Sub-bituminous coal

Sub-bituminous coal is a type of coal whose properties range from those of lignite to those of bituminous coal and are used primarily as fuel for steam-electric power generation.

Properties

Sub-bituminous coals may be dull, dark brown to black, soft and crumbly at the lower end of the range, to bright jet-black, hard, and relatively strong at the upper end. They contain 15-30% inherent moisture by weight and are non-coking (undergo little swelling upon heating).^[1] The heat content of sub-bituminous coals range from 8300 to 11,500 BTu/lb or 19.3 to 26.7 M J/kg. Their relatively low density and high water content renders some types of sub-bituminous coals susceptible to spontaneous combustion if not packed densely during storage in order to exclude free air flow.

Reserves

A major source of sub-bituminous coal in the United States is the Powder River Basin in Wyoming.

Current use

Sub-bituminous coals, in the United States, typically have a sulfur content less than 1% by weight, which makes them an attractive choice for power plants to reduce SO₂ emissions under the Acid Rain Program.

References

^ The Babcock & Wilcox Company. Steam: its generation and use. The Babcock & Wilcox Company. pp. 36–5. ISBN 0-9634570-1-2. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)

[1] The Babcock & Wilcox Company. Steam: its generation and use. The Babcock & Wilcox Company. pp. 36–5. ISBN 0-9634570-1-2. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)

[1]

v t e Coal
Coal types by grade (lowest to highest)	Xylit Peat¹ Lignite Sub-bituminous coal Bituminous coal Anthracite Graphite¹
Coal combustion	Ash pond Asian brown cloud Asthma Black coal equivalent Char Charcoal Coal combustion products fired power station gas phase-out pollution mitigation power in China power in the United States preparation plant seam fire tar Coke Coking Energy value Flue gas Fly ash Fossil fuel Fossil fuel phase-out Great Smog of London Greenhouse gas emissions Metallurgical coal NOx Smog Sulfur dioxide Toxic heavy metals
Coal mining	Blackdamp Black lung disease Coal dust Coalfields Coal gas homogenization liquefaction mining disasters in the United States mining region refuse slurry town Environmental issues in Appalachia Environmental justice and coal mining in Appalachia Firedamp Health and environmental impact of the coal industry Health effects of coal ash History of coal mining Hydrogen sulfide Mining regions Outbursts Peak coal Problems in coal mining Refined coal Whitedamp
Note: [1] Peat is considered a precursor to coal. Graphite is only technically considered a coal type.

Properties

Reserves

Current use

See also

References