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
Direct carbon fuel cell Direct carbon fuel cell A Direct Carbon Fuel Cell (DCFC) is a fuel cell that uses a carbon rich material as a fuel such as bio-mass or coal. The cell produces energy by combining carbon and oxygen, which releases carbon dioxide as a by-product. It also called coal fuel cells (CFCs), carbon-air fuel cells (CAFCs), direct carbon/coal fuel cells (DCFCs), and DC-SOFC. The total reaction of the cell is C + O → CO. The process in half cell notation: Despite this release of carbon dioxide, the direct carbon fuel cell is more environmentally friendly than traditional carbon burning techniques.