Clean coal is a concept for processes or approaches that mitigate emissions of carbon dioxide (CO2) and other greenhouse gases that arise from the utilization of coal, mainly for electrical power generation, using clean coal technology. Currently, the term clean coal is used in the coal industry primarily in reference to carbon capture and storage, which pumps and stores CO2 emissions underground, and plants using integrated gasification combined cycle (IGCC). IGCC involves coal gasification, which provides a basis for increased efficiency and lower cost in capturing CO2 emissions. Prior to the current focus on carbon capture and storage, the term clean coal had been used to refer to technologies for reducing emissions of NOx, sulfur, and heavy metals from coal combustion.
Within the United States, Carbon Capture and storage technologies are mainly being developed in response to regulations by the Environmental Protection Agency—most notably the Clean Air Act—and in anticipation of legislation that seeks to mitigate climate change. Currently, the electricity sector of the United States is responsible for about 41% of the nation's CO2 emissions, and half of the sector's production comes from coal-fired power plants.