Residential wood combustion in two domestic devices: relationship of different parameters throughout the combustion cycle

Abstract

Logs of three common Southern and mid-European woods (Quercus pyrenaica, Populus nigra and Fagus sylvatica) were burned in two different combustion appliances, a fireplace and a stove. The flue gas composition was monitored continuously in the exhaust ducts of both burning appliances for total hydrocarbons (THC) and carbon oxides (CO2 and CO). Particulate matter with aerodynamic diameter below 2.5 mm (PM2.5) was sampled in a dilution tunnel under isokinetic conditions and chemically characterised for water soluble-inorganic ions, organic and elemental carbon and levoglucosan, mannosan, and galactosan. The evolution of the emission factors of these components throughout the combustion cycle was studied. The fireplace was the combustion appliance with the highest CO, CO2, THC and PM2.5 emission factors. The carbonaceous matter represented 72e84% of the particulate mass emitted, regardless of species burned and combustion devices. OC/EC ratios were higher for the fireplace than for the stove, and showed a significant potential relation with Kþ/levoglucosan. The dominant water soluble inorganic ions in smoke particles were Kþ, PO3 4 , SO2 4 , and Naþ. Anhydrosugar emissions were strongly enhanced in the start-up phase, when lower temperatures are registered, and decreased progressively until the glowing combustion phase. However, Kþ emission seems to be higher in flaming-dominated combustion at higher temperature. Statistical analyses, including the KruskaleWallis test, principal component analysis and Pearson correlation between emission factors, were carried out. A significant correlation between NH4 þ and levoglucosan was found for both appliances.