MONITORING & METERING


A MEASURABLE STRATEGY FOR METHANE


METHANE DETECTION


Mark Naples, managing director at Umicore Coatings Services,


explains how detecting and fixing methane


leaks from the oil and gas industry can be a game-changer in the fight against climate change


O


ver the last few years, climate change and its impacts have become all too real for


millions of people across the globe. Wildfires, flooding and other extreme weather events have been a fixture in news headlines in recent times, with increasing numbers of people experiencing the wrath of our planet firsthand. It is an issue that affects us all, which means


that we all have some part to play – although some parts are bigger than others. The oil and gas industry arguably has the biggest. The production and consumption of fossil fuels account for over 75% of all global greenhouse gas emissions and nearly 90% of all carbon dioxide emissions, according to the UN[1]


. That is simply unsustainable if we are to keep


global heating under the 1.5˚C threshold set in the Paris Agreement. The industry, however, has the means to rectify this, with the IEA targeting a 60% cut in emissions caused by oil and gas operations by 2030[2]


. In particular, it can have a relatively rapid


impact on global heating by focusing on methane emissions. According to the IEA, the downstream segment alone accounted for 20% of total fossil methane emissions[3]


that, when first emitted into the atmosphere, methane traps between 80-100 times more heat than the equivalent amount of carbon dioxide. And, when methane is burned, one of the by- products it creates is carbon dioxide, meaning its impact is felt in both the long and short term. However, methane also has a much shorter lifespan once it is in the atmosphere than carbon dioxide – it persists for around ten years before decaying rapidly, whereas carbon dioxide remains for around a century. In other words, methane emissions represent ‘low- hanging fruit’ – while emissions of methane are driving us towards climate ‘tipping points’ at an unsustainable speed, cutting them will deliver rapid returns as humanity works towards achieving that sub 1.5˚C target. Failing to achieve this will result in the planet


rapidly accelerating towards these ‘tipping points’, which include the collapse of ice sheets and ocean currents, the mass die-off of the tropical coral reefs, and a shift in the West African monsoon season. Passing these tipping points means the world will enter a feedback loop in which global heating becomes self- sustaining – and ultimately, irreversible. The problem is that, in the downstream segment,


actually tackling these emissions is easier said than done. Many methane leaks occur unexpectedly, as a result of ageing pipeline and storage infrastructure. And, given many pipelines can run for miles, checking for leaks can involve monitoring a vast area. Without using modern sensing technology, doing so is time-consuming and costly. Other emissions are intentional. These often


. This means


it has the potential to make a significant impact in the fight against climate change if it can get its methane emissions under control.


IDENTIFYING THE PROBLEM Methane is often compared directly to carbon dioxide, but the relationship between the two gases is complex. Methane’s molecular structure means it traps infrared radiation – heat – very effectively, much more so than carbon dioxide. It is estimated


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come in the upstream segment in the form of venting. As the world’s focus on carbon emissions means many countries are banning flaring – the practice of burning gaseous byproducts of oil extraction – due to the carbon dioxide it produces, many oil operations are simply venting methane into the atmosphere instead. This is a particular problem in areas that are unengaged with the global political community, which may engage in venting precisely because methane is much harder to detect. However, in these countries, leaks from antiquated infrastructure likely play a role, too. Without a dedicated focus on the most serious


methane emitters – international pariah states, and the oil and gas industry at large - it may prove difficult to cut emissions to the level required. But how can this focus be achieved without a solid foundation of emissions data to build upon? This data we need to hold the industry to account


ENERGY & SUSTAINABILITY SOLUTIONS - Autumn 2023


is already out there. All we need is the right equipment to collect it.


LASER ABSORPTION SPECTROSCOPY Laser absorption spectroscopy is arguably the most powerful tool we have for gathering this data. This means it has a big role to play in identifying and subsequently reducing methane emissions. The infrared-trapping property of methane molecules means they are easy to differentiate for highly sensitive infrared spectroscopy sensors. While laser sensors can be designed for any


region of the electromagnetic spectrum, many gas analysis devices operate in the infrared spectrum. This is because many small gaseous species, like methane, carbon dioxide, and other hydrocarbons, absorb infrared light very strongly, so it is easy to design devices with a sensitivity that extends into the parts per billion range. An additional advantage is that many different spectral lines characterise the absorption profile of these gases in the infrared. This means many features in the spectra can be used to identify chemical species with greater accuracy, and the wealth of information that can be provided with laser sensors makes gas analysis a powerful tool in industrial processing. This form of detection is based on the absorption


of light as it passes through a medium. Emitters within the sensor generate beams of IR light that pass through a sampling chamber containing a filter. The filter only allows the required wavelengths – in this case, the ones absorbed by methane - to make it past, meaning only those wavelengths can reach the detector. Different filters allow different wavelengths of light to reach the detector, which can, in turn, be used to detect different gases and distinct particles. This enables sensing devices to be tuned to different wavelengths. Newer gas analyser instruments use a laser diode


mounted on a thermo-electric cooler to tune a laser’s wavelength to the specific absorption wavelength of a particular molecule. They exploit their high-frequency resolution, which results in enhanced sensitivity - more significant levels of interaction between gas molecules and light in the order of parts per billion - and discrimination, as they are tuned to specific gas compounds. This lowers the risk of false alarms, which can become a serious issue with other common gas detection technologies. The benefits of these sensors include fast response times and accurate results without using any additional gases to operate. Modern detectors can now continuously monitor for combustible gases and vapours within the lower explosive limit and provide alarm indications. These can be deployed within oxygen-deficient or enriched areas, require little calibration, and are immune to sensor poison, contamination or corrosion.


LOCAL SOLUTIONS TO A GLOBAL PROBLEM Industrial gas detection is a mature market that continues to expand as devices become cheaper at the compliance end of the market and smarter at the top end. On the one hand, at Umicore, we work with OEMs stripping their devices back to basics, focusing on functionality and cost for low-cost markets. On the other, we assist in


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