Cleaner burning than other fossil fuels, the combustion of natural gas produces negligible amounts of sulfur, mercury, and particulates. However, natural gas does produce nitrogen oxides (NOx), which contributes to smog.
Solutions designed to reduce NOx emissions include SCR and SNCR. SCR (Selective Catalytic Reduction) is a means of converting NOx with the aid of a catalyst into diatomic nitrogen (N2), and water (H2O). In contrast, with SNCR (Selective Non-Catalytic Reduction), either ammonia or urea is injected into the boiler to react with the nitrogen oxides formed in the combustion process. The resulting product of the chemical reaction is diatomic nitrogen, water, and carbon dioxide (CO2).
CECO’s Peerless, Aarding and CCA Combustion Systems brand products and solutions below fit within the classification of De-NOx: