Since 1981, EPA, followed by GRI, DOE, and others, sponsored the development of natural gas reburn. Several demonstration sites have retained their reburning installations for potential future use. A utility and an industrial firm have since purchased and installed commercial natural gas reburning systems. Reburning involves the injection of natural gas above the coal burners of a boiler to create a fuel-rich zone, where chemical reactions reduce NOx to harmless nitrogen.
Air is injected above the reburning zone to burn out combustibles while minimizing NOx formation.
EPA s work is represented through its National Risk Management Research Laboratory in Research Triangle Park, NC, which performs combustion research and studies its impact on air emissions. DOE s Federal Energy Technology Center in Pittsburgh performs research and development on coal-based technologies. GRI, headquartered in Chicago, manages a cooperative research, development and commercialization program for the mutual benefit of the natural gas industry and its customers.