Sub-bituminous coal

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). The heat content of sub-bituminous coals range from 8300 to 11,500 BTu/lb or 19.3 to 26.7 MJ/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.

Application

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.

Sub-bituminous coals release large quantities of greenhouse gases when burned, compared to higher grades of coal.

References

it:Carbone#Litantrace sub-bituminoso

References

1. "Coal explained". [[Energy Information Administration]].
2. "Subbituminous coal". Energy Dictionary.
3. The [[Babcock & Wilcox]] Company. (2005). "Steam: its generation and use". The Babcock & Wilcox Company.
4. (14 July 2021). "NZ imported more than a million tonnes of 'dirty' coal last year". [[RNZ]].