035,
worldwide demand for electricity
is expected to grow 84% over
2008 levels, with most of that
generation coming from coal.
Steel intensity is a measure of steel
consumption as an economy develops.
It is the ratio of steel consumption per
capita to a country’s gross domestic
product (GDP) per capita. Developing
countries require growing quantities of
steel to build their infrastructure, but
they do not have sufficient available
economic resources to meet their steel
demand. Developed countries, on the
other hand, have ample economic
resources, but their demand for steel
typically stabilizes because their infrastructure is largely complete.
2011 World Electricity Generating Capacity
Source: EIA
The chart below shows the major
steel consuming countries, sized by
their population. The line represents
the typical path countries follow as
they develop their economies. From
the graphic, we can see that the
developing countries, notably China
and India, are expected to significantly
increase their steel consumption as
their economies grow. With over 35%
of the world’s population, demand for
steel in China and India should drive
healthy demand for steel and metallurgical coal in the future.
International Steel Intensity
Source: EIA
8
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9
Coal Supply & Demand
World Coal Overview
Internationally Traded Met Coal Demand
Internationally Traded Met Coal Supply
Primary consumers of internationally
traded metallurgical coal are Europe
and Asia. Europe has a well-established
steel making industry but lacks the
metallurgical coal resources to supply
its own requirements. This is also the
case for Japan which has long been a
large scale importer of metallurgical
High quality metallurgical coal is only
found in a handful of areas worldwide.
Australia is by far the largest producer
and exporter of met coal, followed
by the United States and Canada.
Other major producers include Russia,
Poland, South Africa, and Colombia.
coal. Imports to India and China have
also grown tremendously as these
countries develop. Growing Asian
economies fueled primarily by India
and China are expected to support
growth in internationally traded
metallurgical coal going forward.
Internationally Traded Met Coal Demand
10
Developing regions of metallurgical
coal production are in Mozambique
and Mongolia. Some of the highest
quality coals are generally found in the
United States and Australia and will
likely remain in demand as there is no
suitable replacement.
Internationally Traded Met Coal Supply
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11
Coal Supply & Demand
U.S. Coal Overview
U.S. Coal Supply
According to the U.S. Mine Safety & Health
Administration (MSHA), U.S. coal mines
produced 1.094 billion short tons in 2011.
Coal is mined in 26 states. Wyoming
produces the most coal, followed by West
Virginia, Kentucky, Pennsylvania, and
Montana. The Powder River Basin contains
some of the largest surface coal mines in the
world. About a third of U.S. coal is produced
in the Appalachian coal basins, led by West
Virginia.
About 9.8%, or 107 million tons of the coal
produced in 2011 was exported. The top
five countries for U.S. coal exports were the
Netherlands, South Korea, Brazil, the U.K,
and Japan. About 13.1 million short tons of
coal were imported into the U.S. in 2011.
The top five countries of origin of U.S. coal
imports were Colombia, Canada, Indonesia,
Venezuela, and the Ukraine.
U.S. Coal Basins
Major U.S. Coal Seams
2011 U.S. Coal Production by Basin
Northern
Lignite
PRB
NAPP
Rocky/
ILB
Uinta Basin
Basin
Source: EIA
ILB
ILB
NAPP
NAPP
NAPP
NAPP
NAPP
NAPP
PRB
PRB
PRB
PRB
CAPP
CAPP
CAPP
CAPP
CAPP
CAPP
CAPP
CAPP
CAPP
CAPP
CAPP
CAPP
CAPP
Rocky/Uinta
Gulf Lignite
N. Lignite
Seam
Herrin No 6
Springfield No 5
Pittsburgh
Lower Kittanning
Upper Freeport
Middle Kittanning
Lower Freeport
Upper Kittanning
Anderson
Canyon
Smith
Felix
Coalburg
Pocahontas No 3
Hazard
Jawbone
Lower Elkhorn
Raven
Splashdam
Fire Clay
Lower Banner
Upper Banner
Clintwood
Sewell
Eagle
Lower
Lower Sunnyside
Sunnside
Wilcox Group
Beulah-­‐Zap
CAPP
Est. Avg. Est. Avg. % Est. Avg. % Est. Maximum Est. Maximum Met/Steam
Btu/lb
Sulfur
Ash
Depth Thickness
11,484
11,756
12,159
13,101
12,929
12,785
13,086
12,767
8,835
7,998
9,463
7,807
12,788
13,862
12,651
13,085
13,069
12,875
13,782
12,702
13,497
13,615
13,770
13,762
13,564
13,133
6,597
6,439
3.4
4.2
4.2
2.7
2.3
2.4
2.2
2.1
0.8
0.5
0.8
1.2
0.8
0.7
1.2
0.9
1.1
0.9
1.1
1.3
0.9
0.9
1.6
0.9
1.5
1.0
0.9
0.9
10.8
12.0
11.9
11.5
13.5
12.3
10.7
13.0
6.8
6.5
8.9
10.2
11.4
8.6
10.4
12.2
10.4
6.0
8.2
11.2
9.9
8.4
6.7
5.9
8.2
5.9
12.6
7.9
1,000 ft
1,000 ft
2,000 ft
2,000 ft
2,000 ft
2,000 ft
2,000 ft
2,000 ft
2,000 ft
2,000 ft
1,000 ft
1,000 ft
2,000 ft
2,000 ft
1,000 ft
1,000 ft
1,000 ft
1,000 ft
1,000 ft
1,000 ft
1,000 ft
1,000 ft
1,000 ft
2,000 ft
2,000 ft
3,000 ft
Unclassified
Unclassified
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>10 feet
>10 feet
>10 feet
>10 feet
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
>42 inches
Unclassified
Unclassified
Steam
Steam
Met/Steam
Met/Steam
Met/Steam
Met/Steam
Met/Steam
Met/Steam
Steam
Steam
Steam
Steam
Steam
Met
Steam
Met/Steam
Met/Steam
Met/Steam
Met/Steam
Steam
Met/Steam
Met/Steam
Met/Steam
Met/Steam
Met/Steam
Steam
Steam
Steam
Source:USGS
Source: Velocity Suite
12
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13
Coal Supply & Demand
U.S. Coal Overview
How much coal does the U.S. have?
The image below shows estimated coal
reserves and resources in the U.S. The
estimated recoverable reserves only
include the coal that can be profitably
mined with today’s mining technology at
today’s coal prices.
U.S. total coal resources, which are
substantially larger than coal reserves,
are estimated to be over 4 trillion
tons—equivalent to over 4,000 years of
coal supply for the United States. Coal
resources include all coal that has been
identified or is assumed to be beneath
U.S. soil. It includes recoverable reserves
as well as coal that is currently not
economically accessible using today’s
technology. As mining technology
continues to advance and extraction
economies continue to improve, much of
the coal currently classified as a resource
will eventually be mined.
Recoverable coal reserves will last the
U.S. approximately 239 years, based on
2010 production levels. According to the
EIA, if coal consumption grows at an
annual rate of 0.4%, U.S. coal reserves
will be depleted in 168 years, if mining
technology does not improve, and if coal
prices do not rise.
U.S. Electricity Generation
The United States generated over 4,100
billion kilowatt hours of electricity
in 2011, with over 40 percent of that
coming from coal. By 2035, the EIA
expects coal-fired generation to
increase 8.5 percent, representing
39 percent of total U.S. electricity
generation.
Future U.S. Electricity Generation
(in billion kilowatt hours)
U.S. Coal Resources and Reserves
Billion Short tons as of January, 2011
Recoverable
Reserves at
Active Mines
17.9
Estimated
Recoverable
Reserves
259.5
484.5
Demonstrated
Reserve Base
Identified
Resources
1,672.9
Source: EIA
Total Resources
4,475.3
Source: EIA, North Dakota Geological Survey
14
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15
Coal Supply & Demand
U.S. Coal Overview
Average Retail Price of Electricity per Kilowatt-Hour, and
U.S. Electricity Generation with Renewable Breakout, 2011
Percent
of Electricity
Generated
by Coal
(2010)
Average Retail
Price
of Electricity
per
Kilowatt-Hour,
and
Percent of Electricity Generated by Coal (2009)
Source: EIA, Velocity Suite
WA 8%
MT 62%
ND 82%
MN 52%
ME 1%
OR 7%
ID 1%
SD 33%
WI 62%
WY 89%
NV 20%
CA 1%
NE 64%
UT 76%
CO 68%
PA 48%
IA 72%
IN OH 82%
IL 46% 93%
WV
97%
KS 68%
MO 81%
AZ 39%
NM 71%
NY 10%
MI 59%
OK 44%
AR 46%
KY 93%
TN 53%
VA 35%
NH 14%
MA 19%
RI 0%
CT 8%
NJ 10%
DE 46%
MD 54%
DC 0%
NC 56%
SC 36%
MS
GA 53%
25% AL 41%
TX 36%
Source: EIA
Coal % of Total Electric Generation
2009 Retail Elec. Price (¢/kWh)
LA 23%
FL
26%
Source: EIA, Velocity Suite
Greater than 14.0¢ /kWh
11.5 to 14.0¢ /kWh
8.5 to 11.5¢ /kWh
7.0 to 8.5¢ /kWh
Less than 7.5¢ /kWh
16
Return to Contents
17
International Coal Overview
Coal
Formation of Coal
Mine Reclamation
Formation of Coal . . . . . . . . . . . . 20
Quiz: Which are Reclaimed Mines? . . . 32
Coal Rank . . . . . . . . . . . . . . . . . 21
Coal Beds . . . . . . . . . . . . . . . . . 21
Mining
Coal Mining Introduction . . . . . . . . . 22
Mine Types . . . . . . . . . . . . . . . . 24
Preparation and Processing . . . . . . . 34
Transportation
Extraction Methods . . . . . . . . . . . 26
Modes of Coal Transport . . . . . . . . . 36
Surface Mining . . . . . . . . . . . . . . 28
Major U.S. Coal Export Options . . . . . 38
Mining Laws and Regulations
Mining Laws and Regulations . . . . . . 30
18
Preparation and Processing
Coal
Formation of Coal
Formation of Coal
Coal is a sedimentary deposit comprised
of the remnants of decayed plants,
in contrast to minerals which are the
building blocks for rocks. The plant
remains that contribute to coal deposits
depend on the type of plants that existed
at the inception of the coal formation. The
depositional environment determined the
chemical, physical and biological changes
that took place to the accumulated plant
remains over time. Like minerals found
in rocks, the preserved plant remains are
metamorphosed over millions of years
by pressure and temperature into various
kinds of coal. For coal to be preserved in
the geologic record into a merchantable
and mineable seam thickness requires
a depositional environment where plant
debris can accumulate faster than it
decays.
Depositional Environments – A thick,
mineable accumulation of coal requires
a depositional environment
or geographic setting with
rapid plant growth. Plant
material and debris are
preserved by accumulating faster than they
decay. Tropical rainforests
or swamps along a
low-lying coastal delta
are both examples of
depositional environments that encourage
thick accumulations of plant material,
known as peat.
Time – Accumulations of plant material
that have become coal are found in
sedimentary rock layers throughout the
world that are less than 350 million years
old. The reason that the coal deposits are
not found in older rocks is that plants only
evolved and became numerous enough
to form coal deposits about
350 million years ago.
Temperature – As the peat becomes more
deeply buried, it becomes heated due
to the geothermal gradient. Geothermal
gradient is defined as the rate of increase
of temperature with increasing depth from
the Earth’s surface. In areas of tectonically
stable sedimentary rock, the geothermal
gradient starts at approximately 400
feet of depth and is approximately 1°F for
every 100 feet of depth.
Origins and Formation of Coal
source: www.truthaboutsurfacemining.com
20
Pressure – The depositional environments for coal typically subside as the
peat and underlying sediments compact.
This, along with fluctuating sea levels,
allows sand, silt, and clay to be deposited
on top of the peat. This sediment
accumulates causing pressure that, along
with the heat generated by depth of
burial, results in chemical and compositional changes, turning peat into lignite.
Additional pressure turns lignite into
bituminous coal, and then into anthracite
coal, a process called coalification.
Coal Rank
Coal rank describes the amount of
metamorphosis the coal has undergone
and is used by industry to classify coals
for certain uses. Properties of coal rank
include carbon content, volatile matter
content, moisture, and heating value.
Lignite – Commonly referred to as brown
coal, lignite is soft and brownish-black
in color. Lignite represents the largest
portion of the world’s coal reserves. This
geologically young coal has the lowest
carbon content of all coal ranks, offering
low heat value of 4,000-8,300 Btu/lb on a
moist, mineral matter free (mmmf) basis.
Lignite is mainly used for electric power
generation.
Subbituminous – This dull black coal
gives off more heat than lignite, 8,30011,500 Btu/lb, and is cleaner burning
than other coals due to its lower sulfur
content. Subbituminous coals are mined
in Wyoming, Montana, and a few other
western states.
Return to Contents
Bituminous – Mined in the Appalachian,
Illinois, and Rockies regions, most
bituminous coal was formed during the
Pennsylvanian and Permian geologic
ages. With a highly variable sulfur
content and usually a high heat content
(>10,500-14,000 Btu/lb), it is used for
power generation, cokemaking, and other
industrial uses.
Anthracite – Anthracite coal is the
highest rank, having undergone the
most metamorphosis; it contains the
highest fixed carbon content. There are
few anthracite coal reserves around the
world to be mined. The U.S. reserves are
located primarily in Pennsylvania. Used
mostly for home heating, anthracite coal
makes up a very small component of coal
production nationwide. Anthracite coals
contain heat values of 12,500+ Btu/lb. It
is a misconception that anthracite coals
contain the highest heat value due to their
rank. The highest rank bituminous coals
contain the highest heat values.
Coal Beds
A coal bed is simply the layer of coal.
• Beds vary from a few inches to 100' or
more.
• The rock layers on top of a coal bed
are called “overburden.” The rock
layers between coal beds are called
“interburden.” The rock layers below
a coal bed are called “floor rock.”
• 60% of the world coal production
requires underground mining.
21
Coal
Mining
Coal Mining Introduction
Mining is one of the oldest and most
important contributors to modern
societies. The minerals and precious
metals that are extracted are vital to
energy, electronics, transportation,
infrastructure, and other aspects of
everyday life. Coal mining in the United
States is highly regulated at both the
federal and state levels to protect
the safety of miners and ensure the
least environmental impact possible.
Coal mining creates high paying jobs,
supports local, state, and federal
economies, and produces one of the
only fully domestic energy resources
available to the American people.
Permitting
Before a company can begin mining,
it must go through the rigorous
process of obtaining a mining permit.
The permit application process
begins by collecting baseline data to
adequately characterize the pre-mine
environmental condition of the permit
area. This work includes surveys of
cultural and historical resources, soils,
vegetation, wildlife, assessment of
surface and groundwater hydrology,
climatology, and wetlands. In
conducting this work, the company
collects data to define and model the
soil and rock structures and coal that
will be mined. The company develops
mining and reclamation plans using
this data and incorporating elements of
the environmental data.
22
Once a permit application has been
prepared and submitted to the
regulatory agency, it goes through a
completeness and technical review.
Proposed permits also undergo a
public notice and comment period,
allowing the public and other agencies
to comment on the permit. Some
mine permits may take several
years or even longer to be issued.
Regulatory authorities have considerable discretion in the timing of the
permit issuance, including through
intervention in the courts. Before a
mine permit is issued, a mine operator
must submit a bond or otherwise
secure the performance of reclamation
obligations.
Mining and water interact, as with
any land disturbance. The effects
depend on the location of the mine, the
hydrology and climate of an area, and
the physical and chemical properties of
the coal, associated strata, and residual
materials. The quality and quantity of
surface water and groundwater can
be protected both within a mine and
in the surrounding areas if modern
mining techniques and procedures
are followed. Unfortunately, in the
past, many sites were abandoned with
inadequate reclamation measures,
leaving a legacy of contaminated
drainage and water pollution. However,
today’s mitigation technologies offer
solutions to past problems caused by
out-of-date mining practices.
Coal Mining and the Environment
The health of the environment is
always analyzed prior to mining
through baseline monitoring and
analysis. Then, based upon proven
engineering principles, data, and
experience, engineers can prepare
mine plans that eliminate and/or
minimize the impacts of mining.
Mine planning must mitigate those
impacts. Before any mining begins,
the post-mine land use must be
addressed in such a way that the
operator restore the land to a
condition capable of supporting the
uses it could support prior to mining,
or to “higher or better uses.”
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23
Coal
Mining
Mine Types
Slope Mine
Slope mines are another kind of
underground mine. Slope mining uses
shafts that are slanted down to the coal
or mineral bed, in lieu of drilling shafts
straight down.
Open Cast Mine
Open cast mining simply means mining at
the surface, rather than underground. The
mineral deposit is covered by soil, which
is removed and stored for use after mining
by large machines, and then explosives
break up the overburden and ore deposit.
Overburden is the layers of soil and rock
that cover a coal seam.
• Slope mines are usually not as deep
as shaft mines.
• Conveyors bring the coal out of the
mine using the slope tunnel.
• Sometimes there are three slopes –
one takes workers in and out of the
mine and provides an intake for fresh
air, the second takes coal out on a belt
and the third provides an exhaust for
returned or used air.
• The greatest number of open cast mines
in the U.S extract bituminous coal.
• Globally, about 40% of coal production
involves surface mining.
Shaft Mine
When the top of a vertical excavation is
the ground surface, it is referred to as a
shaft, hence the term “shaft mining.” Shaft
mining uses a vertical mineshaft, a tunnel
where miners travel up and down in an
elevator. Mine ventilation is also provided
through the shafts. Tunnels are dug out
from the mine shaft into the mine seam.
Once the coal is mined, it is transported
to the surface typically through a second
vertical shaft.
Drift Mine
Drift mining is used when the coal or
mineral is accessed from the side of a
mountain. The opening to the mine is
dug from a bench to the coal or mineral
vein.
• Drift mines have horizontal entries,
called adits, in the coal deposit from a
hillside.
• Conveyance/transportation equipment
often contains conveyor belts, rubbertired equipment, or track equipment.
source: www.truthaboutsurfacemining.com
source: www.truthaboutsurfacemining.com
24
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25
Coal
Mining
Extraction Methods
Long Wall Mining
Room & Pillar Mining
This highly productive underground
coal mining technique occurs when a
long wall, about 250-400 meters long
of coal, is mined in a single slice,
typically 1-2 meters thick. Long wall
mining machines consist of multiple
coal shearers mounted on a series
of self-advancing hydraulic ceiling
supports. Long wall miners extract
“panels,” or rectangular blocks of
coal as wide as the mining machinery
and as long as 12,000 feet.
The most common type of
underground coal mining involves
the excavation of a room or chamber
while leaving behind pillars of coal
to support the roof. Coal seams are
mined using a continuous miner,
a machine that extracts the coal
without interrupting the loading
process. Excavation is carried out in
a pattern advancing away from the
entrance of a mine. Once a deposit
has been exhausted, pillars may
be removed, or pulled, in a pattern
opposite from which the mine
advanced, known as retreat mining.
Short Wall Mining
Similar to the long wall method,
except the blocks of coal are no
longer than 100 meters wide and
removed by a continuous miner. The
roof support also operates similarly
to long wall shields, allowing it
to collapse once the miner has
advanced. It currently accounts for
less that 1% of deep coal production.
Coal panels are 150-200 feet wide and
more than a half mile long.
source: www.truthaboutsurfacemining.com
source: www.truthaboutsurfacemining.com
26
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27
Coal
Mining
Surface Mining
Mountaintop Mining
Auger Mining
Used where the presence of
multiple coal seams allow for
coal extraction across the entire
area rather than around edges
as in contour mining. Large
scale equipment is used to move
overburden from above coal
seams and extract coal.
Working on a contour mining
bench, or in an open mine pit,
horizontal holes are drilled up to
a distance of 300 feet into a coal
seam. The coal is removed by a
special auger through a screw-like
action.
Open-Pit Mining
Contour Mining
Appropriate only where terrain
is flat or only slightly rolling and
where coal seams are very thick.
