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by Derek Green on Wed, Apr 24, 2024 @ 06:04 AM
Hydrogen, being nontoxic and less volatile, can pose fewer hazards than conventional fuels. In this article we look at relative vapor density, oxygen concentrations, and autoignition temps; offer a new infographic; and invite you to download details on our hydrogen-specific products and services.
There is a common misperception that hydrogen gas storage is inherently riskier than storage of oil or gasoline. But when handled and maintained properly, pressurized gas storage is safe. Let's look at three factors to consider:
1. Relative vapor density
Hydrogen, being 14 times lighter than air and 57 times lighter than gasoline vapor, disperses quickly into the atmosphere when leaked. This rapid dispersion reduces the risk of localized explosive concentrations forming, making immediate ignition less likely compared to heavier gases that linger near their leakage points. On the other hand, its low density allows hydrogen to spread over a larger area, potentially reaching ignition sources far from the leak's origin.
Safely storing hydrogen requires understanding its tendency to rise and accumulate in enclosed spaces, risking explosive mixtures without adequate ventilation. Conversely, gasoline vapor, being heavier than air, pools at ground level, creating different hazards that need containment to avoid accumulation. Designing storage facilities thus demands a thorough grasp of these gases' behaviors to customize ventilation, leak detection, and containment strategies to their specific properties.
2. Oxygen concentrations
Hydrogen disperses quickly when leaked due to its low density, significantly reducing the risk of accidental ignition and explosion compared to gasoline. This rapid dispersion minimizes the formation of explosive concentrations near the leak source, unlike gasoline vapor, which, being heavier than air, accumulates at ground level, increasing the risk of ignition. The inherent property of hydrogen to quickly mix with air and dilute reduces the likelihood of localized flammable conditions, making it inherently safer in the context of leak scenarios.
3. Autoignition temperatures
Gasoline has an autoignition temperature of 536°F, significantly lower than hydrogen's 995°F. This higher autoignition threshold makes hydrogen storage inherently safer, as hydrogen requires much higher temperatures to ignite spontaneously compared to gasoline.
Hydrogen's higher autoignition temperature reduces the likelihood of accidental ignitions in scenarios where external heat sources might be present, offering an additional safety margin in the storage and handling of hydrogen.
Members of the public may view hydrogen gas leaks as more dangerous than conventional fossil fuel leaks due to hydrogen's association with high-profile accidents and its characteristics like flammability and invisibility when burning. This perception doesn't square with the extensive safety measures and technological advancements that have been developed to mitigate risks, along with hydrogen's successful safety record in industrial applications.
Hydrogen myths infographic (click image for full size)
Learn more and download resources
View our website page about products and services for the hydrogen industry. It covers hydrogen-compatible Swagelok products, fluid system assemblies for hydrogen applications, and advice we can offer on fluids issues in electrolyzers, micro-grids, fuel cells, virtual pipelines, and more.
