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).
Selective Catalytic Reduction (SCR)
By adding an ammonia/urea solution to the flue gases, NOx can be converted to N2+H2O. When it is necessary to comply with more restrictive levels, it may be necessary to work on a reactor with a catalyst at a lower temperature to increase the efficiency of the conversion.
The reducing agent is injected into the gas stream prior to entering a reactor, where the reducing reaction takes place on a bed of several layers of porous catalyst at lower temperatures (200-400 ° C), being able to obtain reductions even higher than 90%.
Selective Non Catalytic Reduction (SNCR)
Solution for the elimination of NOx that is cheaper than catalytic systems, as long as there is sufficient temperature in the process to complete the reaction of urea+NH3 and nitrogen oxides. They can achieve yields of up to 60% and include injection systems and dosing of mixtures in the home/flue and control system.
Based on the chemical reduction of the NOx molecule to molecular nitrogen (N2) and water vapor (H2O), urea or ammonia is injected directly into the flue gases at high temperature in a suitable way, without the need to use a catalyst.