How Is Methane Monitored
Methane is an important and useful gas, but it can also be hazardous. Monitoring methane is an important part of ensuring its safety and making sure it’s being used responsibly. From technological sensors to traditional methods, there’s a range of different methods. And by understanding the different ways to monitor methane, we can better understand how to keep it safe and use it effectively.
Airborne monitoring
Active sensing utilises laser technology that shoots a beam of light towards the ground, where it is absorbed and then reflected back to the sensor. This information allows researchers to gain insight into the concentration of methane in the atmosphere and provides an efficient way of measuring large areas.
Passive sensing, meanwhile, uses aircraft to collect data on methane concentrations without actively shooting light towards the ground. Instead, these sensors measure the natural thermal radiation emitted by the Earth. The sensors capture a variety of infrared signals, allowing for accurate readings of methane levels.
Ground-based Monitoring
Infrared cameras measure the heat signature of methane gas to detect leaks. This method is very effective in locating methane plumes emitted from a pipeline or wellhead. The advantage of this technology is that it is non-contact and can be used in many different terrain types.
Acoustic leak detection involves the use of a microphone to listen for the sound of escaping methane gas. This method is particularly effective in noisy environments and can detect the faintest sound of escaping gas.
An alternative method is through sniffer systems, which involve placing probes on the ground that are sensitive to methane gas. These systems are typically portable and can quickly detect the presence of methane in a given area.
Remote sensing is another way of detecting methane. By using various instruments mounted on satellites, data can be collected on concentrations of methane over large areas. These readings are usually collected several times per day over periods spanning weeks or months. A longer term monitoring system could also be set up to continually collect data on local concentrations of methane over time. Aerial surveillance is also a popular technique for detecting methane as aeroplanes fly across large tracts of land taking readings every few miles or so. Finally, continuous monitors placed directly onto wells or pipelines can measure the amount of methane being released into the atmosphere at all times giving real time data on possible leaks. All these methods together give an invaluable insight into how much methane is released into the atmosphere from our energy resources, which helps inform how we should manage them in future.
Passive Sampling
These passive samplers are used in both indoor and outdoor environments, depending on the type of sampler being used. Most passive samplers use simple absorption tubes, which are filled with an adsorbent material that attracts gases. As air passes through the tube, the gases are captured and stored until the sample is analysed. In addition to this basic design, some passive samplers have more sophisticated components such as temperature sensors or humidity probes to provide more detailed data.
Passive sampling can be conducted over long periods of time (months to years) to measure concentrations at low levels with great accuracy. They are also relatively inexpensive compared to active monitoring devices. This makes them ideal for monitoring areas where resources may be limited, such as remote locations. However, since they only collect a snapshot of a particular area at one point in time, these types of samples may not capture all of the important details when monitoring highly-variable emissions sources.
Active monitoring methods, such as gas chromatographs and mass spectrometers, are often better suited for sites with large emission rates because they provide near real-time data on methane concentration. For example, many oil and gas companies deploy portable gas chromatographs to detect and analyse fugitive gas leaks from pipelines and other equipment. These instruments continuously monitor the environment around them and provide operators with up-to-date information on methane concentrations. By incorporating automated leak detection algorithms into their systems, operators can quickly pinpoint leaks and take steps to reduce emissions. With these technologies, companies can ensure their operations remain compliant with regulations while keeping their costs down by preventing losses from fugitive gas leaks.