|Abstract Title:||Development of a UAV-deployable fugitive methane sensor using wavelength modulation tunable diode laser absorption spectroscopy|
|Presenter Name:||Dr Jalal Norooz Oliaee|
|Co-authors:||Mr Nicaulas Sabourin|
Dr Kevin Thomson
Dr Greg Smallwood
|Company/Organisation:||National Research Council Canada|
Abstract Information :
Significant methane emissions in Canada are released during the production and transport of oil, natural gas, and coal. In line with the Paris agreement, the Canadian federal and provincial Alberta governments are committed to reduce methane emissions from the oil and gas sector by 40% - 45% below 2012 levels by 2025 under the Climate Leadership Plan. However success of regulations and proven emission reductions are hindered by large uncertainties in true emission levels. The National Research Council Canada (NRC) is developing an unmanned aerial vehicle (UAV)-deployable methane sensor for measurement of emissions from the oil and gas sector in western Canada as well as for other industrial and environmental monitoring applications. The system benefits from the specificity and rapid response of tunable diode laser absorption spectroscopy (TDLAS) to provide accurate, real-time methane concentrations. The methane sensor employs a thermoelectrically (TE)-cooled GaSb-based distributed feedback (DFB) laser with single-mode emission around 3270 nm to probe the fundamental v3 band of methane around its R(3) transitions, and is detected with a TE-cooled HgCdTe detector. For increased sensitivity to fugitive emissions, the laser is operated in wavelength modulation mode (2f-WMS) and coupled to a compact and light open-path Herriott-type multi-pass absorption cell with a total absorption pathlength of 6.73 meters over 37 passes. Noise reduction and optimization of the 2f-WMS signal has resulted in a 1-Hz sensitivity better than 0.05% around the global atmospheric methane emission levels (1.8ppmv) making the sensor suitable for fugitive emissions detection.