Is Hydrogen Safe?
Is hydrogen safe? Well, I would say so. But, let me explain.
Hydrogen is a fuel, which means that it's an energy carrier. Many argue that hydrogen is the safest fuel out there. Let me explain why they say that. When we talk about a petrol car, then when there is a leak on the fuel system of a petrol car, let's say on the fuel tank, then there is going to be petrol leaking out of the car onto the concrete. That fuel is going to be there for a relatively long period of time, which means that the energy, the danger, the fuel is going to be there waiting for an ignition source to blow it up.
On the contrary, when we look at a hydrogen car, if there is a fuel leak on the hydrogen car, the fuel is going to dissipate into the atmosphere, because hydrogen is so much lighter than air. In fact, hydrogen is even lighter than helium. That will mean the hydrogen will just rise up very rapidly into the air. It will dissipate, it will go below the lower explosive limit (LEL) of hydrogen. And that means that danger is no longer there. So there is no such thing as a safe fuel. However, hydrogen does take quite a lot of the boxes for being a relatively safe fuel. Now, when we talk about hydrogen, there is quite a lot of other properties that we must take into account to design safe hydrogen systems. These include:
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Flammable range of hydrogen
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Lower Explosive Limit (LEL) and the Upper Explosive Limit (UEL)
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Hydrogen embrittlement
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Gas transfer properties of hydrogen
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Very low ignition energy
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Invisible flame.
There is no such thing as a safe fuel. However, we must ensure that our design engineers, process engineers, validation engineers, test technicians, commissioning technicians, and engineers, are up to speed and have been fully trained on hydrogen safety and the hydrogen properties to ensure that we go into a safe energy, transition into the future.