July 2021, Vol. 248, No. 7
Features
Cost of Hydrogen Gas Leaks Worth Taking into Consideration
By Bob Vigdor, NevadaNano
As companies around the world identify ways to combat climate change and mitigate their environmental impact, hydrogen is becoming a staple in many industrial and commercial industries. The use of hydrogen in the production of fuels and other industries has more than tripled since 1975, and this level of consumption shows no indication of slowing down.
In fact, future projections show continued exponential growth and estimate the global hydrogen market will exceed $160 billion by 2026.
This growth is no surprise to many who work with this versatile gas. Hydrogen is incredibly useful for various commercial and industrial purposes such as oil refining and the production of ammonia, steel and methanol. Hydrogen is also used to treat metals, produce fertilizer and process foods. But its future growth is dependent upon its link to clean energy production and consumption.
The history behind hydrogen and energy is long. The gas was used to power the first internal combustion engine before becoming a staple in the refining industry.
Once adapted for the petroleum refining industry, the use of hydrogen became widespread. It can reduce heavy gases and oils to lower molecular weights, reduce the sulfur content of fuels, treat gas in catalytic reforming and help meet regulatory standards for environmental safety.
Currently, as an abundant resource, hydrogen is one of the leading options for storing and producing renewable energy. There are multiple characteristics of hydrogen that make it an ideal source of clean energy. It is light, storable and energy-dense. It produces no direct pollutants, emissions or greenhouse gases.
Also, there are no carbon dioxide emissions, and it can be made from renewable energy. While these traits are attractive for many current uses, this potential has not been fully realized. It is likely to be integrated into transporting, building and powering the infrastructure of the future.
Hydrogen gas provides the benefit of reducing fuel costs and emissions when used in transport. It can provide energy to buildings and residences when blended into existing natural gas networks, while reducing emissions in traditional energy production.
Discussions related to technological advances in hydrogen are occurring globally as political leaders and the scientific community, stress the gravity of climate change effects. Despite rapid growth in recent decades, the potential for greater use is incredibly high, leading to a rapidly evolving and growing hydrogen market.
Dangers of Hydrogen
Despite hydrogen’s widespread appeal and many benefits, it is imperative to remember that it is still a potentially dangerous gas. It is colorless and odorless, making it naturally imperceptible to humans.
It is also lighter than the surrounding air, which means it rises quickly when leaked into the atmosphere. This property makes it challenging to detect leaks. Even a small hydrogen leak can escalate into a major disaster if it is not detected and mitigated quickly.
The primary hazards associated with hydrogen are the following:1
Physiological: Hydrogen has the potential to cause burns and respiratory problems for individuals who are exposed to it. The severity of the damage is often contingent upon the duration and concentration of the exposure. Asphyxiation is also possible in high concentrations. The presence of hydrogen displaces air, depriving those in the vicinity of adequate oxygen. And since the gas is odorless and tasteless, some individuals may not even be aware of the danger if there is no monitoring system in place.
Physical: When hydrogen reacts to certain environmental conditions, various physical effects can occur, such as component failures due to low-temperature deterioration of mechanical properties, thermal contraction and hydrogen embrittlement. Hydrogen embrittlement erodes the strength of containment vessels, piping and other components. This process introduces an increased risk of leaks or ruptures, resulting in the risk of mechanical failures that can have an impact on industrial or commercial operations.
Chemical: The primary hazard with hydrogen is it can inadvertently produce a flammable or explosive mixture with air. The gas is flammable and combustible, making it easy to ignite. It also has a lower ignition point than gasoline or natural gas. Because of this, once it is ignited, it can spread rapidly if other gases are present (such as in a petroleum refinery), making it a tremendous hazard for severe fires or explosions.
Many hydrogen leaks are caused by defective seals or gaskets and the misalignment of valves or failures in equipment. While the risks posed by hydrogen leaks can be minimized by the gas’ tendency to disperse quickly across the atmosphere (especially in windy conditions), its risks remain high.
