What Are Coal Combustion Products and How Are They Created?

Currently over half of the electricity produced in the United States is generated through burning coal. According to the United States Environmental Protection Agency when coal is burned in a power plant to generate electricity, it leaves behind residues that can be used as products or raw materials, primarily in the construction industry. These materials are known as coal combustion products (CCPs) and include fly ash, bottom ash, boiler slag, and flue gas desulfurization gypsum.

The EPA generally refers to the larger ash particles that fall to the bottom of a power plant furnace as bottom ash, and smaller ash particles that are carried upward by the hot combustion gases of the furnace as fly ash. Boiler slag is created instead of bottom ash when combustion occurs in a wet boiler, and flue gas desulfurization gypsum is produced from scrubbers used to remove sulfur from air emissions.

 

Generation of Coal Combustion Products

 

 

 Source American Coal Ash Association