A study compares measured emissions and reported emission estimates of volatile organic compounds (VOCs) from oil sands surface mining facilities. VOCs are associated with ozone and aerosol formation. VOC emission estimates from oil sands facilities are reported based on widely accepted estimation methods. However, uncertainties in the reports have not been evaluated, partly due to technical challenges tied to direct emissions measurements. Using an instrumented aircraft during summer 2013, Shao-Meng Li and colleagues determined VOC emission rates from four facilities in Alberta, Canada. The measured aggregate emission rate of VOCs was approximately 50 to 70 tons per day, depending on the facility. The facilities’ reported emission rates were lower than the aggregate rates by factors of approximately 2.0 to 4.5, indicating that reported emission rates were underestimated. For 11 of the 93 VOCs that were individually reported for all four facilities, the measured and reported emission rates were similar, whereas the measured rates for the rest of the VOCs were higher than the reported rates. Furthermore, depending on the facility, 9 to 53 VOC species were not included in emission reports, despite meeting minimum reporting requirements based on the measurements. According to the authors, the analyses suggest that improvements in VOC emission estimation methods could enhance the accuracy and completeness of emission estimates. - Read at PNAS
Article #16-17862: “Differences between measured and reported volatile organic compound emissions from oil sands facilities in Alberta, Canada,” by Shao-Meng Li et al.