Which gases are best detected with the infrared technology and why ?

Which gases are best detected with the infrared technology and why ?

March 30, 2023 . 3min read

The dangers arising from a gas leak at an industrial plant can have far-reaching consequences, such as spreading contamination across the environment, compromising the health and safety of all those within the leak's hazard radius, and dragging down the plant's bottom line since fugitive emissions could equate to a significant loss of revenue.

That explains why the ability to detect gas leaks is a mission-critical issue, but optical gas imaging (OGI) is capable of addressing that challenge with its specific characteristics and performance levels, and the technology's prowess is especially remarkable when it comes to detecting certain hazardous gases.

This article offers an insight into how OGI detects those gases, what those hazardous gases are, and the applications offering the best fit for OGI-based detection.


How does OGI work?

Optical gas imaging exploits the property of certain gases to absorb infrared radiation. Those gases can then be visualized in their native environment through the changes in light intensity. Optical systems incorporating the IR technology need to be tuned to very narrow spectral bands. As such, they are highly selective and they also need to be very sensitive.

Only gases absorbing infrared radiation in the filtered bandpass configured on the camera (and mainly by the detector) can be detected.

There also needs to be radiant contrast between the gas plume and the background. Finally, the temperature of the plume must be different to the background temperature.

When these conditions are met, the leak can be visually located from a distance in real time.


The three gases best identified with an OGI camera

  • Methane (CH4)

Methane emissions mainly come from agricultural activities, coal mines, landfills, wastewater, and oil & gas facilities. Driving down methane emissions during the oil and gas production process is actually one of the highest priorities in current climate policies.

Methane represents the second most influential anthropogenic greenhouse gas contributing to climate change, after carbon dioxide (CO2). That explains why detecting and curbing methane emissions is such a major issue for protecting the environment, especially since methane has 84 times the warming power of CO2 over the first 20 years. Therefore, lowering CH4 emissions can have a quick and effective impact on tackling global warming, so governmental agencies are giving the issue their undivided attention. A European summit is actually being held on March 27 in Amsterdam on the topic of mitigating methane emissions. (https://www.oilandgasiq.com/events-methane-mitigation-europe)

  • Sulfur hexafluoride (SF6)

This gas is primarily used for its arc quenching capabilities (100 times faster than air) in electrical power distribution facilities. It has been used as an insulator in medium and high-voltage circuit breakers for decades. It can be used to build increasingly compact and cost-effective systems, combined with its ability to provide greater switching capabilities and make installations safer. To put its use into perspective, 80% of the SF6 produced around the world is used in high-voltage circuit breakers and metal-enclosed switchgear.

But sulfur hexafluoride (SF6) is a greenhouse gas with an estimated atmospheric lifetime of 3,200 years (compared to 100 years for CO2). Its global warming potential (GWP) is 22,800 times higher than CO2. SF6 belongs to the halogen gas family, which is the fourth largest contributor to global warming.

It goes without saying that the gas is extremely harmful to the environment, so detecting leaks and reducing emissions is a top priority.

  • Refrigerants

Refrigerants are used in industrial refrigeration systems for the food production, storage and retail sectors. They are also widespread across the chemical, pharmaceutical and automotive industries, as well as in air conditioners and heat pumps. They represent a major contributor to the depletion of the ozone layer and global warming due to their environmental impact. The infrared technology is currently one of the best suited methods for detecting refrigerant leaks.


Which market stands to benefit the most from OGI?

OGI dovetails seamlessly with the industrial process control applications in the chemical, pharmaceutical, biotechnology, power, and oil & gas industries.

In an effort to improve safety, regulations aimed at preventing the risk of exposure to hazardous substances require organizations to check their exposure limit values (OEL and STEL), define action plans and implement air monitoring, handling and ventilation solutions. In this respect, companies can leverage the capabilities of an OGI system to meet these obligations.

With the aim of protecting the environment, atmospheric emissions are regulated by major hazard facility legislation and local regulations specific to certain areas or activities (petrochemical, chemical and pharmaceutical industries). Regularly measuring emissions is a legal requirement.
Finally, air quality issues and hazardous gases can also affect productivity.


As technologies go, thermal imaging holds plenty of promise for detecting gas leaks, especially its ability to spot several different gases that are dangerous to people and harmful to the environment, such as the examples mentioned earlier, as well as carbon monoxide (CO) and carbon dioxide (CO2).

For a closer look at how the infrared technology is being rolled out to detect hazardous gases, download the free PESTEL analysis on the OGI market, which provides an overview of the macro-environmental factors that can influence the technology's development.



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