[Zurück]

B. Kirchsteiger, M. Kistler, T. Steinkogler, F. Kubik, H. Stressler, R. Sturmlechner, J. Kelz, A. Kasper-Giebl:
"PAH emission patterns from different domestic firewood combustion devices";
Vortrag: ICCPA International Conference on Carbonaceous Particles in the Atmosphere, Palais Eschenbach, Eschenbachgasse 11, 1010 Vienna, AUSTRIA; 03.04.2019 - 06.04.2019; in: "12th International Conference on Carbonaceous Particles in the Atmosphere", (2019), S. 33.

Emissions from residential wood combustion contribute significantly to the overall particulate matter (PM) generation in Austria as well as in Europe. Here we focus on carbonaceous compounds including polycyclic aromatic hydrocarbons (PAHs) in PM originating from small-scale heating devices. PAHs are produced during incomplete combustion processes or pyrolysis of organic material and are emitted as complex mixtures containing structural isomers and derivates. As they undergo long-range transport PAHs can be found in urban as well as rural areas.

This work presents emission patterns of PAH concentrations of different small scale domestic firewood combustion devices containing the 16 US EPA priority PAHs (PAH16). The combustion devices were operated representing real life operation. TSP measurements were performed in the hot and cooled flue gas. TSP emission samples were collected before and after training the users to optimize firing conditions. Here we present first results of six firewood combustion appliances, all of them operated in a rural area in Styria, Austria. For every heating device, two or three consecutive batches were evaluated according to the users habit. Besides PAHs, major contributors to the chemical composition of TSP were characterized using different analytical methods, i.e. the carbonaceous fraction, anhydrosugars, inorganic ions, humic-like substances. Total PAH emissions decrease after user training and also a shift in PAH patterns can be observed. PAH concentrations determined within the hot or the cooled flue gas reflect the known partitioning of PAHs between the gas and particle phase, driven by their molecular weights. The major PAH amount is quantified in cooled TSP samples, i.e. in the cold flue gas / after dilution. Samples taken from the hot-phase mainly consist of PAHs with higher molecular weights (MW), i.e. MW starting with 228. PAH patterns from cooled-phase samples mainly consist of PAHs with lower molecular weights, i.e. MW starting with 128. Before user training the maximum concentrations of PAH16 was 4.2 mg/filter, while a maximum concentration of PAH16 of 0.2 mg/filter was determined after the user training.
Similar to the PAH content, a higher amount of levoglucosan was quantified in cooled-phase samples than in hot-phase samples. Also, a characteristic distribution of EC (elemental carbon) and OC (organic carbon) was observed in these two sample fractions. The major amount of elemental carbon was observed in the hot-phase samples, while the cooled-phase samples primarily consist of organic carbon.

PAH, emissions, combustion