Application: Flue gases are treated with ammonia: ExxonMobil’s Research & Engineering’s (EMRE’s) proprietary selective noncatalytic NOx reduction technology—SNCR THERMAL DeNOx (TDN). NOx plus ammonia (NH3) are converted to elemental nitrogen and water if temperature and residence time are appropriate. The technology has been widely applied since it was first commercialized in 1974.
Products: If conditions are appropriate, the flue gas is treated to achieve NOx reductions of 40% to 70%+ with minimal NH3 slip or leakage.
Description: The technology involves the gas-phase reaction of NO with NH3 (either aqueous or anhydrous) to produce elemental nitrogen if conditions are favorable. Ammonia is injected into the flue gas using steam or air as a carrier gas into a zone where the temperature is 1,600°F to 2,000°F. This range can be extended down to 1,300°F with a small amount of hydrogen added to the injected gas. For most applications, wall injectors are used for simplicity of operation.
Yield: Cleaned flue gas with 40% to 70%+ NOx reduction and less than 10-ppm NH3 slip.
Licensor: ExxonMobil Research and Engineering Co., via an alliance with Engineers India Ltd. (for India) and Hamon Research-Cottrell (for the rest of the world).