5:15 PM - 7:15 PM
[AAS11-P20] A method for continuous measurements of atmospheric CH4 and C2H6 using a commercial mid-infrared laser absorption spectrometer
Keywords:methane, ethane, mid-infrared spectroscopy, in-situ measurement
The Climate and Clean Air Coalition has implemented strategies to reduce emissions of short-lived climate forcers (SLCFs) like methane (CH4), hydrofluorocarbons, black carbon and tropospheric ozone for achieving the goals of the Paris agreement and hold warming to 1.5 ℃. Especially for CH4, increased attention has been paid to mitigate climate change impacts in short term, and therefore precise estimates of CH4 emissions from a variety of biogenic and anthropogenic sources are now required.
In this study, a method for continuous measurements of atmospheric CH4 and C2H6 using a compact commercial mid-infrared laser absorption spectrometer (AERIS Technologies, Mira Ultra) has been developed. The laser instrument measuring CH4 and C2H6 simultaneously has great advantage to investigate thermogenic CH4 emissions related to oil and gas facilities because C2H6 can be a powerful tracer for the thermogenic emissions. Before exploring the CH4 emission sources using the method, stability and accuracy of the method was examined through an inter-comparison experiments. In the experiments, measurements of atmospheric CH4 and C2H6 from the Mira Ultra were compared with those from two different analytical instruments (PICARRO laser instrument for CH4, GC/MS measurement system for C2H6). The Mira Ultra showed slight positive bias for C2H6, but excellent agreement was obtained for CH4. This result suggests that the Mira Ultra can contribute to the detection of the thermogenic emissions, especially for mobile platform observations with the advantage of high-time resolution measurements. After the experiments, the method was applied to in-situ measurements of atmospheric CH4 and C2H6 onboard a commercial cargo vessel which sails between Kawasaki (Kanagawa Pref.) and Kanda (Fukuoka Pref.) along the southern coast of the main Island of Japan.
In this presentation, we will show the results obtained from the inter-comparison experiments and from the onboard measurements.
In this study, a method for continuous measurements of atmospheric CH4 and C2H6 using a compact commercial mid-infrared laser absorption spectrometer (AERIS Technologies, Mira Ultra) has been developed. The laser instrument measuring CH4 and C2H6 simultaneously has great advantage to investigate thermogenic CH4 emissions related to oil and gas facilities because C2H6 can be a powerful tracer for the thermogenic emissions. Before exploring the CH4 emission sources using the method, stability and accuracy of the method was examined through an inter-comparison experiments. In the experiments, measurements of atmospheric CH4 and C2H6 from the Mira Ultra were compared with those from two different analytical instruments (PICARRO laser instrument for CH4, GC/MS measurement system for C2H6). The Mira Ultra showed slight positive bias for C2H6, but excellent agreement was obtained for CH4. This result suggests that the Mira Ultra can contribute to the detection of the thermogenic emissions, especially for mobile platform observations with the advantage of high-time resolution measurements. After the experiments, the method was applied to in-situ measurements of atmospheric CH4 and C2H6 onboard a commercial cargo vessel which sails between Kawasaki (Kanagawa Pref.) and Kanda (Fukuoka Pref.) along the southern coast of the main Island of Japan.
In this presentation, we will show the results obtained from the inter-comparison experiments and from the onboard measurements.