Real-world emission factors for Caterpillar 797B heavy haulers during mining operations

Real-world fuel-based emission factors (EFs) from Caterpillar 797B diesel heavy haulers when used for oil sands mining operations were measured using an on-board portable emissions monitoring system. Average EFs (in g/kg fuel) for 16 separate tests on four trucks were 3150 +/- 4 for CO2, 2.51 +/- 1.30 for CH4, 10.28 +/- 3.21 for CO, 0.61 +/- 0.32 for non-methane hydrocarbons, 55.49 +/- 9.75 for NOx (reported as NO2), 0.70 +/- 0.17 for PM2.5 (mass of particles with aerodynamic diameter <2.5 mu m), and 0.34 +/- 0.05 for black carbon (BC). Ultrafine particle numbers averaged (4.7 +/- 4.1) x 10(15) particles/kg fuel. Fuel-based EFs of NO, NO2, and particle numbers were higher during idling, whereas PM2.5 and BC EFs were higher during traveling without a load. A comparison of emissions with those reported by oil sands facilities showed large variations, both among the facilities and between the reported emissions and the real-world measurements

Wind erosion potential for fugitive dust sources in the Athabasca OilSands Region

This study characterized the generation of windblown dust from various sources in the Athabasca Oil Sands Region (AOSR) in Alberta, Canada. The Portable In-Situ Wind Erosion Laboratory (PI-SWERL) equipped with two real-time dust monitors and nine-channel filter packs was used to simulate wind-driven erosion and measure emissions. Sixty four sites were measured, including oil sands mining facilities, quarry operations, and roadways in the vicinity of Ft. McMurray and Ft. McKay. Key parameters related to windblown dust generation were characterized including: threshold friction velocity, reservoir type, and particle size-segregated emission potential. The threshold wind speed for particle suspension varies from 11 to 21.5 km/h (u10 + ; measured at 10 m above ground level), and saltation occurs at higher speeds of u10 + &gt;32 km/h. All surfaces have limited dust supplies at lower wind speeds of &lt;27 km/h, but have unlimited dust supplies at the highest wind speed tested (56 km/h). Unpaved roads, parking lots, or bare land with high abundances of loose clay and silt materials along with frequent mechanical disturbances are the highest dust emitting surfaces. Paved roads, stabilized or treated (e.g., watered) surfaces with limited loose dust materials are the lowest emitting surfaces. Surface watering proved effective in reducing dust emissions, with potential emission reductions of 50&ndash;99%. Surface disturbances by traffic or other activities were found to increase PM10 emission potentials 9&ndash;160 times. These data will improve the accuracy of emission inventories, dust dispersion, transport, and source apportionment models, and help design and evaluate dust control strategies.</p