An open pit is excavated with
terraces, or benches, that expose
the coal seam for extraction.
Follows the contours of one
or more coal seams around a
hillside where these are exposed.
Overburden is excavated and
the coal is removed creating a
working bench referred to as a
“contour bench.” When mining
is finished the contour bench is
filled in.
Highwall Mining
source: www.truthaboutsurfacemining.com
Holes or entries are excavated
up to a distance of 1,000 feet into
a coal seam. A special highwall
mining machine advances into
the coal seam. Its cutting head
removes the coal and moves it
to conveyor cars attached to the
machine.
U.S. Surface Mining Fast Fact
Approximately 69% of U.S. coal
production is from surface mines.
source: www.truthaboutsurfacemining.com
28
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29
Coal
Mining Laws and Regulations
Mining Laws and Regulations
Surface Mining Control and
Reclamation Act (SMCRA)
This act governs valley fill engineering,
water drainage controls, stabilization of soils and reforestation. Mining
companies must minimize disturbance
of the hydrologic balance within the
permit and adjacent area while mining,
and leave the land after mining in
a state equal to or better than the
pre-mining state. Companies must
post bonds which cannot be released
until the post-mining plans are fully
completed and the land is demonstrated to be at least as productive as
its pre-mining state.
Clean Water Act (CWA)
Sections of this act, along with states’
National Pollutant Discharge Elimination System (NPDES) permit, govern
stream and wetland restoration and
continuous water quality monitoring at
all water discharge points from mines,
preparation plants and coal handling
facilities. Section 404 of the CWA
specifically regulates the discharge of
dredged and fill materials into waters of
the U.S. and is used to regulate mining.
Clean Air Act
Limits the amount of particulate
or fugitive matter that can be
gener­ated at a mine site. Sources
include dust generated by mining
equipment and haul trucks moving
across unpaved areas.
30
Other Environmental Laws and
Regulations
Other regulations that impact coal
mining include: Safe Drinking Water
Act, Solid Waste Disposal Act, National
Environmental Policy Act, Resource
Conservation and Recovery Act, Comprehensive Environmental Response,
Compensation and Liability Act, Toxic
Substances Control Act, Migratory Bird
Treaty Act, Endangered Species Act,
National Historic Preservation Act, and
various state statutes and regulations.
Stream Buffer Zone
This rule was issued by the Office
of Surface Mining Reclamation and
Enforcement (OSM) in 2008 under
requirements of the SMCRA. The rule
puts restrictions on how coal miners
can dispose of coal mine waste and
spoils created by the mining operation.
The rule requires mine operators to
avoid disturbing streams to the extent
possible and when operators must
maintain a buffer between mining
operation and streams.
Stream Protection Rule
The OSM is in the process of
developing a new rule to replace the
Stream Buffer Zone rule. This draft rule
is referred to as the Stream Protection
Rule. OSM is conducting an Environmental Impact Statement for the new
rule and a new proposed rule may
follow after completion of the EIS.
“Permitorium”
In June 2009, a Memorandum of
Understanding (MOU) on Appalachian
Surface Coal Mining was issued by
the Environmental Protection Agency
(EPA), Dept. of the Interior (DOI), and
the U.S. Army Corps of Engineers
(Corps) to immediately implement
an “Enhanced Coordination Process”
(ECP) to more closely scrutinize CWA
fill permits issued by the Corps.
The EPA developed a Multi-Criteria
Integrated Resource Assessment
(MIRA) process to help decision makers
to make more informed decisions
that included stakeholder concerns.
The ECP/MIRA process was supposed
to streamline the permitting process
according to the MOU, however new
permit issuance effectively stopped.
Over 230 §404 permits have been
stalled by the EPA. In October 2011,
the D.C. District Court invalidated the
process, concluding the EPA “exceeded
the authority conferred upon it by the
Clean Water Act.”
The EPA has also issued new water
quality guidance for surface mines in
Appalachia, which stipulates that water
discharging from mining disturbances
must not exceed 500 microSiemens
per centimeter (µS/cm, a unit of
measurement of conductivity), and
water in excess of as low as 300 µS/
cm would be cause for close, critical
scrutiny of the mining operation’s
permit conditions. These values are
extremely low and difficult to achieve,
thus effectively eliminating mining
Return to Contents
in that region. In addition, electrical
conductivity is a non-specific parameter
that does not specifically characterize
water quality or define its impact on
aquatic life and therefore is an inappropriate regulatory metric.
It is unlikely permitting will return
to historical levels due to additional
tactics employed by regulating bodies
such as the OSM’s Stream Protection
Rule, EPA’s permit veto authority, and
the Corps’ suspension of Nationwide
permits (NWP 21) in Appalachia,
together with additional guidance
documents that are expected in the
near future.
Reclamation
All surface mines must be reclaimed
to a state equal to or better than
the pre-mining state. This involves
restoration of disturbed land, soil
stabilization, water drainage control,
reforestation, and water quality mining.
Below is an image of a once active
mine site (left) and its current state
(right) almost 30 years later.
Reclaimed Mine — Before and After
31
Coal
Mine Reclamation
Quiz:
Which of the following are reclaimed mine sites?
4. A forest in Logan County,
West Virginia
To learn more, go to: www.truthaboutsurfacemining.com.
1. Big Sandy Regional
Airport in Debord,
Kentucky
5. A farm in
Southwest Virginia
2. Pete Dye Golf Club in
Bridgeport, West Virginia
3. A stream in
Southwest Virginia
6. YMCA Paul Cline
Memorial Youth Sports
Complex in Beckley,
West Virginia
Quiz Answer: All six of these images are of reclaimed mine sites in Appalachia.
32
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33
Coal
Preparation and Processing
Preparation and Processing
After mining, coal is washed to remove
impurities and increase heating value.
Preparation plants remove rock,
sulfur, and other particulates from
the run-of-mine coal. These plants
also allow mining companies to sort
coal based on quality, enhancing their
ability to serve customers’ various
specifications.
Each coal preparation plant has three
primary sections:
1. Sizing: Coal is usually separated
using grates of three sizes: coarse,
intermediate, and fines. Each size
follows a different path through the
plant.
a. Most utility coal specifications
will require a 2” x 0 (2 inch or
less) product with a maximum
percentage of fines. This allows
for efficient shipping & handling
of the coal before being
pulverized for combustion.
b. Some customers, especially in
the industrial sector, will request
stoker coal which is smaller and
relatively uniform in size since it
will not be crushed again before
burning.
2. Processing: This is where rock and
other contaminants are removed.
a. Coarse coal is separated using
a heavy media bath which is a
34
mixture of magnetite and water.
Less dense coal floats to the top
and is skimmed off.
b. Intermediate sizes use a similar
technique, however, the coal
and heavy media mixture is
spun in a cyclone to speed up
the process. Less dense coal
spins out of the top of the
cyclone while rock falls out of
the bottom.
c. Fines, particles of coal usually
less than one-sixteenth inch, are
separated first by a cyclone then
recovered by froth flotation. The
fines/rock mixture is added to
a tank where special chemicals
help the coal to adhere to air
bubbles rising through the tank.
The coal is skimmed off the top.
The fine rock is then removed
using a thickening agent and a
skimmer.
3. Dewatering: Coarse and intermediate coals are first rinsed to remove
any remaining magnetite. They are
then spun in a centrifuge to remove
excess water. Fines are dewatered
using vacuum disk filters. The filter
disks are placed under a vacuum
which pulls the water from the
fines. Once the vacuum pressure is
removed the fine coal falls from the
disk. Fines may also go through a
secondary thermal dryer.
Waste coal is a byproduct of coal
processing operations, usually
composed of coal, soil, and rock
fragments.
mentary products having different
mining costs such that the final product
can achieve a customer’s price and
quality objectives. Benefits are:
Coal Is Cleaned
• Optimizes plant fuel usage,
controlling coal quality.
After coal is mined it generally
goes through a process known as
preparation or coal cleaning. Removing
impurities from coal is done in order to:
• Maximizes fuel efficiency in
response to forecasted generation
needs.
• Improve power plant capacity.
• Minimizes coal quality events,
reducing fouling, slagging, and
emission occurrences.
• Reduce maintenance costs at the
power plant and extend plant life.
Coal Is Sized to Specifications
• Boost the heat content of the coal.
• Reduce potential air pollutants,
especially sulfur dioxide.
Coal Is Blended
Blending is simply a mixture of two or
more types of coal. This provides, for
example, the potential to mix lower
cost or low quality coals with higher
cost or higher quality coals and reduce
the overall cost of the final blend.
Blending of two or more kinds of coal
together into a shipment provides a
seller the opportunity to mix comple-
Return to Contents
Sizing coal is the process of
segregating lumps of coal that are
similar in size. Coal passes over one or
more vibrating screens and the larger
sizes not passing through each screen
are separated.
• The sizes of coal produced may vary
depending on customer needs and
type of coal.
• The desired outcome is the same:
coal that can be handled and burned
more advantageously.
35
Coal
Transportation
Modes of Coal Transport
Trucks – For shorter hauling distances,
smaller quantities, and access to certain
loading points, trucks meet the need.
They are used mainly in short hauls to
nearby electric and industrial plants.
Multimodal deliveries can include
trucks, railcars, and barges. Trucks are
often the quickest and easiest way to
move product and are able to be scaled
up or down as needs change. Highway
trucks haul coal in loads typically under
25 tons.
Trains – Rail is an effective way to
move large quantities of coal over long
distances. Nearly three-fourths of the
coal produced annually in the U.S.
moves by rail. A typical coal train travels
over 800 miles from a mine to a plant
or terminal, carrying about 12,000 tons
of coal in 100 to 120 cars, but trains
can be up to 150 cars long. Each coal
train is about a mile long, or more.
Railroads carry more coal than any other
commodity. Coal is about 40% of the
annual volume hauled by rail in the U.S.
Barges – The river system in the U.S.
includes 12,000 miles of waterways.
For coal with access to this system,
barges are a good way to move it. One
barge carries up to 1,700 tons of coal.
Below is a list of the options for transporting coal. There is no specific tonnage for
bulk carriers, but deadweight tonnage (dwt) should be used as an estimate.
A common barge tow of a towboat and
15 barges can haul 25,000 tons of coal.
20% of the coal used in U.S. electricity
generation travels by inland waterways.
Although slower, barges are cost
effective and fuel efficient, hauling one
ton of cargo 576 miles per gallon of fuel.
Transportation
Bulk Carrier – Single deck ship designed
to carry homogeneous dry cargoes,
such as coal, ores, grains, etc.
Storage – Coal is often stored at a plant,
river port, or import/export terminal.
Without some type of storage, the
logistics of supplying coal would be
far more difficult and costly. This also
allows the blending of different coal
products to better meet customer needs
while optimizing the value received
by the mine operators. Coal storage
must be managed and controlled
using proven practices, since some
coals, especially lower rank coals, have
a natural tendency to heat through
spontaneous combustion.
Reclaimed mines are: A, B, D, F
U.S. Transportation Fast Facts
Transportation
Mode*
Million Tons
(2011)
Railroad
700
River
105
Truck
110
Other
63
Mode
Approximate
Capacity (tons)
Truck
< 25
Rail car
100 to 125
Unit train
(100 to 150 cars)
10,000 to 18,750
River barge
1,700
River barge tow
(~15 barges)
25,000
Mode
Deadweight
Tonnage (Dwt)
Handysize
> 10,000 - 40,000
Handymax/
Supramax
> 40,000 to 60,000
Panamax/
Post-Panamax
> 60,000 to 100,000
Capesize
100,000 +
Source: EIA
*Tons of coal by mode of terminating receipt.
36
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37
Transportation
Major U.S. Coal Export Options
Major U.S. Coal Export Options
Metallurgical
Coal
Ridley, Prince
Rupert, BC
Vancouver BC
BN
BN
SF
Seattle
BNS
SF
- CP
F
Columbia
-C
PCN
- CN
UP & BN
SF
PRB
UP
UP
UP
Legend
F
CSX
ILB
CAPP
CN
CSX
Houston
Philadelphia
NAPP
Rocky Mtn
SF
BN
Long Beach &
Los Angeles
NS
&
UP
Richmond
&B
Mobile
New Orleans
& NS
Baltimore
Iron Making
Metallurgical Coal Overview . . . . . . . 40
Blast Furnace Iron Making . . . . . . . . 48
Metallurgical Coal Properties . . . . . . . 41
Pulverized Coal Injection (PCI) . . . . . . 48
Coke
Finished Steelmaking
Coke Making . . . . . . . . . . . . . . . 46
Finished Steelmaking . . . . . . . . . . . 50
Hampton Roads
Charleston
Jacksonville
Coke Properties . . . . . . . . . . . . . 47
Port
Rail Movement
Water Movement
Potential Movement
Export Volume
38
Metallurgical Coal
Return to Contents
Metallurgical Coal
Metallurgical Coal
Metallurgical Coal Overview
Metallurgical Coal Properties
Coal is a heterogeneous mixture of
organically derived plant remains
which have undergone chemical and
physical changes in response to biologic
and geologic processes. The right
conditions must exist for plant materials
to accumulate and be preserved in the
geologic record. Coal formation occurred
as far back as 350 million years ago and
as recently as 2 million years ago.
Petrographic analysis is used to assess
• Liptinite, which is comprised of spores,
the utilization potential of coals and has
resins, and cuticles of the preserved
proven particularly useful in gaining
plant remains, is also very reactive. In
insight into their coking potential— being
terms of coking properties, members
the only test available that can dissect coal
of the liptinite group have much lower
into its integral parts and characterize them
coke yields than their associated
by rank, type, and grade simultaneously.
vitrinite and contribute more heavily
to the by-products during coke making
Coal is comprised of three major maceral
(i.e., gas, tars, and light oils). Liptinite
groups — vitrinite, inertinite, and liptinite —
matures much more slowly than its
which proceeded along distinctly different
associated vitrinite in the early stages
metamorphic paths.
of coalification, up through high volatile
A bituminous in rank, and then very
• Vitrinite is the predominant maceral
quickly in the medium volatile rank
constituent in nearly all coals, originating
range where it becomes optically indisfrom the woody tissue of plants. It’s
tinguishable from the vitrinite.
the most abundant of the macerals and
matures the most uniformly throughout
• Mineral matter, which comprises
the coalification process. Its reflectance
the ash and sulfur found in the coal,
in plane polarized light is often used
can be quite variable depending on
as the ultimate indicator of rank. In
its origin, and its level of concentraterms of coking properties, vitrinite
tion can impact utilization potential.
is the predominate reactive binder
The inherent ash forming minerals
forming the wall and pore structure
which contribute to a plant’s nutrients
of coke and acting as the cement
represent the more basic components
necessary to assimilate and bond the
in the ash, while its inherent sulfur is
aggregate, which originates with the
of the organic variety. Ash forming
inertinite group.
minerals added later as impurities
during or after the biochemical
• Inertinite is comprised of various plant
stage can be basic or acidic in nature
remains which achieved a high rank
depending on their origin. Pyritic sulfur
early in the coalification process such
can also be of primary or secondary
as fusinite and semifusinite which
origin, originating from bacterial
originated from woody tissue exposed
action or the precipitation from sulfur
to fire and converted to charcoal, or
bearing waters. Met coal, and the
micrinite which is believed to be the
resulting coke, must have low ash and
product of accelerated decay of a variety
sulfur content for it to be used in the
of plant tissues during the inception of
steelmaking process.
coal formation. Most inertinite, as the
name implies, is inert.
Coals are classified on the basis of
rank, type and grade. Older deposits are
more likely to be higher in rank as their
biologically digested plant remains were
buried deeper, exposing them to higher
temperatures and pressures, which
advance the process of coalification.
Rank refers to the degree of alteration
or metamorphism of the plant remains.
Type refers to the variety of plant
remains preserved, known as macerals,
and grade refers to the minerals
associated with and/or accompanying
the plant remains during the inception
of coal formation.
where the volatiles from the coal
escape, leaving behind what is referred
to as metallurgical coke, which reaches
a temperature of approximately
1,000°C before being removed from the
ovens. The coking cycle normally takes
place in 18 hours for an oven width of
18 inches, or one inch per hour. Coke is
used primarily as a fuel and a reducing
agent in a blast furnace during the
smelting of iron ore into iron before it
is converted into steel.
Nearly all of the U.S. metallurgical coal
mines are located in Appalachia which
extends from Pennsylvania to the north
and Alabama to the south with the
vast majority of production clustered
around the borders of southern West
Virginia, eastern Kentucky, and western
Virginia.
Major U.S. Metallurgical Coal Mines
Metallurgical coal, also referred to as
met coal or coking coal, ranges from
high volatile A through low volatile
bituminous in rank, and possesses the
ability to soften and re-solidify into a
coherent, porous mass, when heated
from 300 to 550°C in the absence of air
in a confined space. The conversion
from coal to coke occurs in long, tall,
slender chambers called coke ovens
Source: Velocity Suite
40
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41
Metallurgical Coal
Metallurgical Coal
Metallurgical coals are usually classified
as high, medium, and low volatile
based on their dry, mineral matter
free volatile matter (dmmf VM). High
vol coals are typically between 31%
and 38%, while mid vols between 22%
and 31%, and low vols between 17%
and 22% volatiles. There is usually
a strong inverse relation between
vitrinite reflectance and dry ash free
volatile content. Other terms used to
describe metallurgical coals are hard
coking, semi-soft, and PCI. Coking
coal, by definition, must be hard and
the term hard coking coal is a general
term used to describe coking coals
with superior coking properties relative
to their semi-soft counterparts. As
described earlier, coking properties are
rank dependent and the term semi-soft
Met Coal Properties
Analysis
Focus
Test
Moisture
Proximate
Ultimate
Chemical
Ash
Volatile
Low Vol
Mid Vol
High Vol
ideally, as low as possible
ideally, as low as possible
17 - 22% dry
22 - 31% dry
Importance
consumes energy
coke impurity
31 - 38% dry
impacts coke yield
Fixed Carbon
ideally, as high as possible
impacts coke yield
Sulfur (S)
ideally, as low as possible
hot metal impurity
C, H, N, O
composition of coal
Initial Deformation
Ash Fusion
Softening (H=W)
Hemispherical (H=1/2W)
ideally, as high as possible - >2,700°F
low fusion temperatures
can cause ash to deposit
on coke oven walls
chemistry impacts coke
CSR
Fluid
Physical
Ash Mineral
SiO 2, Al 2 O 3 , TiO2 , CaO, MgO,
K 2 O, Na 2O, Fe 2 O 3 , P 2 O 5 , SO 3
low base/acid ratio (<0.20), low alkalis (<3%
K 2 O + Na 2 O), low P 2 O 5 (<0.02%)
Oxidation
Light transmittance test
want non-oxidized coal; oxidized coal creates poor coke
Hardness
Hargrove Grindabilty Index
measure's coal resistance to crushing
Gieseler Plastomer Test (DDPM)
20 - 1,000
Gieseler Plastic Temp Range
Rheological
Plasticity
Dilatometer Test (% Dilatation)
Free Swelling Index
<200 - 20,000 5,000 - >30,000
want wide plastic temp range to blend with
other coals
<0 - +200%
+100 - +250%
+50 - +300%
higher values are better,
most coking coals >6
1.15 - 1.40%
0.70 - 1.12%
best rank indicator;
correlates with most
other coking coal
evaluation parameters
Rank
Vitrinite Reflectance
Type
Maceral
Optimum ratio of reactives to inerts for any particular reflectance for
maximum coke strength
Grade
Mineral
ash constituents, see above
Petrographic
1.45 - 1.7%
Tests rheological or
plastic properties - the
ability, when heated in
the absence of air, to
soften, swell, and then
resolidify to form a
porous, hard coke
structure
normally applies to lower rank high
vol coals. PCI is described in the blast
furnace ironmaking section.
