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Space/Science » in reply to Yes. And I'm not certain hydrogen can be stored safely at 10,000 psi

re: Yes. And I'm not certain hydrogen can be stored safely at 10,000 psi
Yeti — (archived)

"If a car got in an accident and the hydrogen tank was punctured, there would not have to be a spark to ignite it. It would simply spout a flame, and the next stop for the car would be low-earth orbit."

More to the point, at 10,000+ PSI, you don't need ignition to have a problem. The Kinetic energy alone of that much gas at 10,000 PSI being released through any sort of breach would either be the equivalent of an explosion, or of a rocket motor depending on the size of the breach. Helium storage tanks can take off like rockets tha can punch through concrete walls- and I assure you the volume and pressure is far less than what is uner consideration here.

However: pressure storage tanks are not necessarily needed- hydrogen abortive materials are being researched (google: porous metal-organic framework) that could store large amounts of hydrogen at low pressures and reasonable temperatures.

No, the biggest barriers to hydrogen being a reasonable fuel source are, in my mind:

• Its not free- it takes energy to produce- significantly more than it contains- and hydrogen is only as 'green' as that mode of production
• it requires the 'cracking' of something, and the most efficient something turns out to be hydrocarbon- which makes it just as carbon positive as burning that hydrocarbon, even assuming a zero-emmission energy source
• It requires a global infrastructure that we neither have the technology in place for, nor the means to build- and building such infrastructure will have an obvious environmental impact
• Since hydrogen must be produced as a fuel using electricity (or in the case of pebble-bed reactors, thermal energy that could be used to make eletricity), and since that production consumes more energy than hydrogen contains, it makes more sense to simply use the energy produced itself to 'do work' (IE, power the car, boat or etc) than to produce hydrogen. Especially given the second point above

Our esteemed local 'energy expert' has not and will not answered these points, perhaps you will have better luck with the fellow. For without decisive answers to any and all of these issues, hydrogen seems like a cute toy and not much of an answer to any particular problem

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