Control of NOx emissions of a domestic/small-scale biomass pellet boiler by air staging

- Two types of wood pellets were tested with a 50 kW underfeed stoker boiler.
- Considerable reductions of NOx emissions were achieved by air staging.
- The position of the 2nd air inlets greatly impacted NOx emissions.
- There is a trade-off between NOx and CO emissions when air staging is applied.