Coal pollution mitigation emissions of sulfur dioxide or oxides of nitrogen associated with the utilization of coal in the generation of electricity." Before being adopted in this fashion, historically "clean coal" was used to refer to clean-burning coal with low levels of impurities, though this term faded after rates of domestic coal usage dropped. The term appeared in a speech to mine workers in 1918, in context indicating coal that was "free of dirt and impurities." In the early 20th century, prior to World War II, clean coal (also called "smokeless coal") generally referred to anthracite and high-grade bituminous coal, used for cooking
Cannel coal yellow flame and little ash. The modern Lycopodiopsida relatives of these lycopsids (scale trees), with their similar high oil content, high surface area spores, are the source of highly flammable lycopodium powder. Cannel coal is also lower in fixed carbon than typical bituminous coal. It includes various amounts of vitrinite and inertinite. Analytically, cannel coal consists of micrinites, macerals of the exinite group, and certain inorganic materials. Cannel coal Cannel coal or candle coal, is a type of bituminous coal, also classified as terrestrial type oil shale. Due to its physical morphology and low mineral content cannel coal is considered