Energy Resource

Heat Value

commonly measured in Btus per pound of coal.

Btu

the amount of heat needed to raise one pound of water one degree Fahrenheit.

10,000 to 14,000 Btus per pound

Coal found in the Eastern and Midwestern regions of the United States have a heat content ranging from

8,000 to 10,000 Btus per pound

coal found in the Western United States ranges from

Sulfur Content

can vary from one seam to another and even within the same seam.

Compliance coal

releases 1.2 pounds or less of SO₂ per million BTUs and meets the standards of the Clean Air Act Acid Rain Program.

Low-sulfur coal

releases about 1.6 pounds or less of SO₂ per million BTUs.

Mid-sulfur coal

releases more than 1.6 but less than 2.5 pounds of SO₂ per million BTUs.

High-sulfur coal

releases more than 2.5 pounds of SO₂ per million BTUs.

Ash

is the inorganic residue remaining after the combustion of coal. It is the non-burnable material left after coal is burned.

Moisture Content

depends on the coal type, mining location, and position in the seam.

More moisture

means less energy per pound and higher cost per unit of energy.

Coal usually contains

5% to 30% moisture.

Coal

a sedimentary rock formed in swamps with rivers and forests. Plant and tree remains were preserved by mud and water.

Coal

is usually black but can be brownish-black. It forms when pressure over time turns dead plant matter into

Peat

Considered to be the precursor of coal.

Lignite

also known as brown coal and it is the lowest rank of coal.

Lignite

Jet

is a compact form of lignite used for ornamental purposes.

coal gasification

lignite can be chemically converted into synthetic natural gas, which provides more energy and is easier to use in large-scale power generation.

Heating Value of Lignite

4,000 to 8,300 Btu per pound.

Carbon Content of Lignite

25-35%

Moisture Content of Lignite

20-40% by weight, 60-70%

Sulfur Content of Lignite

<1%

Ash Content of Lignite

4%, up to 50% by weight

Availability of Lignite

Moderate

Sub-Bituminous Coal

is considered a black coal or black lignite. is widely used for generating steam power and industrial purposes

Sub-Bituminous Coal

not stable when exposed to air

Heating Value of Sub-Bituminous

8,500-13000Btu per pound

Carbon Content of Sub-Bituminous

35-45%

Moisture Content of Sub-Bituminous

10-45%

Sulfur Content of Sub-Bituminous

under 2% by weight

Ash content of Sub-Bituminous

up to 10% by

Availability of Sub-Bituminous

Moderate

Bituminous coal.

This is a dense black or dark brown coal and it is the most abundant

Bituminous coal includes 2 subtypes

Thermal

Metallurgical

Thermal coal

is called steaming coal because it is used to fire power plants that produce steam for electricity and industrial uses.

Metallurgical coal

is sometimes referred to as coking coal, because it is used in the process of creating coke necessary for iron and steel-making.

Coke

a porous, hard black rock of concentrated carbon that is created by heating bituminous coal without air to extremely high temperatures.

Heating Value of Bituminous coal

10000-15000% Btu per pound

Carbon Content of Bituminous coal

up to 85%

Moisture Content of Bituminous coal

up to 17%

Ash Content of Bituminous coal

up to 12% by weight

Availability of Bituminous coal

Abundant

Anthracite

it is the highest rank of coal; hard glossy-black coal. It consists of up to 95% carbon; low sulphur content and it burns slowly with a smokeless flame

Anthracite

the cleanest-burning coal. It produces more heat and less smoke than other coals, produces a very hot blue flame

Tar

Bitumen from bituminous coal is a thick black material, usually called

Heating Value of Anthracite

13000-15000% Btu per pound

Carbon Content of Anthracite

80-95%

Moisture Content of Anthracite

5-15%

Sulfur Content of Anthracite

very low sulfur <1%

Ash Content of Anthracite

10-20%

Availability of Anthracite

Scarce

Culm

is the low-quality coal left over from anthracite mining.

Graphite

is used as pencil lead and in a powdered form as a lubricant