Developing a New Laser to Detect Methane Leaks
6/26/2013 - University of Adelaide - University of Adelaide
researchers are developing a new type of laser system that will
monitor methane, the main component of natural gas, levels across
large areas. This will provide a useful tool for monitoring
greenhouse gas emissions.
The system has the potential to detect methane leaks from
long-distance underground gas pipelines and gas fields, including
coal seam gas extraction operations, and to measure methane
emissions from animal production.
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,” says 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 25 square kilometres in a very short time. At the moment current
technology only allows detection at a single point source as it
blows past the detector.”
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 ‒ important when the lasers are to be
used in the environment and not confined to a regulated laboratory.
“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 says.
“Methane is a very important gas in terms of climate change. It
absorbs radiation, which warms the atmosphere, at a rate more than
20 times larger than that of carbon dioxide. This technology has
great potential to help reduce our methane emissions from gas
pipeline leaks or from coal seam gas operations, and may be
important for monitoring agricultural emissions over time.”