Monitoring of GHGs, VOCs, and Odour Compounds Using OP-FTIR in the Oil Sands Region in Alberta: a Case Study

摘要

Greenhouse gases (GHG) and fugitive emissions from oil and gas industry have drawn increased attentions from regulators and general public. Alberta's oil sands are sources of GHG, Volatile Organic Compounds (VOCs), and odour compounds. Continuous and speciated air monitoring data with high spatial and temporal resolution is necessary to improve the characterization of fugitive emissions from the oil sands operations. Open Path Fourier Transform Infrared Spectrometer (OP-FTIR) has been used for monitoring of multiple gaseous compounds in a variety of applications worldwide. To demonstrate the feasibility of using OP-FTIR for air monitoring in the oil sands region, a unit was deployed at two air monitoring stations (namely AMS1 from August 2014 to October 2014 and AMS9 from August 2015 to October 2015). Methane (CH_4), alkanes (using n-butane and n-octane as surrogates), VOCs, and ammonia were detected. Average hourly CH4 concentration was 1.9 ppmv (the same as in Edmonton, Alberta, Canada) at both locations. Hourly concentrations of n-butane, n-octane, formaldehyde, methanol, and ammonia were quantified at ppbv levels. Hourly CH4 concentrations from OP-FTIR were in good agreement with the co-located CH4 measurements. Composite hourly (each data point is an average of all data points collected in a specific hour (e.g., the hour ending at 12:00 pm) every day) CH4 concentrations varied less than 0.2 ppmv diurnally. Daily CH4 concentrations were fairly stable at both AMS1 and AMS9 (RSD 5% and 4%, respectively). Concentrations of select . organic compounds were compared to relevant odour thresholds. For the major emission episodes, 5-min average THC concentrations from OP-FTIR correlated well with those from AMS1 and AMS9. NMHC accounted for 0% to 29% (average 5%) of THC at AMS1 and 0% to 71% (average 21%) at AMS9. Elevated (>2.5 ppmv) THC concentrations were recorded under several wind directions, mostly under north-south to northeast-southwest winds due to the channelling effect of the Athabasca River valley. Challenges and lessons learned from the field campaigns are discussed. OP-FTIR is found to be suitable for air monitoring in the oil sands region in Alberta and the results helped better characterize the air emissions from the oil sands and related activities.