Polycyclic aromatic hydrocarbon emission loads and profiles from the burning of locally grown wood species in Victoria, Australia - Some pilot project results

A testing facility for combustion of biomass and sampling of emissions has been established at Deakin University. In this pilot project using this facility, four kinds of locally grown wood species were burned and the particle emissions sampled and analysed for Polycyclic Aromatic Hydrocarbons (PAHs). The selected wood species covering pine, red gum, yellow box and sugar gum, are the most popular domestic fuel wood in Australia. Particulate matter emissions from burning of each load of wood were sampled from the flue using a standard stack emission sampling train. The particle-laden filters were extracted and the .extract analysed to determine PAH concentrations by Gas Chromatographyl Mass Spectrometer (Gc/MS). The sampling was conducted under two different burning conditions with the air inlet of the combustion chamber fully open and with it half open. A suite of 15 PAHs, ranging from naphthalene (C IOHB) to dibenzolahlanthracene (C12H14), were selected for analysis. PAH profiles for the four wood species, under the different burning regimes, have been generated. Some preliminary emission factors for the different wood species have been derived as microgram of summed PAHs (rPAHs) emittedlkilogram of wood burned. Total Particulate Matter (TPM) emission factors were also obtained from gravimetric measurement of the sample filter before and after the combustion. Based on these emission factors, pine displayed the highest level of rPAHs emitted from the combustion of the four wood species, with sugar gum showing the lowest level of rPAHs emission. Emission factors associated with the slow burning condition clearly showed higher l:PAH levels compared to the faster burning condition. During the faster burning condition, red gum and pine show a higher percentage of rPAH to TPM than sugar gum or yellow box. Under the slower burning. the l:PAHlTPM ratio in every case was greater.