Influence of pellet length, content of fines, and moisture content on emission behavior of wood pellets in a residential pellet stove and pellet boiler

Abstract In Germany, wood pellets must fulfill high quality standards to be utilized in small-scale furnaces. According current legislation, i.e., the 1st BImSchV, only EN plus A1–certified may used. Despite these strict requirements, physical fuel parameters can vary within permissible range and variation usually increases due transport storage. Fluctuations have a strong influence on combustion, especially pellet stoves with low degree of automation regarding control air supply. During this study, length, moisture content, content fines spruce were varied artificially at three levels for each parameter. All analyzed according international solid biofuels. Fuels combusted 6 kW stove selected assortments 15 boiler. For stove, length had significant gaseous but not total particulate matter (TPM) emissions. Both, rather short (10.3 mm) long (17 caused an increase contrast, boiler, no effect TPM emissions was observed. A (3 w-%) led increased CO, organic carbon (OGC), stove. This could relevant furnaces very simple or heat output as it is common most stoves. High 10 (CO up fivefold, OGC tenfold) (up 1.4-fold) likely elevated particle entrainment. Overall, state-of-the-art showed larger sensitivity towards variable qualities compared automatically stoked boiler; thus, improvements design technology are recommended. study has provided important insights into from boilers, which help drive future technical development areas flexibility emission reduction.