Top-Down Determination of Black Carbon Emissions from Oil Sand Facilities in Alberta, Canada Using Aircraft Measurements

Black carbon (BC) emissions from the Canadian oil sand (OS) surface mining facilities in Alberta were investigated using aircraft measurements. BC emission rates were derived with a top-down mass balance approach and were found to be linearly related to the volume of oil sand ore mined at each facility. Two emission factors were determined from the measurements; production-based BC emission factors were in the range of 0.6-1.7 g/tonne mined OS ore, whereas fuel-based BC emission factors were between 95 and 190 mg/kg-fuel, depending upon the facility. The annual BC emission, at 707 ± 117 tonnes/year for the facilities, was determined using the production-based emission factors and annual production data. Although this annual emission is in reasonable agreement with the BC annual emissions reported in the latest version of the Canadian national BC inventory (within 16%), the relative split between off-road diesel and stack sources is significantly different between the measurements and the inventory. This measurement evidence highlights the fact that the stack sources of BC may be overestimated and the off-road diesel sources may be underestimated in the inventory and points to the need for improved BC emission data from diesel sources within facilities.