(Alan) wrote in
:

In article Bertie the
Bunyip writes:
"Mike Isaksen" wrote in
news:KRwKj.1375$XC1.1247 @trndny08:


"Alan" wrote ...
Bertie the Bunyip writes:
I will fly as long as there is air. Gasoline be damned.
I started without it and I'll finish withour if needs be.

You say you started without - how?
Even gliders seem to need tows.

Maybe he'll build an electric motor rope launch skid powered by wind
turbines.



Could do. There's lots of ways you can winch launch. The current world
record distance flight was launched off the back of a car. Probably a
thirty second tow, if that.

I doubt that this was an electric car charged from solar or wind
power,
was it? I'll bet it burned gasoline (or perhaps diesel fuel).

Point is, there's a million ways to skin a cat. If neceesity dictated,
a way would be found.

And your answer is?

Unless you have a better answer, I suggest folks start building
nuclear
power plants, and looking hard at extracting carbon from the
atmosphere to combine with hydrogen from water to produce various
petroleum fuels. We are not prepared to deal with hydrogen -- I can
just imagine the news stories about the result of accidents at
hydrogen fueling stations.


BTW, hydrogen is no real problem in regards to that. It can be used
safely in surface transport and fuelled safely as well. The real problem
with it is making it.
It's not so good for airplanes. You have three storage options, one, as
a straight gas inside a cylinder, which is not such a good idea for a
lot of reasons. The volume required, even at a relatively high pressure,
to give you any sort of range, would be ferocious. A second option is to
carry it as a liquid, which requires extremely low temps. Fine for a
once off use, but once you leave your contraption parked for any length
of time the H2 is going to want to get out once it warms up a bit.
NASA was flying a Musketeer about thirty years ago with a liquid
hydrogen setup. It had thermos bottle fuel tanks that NASA said could
keep a cup of coffee hot for ten years, but even this approach is
fraught with problems. The Russians were flying a jet airliner on H2 as
an experiment in the 70's as well and the first succesful jet engine run
by von Ohain in the thirties was run on H2.The russians needed most of
the fuselage volume to carry the fuel. Not a great commercial idea.
Also, the DC-10 was actually designed with possible conversion to H2 in
mind. It would have required fuselage plugs to install fuel tanks in a
stretched fuselage as the volume available in the wings would not have
been sufficient. Note that the energy value by weight is considerably
better for hydrogen, so you'd go further for a given fuel weight penalty
in an airplane as opposed hydrocafbon fuels. Bit scary to have two big
fuselage tanks filled with the stuff as a loose gas, though. Having said
that you're sitting on a lot of high explosive in the center tank on an
airliner anyway.
The third option is to have fuel tanks filled with a metal hydride. This
allows a good deal of hydrogen to be carried at a low pressure and if
the tank ruptures the only fire would be at the hydride surface. This
third option is much less of a risk than carrying gasoline. Much much
less. But the tanks are extremely heavy. A tank to carry enough fuel to
propel a family sized car an equivelant distance to 15 gallon fuel tank
would weigh in the region of 300-400 lbs. Less for a good fuel cell
powered car.It's clearly not a runner for an airplane.
Still, it's an option I would go for now for my car if the H2 was made
in a friendly manner. There are people doing this at home, BTW, using
solar and/or wind. It's expensive to gear up for it. Very expensive. But
it can be done and it would be cheaper were it done on a larger scale
and with metal hydride tanks it's very safe. If you want, you can do
this right now. Today. Converting an IC car to hydrogen is not difficult
and the stuff to do it is freely available. The new Morgan sports car is
available as a dual fuel car. And there is a fuel cell powered
motorcycle for sale as well, the "NV". It's a kind of a trail bike.
Neither is cheap, but again, neither is that much more expensive than a
standard issue contraption
There are already many countries using LPG for fuel. The refueling
challenges are exactly the same and it's being done safely, so that's no
excuse either... In any case look at the death and destruction on the
roads we count as acceptable in our love affair with the car. Do you
think a handful of refuelling explosions would stop people if it were
the only way? Thankfully that's not an issue anyway.
The only real problem with hydrogen for surface use is the clean
manufacture of it and that is a big problem. It's a plentiful resource
only if you can extract it from water without using something dirty and
nasty to do so.



Bertie