Coals considered as candidates for use
in cokemaking must pass a barrage
of analytical tests before they can
be considered suitable for use. Met
coals are analyzed for their chemical,
physical, rheological (coking process),
and petrographic (rank, type, and
grade) properties. The preceding
table identifies the majority of characterization tests performed and the
importance of each in the context of
cokemaking.
The amount of volatile matter in met
coal impacts coke yield - the amount
of coke and by-products produced per
ton of coal charged. Increased moisture
has a comparable impact on coke yield
and can also impact bulk density in the
ovens and the underfiring requirements
in tems of btu/lb of coal carbonized.
The ash in met coal becomes an
impurity in the coke and therefore
displaces carbon in the blast furnace.
Consequently, ash contributes to
higher coke rates, and it reduces hot
metal production due to increased slag
volumes and the additional coke and
limestone required to smelt out the
ash. The composition of the ash is also
important because certain components
of the ash, such as the alkalis and
phosphorus pentoxide content, will
also impact coke rate and hot metal
quality. Ash composition has also been
found to impact coke reactivity and
the all-important coke strength after
reaction (CSR) results. The composition
of the ash should have as low a base/
acid ratio as possible with low alkalis
(K2O and Na2O) and low phosphorus
pentoxide (P2O5) content.
Sulfur, like ash, must be removed from
the hot metal, either within or outside
the furnace, and like ash, contributes to
higher coke rates and lower hot metal
productivity.
The ash fusion test is performed in a
reducing atmosphere and helps assess
the combined effect the ash forming
minerals have on ash softening
properties at different temperature
levels. Higher ash fusion temperatures
prevent ash from depositing on coke
oven floors and walls or freeing up
fresh carbon surfaces to reactive gases.
The light transmittance test was
developed to detect weathered
or oxidized coal found primarily
in surface mined coking coal. The
presence of even small amounts of
oxidized coal will decrease fluidity,
dilatation, coke strength, and lead to
excessive fines generation which in
turn create coal handling problems
and decreased oven bulk densities.
Oxidized coal also contributes to
reduced by-product yields and
increased heating requirements
during the conversion of coal to coke.
Source: SGS
42
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43
Metallurgical Coal
Metallurgical Coal
Coke produced from coal charges
containing oxidized coal will also
increase the coke reactivity index (CRI)
and decrease its corresponding CSR.
Plasticity tests measure the degree
to which coking coals soften, swell,
dilate, and subsequently resolidify over
the temperature range from 300°C to
550°C when heated in the absence of
air. Some plasticity tests also measure
the ability of a coal to agglomerate
and assimilate inert material over this
same temperature range. The Gieseler
plastometer test measures the fluidity
or plasticity of coking coal in a cylinder
with a stirrer inserted inside. The
cylinder of coal is heated at a constant
rate as steady torque is applied to the
stirrer. As the coal heats up, it softens
and the stirrer rotates. The DDPM (dial
divisions per minute) is the maximum
amount of revolutions the stirrer
completes. The test is logarithmic with
high volatile coals exhibiting fluidities
many multiples higher than low volatile
coals, with medium volatile coals
generating values in between those
extremes. Since the combined effect of
the test procedure and equipment on
the ddpm results can contribute to an
unacceptably high reproducibility, the
plastic range is a more useful indicator
of coking performance and ties more
closely to the dilatometer results where
the reproducibility is much better.
44
The Dilatometer test measures the
contraction and dilatation of a 60mm
pencil of coal in an oven of rising
temperature. The dilatometer results
are particularly useful because they
indirectly measure the thickness and
viscosity of the plastic layer, and how
they are impacted by the amount and
rate of gas evolution during softening
and re-solidification. The Free Swelling
Index (FSI) also tests the plastic
properties of coal; however its value as
a rheological test is limited because it
is more of a threshold test having little
quantitative value. The test involves
heating a gram of coal in a crucible
to 800°C and then visually comparing
the resulting coke button to a standard
chart of shapes and sizes to determine
the FSI value on a scale of one to nine.
Most coking coals have an FSI value
greater than six. Other rheological
tests used around the world include
the Gray-King test, the Roga index, the
G caking index, and the Sapozhnikov
plastometer. The sole-heated oven
test, the pressure oven test, and the
movable oven wall test are technically
classified as rheological tests but are
intended to measure the performance
of formulated blends in terms of
contraction away from the oven walls,
the pressure exerted against the oven
walls, and the quality of coke expected
to be produced respectively.
Met Coal Blends
Met coal blends are generally
formulated from a variety of different
ranks, types and grades of coals
sourced from different geographic
regions with the purpose of producing
the highest quality coke at the lowest
possible cost while protecting the
ovens in which those blends will be
carbonized.
Most North American coal blends
are formulated to fall between
1.16% and 1.20% mean maximum
reflectance (27.5 - 29.5% volatile matter
content)—a level necessary to achieve
maximum coke strength safely,
after factoring in all the operational
constraints of by-product slot ovens.
Coal blends must perform optimally
in the confined space of the ovens in
which they are carbonized, while at
the same time ensuring oven safety.
The coking pressure of the coal blend
being carbonized must be kept within
strict limits, based on the age and
height of the ovens to avoid undue
pressure on the walls which can lead
to their premature failure. The coal
blend which initially expands during its
conversion to coke must also contract
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sufficiently away from the oven walls
in order to allow for its easy discharge
from the oven.
Other process variables in the coking
process that must be controlled
include coal blend moisture, pulverization, charge bulk density, and coking
rate. The coal charge bulk density,
measured in pounds per cubic foot,
must be controlled to maximize oven
productivity and coke stability, while
maintaining safe coking pressure
and blend contraction. Increased coal
pulverization increases coke strength
and blend homogeneity, however too
finely ground coal is more difficult to
handle and often leads to lower oven
bulk densities and more problems
with emissions and carryover in the
by-product collection system during
oven charging. The coking or heating
rate of the coal charge, as measured in
inches per hour, impacts coke strength,
coke pressure, blend contraction,
carbon formation, and oven productivity. Heat of carbonization and coking
times, which are more coal-blend
related, are also impacted by changes
in operating practice.
45
Metallurgical Coal
Coke
Coke Making
Most metallurgical coke is produced
in airtight slot ovens operated under
slight positive pressure, whereas the
more recent adoption by the industry
of non-recovery ovens operate under
slight negative pressure to avoid air
emissions. In both cases, the coke process
is considered complete once the center of
the oven charge reaches a temperature
approaching 1000°C. The end product is
called coke. In slot ovens which are 18” in
width this normally takes around 18 hours
whereas in non-recovery ovens the coking
cycle per oven is between 40 to 48 hours
due to their thicker beds. A series of coke
ovens is referred to as a coke battery.
In a by-product coke battery, one ton of
met coal yields approximately:
• 1,300-1,400 lbs coke
• 100-500 lbs coke breeze (fines)
• 8-12 gal. tar
• 20-28 lbs ammonium sulfate
• 15-35 gal. ammonia liquor
• 2.5-4.0 gal. light oil
• 9,500-11,500 cu. ft. coke oven gas
(~550 Btu/cu. ft.)
North America has the capacity to make
roughly 19-20 million tons per year
of coke.
46
Coke is far stronger than coal and is
able to support the blast furnace burden
which includes iron ore in the form of
pellets, sinter, and/or lump ore as well as
limestone. In addition to providing the
required permeability necessary to blow
wind up into the furnace, which enhances
productivity, coke also supplies much of
the heat required to melt the iron ore and
the carbon necessary to complete the
reduction process.
The most important chemical properties
of coke are its ash and sulfur contents,
along with its alkali, phosphorous, and
base/acid ratio in the coke ash. Physical
properties analyzed are size, strength (or
hardness), coke strength after reaction
(CSR), and coke reaction to CO2 (CRI).
The coke reactivity index and coke
strength after reaction tests are intended
to simulate the strength properties of
coke as it descends in the blast furnace
and is exposed to increasing quantities of
reducing gases at higher temperatures.
CSR has become a more important quality
parameter for blast furnace operators as
coke rates have declined and the amount
of pulverized coal and other fuel injectants
increased.
Analysis
Chemical
Physical
Test
Coke Property
Ash
ideally, as low as possible - coke impurity
Sulfur
ideally, as low as possible - coke impurity
Size
consistent for blast furnace air flow
Strength/Hardness
stronger is better
Coke Strength after Reaction
> 60%
Coke Reactivity Index
< 25%
Iron Ore
Iron ore is predominantly used for
steelmaking and mined in deposits
around the world. The largest
producing countries of iron ore are
Australia, Brazil, China and India.
Iron ore pellets are the most common
iron bearing material used in North
America; ore is processed near the
mine sites into small pellets containing
60% to 65% iron.
Iron ore sinter is most common in
Europe and Asia. Iron ore sinter is
processed at the steel plant where iron
ore is heated along a slow moving belt
to form lumps of sinter.
impurities in the slag.
High-quality lump iron ore is also
directly charged into the blast furnace.
Flux
Flux, which is crushed limestone, is
also charged into the furnace to capture
impurities and reduce the melting
point of the slag. The calcium in the
limestone combines with the silicates
coming from the coke ash and iron
ore burden, and any sand that might
be added at times to balance the slag
basicity to the desired levels in order
optimize the capture sulfur, alkali and
other unwanted impurities.
Both pellets and sinter can be of the
acid or flux variety. Many operators
have found it advantageous to use
flux burdens because the gangue in
the pellets and sinter can displace
some of the limestone used to capture
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47
Metallurgical Coal
Iron Making
Blast Furnace Iron Making
Coke is combined with an iron (Fe)
bearing material to be smelted into pig
iron. Coke, iron oxide, and limestone
are charged into the top of a blast
furnace in alternating layers.
Within the blast furnace, the iron
oxides are reduced; meaning oxygen
is removed in a chemical reaction. In
the lower part of the furnace direct
reduction occurs where carbon (C) in
the coke and PCI (see below) reacts
with the FeO to produce Fe and CO,
which is a very endothermic reaction.
When the hot air blast ignites the
carbon contained in the coke and
pulverized coal it also produces CO.
Higher up in the furnace, indirect
reduction occurs where reducing
gases like carbon monoxide (CO) and
hydrogen (H) originating with coke,
PCI, and moisture in the blast are used
to strip away oxygen (O2) from Fe2O3
and Fe3O4. This reaction is only slight
endothermic. The lowest amount of
heat required to convert iron oxides to
iron is achieved with a balance of 55%
indirect and 45% direct reduction.
Eventually the reduced iron oxide
becomes molten and accumulates
at the bottom of the furnace. The
limestone flux descends through the
furnace and bonds to the sulfur in the
iron, and becomes part of the slag.
When the furnace is tapped, liquid
metal (pig iron) and slag flow out. The
slag is skimmed off the top of the liquid
48
Diagram of a Blast Furnace
metal, hardens as it cools, and then
is granulated to make aggregate. The
liquid iron is then transported to the
next stage of the steelmaking process.
Top Gas
Ore
Coke
Pulverized Coal Injection (PCI)
Additional fuels, specifically natural
gas and/or coal, can be injected into
the blast furnace to reduce the use
of expensive coke. Coal must be
pulverized and injected directly into
the bottom of the furnace in a process
called pulverized coal injection (PCI).
PCI has a high installation cost, but
increases the productivity and reduces
overall operating costs of a blast
furnace, making it an attractive option
to integrated steel makers. Some
facilities co-fire PCI coal and natural
gas together.
Low rank high vol and high rank
low vol coal or blends of both are
commonly used for PCI. Other fuels
like natural gas and recycled oil are
also used to supplement coke rates.
Variations in their hydrogen, carbon
content, and heat of combustion result
in varying coke replacement ratios,
but in general terms one pound of
coal injected through the tuyeres at
the bottom of the blast furnace will
replace approximately one pound of
coke per ton of hot metal produced. It
is also becoming more commonplace
to see coal and gas being co-fired.
The advantage of using coal over
Stack Zone
Cohesive Zone
Active Coke Zone
Hot Blast
Stagnant
Coke Zone
Hearth
Raceway
Slag
Hot Metal
Source: OSTI
other fuels is that it has the potential to
replace the largest quantity of coke in
the blast furnace; today some furnaces
regularly operate with as much as
550 pounds of injectant per ton of hot
metal. Since the coal is pulverized to
70-80% minus 200 mesh before it can be
injected into the furnace, whatever coal
source is chosen for PCI must handle
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well and its grindability must match the
equipment design in order to achieve
the rated capacity for the installation. As
in the case of coke, lower ash and sulfur
of the PCI is more desirable as they
effect coke rates and iron production
much the same way elevated levels in
the coke do. The same can be said about
the ash composition of the PCI.
49
Metallurgical Coal
Finished Steelmaking
Diagram of Steelmaking
Finished Steelmaking
In a basic oxygen furnace, molten
pig iron, along with as much as 30%
scrap steel is charged into the furnace.
Oxygen (O2) is blown through the
hot metal, igniting and reducing its
carbon (C) content, forming CO2 and
CO. During this process, the hot metal
is further refined to remove impurities
such as sulfur and phosphorus;
special additives such as nickel and
manganese are incorporated to do this.
BOF accounts for about 42% of U.S.
steel production, and about 90% of the
steelmaking in China.
Secondary steelmaking involves the
recycling of steel scrap in an electric
arc furnace (EAF), which accounts
for about 58% of U.S. production.
An electric arc is generated and
passes through the furnace melting
its contents. These furnaces can be
charged with either scrap and/or pig
iron, or direct reduced iron, giving
operators additional flexibility. In
general, nations further into their
industrial lifecycle, such as the U.S,
produce a greater percentage of EAF
steel while developing nations, such as
China produce a greater percentage of
primary steel.
Steel Fast Facts
Electric Arc Furnace
Produces Molten Steel
Steel Refining
Facility
Iron Ore
Coal Injection
Coal
1.43 tons of coal per ton of coke
Natural Gas
Primary steelmaking is the process of
further refining blast furnace hot metal.
There are two types of steelmaking:
basic oxygen furnace (BOF) and electric
arc furnace (EAF).
Direct Reduction
Produces Solid,
Metallic Iron
from Iron Ore
Recycled Steel
0.40 tons of coke per ton of iron
0.80 tons of iron per ton of liquid steel
1.07 tons of liquid steel per ton of finished steel
Global crude steel production (2011) =
1,490 million tonnes
Coal
By-Products
Limestone
Top crude steel producer (2011) =
China; 683 million tonnes
Basic Oxygen Furnace
Produces Molten Steel
Coke Oven
Slag
Molten Iron
Blast Furnace Produces Molten Pig
Iron from Iron Ore
U.S. crude steel production (2011) =
86 million tonnes
Pig Iron Casting
U.S. coke production (2011) = 15.4 million tons
U.S. met coal exports (2011) = 69.5 million tons
Source: WSA, EIA
Slabs
Thin Slabs
Blooms
Billets
Continuous Casting
Source: OSTI
50
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51
Electricity
Coal
Renewables
Steam Turbine/ Pulverized
Coal Combustion . . . . . . . . . . . . . 54
Wind Power . . . . . . . . . . . . . . . 70
Integrated Gasification Combined Cycle . 56
Fluidized Bed Combustion . . . . . . . . 58
Hydropower . . . . . . . . . . . . . . . 72
Geothermal Power . . . . . . . . . . . . 74
Solar Power . . . . . . . . . . . . . . . 76
Hydrogen Fuel Cells . . . . . . . . . . . 78
Natural Gas
Combustion Turbine . . . . . . . . . . . 60
Combined Cycle . . . . . . . . . . . . . 62
Nuclear
Nuclear Fission . . . . . . . . . . . . . . 64
Biomass Power . . . . . . . . . . . . . . 80
Ocean Power . . . . . . . . . . . . . . . 82
Cooling Systems
Cooling Systems . . . . . . . . . . . . . 84
Boiling Water Reactor . . . . . . . . . . 66
Turbines and Generators
Pressurized Water Reactor . . . . . . . . 68
Turbines and Generators . . . . . . . . . 86
Transmission and the Grid
Transmission . . . . . . . . . . . . . . . 88
The Grid . . . . . . . . . . . . . . . . . 90
Energy Storage
Energy Storage . . . . . . . . . . . . . . 92
Electricity
Electricity
Coal
Steam Turbine/ Pulverized Coal Combustion
Much of the world’s coal-fired
electricity is produced using pulverized
coal combustion. Coal is crushed
into a powder and blown into a boiler
with air where it is combusted. This
provides heat that is used to produce
superheated steam. The expanding
steam drives turbines and generates
electricity. The average efficiency for an
existing coal plant in the U.S. is 34%.
A typical new supercritical pulverized
coal plant has an efficiency around
40%, while ultra-supercritical plants
have potential efficiencies around 47%.
Diagram
Steam Turbine
Turbine Plant
Plant
Diagram of
of a
a Coal-Fired
Coal-Fired Steam
Supercritical plants operate at temperatures and pressures in excess of the
critical point of water, 705°F and
3,208 psi (374°C/22.1 MPa), where
liquid water and steam are indistinguishable. A typical supercritical plant
operates around 1,100°F and 3,500 psi
(593°C/24.1 MPa).
Boiler
(Furnace)
Turbine
Steam
Ultra-supercritical plants operate
around 1,400°F and 5,000 psi
(760°C/35 MPa).
Transmission
Lines
Coal
The most technologically advanced
plants use high-strength alloy steels,
which enable the use of supercritical
and ultra-supercritical steam pressure.
A typical pulverized boiler heats the
water to around 1,050°F and to
2,400 psi (566°C/16.5 MPa).
Water
Generator
Transformer
River
Condenser Cooling Water
Condenser
Source: Tennessee
TennesseeValley
ValleyAuthority
Authority
Source:
Ranking
U.S. Coal-Fired Steam Turbine Fast Facts
Clean
Coal-fired steam turbine capacity (GW)
332
Inexpensive
Efficiency of current fleet (%)
32
Number of units
1,309
Reliable
Number of plants
542
Safe
Percentage of U.S. generation (2011)
41
2011 Capacity factor (%)
63
Domestic
Abundant
Source: Velocity Suite
54
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55
55
Electricity
Coal
Integrated Gasification Combined Cycle (IGCC)
Coal is gasified with steam and
air under high temperatures, and
pressures in a gasifier. Heat and
pressure break the chemical bonds in
the coal, which reacts with steam and
oxygen to form syngas, mostly carbon
monoxide and hydrogen. The sulfur
dioxide (SO2) and nitrogen oxides
(NOx) can be removed from the syngas
before it is combusted in a turbine to
generate electricity, eliminating the
constituents.
The integrated gasification combined
cycle (IGCC) system generates
electricity in two ways. First, a gas
turbine burns syngas similar to a
jet engine. Because coal cannot fuel
a combustion turbine without coal
ash particles damaging the turbine
components, the coal must first be
converted to syngas. The exhaust
rapidly turns a turbine to generate
electricity. Second, the exhaust heat
from the gas turbine is sent to a heat
recovery steam generator (HRSG) to
produce steam to power a traditional
steam turbine, producing additional
electricity.
The combined cycle, therefore,
combines the electricity produced from
a combustion turbine and generator,
and a heat recovery steam generator
and turbine, resulting in high efficiency.
Greater efficiency means less fuel and
fewer emissions to produce the same
power.
IGCC plants can emit 40% less carbon
dioxide (CO2) than a typical coal
combustion plant, as well as little to no
SO2 and NOx emissions, depending on
the removal rate in the syngas.
Diagram of an Integrated Gasification Combined Cycle (IGCC)
Particulate
Removal
Syngas
Slurry
Plant
Entrained-Flow
Gasifier
Second Stage
Coal
Water
Candle
Filter
Syngas
Cooler
Sulfur Removal
& Recovery
Steam
Oxygen
Plant
Char
First
Stage
Slag
Liquid Sulfur
By-Product
Slag Quench
Water
Fuel-Gas
Preheat
Steam
Steam
Slag By-Product
Generator
Stack
Steam
Steam Turbine
Generator
Heat Recovery
Steam
Generator
Gas Turbine
Source: NETL
Ranking
Clean
Inexpensive
U.S. IGCC Fast Facts
Capacity (GW)
0.6
Efficiency of current fleet (%)
33
Number of units
2
Reliable
Number of plants
2
Safe
Percentage of U.S. generation (2011)
0.03
2011 Capacity factor (%)
31
Domestic
Abundant
Source: Velocity Suite
56
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57
Electricity
Coal
Fluidized Bed Combustion
Diagram of a Coal-Fired Atmospheric Fluidized Bed Power Plant
Fluidized bed combustion (FBC)
suspends solid fuels on upward
blowing jets of air. The turbulent action
provides more effective chemical
reactions and heat transfer than a
standard boiler. FBC reduces SO2
emissions when the flue gas mixes with
added limestone in the boiler.
