Selective catalytic reduction (SCR) of NOx

DeNOx is the abbreviation used for removing nitrogen oxides (NOX) from exhaust gases. For this reason the process is referred to colloquially as denoxing. The DeNOx process used by us is based on the method of selective catalytic reduction (SCR), in which nitrogen monoxide (NO) and nitrogen dioxide (NO2) are reduced to nitrogen (N2) on the catalyst using a reactant added to the exhaust gas mixture. The reduction rate depends on the temperature of the exhaust gases, the type and volume of the catalyst, and the degree of mixing of the reactant with the exhaust gases.

SCR systems consist of:

  • Dosing system, which adds the reactant to the exhaust gases,
  • Injection/mixer unit, in which the reactant is added to and mixed with the exhaust gas,
  • Reactor unit housing the catalyst.

In the ideal scenario, all the pollutants are converted into nitrogen (the main element of the air we breathe) and water. However, excessive doses of reactant can lead to harmful ammonia slip (NH3). To avoid this, our dosing strategy and catalytic systems are finely tuned to meet the specific requirements of each application.