While initially intended to detect methane leaks from long-distance underground gas pipelines, coal seam gas extraction operations and from animal production, over time it could be applied to agricultural emissions and landfill.
The researchers, based in the University’s Institute for Photonics and Advanced Sensing, have conducted a preliminary study and are developing the laser system for further testing.
“We hope to accurately measure methane concentrations up to a distance of 5km,” said project leader Dr David Ottaway, senior lecturer in the School of Chemistry and Physics.
“This will give us an ability to map methane over an area as large as 25sq.kmin a very short time. At the moment current technology only allows detection at a single point source as it blows past the detector.”
Dr Ottaway said they had considered landfills, but not done any work mapping out the issues. However, he suspects the smaller distances and potentially higher concentrations than with gas fields would make it easier to detect.
The system uses laser-based remote-sensing technology called DIAL. Laser pulses are emitted with alternate frequencies, one of which is absorbed by the methane. The methane concentration is measured by observing the difference between the amounts of light scattered back to the detector. The laser system will then be swept through a circle to determine the methane concentration over a wide area.
To produce a powerful cost-effective laser system, the researchers are developing an erbium-YAG laser source. These lasers have the advantage of emitting light that cannot be seen by humans and is not hazardous to the human eye.
“We believe we are the only group working on an erbium-YAG DIAL system and we are very excited about the possibilities that this system could offer for reducing greenhouse gas emissions in a cost-effective manner,” Dr Ottaway said.
They are hoping to raise funding to support the research, which if successful would have a straight-line prototype in 2-3 years.