Methane is a flammable gas which is used to produce natural gas fuel. It has become favoured over other fossil fuels like coal as it burns much more cleanly, however it can pose significant issues if it is allowed to leak from an enclosed system into the environment.

While carbon dioxide is probably the best known greenhouse gas, methane is one of the most damaging. In fact, methane is 25 times more effective than carbon dioxide at trapping heat near the surface of the Earth, and so its heating effect is much greater than that of most other greenhouse gases.

As well as being damaging to the environment, methane can cause injury and ill health, especially if exposure takes place in poorly ventilated areas. Poor ventilation compounds the effects of methane exposure, increasing the risk of severe injury and even death, read more on what are the dangers of methane gas.

Biomethane is the form most commonly used for industrial applications, and this has a methane concentration of 90% or higher so that it is chemically identical to natural methane found in underground reserves. As it has the same composition as natural gas, it has a wide range of industrial, domestic, and commercial applications including cooking, heating, fuelling vehicles, among other uses.

Detecting methane gas

Methane gas analysers and gas detectors and monitoring equipment play a vital role in the environments that such gases are used. Identifying leaks in supply and distribution systems quickly and accurately allows companies to protect their staff and infrastructure allowing for continued operation with minimal disruption, this can be achieved through natural gas leak detection.

Often, the first sign that there is a methane leak somewhere in the system is the distinct and unpleasant smell of rotten eggs. This is a strong indicator, and is caused by the addition of methanethiol. This sign should never be used as the sole indicator of leaks, and so it is always recommended that further, more reliable detection methods are used. This is especially important in large or well ventilated spaces which may conceal the smell.

Sensitive monitors should be used throughout the entire system so that leaks can be reported accurately and located quickly. The most reliable versions make use of lasers to detect the chemical signature of methane and gain an accurate picture of its saturation levels in the air, read more on how to measure methane emissions.

The light spectrum of the sample is analysed and only the specific wavelength produced by methane (CH4) is measured. The figure is given as parts per million of methane, and even levels as small as 0.5 parts per million can be detected. The time and GPS location that the sample was taken must be recorded, and many handheld devices allow for this function to increase the convenience of the analysis.

There are, of course, other instances which call for the accurate monitoring of methane levels locally. Landfills and refuse management plants must also pay close attention to the methane levels generated by bacteria during the decomposition process. Mobile monitors and sensors can be used to detect problem areas, allowing them to be remedied appropriately.

In these circumstances, water testing can also be used to detect any methane which may be leaching into groundwater and other watercourses. Leaching can occur when subterranean supply pipes become eroded or damaged over time, as well as in the waste management sector. Environmental pollution incidents can incur hefty penalties, and so proactive monitoring is the most cost effective and failsafe way to prevent major incidents from occurring.

What to do if a methane leak is suspected

Whether the distinct smell of a methane leak has been reported, or issues with gas supply pressure are detected, the source of the leak must be quickly identified and rectified. If necessary, workers must be evacuated from the area to minimise risks to their wellbeing. Handheld monitors should be used to hone in on the source of the leak, and where possible the supply should be switched off.

A qualified technician will be able to find the source of the leak and analyse the cause. Once this is done a plan of action can be formed and any repairs can safely take place in accordance with current regulations. Repairs must always be undertaken by an experienced gas engineer to ensure stringent standards are met.