Many of the actual hazards faced when handling hydrogen stem from the fact that the gas is odorless, colorless and tasteless. It is imperceptible to the human senses. Natural gas has a similar composition, but to alert those who work with the gas of leaks, odorants generally are used.
Hydrogen Safely
Even though the properties of hydrogen make it a dangerous gas to transport, store and use, it still offers tremendous advantages for clean energy production and use. But working with hydrogen requires that leak detection sensors, like the Molecular Property Spectrometer (MPS) Flammable Gas sensor from NevadaNano, be used to alert those in the vicinity of a leak.
When high safety standards are implemented, and reliable leak detection systems are in place, hydrogen can be used safely for many commercial and industrial purposes.
The proper detection technology combined with safe handling practices helps manufacturers reduce the threat of a fire or explosion and avoid millions of dollars of costs related to lost productivity, the rebuilding of equipment and the potential loss of life of workers who may have been present. The potential savings resulting from avoiding hydrogen-related disasters is incalculable.
The defense used most often to prevent hydrogen-related catastrophes is hydrogen sensors. Modern hydrogen sensors use several mechanisms to detect the presence and concentration of hydrogen, including gas chromatography, mass spectrometry, catalytic bead and thermal conductivity.
Additional technological breakthroughs also have seen the introduction of palladium-based sensors, which have the advantage of working reliably in low- or no-oxygen environments.
Selecting the best sensor for your environment often means understanding the characteristics of each type – including their limitations – and understanding the environmental conditions where it will be in use. Before selecting a hydrogen sensor or detector, the following parameters should be considered:
n Performance: The optimal performance of hydrogen sensors is best achieved when the most suitable sensor is selected for a specific application. Sensors can be purchased with a wide operating range, optimized sensitivity below the lower flammability limit (LFL) in air, fast response times, continuous operation and for use in wet conditions. Some options can even work in low- or no-oxygen environments. Users should consider what environmental factors may be present when testing to help identify the most suitable sensor.
n Lifetime: To determine current and future application and operating costs, as well as identify replacement and maintenance needs, a suitable lifetime should be identified for any gas detection equipment or systems.
n Reliability: Sensors must have long-term reliability that produces consistent results. It is also good to gain a complete understanding of any testing conditions that can cause false alarms or damage the sensor in a way that will impact its reliability. This knowledge will ensure that users understand the sensors and interpret data correctly.
n Cost: While some lower-end detectors may come with minimal costs, performance, reliability and lifetime value should not be sacrificed. The risk that comes with an unreliable sensor is too great to cut corners. Total cost of ownership must be considered when considering a sensor, because service and replacement costs add up quickly. Reliable gas sensors also can be quite affordable when working with reputable vendors who understand gas detection.
n Multigas accuracy: Legacy sensor technology is only accurate to the one gas they are calibrated to read, and incidental readings of other gases can be misleading.
Increasing Role
Hydrogen will continue to play a vital role in energy production. It also will likely find more uses in a wide range of other industrial and commercial operations. The demand for hydrogen is expected to grow exponentially in the next several decades.
As an environmentally friendly option, hydrogen will be incredibly desirable. However, the safe handling of hydrogen is crucial. It poses a huge risk to those who work with it. And, a hydrogen-related disaster can be devastating for any company.
Prompt leak detection is required to minimize the risk of a small leak becoming a huge hazard. Sensors should be selected based on the environmental conditions present where the leak may occur.
The functional parameters of the sensors also should be taken into consideration, including their performance, lifetime expectancy, reliability and cost. The ability to detect and mitigate leaks is imperative in handling and working with hydrogen, which will be more commonplace in the coming year.
FOOTNOTE:
1Rigas, F. and Amyotte, P. (2013). “Myths and Facts about Hydrogen Hazards.” Chemical Engineering Transactions, 31, 913-918. .
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