Re: Remember "Bit-Slice" Chips ?

D <nospam@example.net> wrote:

 
 
On Sun, 8 Dec 2024, Rich wrote:
 

D <nospam@example.net> wrote:

>
What about storing it as water, and producing it close to where cars need
to be fueled up? I assume it would be very inefficient and probably
difficult, or else someone would already have done it. But I do not know
any specifics, so just genuinely curious.

>
Hydrogen can be stored very safely as water.  The earth's covered in a
significant amount of "water stored hydrogen". :)
>
The tricky part is you have to put in a rather significant amount of
energy to convince it (the hydrogen) to let go of it's grip with the
oxygen atoms that make up the water.
>
And once you create it, and pump it into the car's pressure tank
(you'll need a pressure vessel unless the car has a cryo-cooler on
board, and the energy expended by the cryo-cooler would dwarf the
energy needed to propel the car), you are right back to the
'embrittlement' problem again.
>
And consider the explosive force stored in a 350-700 bar (your
AI's number) pressure vessel that becomes brittle enough to go "bang".
That's one hell of a bang, even without the hydrogen itself explosively
combusting as part of the pressure release.
>
Plus, the walls of the pressure vessel quite effectively become a
'fragmentation grenade' in the process of going bang.

 
But how is this solved in existing hydrogen cars?

I have no idea.

Hydrogen cars exist, so surely they must have some way to at least
mitigate this problem?

Do they really?  On more than a 'lab experiment' model?

As for converting hydrogen "on site" I can imagine two limiting factors.
 
1. The speed of conversion. Can you convert hydrogen on site, fast enough,
to fill up a car in 5-10 minutes?

That would likely require some major power input for the "splitting up" of
water molecules on site.  Likely somewhere on the order of existing
electric car "super chargers" -- or perhaps even more.

and
 
2. The cost of converting water to hydrogen in a smaller setup, vs doing
it somewhere central and shipping it.

You can convert water to hydrogen using just a battery, some wire, and
some containers.  It is (or at least was) a common physics experiment
in high school physics class.

Now, doing so, even on a small scale, in a volume sufficient to fuel a
hydrogen powered car, well that's a whole level more complex than the
physics experiment demonstration.  That is if you want your "hydrogen
generator" to be reasonably safe for the "average joe" to use and
reasonably long lived.  Not the least of which the compressor to
achieve 450-700 bar (your AI's numbers again) worth of compression to
fuel the car will be a somewhat expensive component, and every "unit"
will need one unless the car comes with its own built in pressure boost
unit.