4 ms·

More than a gasoline bomb, hopefully. Gasoline is more dangerous.

• baybal2 5y ago
  Few kg of hydrogen are surely more dangerous than 50 kg of gasoline.
  • MayeulC 5y ago
    120 MJ/kg for H2 vs 46 MJ/kg for gasoline. Both are explosive, so I think (I'm no authority on this) we can compare those values directly, without taking into account the storage pressure. Source: https://hypertextbook.com/facts/2005/MichelleFung.shtml https://hypertextbook.com/facts/2005/MichelleFung.shtml https://hypertextbook.com/facts/2003/ArthurGolnik.shtml https://hypertextbook.com/facts/2003/ArthurGolnik.shtml
    • jandrese 5y ago
      Gasoline will not explode in normal conditions. Even in an accident it is pretty safe, although the risk of fire must always be considered. A 10k PSI H2 tank is a straight up bomb. A gasoline tank can start a nasty fire but nobody is going to be torn apart by shrapnel or killed by the overpressure wave in an accident. Gasoline cars don't explode like they do in the movies. It must also be noted that the large batteries in EVs are also a fire hazard and in some ways worse than gasoline. For gasoline to act like a bomb it has to be aerosolized first and then ignited. In an accident there's not much that could achieve that. With a high pressure H2 tank something that cracked it open and allowed all of the H2 to be released at once would instantly create the conditions for a massive explosion. All it would need is a single spark.
  • jacquesm 5y ago
    The total amount isn't as much a problem as is the activation energy. Hydrogen will explode when you look at it cross eyed. For gasoline you will have to do some work.
    • goodpoint 5y ago
      Hydrogen does not explode unless mixed with oxygen or other comburents.
      • jacquesm 5y ago
        Fortunately there isn't any free oxygen in the atmosphere. Oh, wait.
        • goodpoint 5y ago
          Fortunately the atmosphere is not inside the hydrogen tank. That's why it can flame out when pierced but not explode.
• adrianN 5y ago
  I'm relatively sure that a tank of hydrogen at ridiculous pressure makes a nicer fireball than a tank of gas at no pressure.
  • goodpoint 5y ago
    No: it's a myth that a hydrogen tank simply explodes. It would need to be mixed with oxygen. Instead, liquid flammables can leak around and then ignite. https://www.computerworld.com/article/2852323/heres-why-hydrogen-fueled-cars-arent-little-hindenburgs.html https://www.computerworld.com/article/2852323/heres-why-hydr... https://hydrogen.wsu.edu/2017/03/17/so-just-how-dangerous-is-hydrogen-fuel/ https://hydrogen.wsu.edu/2017/03/17/so-just-how-dangerous-is...
• hydrogtehd 5y ago
  No, it isn’t. Gasoline is dangerous, but it’s a liquid. H2 is a gas, under extreme pressure, and with a very low spark energy. The spark (ignition) energy is very important safety wise. Nothing will light without an ignition source. In fact hydrogen is more dangerous wrt to gasoline than gasoline is wrt to flour (yes, flour can explode). That is: Flour:gasoline < gasoline:hydrogen Hydrogen is dangerous. And that’s fine. [1] http://www.explosionsolutions.co.uk/110411020.pdf http://www.explosionsolutions.co.uk/110411020.pdf