A selective laser-based sensor for fugitive methane emissions
At the beginning of 2023 scientific group from the King Abdullah University of Science and Technology, Saudi Arabia published in Scientific Reports (Nature) article where they describe a mid-infrared sensor for methane concentration measurements using VIGO detector.
Methane concentration increasing steadily due to anthropogenic activities. It is the third most important greenhouse gas. Methane has strong absorption lines in the 3 – 3.5 μm region. Therefore, the researchers used distributed feedback interband cascade laser emitting near 3.3 μm and thermo-electric cooled photodetector PVI-4TE-3.4–2 × 2 made by VIGO Photonics working in 2.2 – 3.6 µm range. Described system using time-domain absorption spectroscopy. It is able to separate methane absorbance from benzene absorbance and baseline laser intensity, which is very important in the measurements of fugitive methane emissions. The authors present results of the minimum detection limit of the sensor on level of approx. 110 ppm.
The authors suggest, that the proposed sensing strategy can be utilized to measure methane leaks in harsh environments and in the presence of interfering species in environment-monitoring applications.