FBC reduces NOx and SO2 emissions
compared to traditional coal boilers.
FBC is being widely implemented
largely due to its ability to burn virtually
any combustible matter such as coal,
biomass, or municipal waste, as well as
its ability to control emissions without
external controls such as scrubbers.
Combustion temperatures are typically
between 1,400°F and 1,700°F, below
the 2,500°F threshold where NOx are
formed. NOx emissions from FBC are
70% to 80% lower than conventional
boilers.
The first generation of PFBC was a
“bubbling bed” technology – where
air is used to suspend, or fluidize, the
combustible materials. This technology
uses a low air velocity to suspend
the bed with the heat exchanger to
generate steam.
Atmospheric Circulating
Fluidized-Bed Boiler
Cyclone
Heat
Exchange
Cyclone
Fabric Filter
Coal Limestone
Atmospheric fluidized bed combustion
(AFBC) operates at atmospheric
pressure. Pressurized fluidized
bed combustion (PFBC) operate at
pressures 6 to 16 times greater than
atmospheric, enabling higher efficiency
by generating enough flue gas energy
to drive a gas turbine and operate in a
combined cycle.
Ranking
The second generation of PFBC is a
circulating fluidized bed (CFB). CFB
uses increased air velocity to move
the combusting materials to cyclone
separators before the cleaner flue gas
contacts the heat exchanger to produce
steam. This reduces emissions and
increases efficiency.
Capacity (GW)
6.8
Inexpensive
Efficiency of current fleet (%)
30
Number of units
64
Reliable
Number of plants
44
Safe
Percentage of U.S. generation (2011)
0.5
2011 Capacity factor (%)
42
Abundant
Stack
Fly Ash
Steam
Secondary
Air
Air
Air
Ash
Steam
To Boiler
Feed Water
Generator
Source: NETL
Solid Waste To Disposal
Steam Turbine
Source: NETL
U.S. FBC Fast Facts
Clean
Domestic
Combustion
Chamber
Partition
Source: Velocity Suite
58
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59
Electricity
Natural Gas
Combustion Turbine
Natural gas-fired combustion turbines
are designed to start quickly and
cycle repeatedly to meet demand
for electricity during peak operating
periods.
Turbines operate like a jet engine
where outside air is drawn into the
unit and compressed. The compressed
air is mixed with the fuel (natural gas)
and ignited, where it rapidly expands.
Instead of using steam to drive the
turbine, a combustion turbine uses
expanding air. The hot combustion
Diagram of a Natural Gas-Fired Combustion Turbine Power Plant
gases expand through the turbine
blades, spinning the turbine. The
turbine in turn spins a generator to
produce the electricity.
Approximately two-thirds of the usable
energy rotates the air compressor
blades and the remaining one-third
spins the electric generator.
Turbine
Air
Intake
Exhaust
Transformer
Compressor
Combustion
Chambers
Generator
Natural
Gas
Source: Tennessee Valley Authority
Ranking
Clean
U.S. Natural Gas Combustion Turbine
Fast Facts
Inexpensive
Capacity (GW)
143
Domestic
Efficiency of current fleet (%)
27
Number of units
2,366
Number of plants
902
Percentage of U.S. generation (2011)
2.0
2011 Capacity factor (%)
6.2
Abundant
Reliable
Safe
Source: Velocity Suite
60
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61
Electricity
Natural Gas
Combined Cycle
In a natural gas combined cycle (CC)
operation, electricity is generated in
two steps.
First, natural gas is used to fuel a gas
turbine which spins a generator to
produce electricity. In a gas turbine,
outside air is compressed, mixed with
fuel (natural gas), and ignited, where
it rapidly expands through the turbine
blades, spinning the turbine, which in
turn spins a generator to produce the
electricity.
Diagram of a Natural Gas Combined Cycle Power Plant
Second, the exhaust heat from the
turbine is captured to produce steam to
drive a steam turbine. The steam hits
the blades of the turbine, causing it to
spin, which in turn spins a generator to
produce additional electricity without
using additional fuel.
Steam
Steam
Turbine
Shaft
Generator
Electricity
Combined cycle plants are very
efficient since the waste heat is used to
produce additional electricity, instead
of being released. New natural gas
combined cycle plants can achieve
around 50% efficiency.
Boiler
Feed water
pump
2
Condenser
Heat from
condenser
sent to lake
or cooling tower.
Exhaust Heat
1
Combustion
Turbine
Shaft
Generator
Electricity
Gas Flame
Ranking
Clean
U.S. Natural Gas Combined Cycle
Fast Facts
Inexpensive
Capacity (GW)
247
Domestic
Efficiency of current fleet (%)
46
Number of units
662
Number of plants
512
Percentage of U.S. generation (2011)
20
2011 Capacity factor (%)
45
Abundant
Reliable
Safe
Source: EIA
Source: Velocity Suite
62
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63
Electricity
Nuclear
Nuclear Fission
During nuclear fission, a neutron hits
the nucleus of a U-235 atom. When the
neutron is absorbed by the nucleus, it
becomes a highly excited U-236 atom.
The U-236 atom then splits, resulting
in two fission fragments (Ba-141 and
Kr-92) and three neutrons, along with
large amounts of kinetic energy. These
neutrons then hit other uranium atoms
in a chain reaction.
Diagram of Nuclear Fission
There are three main types of nuclear
power plants; each uses water in one of
three ways:
•
Boiling water nuclear reactor
•
Pressurized water nuclear reactor
•
Pressurized heavy water nuclear
reactor
The energy from nuclear fission is
used to heat water to create steam.
The steam expands through a turbine
causing it to spin, which in turn spins a
generator creating electricity.
Source: EIA
64
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65
Electricity
Nuclear
Boiling Water Reactor
In a boiling water reactor, water is
pumped through the reactor and is
heated by the fuel rods. The heated
fuel rods, heated by the nuclear fission
process, boil the water creating steam.
The expanding steam drives turbines
which spins generators to make
electricity. The steam is then cooled
back into water and reused in the
reactor.
New fuel rods are needed every 18
to 24 months to replace spent rods.
Currently there is no long-term solution
for waste disposal. Spent rods are
typically stored onsite in steel-lined
concrete pools or above ground
concrete and steel canisters.
Diagram of Boiling Water Nuclear Reactor Power Plant
The United States has recently
terminated its plans to develop a
nuclear waste disposal facility at Yucca
Mountain in Nevada. There are no
countries currently with an operational
nuclear waste disposal facility.
Reprocessing, or separating the
fissioned material from the unfissioned
material to be reused as fuel, is
not currently practiced in the U.S.
Radioactive waste must decay to
become harmless, a process that can
take hundreds of thousands of years.
Source: TVA
Ranking
U.S. Boiling Water Nuclear Fast Facts
Clean
Capacity (GW)
37
Inexpensive
Efficiency of current fleet (%)
30
Number of units
35
Reliable
Number of plants
24
Safe
Percentage of U.S. generation (2011)
6.5
2011 Capacity factor (%)
89
Domestic
Abundant
Source: Velocity Suite
66
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67
Electricity
Nuclear
Pressurized Water Reactor
In a pressurized water nuclear reactor,
high-pressure water is pumped through
the reactor and heated by the fuel rods.
High-pressure water does not boil,
remaining in a liquid state.
The hot, pressurized water from
the reactor passes through a steam
generator, heating a secondary loop of
water. The water in the secondary loop
is heated and turns to steam by the
pressurized water in the primary loop.
The expanding steam drives
turbines, which spins generators to
make electricity. The steam is then
cooled back into water and reused in
the system.
Diagram of Pressurized Water Nuclear Reactor Power Plant
A pressurized heavy water nuclear
reactor is a Canadian-designed reactor
which uses heavy water for moderator
and coolant, and natural uranium for
fuel. This design is also referred to
as CANDU, for Canada Deuterium
Uranium.
Natural uranium widens the source
of supply and there is no need for
enrichment. Heavy water, or deuterium
oxide (D2O) does not absorb neutrons
like H2O, and as a result, natural
uranium can be used. Heavy water is
10% heavier than ordinary water due
to the extra neutrons. There are no
heavy water nuclear reactors in the
United States.
Source: TVA
Ranking
U.S. Pressurized Water Nuclear Fast Facts
Clean
Capacity (GW)
70
Inexpensive
Efficiency of current fleet (%)
31
Number of units
66
Reliable
Number of plants
40
Safe
Percentage of U.S. generation (2011)
13
2011 Capacity factor (%)
88
Domestic
Abundant
Source: Velocity Suite
68
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69
Electricity
Renewables
Wind Power
There are two types of wind turbines
used today, Horizontal Axis Turbines
and Vertical Axis Turbines.
Horizontal Axis Turbines are the
most common wind turbines used
today. Horizontal Axis Turbines have
a fan-like rotor that sits on top of a
tall tower, usually consisting of two or
three blades. Each blade works like an
airplane wing – creating lift when the
wind blows causing the rotor to spin,
which spins a shaft and generator to
produce electricity.
Diagram of a Horizontal-Axis Wind Turbine
Conversely, there are two types of
Vertical Axis Turbines, the Darrieus and
the Savonius. The Darrieus turbine has
vertical blades that rotate in the wind –
described as looking like an eggbeater,
and the Savonius turbine is a slow
turning S-shaped drag type turbine
useful for grinding grain and pumping
water but not good for electricity
generation.
Source: EIA, EERE
Ranking
U.S. Wind Power Fast Facts
Clean
Capacity (GW)
Inexpensive
Efficiency of current fleet (%)
N/A
Number of units (turbine groups)
1,063
Reliable
Number of plants (unit groups)
770
Safe
Percentage of U.S. generation (2011)
3
2011 Capacity factor (%)
28
Domestic
Abundant
49
Source: Velocity Suite
70
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71
Electricity
Renewables
Hydropower
Hydropower plants use the energy of
moving water to create electricity.
Impoundment hydropower uses a dam
to store surface water in a reservoir.
Water released from the reservoir
flows through a turbine, which turns a
generator.
Diversion hydropower channels a
portion of a river through a canal and
may not require a dam. Water flowing
through the channel turns a turbine to
generate electricity.
high electrical demand. Electricity from
a nearby power plant is used to pump
water to the higher reservoir at night
when demand is lower. During the day
the upper reservoir is drained to turn a
turbine and generate electricity.
Diagram of Conventional Hydropower Turbine and Generator
There are two main types of
hydropower turbines used in
hydropower. Impulse turbines use the
velocity of the water to strike the blades
to move the runners, while reaction
turbines sit in the water stream, and
use pressure and moving water to flow
over the blades instead of striking.
Pumped storage hydropower stores
energy through pumping water from
a low reservoir to a high reservoir,
releasing the water during periods of
Source: USGS
Ranking
U.S. Hydropower Fast Facts
Clean
Capacity (GW)
100
Inexpensive
Efficiency of current fleet (%)
N/A
Number of units
4,778
Reliable
Number of plants
1,986
Safe
Percentage of U.S. generation (2011)
8
2011 Capacity factor (%)
31
Domestic
Abundant
Source: Velocity Suite
72
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73
Electricity
Renewables
Geothermal Power
Geothermal power uses the energy
from heat deep within the Earth,
accessed through water or steam
wells. The heated water or steam is
channeled to a turbine used to drive
electric generators.
Dry steam plants use steam direct
from underground reservoirs to drive
turbines.
Flash steam plants are the most
common today. High-pressure water
(360°F +) is pumped into a lower
pressure tank causing the water to
vaporize, or flash, which is then used to
power a turbine and generator.
Binary-cycle plants use hot geothermal
fluids to heat a secondary fluid with a
lower boiling point, which causes the
secondary fluid to flash to a vapor to
drive a turbine. Geothermal plants of
Ranking
Clean
Inexpensive
the future will most likely be binary
plants because moderate temperature
water is the most common geothermal
resource.
Geothermal temperature increases with
depth. Away from the boundaries of
tectonic plates, temperature typically
increases by 25°C to 30°C (77°F to 86°F)
per kilometer of depth. The heat source
deep within the earth mostly comes
from radioactive decay and partly
from residual heat from planetary
accretion. Roughly 80 to 100 kilometers
beneath the surface, temperatures
range between 650°C to 1,200°C
(1,200°F to 2,200°F). At the center of
the earth, temperatures are estimated
to be over 5,000°C (9,000°F). As a point
of comparison, temperatures in an
ultra-super critical plant reach 750°C
(1,400°F).
Source: EERE
U.S. Geothermal Fast Facts
Capacity (GW)
3.5
Efficiency of current fleet (%)
16
Number of units
238
Reliable
Number of plants
64
Safe
Percentage of U.S. generation (2011)
0.4
2011 Capacity factor (%)
70
Domestic
Abundant
Source: Velocity Suite
74
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75
Electricity
Renewables
Solar Power
Photovoltaic (PV) materials convert
sunlight into electrical energy by
transferring the energy in the sunlight
to electrons in the atoms of the PV
cell. The electrons escape from their
atoms and become part of an electrical
current. PV cells, also known as solar
cells, connect to form PV modules that
can be several feet in length and width.
Modules connect to form arrays.
Flat-plate photovoltaic systems are
the most common array design. Array
panels are fixed in place or track the
movement of the sun.
Concentrator photovoltaic systems
capture solar energy from a large area
and focus that energy onto a solar cell
using lenses. Concentrating the light
energy increases the cell’s efficiency
and uses fewer PV cells. Concentrator
systems however are significantly
more expensive.
Ranking
Photovoltaic Cell, Module and Array
Concentrated solar power (CSP) does
not use PV materials. CSP technologies
concentrate sunlight to create heat that
is used to produce electricity. CSP technologies use mirrors, called heliostats
to reflect and concentrate the energy of
the sun. There are three types of CSP
systems: power tower, linear concentrator, and dish/engine.
Power tower systems focus sunlight
onto a receiver at the top of the tower.
Fluid within the receiver is heated by
the concentrated sunlight, which in turn
heats water into steam, which powers a
turbine and electric generator.
Diagram of a Concentrated Solar Power System
U.S. Solar Fast Facts
Clean
Capacity (GW)
2.4
Inexpensive
Efficiency of current fleet (%)
N/A
Number of units
950
Reliable
Number of plants
797
Safe
Percentage of U.S. generation (2011)*
0.02
2011 Capacity factor (%)
23
Domestic
Abundant
Source: DOE, EERE
Source: EIA
Source: Velocity Suite
*Value represents photovoltaic generation for transmission
76
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77
Electricity
Renewables
Hydrogen Fuel Cells
Hydrogen fuel cells produce electricity
using only hydrogen and oxygen.
Water and heat are the only byproducts
emitted if pure hydrogen is used.
Fuel cells have two electrodes, an
anode (negative) and a cathode
(positive) sandwiched around an
electrolyte, a substance that conducts
charged ions (protons).
The electrolyte membrane allows the
protons to pass through to the cathode,
the electrons must flow around the
membrane through an external circuit,
forming an electrical current.
Hydrogen Fuel Cell
At the cathode, the negatively charged
electrons and positively charged
protons (hydrogen ions) combine with
oxygen to form water (H2O) and heat.
Hydrogen (H2) fuel is channeled to the
anode, where the catalyst separates the
negatively charged electrons from the
positively charged protons.
Source: EIA
Ranking
Clean
Inexpensive
Domestic
Abundant
Reliable
U.S. Hydrogen Fast Facts
Hydrogen fuel cell technology has not yet
been developed for large scale commercial
generation. Hydrogen rarely exists in elemental
form in nature and often is obtained by
chemically breaking down fossil fuels such
as coal and natural gas.
Safe
78
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79
Electricity
Renewables
Biomass Power
Biopower is the generation of
electricity from biomass resources
– organic matter such as plants, agricultural and forestry residue, and organic
municipal and industrial wastes.
Direct combustion of biomass is the
most widely used form of biopower.
Conventional boilers use primarily
wood products as fuel to heat water
and create steam to spin a turbine and
generator to produce electricity.
Co-firing involves replacing a portion of
fuel in coal-fired boilers with biomass.
Sulfur dioxide (SO2) emissions of
Types of Biomass
coal-fired plants can be reduced with
co-firing and is a low-cost renewable
energy option for power producers.
Types of Biomass
Source: EIA
Anaerobic digestion, or methane
recovery, uses bacteria to decompose
organic matter in the absence of
oxygen to produce methane and other
byproducts that form a renewable
natural gas. Municipal wastes that
contain significant amounts of organic
material can produce methane that
can be harvested in a landfill. Landfill
gas facilities can combust the gas to
produce energy.
Wood
Garbage
Landfill Gas
Ranking
Capacity (GW)
0.6
Inexpensive
Efficiency of current fleet (%)
26
Number of units
199
Reliable
Number of plants
94
Safe
Percentage of U.S. generation (2011)
1.3
2011 Capacity factor (%)
63.6
Abundant
Alcohol Fuels
U.S. Biomass Fast Facts
Clean
Domestic
Crops
Source: Velocity Suite
80
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81
Electricity
Renewables
Ocean Power
Ocean thermal energy conversion
(OTEC) uses heat energy stored in the
Earth’s oceans to generate electricity.
Tidal energy generation uses the
energy in the moving water during
changing tides to turn underwater
turbines, similar to an underwater
wind farm.
Ranking
Clean
Inexpensive
Diagram of a Tidal Turbine
Wave energy systems harness energy
directly from surface waves or from
pressure fluctuations below the surface
of the water.
Ocean energy technologies are not
economical as they require substantial
up-front capital investment and there
are limited areas in the oceans in which
they can be deployed.
U.S. Ocean Power Fast Facts
Source: DOE
Ocean power has not yet been developed for
large-scale commercial generation.
Domestic
Abundant
Reliable
Safe
82
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83
Electricity
Cooling Systems
Cooling Systems
Thermoelectric power plants running
on coal, nuclear, oil, biomass, or
natural gas accounted for 89% of U.S.
electricity generation in 2011. Every
kilowatt-hour of electricity produced
typically requires around 25 gallons
of water, primarily used for cooling
purposes, although pollution control,
ash handling, wastewater treatment,
and wash water are other required uses
of water at a power plant.
There are three main types of cooling
systems used in thermoelectric plants:
•
Once-through cooling
•
Wet recirculating
•
Dry cooling
Once-through cooling involves taking
water from a local body of water, such
as a lake, river, or ocean, and returning
the water after it is used. This type of
cooling requires a large amount water
to be withdrawn, but very little water is
consumed.
Wet recirculating cooling uses either
cooling towers or cooling ponds to
chill the hot water. The hot water from
the power plant’s steam condenser
is cooled in a cooling tower mostly
through evaporation and partially
through direct heat transfer to the
atmosphere. The evaporated water is
84
discharged as a water vapor plume,
and the remaining water is recirculated
in the plant.
Diagram of Water Use in a 520MW Coal-Fired Tower Cooled Plant
Cooling towers must withdraw and
consume a significant amount of water
to replace the losses of evaporation
and blowdown water – which prevents
the buildup of sediment and minerals
in the water and cooling tower. Cooling
ponds are used to cool the water
though natural conduction/convection
heat transfer to the atmosphere.
Wet cooling systems can have
adverse impacts on aquatic life. The
impingement of fish on screens meant
to keep them from entering the cooling
system is an issue. Another issue is
the entrainment of small fish and other
aquatic life with water entering the
cooling system. The EPA has recently
proposed a rule to address these
issues. This rule could have substantial
economic impacts on electric
generating facilities nationwide.
