Nitrogen oxides (NOx) in flue gases are one of the main gases which cause air pollution. Consequently, creation of greenhouse effect gives rise to a variety of diseases indirectly to human beings through environment.

SCR (Selective Catalytic Reduction) method is the most effective method employed in nitrogen oxide (NOx) emission control regarding sources of combustion gases.

It has been observed that a decrease of 98% of nitrogen oxides (NOx) in the flue gases created at the outlet of the combustion systems has been maintained thanks to foregoing method, commercially effectiveness of which has been proven.

Catalyst is the core of the selective catalytic reduction process and through reacting with nitrogen oxides (NOx) and ammonia creates a surface thereby causing the creation of a typical flue gas temperature by virtue of this reaction. Selective Catalytic Reduction (SCR), for cited reasons, is the most common technology employed in DeNOx systems.

Chemical reaction of the Selective Catalytic Reduction (SCR) is as follows;

4NO + 4NH3+O2 → 4N2 +6H2O
6NO2 + 8NH3 + O2  → 7N2 + 12H2O

Facilities where DeNOx Selective Catalytic Reduction (SCR) systems are utilized are as follows:

Power Plants;
- Gas-Fired,
- Oil-Fired,
- Coal-Fired,
- Biomass Fuel,

Industrial Plants;
- Steel Industry,
- Paper Industry,
- Oil Industry,