Editing Solid fuel (section)

===Fossil fuels===

==== Coal ====
{{Further|Coal}}
Coal is a [[combustible]] black or brownish-black [[sedimentary rock]] usually occurring in [[Stratum|rock strata]] in layers or veins called coal beds or coal seams. Throughout history, coal has been used as an energy resource, primarily burned for the production of electricity and heat, and is also used for industrial purposes, such as refining metals. Coal is the largest source of energy for the [[Electricity generation|generation of electricity]] worldwide, as well as one of the largest worldwide  The extraction of coal, its use in energy production and its byproducts are all associated with [[Environmental impact of the coal industry|environmental]] and [[Coal worker's pneumoconiosis|health effects]]. Variations such as smokeless coal can be formed naturally in the form of [[anthracite]], a [[metamorphosed]] type of coal with a very high carbon content that gives off a smokeless flame when set alight. It  is an important type of [[smokeless fuel]].

==== Coke ====
{{Further|Coke (fuel)}}
Coke is a fuel with few impurities and a high [[carbon]] content, usually made from [[coal]]. It is the solid [[carbon]]aceous material derived from [[destructive distillation]] of low-ash, low-sulfur [[bituminous coal]]. Cokes made from coal are grey, hard, and [[porous]]. While coke can be formed naturally, the commonly used form is man-made. The form known as [[petroleum coke]], or pet coke, is derived from oil refinery coker units or other cracking processes.<ref name="soliftec.com" />

==== Smokeless fuel ====
{{Further|Smokeless fuel}}
Solid fuels which produce little smoke or volatiles are made from powdered [[anthracite]] coal and supplied in the form of [[briquettes]] usually for domestic use either in [[stove]]s or open fireplaces. The fuel is replacing coal as a fuel for open fires because of the reduction in particulate emissions and its increased efficiency. Smokeless fuel burns at a higher temperature and more slowly than a coal fire. The term also includes [[charcoal]], made by restricted combustion of dry wood and widely used at open air [[barbecue]]s to cook food on an open fire.