Dry cooling systems employ either
direct or indirect air-cooled steam
condensers.
In a direct air-cooled system, steam
is pumped into a pipe or tubes
surrounded by moving air. Heat
is transferred to the air through
conduction without the loss of water
Source: NETL
to evaporation, as the air and water do
not contact. Direct air-cooled systems
require no cooling water.
Indirect air-cooled systems use a
water-cooled condenser to convert
the steam to water, however the heat
from the water is transferred to the air
Return to Contents
in a closed heat exchanger, preventing
evaporation of the cooling water.
Dry cooling systems use little to no
make-up water, but their cooling efficiencies are lower than wet systems,
and capital costs and operating costs
are higher.
85
Electricity
Turbines and Generators
Turbines and Generators
A turbine converts the kinetic energy of
a moving fluid (steam, water, or gas) to
mechanical energy. Turbines consist of
a number of blades attached to a shaft
that rotates with the force of the fluids
on the blades. The rotating mechanical
energy of the turbine is sent to a
generator to create electricity.
Steam turbines create most of the
electricity in the United States. Steam is
produced through the heating of water
with fossil fuels or nuclear fission.
In a gas turbine, high-pressure hot
gasses produced from the combustion
of natural gas or syngas are passed
through the turbine, which spins the
generator, producing electricity. Hydroelectric turbines use flowing or falling
water as the energy to spin a turbine,
and wind turbines use the energy in
the wind to produce electricity.
86
Diagram of an Electric Generator
A generator converts mechanical
energy into electrical energy. The
generator has a series of coiled copper
wire that form a stationary cylinder.
This cylinder surrounds an electromagnetic rotor. When the excited
rotor spins, it creates a small electrical
current in the wire coil. The small
electric current in each of the wire coils
are added together to form a large
current, which is then transmitted to
the customer.
Electric power generation stations use
turbines, engines, or water wheels to
create the rotating mechanical energy
to drive an electric generator.
Source: EIA
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87
Electricity
Transmission and the Grid
Transmission
Electricity delivery consists of a complex
network consisting of over 160,000 miles
of high-voltage transmission lines, also
known as the “grid.” Local distribution systems consist of smaller, lower
voltage power lines to deliver electricity
to the end customers.
Electricity generated at power plants
travels through a series of substations,
transmission lines, distribution stations,
and distribution lines on the way to the
customer.
A substation is a high-voltage electric
system facility using transformers
to change voltage from one level of
the distribution system to another.
Substations may also measure and
regulate voltage, switch transmission
and distribution circuits into and out of
the grid system, and connect electricity
generation plants to the system.
There are four types of substations:
Step-up transmission substations
receive electric power from a generating
plant and increase the voltage for transmission to distant locations. Increasing
voltage decreases electricity losses
during transmission.
Power Transmission & Distribution System
Typical voltages leaving a step-up
substation are:
High voltage (HV) ac:
69 kV-230 kV
Extra-high voltage (EHV) ac:
345 kV-765 kV
Ultra-high voltage (UHV) ac:
1100 kV-1500 kV
345,000 Volts
Overhead Transmission Lines
20,000 Volts
Power
Generation
Plant
Step-up
Transmission
Substation
Distribution
Substation
Industrial
Customer
69,000 Volts
Overhead Subtransmission Lines
Direct-current high voltage (dc HV): ±250
kV- ±500 kV
440 Volts
Step-down transmission substations are
located at switching points in the grid,
connecting transmission lines to subtransmission lines or distribution lines.
Step-down transmission substations
typically reduce the transmission voltage
to 69 kV sub-transmission voltage.
Distribution substations are located near
the end users and change the voltage
to lower levels, where the power is
distributed to industrial commercial and
residential customers.
4,000 Volts
Industrial
Customer
Distribution
Substation
Step-down
Transmission
Substation
13,800 Volts Distribution System
220/440 V
Distribution
Substation
Underground distribution substations
are also located near end-users and
further reduce the voltage for delivery to
customers.
Industrial
Customer
Underground
Distribution
Substation
120/240 V
Commercial
Customer
20,000 V
Residential
Customer
Underground Distribution Lines
120/240 V
Source: OSHA
Source: OSHA
88
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89
Electricity
Transmission and the Grid
The Grid
The grid is made up of many local interconnected grids, providing dependable
networks for electricity delivery.
The Federal Energy Regulatory
Commission (FERC) is the federal agency
that regulates the interstate transmission
of electricity, natural gas, and oil.
The North American Electric Reliability
Corporation (NERC) was established
to ensure the reliability of the North
American power delivery system. NERC
is a non-government organization with
legal authority to enforce reliability
standards with all users, owners and
operators of the power system in the
U.S., Ontario and New Brunswick,
Canada. There are eight regional entities
of NERC.
NERC Regional Entities
Florida Reliability Coordinating Council
(FRCC)
Midwest Reliability Organization (MRO)
Northeast Power Coordinating Council
(NPCC)
Reliability First Corporation (RFC)
SERC Reliability Corporation (SERC)
Southwest Power Pool (SPP)
Texas Regional Entity (TRE)
Western Electricity Coordinating Council
(WECC)
Independent System Operators (ISOs)
and Regional Transmission Organizations (RTOs) are regional organizations
with similar missions. ISOs are an
90
NERC Interconnections and Regions
independent, federally regulated entity
established to coordinate regional transmission in a non-discriminatory manner
and ensure the safety and reliability of
the electric system. RSOs are a utility
industry concept that FERC embraced
for the certification of voluntary groups
responsible for transmission planning
and use on a regional basis.
ISOs/RTOs
California Independent System Operator
(CAISO)
Electric Reliability Council of Texas
(ERCOT)
Midwest Independent Transmission
System Operator (MISO)
Source: NERC, Velocity Suite
ISO New England (ISO-NE)
RTOs/ISOs
New York Independent System Operator
(NYISO)
PJM Interconnection (PJM)
Southwest Power Pool (SPP)
Alberta Electric System Operator (AESO)
New Brunswick System Operator
(NBSO)
Ontario Independent Electricity System
Operator (IESO)
The U.S. power delivery system is made
up of three grids: the Eastern Interconnection, the Western Interconnection,
and the Texas Interconnection. Electricity
generated within an interconnect is
used almost entirely within the interconnect. Very little electricity is transmitted
between interconnections.
Source: NERC, Velocity Suite
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91
Electricity
Energy Storage
Energy Storage
Electricity generally must be consumed as
it is generated. This leads to challenges to
match the changing demands throughout
the day, especially when demands are at
the greatest, or peak.
Energy storage technologies can help
manage loads during peak periods and
allow less reliable energy sources, such
as wind and solar, to be dispatched as
needed.
Most energy storage technologies with
the potential to serve the grid are fairly
new, with the exception of pumpedhydro storage. A few of the most
promising technologies today are:
•
•
•
•
•
•
•
Lithium-ion batteries,
Sodium based batteries,
Redox flow batteries,
Advanced lead-acid batteries,
Pumped hydro storage,
Compressed air energy storage, and
Flywheel storage.
Lithium-ion battery technologies offer
high energy and power density, along
with almost 100% efficiency. Lithium-ion
batteries are widely used in mobile
electronics and are considered the most
promising technology for use in hybrid
and electric vehicles.
Sodium based battery technologies
are being researched because of their
large-scale energy storage potential.
Sodium (Na) is readily available and
cheaper than other elements, such as
lithium, used in energy storage.
92
Diagram of Pumped Hydro Storage
Redox flow batteries store energy in
liquid electrolytes that convert chemical
energy into electrical energy as the liquid
flows through a cell stack.
Advanced lead-acid batteries, based on
mature technologies, have large-scale
energy storage potential due to low
costs; however, the batteries have short
life cycles, minimizing their effectiveness.
Pumped-hydro storage is a mature
technology where water held in a low
reservoir is pumped to a higher reservoir
during periods of low-demand, and
releases the water from the higher
reservoir during high-demand periods
through a turbine, which generates
electricity.
.
Compressed air energy storage (CAES)
uses power generated at low-demand
periods to compress and store air in
underground salt domes, aquifers, gas
fields or in above ground pipes or tanks.
The compressed air is released during
periods of high demand, heated and
expanded with natural gas in a turbine to
generate electricity.
Flywheels store kinetic energy in the
momentum of a rotating wheel or
cylinder. The energy in a flywheel is
proportional to its mass and the square
of its velocity, which leads to two
techniques, heavy wheels spinning
slowly and light wheels spinning quickly.
.
Source: USGS
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93
Emissions Control
Technology
Emissions Control
Carbon Dioxide (CO2)
Emissions Control . . . . . . . . . . . . 96
Carbon Capture and Storage . . . . . . 104
Particulate Emissions
Mercury (Hg)
Electrostatic precipitators . . . . . . . . 98
Activated Carbon Injection . . . . . . . 106
Fabric filters . . . . . . . . . . . . . . . 98
SO2 & NOx
Sulfur Dioxide . . . . . . . . . . . . . . 100
Nitrogen Oxide . . . . . . . . . . . . . 102
Coal Combustion Laws and
Regulations
Major Coal Combustion Laws
and Regulations . . . . . . . . . . . . . 108
Emissions Control Technology
Emissions Control
Emissions Control
How are NOX, sulfur dioxide, and
notable ionic elements like some
species of mercury controlled?
Sulfur emissions can be cut signicantly by washing the coal in a coal
preparation plant (see Preparation and
Processing) prior to combustion. In
addition, sulfur scrubbers are added to
coal fired plants to capture remaining
sulfur post combustion.
Nitrogen oxides (NOX) emissions have
been reduced through the use of new
combustion technologies that prevent
the formation of the pollutant. Nitrogen
is a common element in the air we
breathe, but the extreme temperatures
achieved during combustion can cause
the nitrogen atoms to combine with
oxygen, forming NOX. Nitrogen capture
Electricity Generation and Emissions
technologies are also used to capture
emission post combustion.
Mercury emissions have declined as a
co-benefit of existing emission controls
for particulates, sulfur dioxides, and
nitrogen oxides. In addition, there are
post combustion mercury capture
methods to further reduce emissions.
Electricity generation from all sources
has been steadily increasing since
1990, and over that period coal has
consistently generated about half of
the generation. So while coal burn
has remained steady, emissions have
continued to decline thanks in part to
new and ever improving emissions
control technologies that make coal a
viable and cleaner source of energy.
Source: Historical Emissions - EPA, Projections and Generation - EIA
96
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97
Emissions Control Technology
Particulate Emissions
Particulate Emissions
Particulate emissions are fine solids
and liquids emitted from power
stations that can affect respiratory
systems, impact local visibility, and
create dust problems. Control technologies for particulates include
electrostatic precipitators and fabric
filters, also known as baghouses.
Diagram of an Electrostatic Precipitator
Fabric filters (FF), or a baghouse,
collect particulates by passing the flue
gas through tightly woven fabric, much
like a vacuum cleaner bag.
Electrostatic precipitators (ESP) can
remove 99% of particulates from
flue gas. They work by creating a
positive charge on the particles, then
attracting the particles to negatively
charged plates.
Source: EPA
98
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99
Emissions Control Technology
SO2 & NOx
Sulfur Dioxide (SO2)
Sulfur Dioxide (SO2) forms during
the combustion of coals containing
sulfur and can lead to acid rain. Sulfur
emissions reductions of 90% or more
are achieved in a process called wet
flue gas desulfurization (WFGD),
otherwise known as a scrubber.
Flue gas desulfurization works by
removing the SO2 from the flue gas
exiting the coal boiler. A mixture of
water and limestone is sprayed into the
flue gas, causing a chemical reaction
to occur with the SO2, resulting in
the formation of gypsum (a calcium
sulfate) which is used in the construction industry. Modern scrubbers also
have varying degrees of effectiveness
removing particulates, acid gases,
mercury, and other heavy metals.
Dry sorbent injection (DSI) is another
technology used to reduce SO2
emissions from coal-fired boilers.
Sulfur dioxide reductions greater than
80% have been demonstrated with
systems using sodium-based sorbents.
100
Diagram of an Advanced Flue Gas Desulfurization Process
Hydrated lime sorbent can be injected
directly into the ductwork before
the particulate control device. The
hydrated lime reacts with the SOX,
or sulfur oxides, and is collected in
the particulate control system. Sulfur
oxides are compounds containing
sulfur and oxygen, such as sulfur
dioxide and sulfur trioxide (SO3).
Trona is the most common
sodium-based sorbent (sodium
sesquicarbonate Na3H(CO3)2. Finely
ground trona is injected into the hot
exhaust gases, reacting with the SO2.
The reacted salts are then collected in
an electrostatic precipitator (ESP) or a
baghouse (filter fabric).
DSI with trona is often advantageous
to wet flue gas desulfurization due to
much lower capital investment, less
physical space, less modification of
existing ductwork at the plant and the
environmental benefits from avoiding
the use of water in the process.
Higher stack temperature also leads
to a higher plume rise and improved
local air quality. DSI with Trona also
consumes less energy to operate
compared to WFGD.
Source: NETL
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101
Emissions Control Technology
SO2 & NOx
Nitrogen Oxides (NOX)
Nitrogen oxides (NOX) form from two
sources when coal is burned. First,
nitrogen embedded in the chemical
structure of the coal combines with
oxygen in the air to form NOX, and
second, the heat from combustion
causes the nitrogen in the air to
combine with oxygen to form NOX.
To reduce NOX emissions, there are
four combustion modification options
coal-fired plants can employ:
1) Low NOX burners (LNB) involve
staged combustion, which reduces
flame temperature and oxygen
concentration, reducing NOX
emissions.
2) Overfire Air (OFA) technology
injects air above the normal
combustion zone. The burners
have lower than normal air-to-fuel
ratio and combustion occurs at
lower temperatures, reducing NOX
emissions.
3) Re-burning technology introduces
a portion of the boiler fuel in
a re-burn zone, reducing the
NOX formed in the normal
combustion zone.
Diagram of an Overfire Air Boiler with SNCR and DSI Emission Controls
4) Flue gas recirculation (FGR) recirculates part of the flue gas to the
furnace, lowering the temperature
and oxygen, reducing NOX
emissions.
There are three post-combustion
treatment technologies available for
reducing NOX emissions from coal-fired
plants:
1) Selective catalytic reduction (SCR)
involves injecting ammonia (NH3)
into the flue gas before passing
over a catalyst, which promotes a
reaction between the NOX and NH3
to form nitrogen and water vapor.
2) Selective non-catalytic reduction
(SNCR) uses a reducing agent,
typically NH3 or urea, injected into
the furnace above the combustion
zone, where it reacts with the NOX.
Source: NETL
Diagram of a Coal-Fired Boiler with SCR Emissions Control Technology
Nitrogen Oxides (NOx)
3) A hybrid process involving SCR
and SNCR used together, or either
process can be used in conjunction
with LNB’s.
Source: NETL
102
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103
Emissions Control Technology
Carbon Dioxide (CO2)
Carbon Capture and Storage
Carbon capture and storage (CCS) is a
process of capturing carbon dioxide (CO2)
that would otherwise be released into the
atmosphere, compressing it after capture,
transporting it, and then injecting it into
deep underground geological formations.
Carbon sequestration is not a new
technology; it has been used for years in
the natural gas industry and to produce
food and chemical-grade CO2. Capturing
CO2 from electric power producers
is more difficult than the successful
processes used today in industrial
applications where the gas streams
contain high concentrations of CO2. Flue
gases from a typical coal-fired power
plant contain roughly 75% nitrogen,
10% to 15% CO2, 8% to 10% water.
The CO2 levels found in the flue gas of
power producers is more diluted and
the scale of power plants is much larger
than industrial applications. Current
technology costs between $60 and $114
per tonne of CO2 avoided, where 70%
to 90% is associated with capture and
compression. These barriers must be
overcome in order to have widespread
commercial development of CO2 capture
in the U.S. CO2 capture systems currently
working at coal-fired generating plants
are capturing 75,000 to 300,000 tons
of CO2 per year, however a 550MW
coal-fired plant capturing 90 percent of
CO2 would capture around 5 million tons.
There are three technologies
for coal-fired carbon capture:
104
Diagram of Pre-Combustion CO2 Capture
pre-combustion, post-combustion, and
oxyfuel combustion.
Air
In pre-combustion capture the CO2
is separated from the fuel before it is
burned. Coal gasification produces two
gases; hydrogen and carbon monoxide
(CO). The hydrogen syngas is used as
fuel in an IGCC power plant and the
CO is converted to CO2 to be captured
and stored.
N2
CO2
Compression
O2
Fuel
CO2 to Storage
O2
Gasifier
CO & H2
Water-Gas
Shift Reactor
CO & H2
CO2 Capture
Process
H2
Combined
Cycle Power
Block
Diagram of Post-Combustion CO2 Capture
In post-combustion capture, the CO2
is separated from the other gases after
combustion of the fuel. Chemicals called
amines bond with the CO2 in the flue
gas. The CO2 is then removed from the
CO2-saturated amine solution, and the
amines can be re-used in the process.
Current amine-based post-combustion
capture technology would increase the
cost of electricity about 80% and the
electricity required to regenerate the
amine solution and compress the CO2
results in a 30% energy penalty.
Oxyfuel (oxyfiring) combustion, or the
combustion of coal in pure oxygen
and recycled CO2, can also be used
to capture carbon. Without nitrogen
present at combustion, the CO2 in the
flue gas is highly concentrated and
easier to capture. Oxy-fuel combustion
systems require high-capital costs and
energy consumption due mainly to
the air separation unit to produce the
oxygen, in addition to the sequestration
and compression costs.
Air
Separation
Unit
Air
CO2 & N2
Boiler
Fuel
CO2
Capture
Process
Steam
CO2
CO2
Compression
N2
CO2 Storage
Power Block
Diagram of Oxyfuel Combustion
CO2 Recycle
Air
Air
Separation
Unit
N2
O2
Boiler
Fuel
CO2
CO2
Compression
Steam
CO2
Power Block
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Compression
Source: NETL
105
Emissions Control Technology
Mercury (Hg)
Mercury (Hg)
Mercury emission reductions from
coal-fired boilers are currently achieved
as a co-benefit through existing
controls for particulate matter (PM),
sulfur dioxide (SO2), and nitrogen
oxides (NOX). Particulate-bound
mercury is captured with existing
PM controls and soluble mercury is
captured with existing WFGD controls.
Research also shows increased
mercury capture in downstream FGD
controls in boilers employing SCR
for NOX controls. The following chart
shows mercury removal rates as a
co-benefit at plants with no mercury
specific control technologies. Plants
burning bituminous coals with fabric
filter PM controls tend to capture the
highest amount of mercury due to the
higher halogen content of the coal and
the tendency of more unburned carbon
accumulating as filter cake on the fabric
filter, allowing for greater adsorption of
the mercury.
106
Mercury Removal Rates by Coal Rank and Emission Controls
Activated carbon injection (ACI) is the
most promising technology to specifically target mercury emissions. This
technology involves injecting dry,
powdered activated carbon (PAC)
into the flue gas. The mercury in the
flue gas is absorbed into the activated
carbon and then collected in electrostatic precipitators or a baghouse. ACI
is projected by some to become the
most widely used process for mercury
removal from flue gas.
Activated carbon removes impurities
from liquids (liquid or gas) by a
process called adsorption: molecules
accumulate on the surface of the
internal pores of the activated carbon
and only occurs where the internal
pores are larger than the molecules
being adsorbed.
Source: EPA
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107
Emissions Control Technology
Coal Combustion Laws and Regulations
Major Coal Combustion Laws and Regulations
Major Environmental Laws
Clean Air Act
This federal law was enacted by the
U.S. Congress to control air pollution
on a national level. It requires the EPA
to develop and enforce regulations to
protect the public from exposure to
airborne contaminants that are known
to be hazardous to human health. The
Clean Air Act was last amended in
1990. The Clean Air Act also establishes
primary and secondary National Ambient
Air Quality Standards for six pollutants:
SO2, particulate matter, NOX, ozone, lead,
and CO. A number of programs under
the Clean Air Act also affect fossil fuel
power generation facilities.
