Emission rate estimates determined for a large number of volatile organic compounds using airborne measurements for the oil sands facilities in Alberta, Canada

In August and September of 2013, aircraft-based measurements of air pollutants were made during a field campaign in support of the Joint Canada-Alberta Implementation Plan on Oil Sands Monitoring in Alberta, Canada. Volatile organic compounds (VOCs) were determined using a high resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) continuously at 2-5 second resolution during the flights, and from 680 discretely sampled stainless steel canisters collected during flights followed by offline GC-MS and GC-FID analyses for four large oil sands surface mining facilities. The Top-down Emission Rate Retrieval Algorithm (TERRA), developed at Environment and Climate Change Canada (ECCC), was applied to the aromatics and oxygenated VOC results from the PTR-ToF-MS to determine their emission rates. Additional VOC species, determined in the canisters, were compared with the PTR-ToF-MS VOC species to determine their emission ratios. Using these emission ratios and the emission rates for the aromatics and oxygenated VOCs, the individual emission rates for 73-90 volatile organic compounds (VOCs) were determined for each of the four major oil sands facilities. The results are the first independently determined emission rates for a large number of VOCs at the same time for large industrial complexes such as the oil sands mining facilities. These measurement-based emission data will be important for strengthening VOC emission reporting.