Emissions from residential combustion of certified and uncertified pellets

Abstract

The aim of the present study was to evaluate the relationship between fuel certification and gaseous and PM10 emissions and their composition. Two pellets labelled as ENplus A1 (certified pellets R and P) and a non-certified brand of pellets were tested in a pellet stove. The impact of operating conditions on emissions was also evaluated. The highest carbon monoxide (CO, 2.7-6.1-fold) and total organic carbon (TOC, 1.9-11-fold) emissions were observed for certified pellets R. Nitrogen oxide (NO) emissions were higher for non-certified pellets (2.5-3.2-fold). The compliance of gaseous emissions with the Ecodesign thresholds was not ensured by certification. Certified pellets P generated significantly lower PM10 emissions than the other two types of pellets at medium and nominal loads. Water soluble ions represented from 36 to 68 %wt. of the PM10 mass. The combustion of certified pellets P and non-certified pellets generated total carbon PM10 mass fractions ranging from 23 to 50 %wt., whereas pellets R resulted in lower mass fractions (7-14 %wt. PM10). The chromatographically resolved organic compounds were dominated by anhydrosugars and alkanols. Pyrene and retene were the most abundant among polyaromatic hydrocarbons.