•
The ozone National Ambient
Air Quality Standards (NAAQS)
controls ground-level ozone, a
principal ingredient in smog linked
to respiratory illnesses. The Clean
Air Act requires the EPA to set
NAAQS for ozone and the five other
pollutants.
•
The New Source Review and New
Source Performance Standards,
also under the Clean Air Act, apply
to all new facilities and expansions.
•
The National Emission Standards
for Hazardous Air Pollutants program
regulates eight air toxic substances
which are to be controlled based on
best demonstrated control technologies and practices.
108
•
The Acid Rain Program was
established by the Clean Air Act
as the market allowance system to
cap SO2 and NOX by establishing
an emissions trading program that
allows coal-burning power plants to
buy and sell emission permits.
Resource Conservation and Recovery
Act (RCRA)
This act establishes a “cradle-to-grave”
system governing the disposal of
solid and hazardous waste management
activities. Subtitle C of this regulation
reclassified fly ash from a waste to a
reusable material, exempting coal ash
from the regulations for hazardous waste.
Clean Water Act
This act regulates the quality standards
for the Nation’s surface waters in
order to maintain their integrity. Under
the regulation, it is unlawful for any
amount of pollutants to be discharged,
both directly and indirectly, into
surface waters. Facilities that intend
to discharge into surface waters can
obtain a permit that will set conditions
and limitations on the discharge.
Emergency Planning and Community
Right-To-Know Act (EPCRA)
Created by amendments to the Superfund, this act improves community
access to information about chemical hazards and potential emergency
responses.
Recent and Proposed
Regulations
Cross-State Air Pollution Rule (CSAPR)
The rule, promulgated by the EPA
(proposed as the Clean Air Transport
Rule), requires 27 states to significantly
reduce SO2 and NOX emissions that
contribute to pollution in other states.
Emission allowances have been set
by the EPA for each coal-fired unit
and state. States are divided into two
groups with group 1 states required
to make additional SO2 reductions in
2014. CSAPR replaces the EPA’s 2005
Clean Air Interstate Rule (CAIR) which
was remanded without vacatur by the
D.C. Circuit Court in 2008. In December
2011, the U.S. Court of Appeals stayed
CSAPR pending judicial review, putting
the CAIR requirements in place during
review.
Mercury and Air Toxics Standards
(MATS) for Power Plants
Commonly referred to as Utility
MACT, this EPA rule aims to reduce
the emissions of toxic pollutants,
primarily mercury and acid gases, from
power plants. The EPA set maximum
achievable control technology (MACT)
standards for electric power plants,
both new and existing.
Cooling Water Intake Rule (316(b))
The EPA, under §316(b) of the Clean
Water Act, has proposed that the
location, design, construction, and
capacity of cooling water intake
systems reflect the best available
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technology for minimizing environmental impact. The proposed rule
applies to over 1,500 industrial facilities
including power plants or other manufacturers that use large volumes of
cooling water from surface waters to
cool their plants.
Coal combustion residuals (CCR)
These are by-products associated with
the burning of coal at electric power
plants. The residues include coal ash
as well as by-products associated
with pollution control technologies.
Concerns about the potential environmental impact from the impoundment
of CCRs in landfills and ponds sparked
the development of this rule. Two
possible options both fall under the
Resource Conservation and Recovery
Act (RCRA). The first proposal would
treat CCR under subtitle C of RCRA
as special wastes. The less stringent
second proposal would treat CCR
under subtitle D for nonhazardous
waste.
The combination of the above rules is
expected to have a significant impact
on coal-fired generation, electricity
prices and the power grid reliability in
the U.S. Of primary concern is the time
line of these regulations. Generators
would have to finance design, permit,
engineer, and construct control technologies in a shortened time frame
to comply with proposed regulations.
Significant increases in electricity
cost are expected as retrofit expenses
will be passed on to rate payers.
109
Coal Combustion Laws and Regulations
Other concerns involve the reliability
of the entire electricity grid including
resource adequacy and the cost of new
transmission to reroute power from
different areas.
110
Additional
Information
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Definitions
112
Conversions and Formulas
132
Abbreviations
126
Useful Websites
141
OTC Specifications
131
Additional Information
Definitions
Definitions
404 Permit: Section 404 of the Clean Water
Act regulates the discharge of dredged,
excavated, or fill material in wetlands,
streams, rivers, and other U.S. waters.
The U.S. Army Corps of Engineers is
the federal agency authorized to issue
Section 404 permits for certain activities
conducted in U.S. waters.
Activated carbon: a form of carbon that
has been processed to make it extremely
porous and thus to have a very large
surface area available for adsorption or
chemical reactions. Activated carbon is
used to capture mercury from flue gases.
Adit: A horizontal passage or opening
from the surface, providing access to the
mine.
Air dry (ad): Coal quality data calculated
to a basis in which only inherent moisture
is associated with the sample. Inherent
moisture is moisture held within the coal
itself as opposed to surface moisture.
For some ranks of coal such as subbituminous, air dry moistures can be below
inherent.
Anthracite: The highest rank of coal
which contains the highest fixed carbon.
Anthracite has been subject to higher
heat and pressure of the Earth longer
than lower rank coals. It is hard, brittle,
and shiny, containing a low percentage of
volatiles.
As received (ar): Coal quality data
calculated at a basis in which all moisture
is associated with the sample. As received
analysis includes both inherent and
surface moisture of the coal sample.
112
mine, prep plant, during shipment, or at
the generating station.
Ash fusion temperature (AFT):
Temperature at which coal ash begins to
deform and melt. It is measured at four
defined points during the deformation
process. The test begins with a molded
cone shaped sample of ash which is
viewed as it is heated. The first of the four
defined pointed is initial deformation and
occurs when the point of the cone begins
to melt. The softening temperature is next
and is defined as the point when the base
of the cone is equal to the height. The
hemispherical temperature is next and
occurs when the base of the cone is twice
the height. The final phase is the fluid
temperature and occurs when the cone is
spreads into a mass no more than 1.6mm
in height.
Bench: A division in a coal seam either
separated by rock or formed by the
process of cutting the coal.
Binder: A streak of impurity in a coal
seam.
Bottom ash: Agglomerated ash particles
formed in pulverized coal furnaces too
large to be carried by the flue gasses.
Bottom ash is commonly used as an
aggregate substitute.
Ash: Residue remaining after burning coal
or coke; also referred to as mineral mater
in coal.
Bituminous coal: Rank of coal formed
when subbituminous coal is subject
to increased heat, pressure and time.
Bituminous coal has less moisture and
higher heat content than subbituminous
coal. Bituminous coal also contains a
higher percentage of carbon than subbituminous coal. It is the most common coal
found in the United States and is used to
generate electricity and to make coke for
the steel industry.
Breeze: Residual fine coke particles
that remain after the coke crushing and
screening process. Coke breeze is mainly
used as a fuel for the iron ore sintering
process. Breeze can also be formed
into bricks and used to feed the Cupola
furnace which is used as a melting device
at foundries. Breeze is also used as an
anti-fissurant in making foundry coke and
as a fuel and reductant in a number of
non-ferrous and chemical processes.
Blasting agent: An explosive material that
consists of a fuel and oxidizer mixture
used to fracture and loosen material
British thermal unit (Btu): The amount
of heat required to raise the temperature
of one pound of water from 39° to 40°
Fahrenheit. Used as a measure of coal’s
heat content, expressed in Btu/lb.
Auger: A rotary drill that penetrates,
breaks, and transports the drilled material
by using a screw device.
Back: The roof in an underground mining
cavity.
Backfill: Rock and mine waste returned
to a mined area from which the coal has
been removed.
Beam: The width at the widest part of a
ship.
Bearing plate: A plate used for the distribution of a load. In roof bolting, it is the
plate used between the bolt head and the
roof.
Bed: A stratum of sedimentary deposit,
typically coal, rock, or soil.
Beneficiation: The treatment of mined
material to enrich or further concentrate
that material.
Berth: Defines a specific location in a
port or harbor where a vessel may moor,
usually for loading or unloading.
Bill of lading: A shipping form which is
both a receipt for property and a contract
for delivery of goods by a carrier.
Bleeder or bleeder entries: Special air
courses designed to ventilate air-methane
mixtures away from the active workings
and into mine-return air courses.
Blending: The practice of mixing or
combining coals with different properties
to produce a coal product that optimizes
desired characteristics depending on
use. Blending coal can reduce the cost
of generation. Blending can occur at the
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Boiler: A tank that heats water and
produces steam.
Borehole: A hole created by drilling into
soil or rock.
Bottom: The underlying surface of an
excavation site, typically referred to in an
underground mine as the “floor.”
Brown coal: Generally, subbituminous and
lignite rank coals.
Bump (or burst): Severe stresses in the
rocks surrounding the mine workings
which cause a disturbance or dislocation
of the mine workings.
113
Additional Information
Definitions
Bunker fuel: Fuel oil used aboard ships.
Calorific value (CV): Measure of the
heating value of coal. Heat content is
usually expressed in metric units of Kcal/
kg or English units of Btu/lb.
Cannel coal: Large, non-caking block coal.
It is characterized by fine, even grain and
a conchoidal fracture. It is easy to ignite,
due to its high percentage of hydrogen
and burns with a long, yellow flame.
Capacity (power plant): Maximum rated
output of electric power production
equipment. Power unit capacities are
expressed as nameplate capacity, net
summer capacity and net winter capacity.
The nameplate capacity is the unit’s
maximum output as designated by the
manufacturer. The net summer capacity
is the units output measured between
June 1 and September 30 whereas the
net winter capacity is measured between
December 1 and March 31. In general,
the net winter capacity is greater than the
summer’s because of the impact of air
temperature and density. Generating units
can intake a greater amount of cooler,
dense “winter” air than comparably
warm, less dense “summer” air increasing
rated capacity.
Capacity factor: A measure of how often
an electric generator runs; it compares
how much electricity a generator actually
produces with the maximum it could
produce, during a specific period of time.
Capesize vessel: Large dry bulk carrier
vessel class with deadweight tonnage
typically above 100,000. The beam and
draft on these vessels makes them unable
to transit the Panama Canal and must pass
the Cape of Good Hope.
114
Carbon dioxide (CO2): Naturally occurring
gas in the Earth’s atmosphere. It is
colorless, odorless, and considered a
greenhouse gas as it traps the sun’s
infrared energy inside the Earth’s
atmosphere. CO2 is released as a
by-product of fossil fuel combustion.
Carbonization: The conversion of any
organic substance into carbon or a carbon
containing substance. Carbonization is
the primary process used in coke making,
where metallurgical coal is heated in
the absence of air to drive off volatiles
such as water and gases leaving behind
carbon-rich coke.
Cast: The overburden above the coal is
thrown directly into the previously mined
area.
CIF (cost, insurance, freight): The seller
delivers the goods on board the vessel or
procures the goods already so delivered.
The risk of loss of or damage to the goods
passes when the goods are on board
the vessel. The seller must contract for
and pay the costs and freight necessary
to bring the goods to the named port of
destination.
Clean spread: Estimated gross margin of
a gas or coal-fired plant in which costs
include fuel, plant efficiency, and carbon
cost. The clean spread is commonly
used to track energy markets and fuel
competition.
Cleat: The joints within coal seams that
break when mined, which creates vertical
cleavage in the coal seam.
Coal: A combustible black or brownishblack sedimentary rock formed by the
partial to complete decomposition of
organic matter over millions of years.
Coal is primarily composed of carbon, as
well as other elements such as hydrogen,
sulfur, oxygen, and nitrogen.
Coking coal: See metallurgical coal.
Coal gasification: The process of
converting coal into gas. The coal gas can
be refined to reduce impurities then used
as fuel.
Combustion chamber: The space within a
device where fuel is oxidized or burned.
Coal liquefaction: The process of
converting coal into liquid fuel.
Coal mine: An area of land and any
structures or equipment used in extracting
coal from its natural deposits in the Earth.
This also includes the coal preparation
facilities
Coal washing: The separation of
impurities or undesirable material from
coal, based on differential densities.
Coke: A hard, dry carbon substance that
forms when coal is heated to a very high
temperature in the absence of air. The
manufacture of iron and steel requires coke.
Coke strength after reaction (CSR):
Measurement of the strength of coke
after heating and reaction. This is one of
the major quality considerations when
assessing the coking coals. To test this
quality parameter a sample of coke is
heated to simulate the blast furnace. Once
cooled the sample is placed in a drum and
rotated for 30 minutes. The percentage of
coke that is greater than 10 mm in size is
the CSR.
Coke reaction with CO2 (CRI): Rate at
which carbon in coke reacts with reducing
gases such as CO2. Coke is heated to
simulate blast furnace conditions. After
cooling the amount of weight lost during
the reaction is measured.
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Colliery: A British term for “coal mine.”
Competent rock: Rock capable of
sustaining openings without any structural
support (except pillars and walls left
during mining).
Compliance coal: Coal that meets sulfur
dioxide emission standards for air quality
without the need for emission controls.
The current maximum sulfur content for
compliance coal is 1.2 pounds per million
Btus.
Conductivity: A measure of a given
quantity of water to conduct electricity at
a specified temperature, predicated upon
the presence of dissolved solids, which
conduct an electrical charge.
Continuous miner (CM): A machine that
extracts coal without interrupting the
loading process, to be distinguished from
a conventional unit which must stop the
loading process to extract coal.
Contract price: Price agreed to in a coal
sales contact. The contract price may differ
from the current market or spot price.
Core sample: A cylindrical sample
obtained by drilling an area of the ground,
generally 1” to 5” in diameter, used to
collect a geologic and/or chemical analysis
of the overburden and coal.
Crop coal: Coal from the outcrop of the
seam usually considered to be of inferior
quality due to partial oxidation.
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Additional Information
Definitions
Crosscut: A passageway created between
an entry and its parallel air course for
ventilation purposes. In vein mining, an
entry perpendicular to the vein.
Dip: The inclination of a geologic structure
(bed, vein, fault, etc.) from the horizontal,
measured downward at right angles to the
strike.
Crucible swelling number (CSN): See Free
Swelling Index.
Dragline: A large excavation machine used
in surface mining to remove overburden
covering a coal seam. The dragline casts
a wire rope-hung bucket to collect the dug
material by pulling the bucket toward itself
on the ground with a second wire rope (or
chain), elevates the bucket, and dumps the
material on a spoil bank, in a hopper, or
on a pile.
Culm: Waste from anthracite preparation
plants, consisting of rock fragments and
up to 30% small-sized coal.
Dark spread: Estimated gross margin of a
coal-fired power plant where generation
costs include only fuel and plant efficiency.
The dark spread is commonly used to
track energy markets and fuel competition.
Deadweight tonnage (dwt): The difference
between loaded displacement and
lightship, consisting of the total weight of
cargo, fuel, fresh water, shores, and crew
which a ship can carry when immersed to
a particular load line.
Demurrage: Money paid by the charterer,
shipper, or receiver for occupying port
space beyond a specified period of time
allowed in the charter party.
Dial divisions per minute (DDPM):
Measure of the fluidity of coking coal
during the coking process. This is a
primary quality parameter of coking coal
valuation. To test, a sample is placed
in a cylinder with a stirrer inserted. The
cylinder of coal is heated at a constant
rate as steady torque is applied to the
stirrer. As the coal heats up it softens and
the stirrer rotates. The DDPM value is
the maximum amount of revolutions the
stirrer completes. In general, low volatile
coals have low fluidity while high volatile
coals achieve higher fluidity.
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Draught (or draft): The vertical distance
measure from the waterline to the lowest
submerged part of a vessel.
Entry: an underground passage used for
haulage or ventilation, or as a manway.
Feeder: A machine that evenly feeds coal
onto a conveyor belt.
Free alongside ship value (f.a.s.): The
seller delivers when the goods are placed
alongside the vessel (on a quay or barge)
nominated by the buyer at the named port
of shipment. The risk of loss of or damage
to the goods passes when the goods are
alongside the ship, and the buyer bears all
costs from that moment onwards.
Force majeure: Clause included in many
types of contracts that frees both parties
from obligation due to an extraordinary
circumstance. The clause is commonly
used in coal sales agreement when an
example of a force majeure may be a
natural disaster.
Face: The exposed area of a coal bed from
which coal is extracted.
Fall: A mass of fallen roof rock or coal
found in any part of a mine.
Drift: A horizontal passage underground
that follows the vein, as distinguished
from a crosscut that intersects it.
Fault: An area between two portions of the
Earth’s surface that have moved relative
to each other, caused by severe Earth
stresses.
Dry ash free (daf): Basis of reporting and
assessing coal quality similar to the dry
basis, however in addition to assuming
zero moisture content the ash content is
also unaccounted for.
Fault zone: An area that consists of
any amount of smaller interconnecting
faults, or a fracture hundreds and even
thousands of feet wide. Also a confused
zone of gouge, breccia, or mylonite.
Dry basis (db): Basis of reporting and
assessing coal quality in which no
moisture is associated with the sample.
The sample is free of both surface or
inherent moisture and moisture associated
with the coal itself.
Federal coal lease: A lease between
the federal government and a mining
company specifying the terms regarding
the extraction of federally owned coal
from a defined area. The mining company
is required to pay royalties to obtain
the lease. These leases are typical in
the Powder River Basin where mining
companies must periodically obtain
leases.
EIA: The U.S. Energy Information Administration.
Electrostatic precipitator: An electrical
device that removes fine particles (fly ash)
from combustion gases before they are
released from a power plant stack.
Energy: the potential to do work.
Federal Energy Regulatory Commission
(FERC): Independent agency that regulates
the interstate transmission of natural gas,
oil, and electricity. FERC also regulates
natural gas and hydropower projects.
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Fouling: The buildup of deposits
inside a boiler in sections that are not
directly exposed to the flame. Fouling
can decrease the boiler’s efficiency by
restricting heat transfer between the
combustion gases and convention pass
tube surfaces.
Fixed carbon: The amount of carbon left
in coal after the volatiles are driven off.
Measurement is used to estimate the
amount of coke that will be yielded from a
sample of coal. .
Float dust: Fine coal-dust particles that
can pass through a No. 200 sieve carried
by air currents and deposited in return
entries.
Floor: The bottom or underlying surface of
an underground excavation, upon which a
person walks and equipment travels.
Flue gas desulfurization (FGD): A process
that removes sulfur compounds formed
during coal combustion. The devices,
commonly called “scrubbers,” combine
the sulfur from gaseous emissions with
another chemical medium, forming waste,
which must then be removed for disposal.
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Additional Information
Definitions
Fluidity: Measure of how fluid coking coal
becomes during the coking process. As
the coal is heating in the coking process
it becomes a liquid. The fluidity of coal
during the coking process as expressed
is DDPMs is a primary measure of coking
coal quality and is used in formulating
coking coal blends.
Fluidized bed combustion (FBC): A
process to remove sulfur from coal during
combustion with a high rate of effectiveness. Coal is burned in a bubbling,
fluidized mixture while an upward
stream of hot air suspends the coal and
limestone in the bottom of a boiler. The
sulfur combines with the limestone, thus
creating a solid compound recovered with
the ash, as opposed to releasing harmful
emissions.
Fly ash: A product of burning pulverized
coal in a boiler, removed from the exhaust
gases by electrostatic precipitators and/ or
baghouses. Some classes of fly ash have
pozzolanic, or cementitious, properties
and are commonly used in cement and
concrete applications.
Fracture: A discontinuity in a body of rock,
caused by a mechanical failure, whether
by shear stress or tensile stress. Fractures
include joints, shears, faults, and planes of
fracture cleavage.
Free on board (FOB):
The seller delivers the goods on board
the vessel nominated by the buyer at the
named port of shipment or procures the
goods already so delivered. The risk of
loss of or damage to the goods passes
when the goods are on board the vessel,
and the buyer bears all costs from that
moment onwards.
