Design and supply of systems for reducing nitrogen oxides present in the generation of NOx: prompt (formed at low temperature at the start of combustion, insignificant), fuel (by the presence of nitrogen in the fuel) or thermal (to be combined with air at high temperatures).
Estos pueden ser:
SNCR (Selective NonCatalytic Reduction)
Either ammonia or urea solution are properly sprayed in the gas stream to be cleaned at high temperature. The reagent converts NOx into N2 and H2O vapor through fast enough reactions without the aid of any catalysts.
SCR (Selective Catalytic Reduction)
Either, ammonia or urea are sprayed in the gas stream but at relatively low temperatures (200÷400°C) because the conversion reaction is accelerated by suitable catalysts. With SCR technology it is possible to exceed 90% NOx removal maintaining very low ammonia slip at the stack (< 5 mg/Nm3).