Influence on CO and PM emissions of an innovative burner pot for pellet stoves: An experimental study

In this study, an extensive set of experiments has been performed to investigate how the emissions of carbon monoxide (CO) and particulate matter (PM) from wood pellet combustion are correlated with the different layout of air inlets in the two burner pots of pellet stoves. In particular, emissions generated using a “traditional” burner pot are compared with those produced with an innovative one. Tests were carried out on four pellet stoves (8–11 kW burning power). Tests show that CO emissions can be reduced close to zero using the innovative burner pot. PM emissions are also reduced, but not as much as those of CO. This phenomenon is explained assuming that CO reduction implies a reduction of the organic part of PM, but not of the inorganic matter. Experiments also show an apparent dependence of PM release on the time from ignition for both burner pot models: PM emissions increase and the color of PM deposited on filters varies over a wide range. It is argued that this effect is due to ash accumulation on the bottom of the burner pot and to its interaction with the primary air stream that flows over it.