118
Free swelling index (FSI): Standard
measure used to determine if coal has
coking properties. A small sample of
coal is heated and forms a button which
is compared to a series of standards.
Standards are ordered 1 through 9, with 9
indicating the most swelling.
Gasification: The chemical process by
which coal is turned into a syngas.
Gross as received (GAR): The heat content
of coal under laboratory conditions where
the impact of the coals moisture on
reducing heat content is removed. GAR,
also known as high heating values, are the
standard in American reporting.
Gob: Loose waste in a mine, or the waste
used to fill up an area of a coal mine from
which coal has already been removed.
Handymax vessel: Class of dry bulk carrier
typically rated at 40,000 to 60,000 tons
deadweight.
Handysize vessel: Class of dry bulk carrier
typically rated at 10,000 to 40,000 tons
deadweight.
Hard coal: Generally, anthracite and
bituminous rank coal.
Hardgrove Grindability Index (HGI):
Quality measure of the hardness of coal,
used to measure the ease of pulverization.
The higher the HGI value the softer the
coal.
Haulage: The horizontal transport of ore,
coal, supplies, and waste.
Hazardous air pollutant (HAP): Pollutants
that cause or may cause cancer or other
serious health effects. The EPA is required
to control these pollutants.
Heat rate: The amount of heat required
to generate one unit of power. Primary
measure of an electric generating unit’s
efficiency usually expressed as Btu/kWh.
Head section: The portion of a belt or
chain conveyor that discharges material.
Heaving: When the removal of coal from
the floor of a seam causes the bottom to
rise.
Henry Hub: A natural gas pipeline located
in Louisiana used as the official pricing
point for natural gas futures on the New
York Mercantile Exchange. Settlement
prices at the Henry Hub are used as
benchmarks for the North American
natural gas market.
Highwall: An unexcavated face of exposed
overburden and coal. Applies to a surface
mine, or the face, or bank on the uphill
side of a contour mine excavation.
Highwall miner: A remotely controlled
continuous miner, which extracts and
simultaneously conveys coal by augers,
belt, or chains to the surface. The cut is
typically a rectangular, horizontal cut.
Hogsback: A sharp rise in the floor of a
seam.
Hoisting: The vertical transport of coal,
supplies, and waste.
Hydrocarbon: A class of compounds
containing only hydrogen and carbon.
Naturally occurring hydrocarbons found
in coal, mineral oil, petroleum, natural
gas, paraffin, fossil resins, and the solid
bitumens in rocks are generally formed
in association with the decomposition of
organic matter.
Inertinite: A maceral which has been
altered or degraded in the coal formation
process. North American coals have
inertinite content ranging from 5% to 40%.
Inherent moisture: Moisture found within
coal. The term is usually referenced in the
coal sampling and testing process.
In situ: In the natural or original position,
from the Latin, translated literally as “in
position.” This term describes rock, soil,
or fossil found in the situation in which it
was originally formed or deposited.
Joint Line: The term commonly used to
describe the Powder River Basin (PRB)
railroad line located in Wyoming which
is jointly owned and served by BNSF
Railway and Union Pacific Railroad.
Kerf: The undercut of a coal face.
Kilocalorie (kcal): Amount of energy
required to increase the temperature of
1 kilogram of water by 1°C. The unit is
used to measure the heat content of coal,
expressed in kcal/kg.
Lift: The amount of coal obtained from a
continuous miner. Typically refers to one
mining cycle.
Haulage rights: similar to trackage rights,
but the tenant’s traffic is hauled in the
owner’s trains.
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119
Additional Information
Definitions
Lignite: Sometimes referred to as brown
coal, lignite is the lowest rank of coal
and is characterized by high moisture
and low calorific content. Lignite is most
commonly used for steam generation in
power plants. It is also a feedstock for
activated carbon used to capture mercury
in coal fired utility flue gas emission
streams.
Liptinite: Maceral derived from waxy or
resinous part of plants. Liptinite usually
makes up 5% to 15% of North American
coal and is usually more prevalent in
Appalachian coals.
Liquefaction: The process of converting
coal into a synthetic fuel.
Lithology: The study of the character of
a rock. This is described in terms of its
structure, color, mineral composition,
grain size, and arrangement of its
component parts. Lithology is the basis of
correlation in coal mines, and is usually
reliable over a distance of a few miles.
Long ton: 1,016 kg or 2,240 lbs.
Longwall mining: This highly productive
underground coal mining technique
occurs when a long wall, about 250
to 400 meters long of coal is mined in
consecutive slices, each typically 1-2
meters in depth. Long Wall mining
machines consist of multiple coal shearers
mounted on a series of self- advancing
hydraulic ceiling supports. Long wall
miners extract “panels,” or rectangular
blocks of coal as wide as the mining
machinery and as long as 12,000 feet.
120
Maceral: Organic particles found in coal.
Macerals are can be broken into three
basic groups: the vitrinite group, the
liptinite group, and the inertinite group.
Each of these groups is characterized by
the source of their organic matter.
Man trip: A carrier of mine personnel to
and from a work area, by rail or rubber
tire.
Maximum achievable control technology
(MACT): National emission standard used
to control HAPs. MACT standards require
pollutant sources to achieve certain
emissions levels already achieved by
their best performing peers. The expected
benefit of this approach is to not penalize
sources who already have effective
emission controls.
Metallurgical or met or coking coal: Coal
that has the unique ability to soften,
transition through a plastic phase before
re-solidifying into a porous substance
called coke. This transition occurs in a
temperature range between 300°C to
550°C in the absence of air.
Methane: The principle component of
natural gas, formed from the decomposition of organic matter. It is frequently
found in underground coal mining
operations, and is kept within safe limits
in a mine via ventilation systems due to its
potentially explosive nature.
Metric ton (t): 1,000 kg or 2,204.6 lbs.
Mine mouth electric generating plant:
A coal-fired electricity generation plant
located near a coal mine that supplies the
plant.
Mineable reserves: See recoverable
reserves.
Net as Received (NAR): The heat content
of coal under laboratory conditions where
the absorbed water in the coal is included.
Net calorific values, also known as low
heating values are standard in European
reporting.
Netback: Calculating the market value of
coal at the source. Used to determine the
potential price at the mine by subtracting
all transportation and handling costs from
a delivered price of the coal. Typically
used to determine the necessary FOB
price for CAPP and NAPP coals into
Europe. (i.e., API 2 market price – ocean
freight – terminal fees – rail freight =
netback price.)
Opencast mine: See surface mine.
Openpit mine: See surface mine.
Overburden: Layers of soil and rock that
cover a coal seam. In surface mining
operations, large equipment removes
the overburden from the site prior to
mining. After the area has been mined, the
overburden is used as backfill, taken to a
dump site, or stored.
Oxidation (coal): the absorption of oxygen
from the air by coal resulting in degraded
chemical and physical properties of the
coal.
Panamax vessel: Bulk carrier with a
maximum beam of 106ft. Such vessels are
capable of transiting the Panama Canal.
Panel: A coal mining block that generally
comprises one operating unit.
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Parting: A small joint in coal or rock, a
layer of rock in a coal seam, or a side track
or turnout in a haulage road.
Petcoke or Petroleum Coke: A residue
high in carbon content from the cracking
process or refining of petroleum products.
Petcoke is generally lower ash, moisture,
and volatiles than steam coal, however it
is also contains a higher heating value and
higher sulfur content. Petcoke is mainly
used as an energy source for cement
production, power generation, and iron
and steel production.
Petrography: Microscopic study of coal
used to determine its exact rank and type.
Pig Iron: Crude iron resulting from a blast
furnace which is later refined into steel, or
other iron products.
Pillar: typically square or rectangular
sections of coal left behind in an
underground room and pillar mine. The
pillar is left in order to support the roof.
Pillar robbing: The systematic removal of
pillars to regulate the subsidence of the
roof.
Pinch: A compression used to squeeze
out the coal, either between the walls of
a vein, or between the roof and floor of a
coal seam.
Power: energy flow or energy divided by
time.
Portal: The structure surrounding the
immediate entrance to a mine.
Preparation plant: A plant where coal is
cleaned, sized, and prepared for market.
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Additional Information
Definitions
Proximate analysis: A physical, or
nonchemical test of the composition of
coal or coke; an assay of the moisture,
ash, volatile matter and fixed carbon and
may also include calorific and sulfur determinations. Provides a determination of
commercial value rather than preciseness.
Recoverable reserves: The portion of
reserves that can be economically and
physically mined using current techniques
after allowing for normal mining losses.
Prompt: The term is used in the pricing
of coal and refers to the nearest delivery
term actively being traded. For example,
prompt month in May is slated for June
delivery. Prompt can also be applied to
quarter or year in addition to month.
Recovery factor: The clean coal portion
of mined material. During the mining
process impurities are mixed with the
coal, which are then removed in the
coal preparation plant. The ratio of clean
coal to the amount of mined material is
referred to as the recovery factor.
Pulverized coal injection (PCI): process
used by blast furnace operators in which
coal is crushed into a fine powder then
injected into the furnace. Blast furnaces
implement PCI in order to reduce their
usage of expensive coke. Lower grade
metallurgical coals that aren’t necessarily
suitable for coke making are used in PCI
applications.
Rank: The classification of coal by degree
of hardness, moisture and heat content.
See anthracite, bituminous, subbituminous, and lignite. In terms of Btu or
heating content, anthracite has the highest
value, followed by bituminous, subbituminous, and lignite.
Raw coal: Coal which has received no
preparation other than possibly screening.
As mined coal.
Reclamation: The process of restoring
land and environmental values to a
surface mine site. This is done after the
coal is extracted, by restoring topsoil and
planting native vegetation.
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Recovery: The amount of coal and ore
mined from the original seam or deposit.
Reflectance: The ability of coal to reflect
light. Macerals are exposed to light and
their reflectance is measure to determine
coal rank. Reflectance is the most accurate
measure of a coal’s rank.
Reserves: The quantity of coal that is
economically and physically recoverable
using current mining techniques.
Resource (indicated): The quantity, quality,
and rank of coal that can be estimated to a
factor to support economic development.
Resource (inferred): The quantity, quality,
and rank of coal that can be estimated but
not confirmed for a reserve.
Resource (measured): The quantity,
quality, and rank of coal that are estimated
to a factor that supports economic
development.
Respirable dust: Dust particles 5 microns
or less in size.
Retreat mining: A system of pillar
robbing. The line through the faces of the
pillars being extracted retreats from the
boundary toward the shaft or mine mouth.
Rib: The side of a supporting pillar or the
wall of an entry in a coal mine.
Rider: A thin seam of coal that overlies a
thicker seam.
Roof: Layer of rock or other material which
overlays the coal seam. This layer acts as
the “roof” of an underground coal mine.
Roof bolt: A long steel bolt that is driven
into the roof of an underground mine. Its
purpose is to support the roof and help
prevent falls which can endanger miners.
Roof support: Support given to a rock
overlying a coal seam in an underground
mine. Posts, jacks, roof bolts, and beams
are typically used for support.
Room and pillar mining: A method of
underground mining in which approximately half of the coal is left in place for
roof support in the general mining area.
“Rooms” of coal are extracted, while
support “pillars” are left behind.
Royalty: Consideration, typically
monetary, paid by a producer to the
mineral owner/lessor for the production
and disposition of coal or other minerals.
Coal royalties are generally calculated on
a percentage of the selling price or on a
per ton basis.
Run-of-mine (ROM): Refers to the coal as
it leaves the mine before it is washed or
sized in the preparation plant. Run-of-mine
coal produced at some mines contains
rock from within, above, and/or below the
seam which is removed in the preparation
plant to enhance its quality
Sampling: The collection and proper
storage and handling of a relatively small
quantity of coal for laboratory analysis for
the purpose of coal resource assessment,
production and processing assessment,
and shipment or receipt monitoring for
adherence to coal contract specifications.
Scrubber: A device that removes sulfur
compounds from the flue gas formed
during coal combustion. They combine
the sulfur from gaseous emissions with
a chemical medium to form a disposable
waste product, referred to as “sludge.”
Seam: A stratum or bed of coal.
Self-contained breathing apparatus: A
self-contained supply of oxygen which
permits freedom of movement for use
during rescue work (coal mine fires,
explosions, etc.).
Self-rescuer: A small filtering device
carried by a coal miner underground,
either on his belt or in his pocket, to
provide him with immediate protection
against carbon monoxide and smoke in
case of a mine fire or explosion. It is a
small canister with a mouthpiece directly
attached to it. The wearer breathes
through the mouth, the nose being closed
by a clip. The canister contains a layer of
fused calcium chloride that absorbs water
vapor from the mine air. The device is
used for escape purposes only because
it does not sustain life in atmospheres
containing deficient oxygen. The length
of time a self-rescuer can be used is
governed mainly by the humidity in the
mine air, usually between 30 minutes and
one hour.
Shaft mine: An underground mine which
uses a vertical shaft as its primary point
of entry.
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Additional Information
Definitions
Short ton (T): 907.18 kg or 2,000 lbs.
Skip: A large bucket or hopper hoisted
from a slope or shaft.
Slag: Byproduct formed in the smelting of
iron in a blast furnace. Slag floats on the
surface of the molten iron, allowing it to
be skimmed off and cooled into a coarse
aggregate used in concrete and road
building.
Slagging: The buildup of deposits inside a
boiler in sections that are directly exposed
to the flame.
Slope mine: An underground mine with a
downward or upward inclined access from
the surface opening to the coal or ore to
be mined.
Sloughing: The deterioration and crumbling
of material from the roof, rib, or face.
Slurry: A mixture of coal, coal waste, and/
or rock and liquid that is a by-product of
the coal mining and preparation process.
Slurry is normally impounded behind an
earthen dam at the mine site.
Spark Spread: Estimated gross margin of
a gas-fired power plant where generation
costs include only fuel and plant efficiency.
Spot Price: The current market price of
coal or other commodity.
Steam or thermal coal: Coal which is
burned, producing heat that is used to
generate steam. The steam expands
through a turbine, which in turn spins a
generator, producing electricity. All ranks
of coal can be used for steam generation,
however the varying heat content between
ranks impact the volume of coal necessary
to produce equivalent amounts of steam.
124
Strike: The direction of the line that
intersects a bed or vein with a horizontal
plane. Strike is perpendicular to the
direction of the dip. The strike of a bed
is the direction of a straight line that
connects two points of equal elevation on
the bed.
Stripping ratio: The amount of overburden
that must be removed to gain access to
a unit amount of coal. Stripping ratios
are expressed as a ratio of overburden
to coal either in the form of thickness,
volume or mass. Stripping ratios are used
to determine the feasibility of surface
mining.
Swell: The increase in volume as material
is disturbed from its compacted state by
mining or excavation, as a percent.
Tuyere: Nozzle located at the base of a
blast furnace through which hot air and
fuel is injected.
Tailgate: A subsidiary gate road to a
conveyor face that commonly acts as a
return airway, supplying road to the face.
Opposite of a main gate.
Ultimate analysis: Precise determination,
by chemical means, of the elements and
compounds in coal.
Tail section: The part of a belt or chain
conveyor system consisting of a frame,
either a tail pulley or tail sprocket, and a
tensioning device around which the belt or
chain travels.
Thermal coal: See Steam coal.
Subbituminous coal: Has a heating value
between bituminous and lignite. It has
low fixed carbon and high percentages of
volatile matter and moisture.
Time Charter: Chartering a ship for a
period of time at a daily cost to the owner.
Crew and equipment are paid for by the
ship owner.
Subsidence: The gradual sinking, and in
some cases the abrupt collapse, of the
rock and soil layers into an underground
mine. Structures and surface features
above the subsidence area can potentially
be affected.
Tipple: Facility used to load coal into
railcars or trucks.
Sulfur: Naturally occurring element
found in varying concentrations in fossil
fuels. When fossil fuels are combusted
the sulfur forms sulfur dioxides which
contribute to air pollution. Coal contains
varying amounts of sulfur with lower
sulfur coals of similar rank demanding
premium prices. Coal plants are able to
reduce sulfur emissions by implementing
scrubbers allowing them to meet federal
emissions standards.
Surface mine: A mine in which the coal
lies at a sufficiently shallow depth to be
economically extracted by first removing
the overburden. The coal is extracted by
removing the covering layers of rock and
soil.
Ton-mile: the movement of one ton of
freight a distance of one mile
Trackage rights: An agreement in which
one railroad (“tenant”) negotiates the
rights to operate its trains over specified
track segments owned by another railroad
(“owner”), typically without rights to serve
customers along that portion of the line.
Trona: The most common sodiumbased sorbent (sodium sesquicarbonate
[Na3(HCO3)]) used in Dry Sorbent
Injection (DSI) technology used to reduce
SO2 emissions from coal-fired boilers. DSI
with trona is advantageous to Wet Flue
Gas Desulfurization (WFGD) due to lower
capital costs, avoiding water use, and
lower energy consumption.
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Unit train: A long train of between 60 and
150 or more hopper cars that transports a
single commodity between a single mine
and destination.
Vitrinite: Maceral which is derived from
the cell walls of plants. This group is the
most common and can make up between
50% and 90% of most North American
coals.
Volatile matter: Constituent of coal, not
including moisture, that is given off as
vapor when coal is combusted. Volatile
matter is measured by heating the coal
in laboratory conditions. After heating,
the weight loss of the coal, excluding
moisture, is measured. Volatiles are a key
indicator of the quality of coking coals.
Waste: Rock or mineral removed from a
mine which has no use or value.
Watt: A unit of power which is equivalent
to one joule per second.
Yield: 1) The amount of coal after
processing as a percent of total input. 2)
The ratio of clean coal to raw coal feed
as a percent. 3) When a pillar of coal in a
mine begins to deform.
125
Additional Information
Abbreviations
Abbreviations
AC
ACI
AFT
AAD
ad
API2
API4
API 6
ar
ARA
ARP
ASTM
atm
bbl
bit
bn
BNSF
BOF
BS Rvr
Btu
CAPP
CAES
CAIR
CC
CCS
CIF
cm
CN
CO
CO2
CP
cP
CRI
CSAPR
CSN
CSP
CSR
CSX
cSt
CV
cwt
daf
db
126
Alternating current
Activated carbon injection
Ash Fusion Temperatures
Audibert-Arnu Dilatometer
Air dried
CIF ARA price benchmark
FOB Richards Bay, South Africa price benchmark
FOB Newcastle, Australia price benchmark
As received
Amsterdam, Rotterdam, Antwerp
Acid Rain Program
American Society for Testing and Materials
Standard atmosphere
Barrel
Bituminous coal
Billion
Burlington Northern Santa Fe Railway
Basic oxygen furnace
Big Sandy River
British thermal unit
Central Appalachia
Compressed air energy storage
Clean Air Interstate Rule (EPA)
Combined cycle
Carbon capture and storage
Cost, insurance & freight
Centimeter
Canadian National Railway
Carbon monoxide
Carbon dioxide
Canadian Pacific Railway
Centipoise
Coke reaction index (coke reactivity)
Cross-State Air Pollution Rule
Crucible Swelling Number
Concentrated Solar Power
Coke strength after reaction
CSX Corporation (Rail)
Centistokes
Calorific value
Hundred weight
Dry, ash free basis
Dry basis
DC
ddpm
dmmf
DOE
DSI
DTA
Dwtat
EAF
EERE
EIA
EPA
ESP
Fas
FBC
FC
FCPA
FERC
FGD
FGR
FOB
FRCC
FSI
FTC
FX
g
GAD
GAR
GW
GWh
HAP
HCC
Hg
HGI
HV
HVA
HVB
IAEA
Direct current
Dial divisions per minute
Dry, mineral-matter-free basis
U.S. Department of Energy
Dry sorbent injection
Dominion Terminal Associates (Hampton Roads, VA; CSX)
Deadweight tonnes all told
Electric Arc Furnace
DOE Office of Energy Efficiency and Renewable Energy
U.S. Energy Information Administration
U.S. Environmental Protection Agency
Electrostatic precipitator
Free alongside ship
Fluidized bed combustion
Fixed carbon
U.S. Foreign Corrupt Practices Act
Federal Energy Regulatory Commission
Flue gas desulfurization
Flue gas recirculation
Free on board
Florida Reliability Coordinating Council
Free swelling index
U.S. Federal Trade Commission
Foreign exchange
Gram
Gross air dried
Gross as received
Gigawatt
Gigawatt hour
Hazardous air pollutant
Hard Coking Coal
Mercury
Hardgrove grindability index
High Vol
High Vol A
High Vol B
International Atomic Energy Agency
Return to Contents
127
Additional Information
Abbreviations
IDT
IEA
IGCC
ILB
IM
IMF
IPP
ISO
J
kcal
kg
km
kV
kW
kWh
L
lb
LCOE
LNB
LNG
LPG
LV
MACT
MATS
Mcf
MF
MHC
MISO
MJ
MM
mmBtu
mmmf
MMR
Mon Rvr
MRO
MSHA
MT
128
Initial deformation temperature
International Energy Agency
Integrated gasification combined cycle
Illinois Basin
Inherent moisture
International Monetary Fund
Independent Power Producer
Independent System Operator
Joule
Kilocalories
Kilogram
Kilometer
Kilovolt
Kilowatt
Kilowatt hour
Liter
Pound
Levelized cost of electricity
Low NOx burners
Liquefied natural gas
Liquefied petroleum gas
Low volatile
Maximum achievable control technology
Mercury and Air Toxics Standard (EPA, proposed rule)
million cubic feet
Maximum fluidity
Moisture holding capacity
Midwest Independent Transmission System Operator
Megajoules
Mineral matter
Million Btus
Moist, mineral-matter-free basis
Mean maximum reflectance
Monongahela River
Midwest Reliability Organization
U.S. Mine Safety and Health Administration (Dept. of Labor)
Million tons
Mt
Mtce
Mtoe
mtpa
MV
MW
MWh
Na
NAPP
n mile
NAICS
NAR
NERC
NETL
NFDL
NGCC
NMA
NOx
NOLA
NPCC
NPDES
NRC
NS
ntp
O&M
OECD
OFA
OSHA
OSM
OSTI
OTC
oz
OZ
Pa
PCI
PJM
ppm
PRB
Million tonnes
Million tonnes of coal equivalent
Million tonnes of oil equivalent
Million tonnes per annum
Medium volatile
Megawatt
Megawatt hour
Sodium
Northern Appalachia
Nautical mile
North American Industry Classification System
Net as received
North American Electric Reliability Corporation
National Energy Technology Laboratory (DOE)
Nonfatal days lost
Natural gas combined cycle
National Mining Association
Nitrogen oxides
New Orleans, Louisiana
Northeast Power Coordinating Council
National Pollutant Discharge Elimination System
Nuclear Regulatory Commission
Norfolk Southern Railroad
Normal temperature pressure
Operations and Maintenance
Organisation for Economic Cooperation and Development
Over-fire air
U.S. Occupational Safety and Health Administration (DOL)
U.S. Office of Surface Mining
U.S. Office of Scientific and Technical Information (DOE)
Over-the-counter
Ounce
Australia
Pascal
Pulverized Coal Injection
Pennsylvania Jersey Maryland power pool
Parts per million
Powder River Basin
Return to Contents
129
Additional Information
Specifications
PV
RGGI
RFC
ROM
RTO
S
SAPP
SCR
SE
SEC
SERC
SG
SMCRA
SNCR
SO2
SOx
SPP
sshinc
T
t
TCE
TM
toe
TRE
TRIR
TS
UMWA
UP
USACE
USEC
USGC
VM
Vol
WECC
WFGD
130
Photovoltaic
Regional Greenhouse Gas Initiative
Reliability First Corporation
Run of mine
Regional Transmission Organizations
Sulfur
Southern Appalachia
Selective Catalytic Reduction
Specific energy
U.S. Securities and Exchange Commission
SERC Reliability Corporation
Specific gravity
Surface Mine Control and Reclamation Act of 1977
Selective Noncatalytic Reduction
Sulfur dioxide
Sulfur oxides
Southwest Power Pool
Saturday, Sunday, holidays included
Short Ton (2,000 lbs)
Tonne or metric ton (1,000 kg)
Time charter equivalent
Total moisture
Tonne oil equivalent
Texas Regional Entity
Total recordable injury rate
Total sulfur
United Mineworkers of America
Union Pacific Railway
U.S. Army Corps of Engineers
United States East Coast
United States Gulf Coast
Volatile matter
Volatile matter
Western Electricity Coordinating Council
Wet flue gas desulfurization
Over-the-Counter (OTC) Specifications
Over-the-counter (OTC) coal markets are used by producers, consumers, and
traders of coal to hedge against price volatility. Most OTC activity occurs around
the CAPP 12,000 Btu/lb Big Sandy barge coal, the CAPP 12,500 Btu/lb CSX rail coal,
and the PRB 8,800 Btu/lb coal.
Central Appalachia
OTC Specs
NYMEX
CSX 1.2
CSX < 1%
NAPP
NS 1.2
NS < 1%
Powder River Basin
Pitt 8 3.4# PRB 8800
PRB 8400
Btu/lb guarantee
12,000 12,500 12,500 12,500 12,500 13,000 8,800 8,400 Btu min reject
11,750 12,200 12,200 12,200 12,200 12,800 8,600 8,200 Sulfur % or #SO2
Sulfur max reject
Ash %
Contract size (tons)
API 4
6,000 kcal/kg 5,850 kcal/kg 6,000 kcal/kg 5,850 kcal/kg 1% or 1.6#
1.2# 1% or 1.6#
3.0#
0.8#
0.8#
1.0%
1.0%
1.0%
1.2#
1% or 1.6#
1.2# 1% or 1.6#
3.4#
1.2#
1.2#
1.0%
1.0%
12.0 12.0 12.0 12.0 12.0 8.0 5.5 5.5 11-­‐15 11-­‐15 15.0 15.0 10 7 7 7 7 8 27 30 12-­‐15 12-­‐15 22-­‐37 22-­‐37 38 40 40 40 40 44 44 7,750 10,000 10,000 10,000 10,000 10,000 14,500 14,500 1,000 metric tonnes 5 barges
unit trains
unit trains
unit trains unit trains unit trains unit trains unit trains
Ohio River
Big Sandy Big Sandy Thacker
Thacker
Big Sandy
Kanawha
Kanawha
Kenova
Kenova
Barge
CSX CSX NS NS Dual Line
Dual Line
Dual Line
NS-­‐CSX
BNSF-­‐UP
BNSF-­‐UP
FOB Origin
Transport Mode
API 2
1.2#
Volatile matter 30 30 30 30 30 % min reject
HGI min reject
fob RBCT
1.0%
Ash max reject 13.5 13.5 13.5 13.5 13.5 Moisture %
cif ARA
Return to Contents
1,000 metric tonnes Richards Bay, South Africa
131
Additional Information
Conversions and Formulas
Conversions and Formulas
Length Conversion Formulas
How to use the conversion tables:
To convert into DESIRED UNITS multiply GIVEN UNITS by the value in the
appropriate box. For example, to convert 100 metric tonnes to short tons, multiply
by 1.102. (i.e., 100 metric tonnes x 1.102 = 110.2 short tons)
Mass Conversion Formulas
Desired Units:
Given Units
Short ton (ton)
Short ton (ton)
Metric Ton Pound (lb)
(tonne)
Kilogram (kg)
1
0.9071
2,000
907.2
Metric Ton (tonne)
1.102
1
2,205
1,000
Pound (lb)
0.0005
0.000454
1
0.4536
0.001102
0.001
2.205
1
Kilogram (kg)
Desired Units:
Square inch (in 2 )
Square foot (ft 2 )
Square yard (yd 2 )
Square meter Square Mile (m 2 )
(mi 2 )
Square Kilometer (km 2 )
Acre
1
Square foot (ft 2 )
144
1
0.1111
0.0929
Square yard (yd )
1,296
9
1
0.83613
3.228 x 10
Square meter (m2 )
1,550
10.7639
1.196
1
3.861 x 10 -­‐7
1.0 x 10 -­‐6
2.471 x 10 -­‐4
2,589,988
1
2.586
640
1,000,000
0.3861
1
247.105
Square Mile (mi 2 )
4.0145 x 109 2.788 x 10 7 3,097,600
Square Kilometer (km 2 )
1.55 x 10 9
Acre
6,272,640
132
10,763,910 1,195,990
43560
4840
6.452 x 10 -­‐4
4046.856
Meter (m)
Kilometer (km)
International Mile (mile) nautical mile (n mile)
Foot (ft)
1
0.3333
0.3048
3.048 x 10 -­‐4
1.894 x 10 -­‐4 1.646 x 10 -­‐4
Yard (yd)
3
1
0.9144
9.144 x 10 -­‐4
5.682 x 10 -­‐4 4.937 x 10 -­‐4
Meter (m)
3.281
1.094
1
0.001
6.214 x 10 -­‐4
5.4 x 10 -­‐4
Kilometer (km)
3,281
1,094
1,000
1
0.6214
0.54
Mile (mile)
5,280
1,760
1,609
1.609
1
0.869
International nautical mile (n mile)
6,076
2,025
1,852
1.852
1.151
1
Megajoule (MJ)
Therm (therm)
Horsepower hour (hp h)
0.001055
1 x 10 -­‐5
3.930 x 10 -­‐4
3.6
0.03412
Desired Units:
Given Units
Square inch (in2 )
2
6.94 x 10 -­‐3 7.716 x 10 -­‐4
Yard (yd)
Volume Conversion Formulas
Area Conversion Formulas
Given Units
Foot (ft)
Desired Units:
Given Units
2.491 x 10 -­‐10 6.45 x 10 -­‐10
1.594 x 10 -­‐7
3.587 x 10 -­‐8
9.29 x 10 -­‐8
2.296 x 10 -­‐5
-­‐7
-­‐7
-­‐4
8.36 x 10
1.653 x 10 -­‐3 4.047 x 10 -­‐3
2.066 x 10
1
Cubic inch (in3 )
Cubic foot Cubic yard Cubic meter (ft 3 )
(yd 3 )
(m3 )
Cubic inch (in 3 )
1
5.787 x 10 -­‐4 2.143 x 10 -­‐5
1.639 x 10 -­‐5
Cubic foot (ft3 )
1,728
1
0.03704
0.02832
Cubic yard (yd3 )
46,656
27
1
0.7646
Cubic meter (m 3 )
61,024
35.31
1.308
1
Energy Conversion Formulas
Desired Units:
British Kilowatt Kilocalorie Given Units
Thermal Unit hour (kWh)
(kcal)
British Thermal Unit 1
0.000293
0.252
(Btu)
Kilowatt hour
3,412
1
859.8
(kWh)
Kilocalorie
3.968
0.001163
1
(kcal)
Megajoule
947.8
0.2778
238.8
(MJ)
Therm
100,000
29.31
25,200
(therm)
Horsepower hour
2,544
0.7457
641
(hp h)
Return to Contents
1.341
-­‐5
0.0041868
3.968 x 10
1
0.009478
0.3725
105.5
1
39.3
2.685
0.02544
1
0.00156
133
Additional Information
Conversions and Formulas
Coal Conversions
Useful power generation factors:
Calorific Conversion Formulas
Desired Units: Kilocalorie/kilogram (Kcal/kg)
Given Units
Kilocalorie/kilogram 1
(Kcal/kg)
Megajoule/kilogram 238.8
(MJ/kg)
British Thermal 0.5556
Unit/pound (Btu/lb)
Megajoule/kilogram (MJ/kg)
British Thermal Unit/pound (Btu/lb)
0.004187
1.8
1
429.9
0.002326
1
1 MWh = 3,600 MJ
1 MW = 1 MJ/s
1 MW (thermal power) = approx. 1,000 kg steam/h
1 MWe = approx. MW (thermal power) / 3
Approximate Btu Values of Selected Energy Sources:
1 Gallon of Gasoline = 125,000 Btu
1 Gallon of Heating Oil = 139,000 Btu
1 Gallon of Propane = 91,000 Btu
1 Cubic Foot of Natural Gas = 1,021 Btu
1 Kilowatt hour of Electricity = 3,412 Btu
Coal Utilization
Other Conversions
Annual coal consumption of a 1,000 MW plant operating at 36% efficiency and 70%
utilization: See Power Plant Burn formula.
Area
1 acre foot coal in place
Cubic ft. of water
=
=
1.850 short tons (approx.)
7.48 gallons = 62.321 pounds
Temperature
Celsius
Fahrenheit
Atmospheric pressure
Heat of vaporization
=
=
=
=
C° = 5/9 x (F° – 32°)
F° = 9/5 x C° + 32°
14.7 lbs/in2
970 Btu/lb
134
Coal Type
PRB
PRB
ILB
Nymex
CAPP Rail
Pitt #8
Return to Contents
Btu/lb.
8,400
8,800
11,500
12,000
12,500
13,000
Tons
3,500,000
3,300,000
2,500,000
2,400,000
2,300,000
2,200,000
135
Additional Information
Conversions and Formulas
Conversions and Formulas
Conversions
Conversionsand
andFormulas
Formulas
Coal Trading Formulas
Standard Btu Price Adjustment:
Coal
CoalTrading
TradingFormulas
Formulas
Sulfurtotolbs
lbsSO
SO
%%Sulfur
2/mmBtu:
2/mmBtu:
%%!"#$"%
!"#$"%
∗ ∗20,000
!"# !"₂/!!"#$
!"# !"₂/!!"#$== 20,000
!"#/!"
!"#/!"
Example:
Example:IfIfcoal
coalhas
has1%
1%sulfur
sulfurand
and12,000
12,000Btu/lb,
Btu/lb,then
then
Example:
Example:IfIfcoal
coalhas
has1%
1%sulfur
sulfurand
and12,000
12,000Btu/lb,
Btu/lb,then
then
11
11
∗ ∗20,000
20,000==1.67 !"# 1.67 !"# !"
!"
∗ ∗2 2==1.67 !"# 1.67 !"# !"
!"
2 /!!"#$
2 /!!"#$
2 /!!"#$
2 /!!"#$
12,000
12,000
12,000 12,000 ∗ ∗ 0.0001
0.0001
Lbs
LbsSO
SO
mmBtu
mmBtutoto%%Sulfur:
Sulfur:
2 per
2 per
!"#/!"
!"#/!"
!"# !"
!"# !"
∗ ∗ ! !"# !!"#$ ! !"# !!"#$ 10,000
10,000
% !"#$"%
% !"#$"%== 22
!"# !"# !"#$% !"#$%&'()& = !"#$% ∗
Standard SO2 Price Adjustment ($/ton):
Emission Price = price of SO2 emission allowance ($/ton of SO2 emissions)
!"₂ !"#$% !"#$%&'()&
= !"#$%&'$ !"# !"! − !"#$%& !"# !"! ∗ !"#$%& !"#/!"
1,000,000
∗ !""#$$#%& !"#$%
Power Plant Capacity Factor (%):
MWh = power plant generation in one year
Capacity = plant capacity measured in MW
!"#"$%&' !"#$%& = !"ℎ
!"#"$%&' !" ∗ 87.6
Power Plant Annual Burn (tons):
%%Ash
Ashtotolbs
lbsAsh/mmBtu:
Ash/mmBtu:
% !"ℎ
% !"ℎ
∗ ∗2 2
!"# !"ℎ/!!"#$
!"# !"ℎ/!!"#$== !"#/!" !"#/!" ∗ ∗ 0.0001
0.0001
$/mmBtu
$/mmBtutoto$/ton: $/ton: $$
!"#
!"#
$$
!!"#$
!!"#$ !"!"
==
500
500
!"#
!"#
Capacity = power plant capacity
Capacity factor = utilization of the power plant (%)
Heat rate = thermal efficient of a power plant (Btu/kWh)
Btu/lb = heat content of coal consumed by the plant
!""#$% !"#$ = !"#"$%&' !" ∗ 4,380 ∗ !"#"$%&' !"#$%& ∗ ℎ!"# !"#$/(
$$
! 500
! 500
$$
!"#
==!"#
!"#
!"#
!!"#$
!!"#$
!"!"
!"#
)
!"
Emissions – Ashing Rate:
$/ton
$/tontoto$/mmBtu:
$/mmBtu:
136
!"#$%& !"#/!" − !"#$%&'$ !"#/!"
!"#$%&'$ !"#/!"
Emissions – SO2 Rate:
% !"ℎ ∗ 10,000
!" !"ℎ
= !"#/!"
!!"#$
*Assumes 100% conversion to SO2
!" !"₂
% !"#$"% ∗ 20,000
= !!"#$
!"#/!"
Return to Contents
123
137
Additional Information
Conversions and Formulas
Conversions and Formulas
Conversions and Formulas
Fuel Cost of Generation:
Calorific value conversions
Heat rate is measured in Btu/kWh
$
∗ !"#$ !"#$
$/!"ℎ = !!"#$
1,000
Btu/lb to kcal/kg:
!"#/!"
!.!""
Kcal/kg to Btu/lb: !"#$/!" ∗ 1.799
Gross As Received (GAR) to Net As Received (NAR):
Calorific Value Conversions
Where: H = % Hydrogen, M = % moisture, O = % oxygen
Kcal/kg
kcal/kg GAR to kcal/kg NAR:
15,000
!"#$/!" !"# = !"#$/!" !"! − 50.6 ! − 5.85 ! − .0191 !
8,000
Btu/lb GAR to Btu/lb NAR:
14,000
!"#/!" !"# = !"#/!" !"# − 91.2 ! − 10.5 ! − 0.34 !
7,500
The approximate differences between gross and net values for typical
bituminous coals (10%M, 25% volatile Matter) are:
260 kcal/kg
or
Btu/lb
470 Btu/lb
7,228
13,000
7,000
6,950
12,500
12,000
6,500
As Received to Dry Conversion:
AR = as received
% !"# !"#$"% = % !"# !"#$%&' !"#$% = 138
6,000
!" % !"ℎ ∗ 100
% !"# !"ℎ = 100 − % !"#$%&'(
5,500
!" % !"#$"% ∗ 100
100 − % !"#$%&'(
!" !"#!"#$ !"#$% ∗ 100
100 − % !"#$%&'(
Return to Contents
126
11,000
10,000
5,000
4,893
4,670
9,000
8,800
8,400
4,448
8,000
139
Additional Information
Conversions and Formulas
Conversions and Formulas
Useful Websites
Heat rate conversions
Plant Efficiency (%) =
Heat Rate =
Alpha Natural Resources
!,!"#
Organizations
The Truth about Surface Mining
National Mining Association
Friends of Coal
Federation for American Coal,
Energy and Security (FACES)
American Coalition for Clean Coal Electricity
CORESafety
American Coal Foundation
American Coal Council
American Coal Ash Association
National Coal Council
Coal Utilization Research Council
National Energy Education Development Project (NEED)
North American Electric Reliability Corporation
World Coal Association
West Virginia Coal Association
Kentucky Coal Associatoin
Pennsylvania Coal Association
Virginia Mining Association
Wyoming Mining Association
American Legislative Exchange Council
!"#$ !"#$
!,!"#
!"#$% !""#$#%&$' (%)
Heat Rate Conversions
Heat Rate
(Btu/kWh)
Plant Efficiency
(%)
3,412
100
5,687
60
6,204
55
6,824
50
7,582
45
8,530
40
9,749
35
11,373
30
13,648
25
Government
U.S. Department of Energy
DOE National Energy Technology Laboratory
DOE Office of Fossil Energy
DOE Office of Energy Efficiency & Renewable Energy
DOE Office of Electricity Delivery & Energy Reliability
Energy Information Administration
EIA’s Kid Page
Mine Safety and Health Administration
MSHA’s Kid Page
U.S. Geological Survey
Bureau of Land Management
Environmental Protection Agency
DOI Office of Surface Mining Reclamation
and Enforcement
Tennessee Valley Authority
Federal Energy Regulatory Commission
U.S. Army Corps of Engineers
140
Return to Contents
125
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