NOx in natural gas combustion: how it is created and how it is limited

Nitrogen oxides (NOx) are key combustion pollutants. Their creation is mainly influenced by flame temperature, residence time, and excess air.

Thermal NOx

It increases when the temperature in the flame zone is very high.

Low-NOx burners

They use specific head geometry and controlled mixing to limit locally high temperatures.

Combustion adjustment

Excessive adjustment of air or gas solely to reduce NOx can increase CO or destabilize the flame.

Proper approach

The adjustment must follow emission specifications and the instructions of the specific burner.