3 ms·
My understanding is that Hydrogen has energy-density problems as a fuel source. To have enough energy density to be useful for a vehicle, you need to keep it li
by philip1209 4y ago
My understanding is that Hydrogen has energy-density problems as a fuel source. To have enough energy density to be useful for a vehicle, you need to keep it liquid. To keep it liquid, you need to refrigerate it - which takes energy.
So, I think the innovation in hydrogen is asymptotically limited by the physics of the H2 molecule.
- bell-cot 4y agoThe required (& wasted) energy - both for the initial liquefaction, and to keep it liquid - are only the beginnings of the pain of dealing with LH. For starters: hydrogen boils at -250C, vs. oxygen at -180C. So a lowish-pressure tank of LH can naturally "condense" liquid oxygen (and nitrogen) from the atmosphere if there are flaws in the tank's insulation. ...and the rule of thumb is that one charcoal briquette soaked in liquid oxygen has roughly the explosive power of one stick of dynamite. (Unlike dynamite, the LOX-soaked briquette can detonate with neither apparent cause nor warning. And this effect is hardly unique to charcoal briquettes. Anything porous and combustible will do.)
- Sohcahtoa82 4y agoYup. BMW made a liquid hydrogen-powered car and the result is...not good. Nothing more than publicity stunt. https://www.youtube.com/watch?v=AouW9_jyZck https://www.youtube.com/watch?v=AouW9_jyZck The TL;DW is that since you can't keep it cold enough, eventually the liquid starts to convert to gas, pressure builds up in the tank, and a vent is needed to allow the hydrogen gas to escape. Which then poses a problem, since hydrogen gas is VERY explosive, you can't keep this car in your garage. You have to keep it outside. Then of course there's the issue of this comically large tank taking up the enter back of the car.