Re: hydrogen powered planes

From:         drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard)
Organization: The Boeing Company
Date:         29 Nov 95 01:36:16 
References:   1 2 3
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In article <airliners.1995.1845@ohare.Chicago.COM>,
Christian F. Goetze <c-goetze@u-aizu.ac.jp> wrote:
>In article <airliners.1995.1818@ohare.Chicago.COM> shevell@leland.stanford.edu (Richard Shevell) writes:
>
>> Hydrogen is a non-starter for aircraft.
>
>> It takes more fossil energy to produce the liquid hydrogen required for
>> aircraft than  it does to just burn the fossil fuel in the aircraft
>> turbines. So it does not save fossil fuel.
>
>Who was talking about using fossil fuel to generate hydrogen? How
>about solar energy?

Fossil fuels are used to manufacture solar cells.  Last time I checked
on that technology, 1988 or so, it still took more fossil fuel energy
to manufacture a solar cell, than a solar cell would generate over its
expected economic life.  I rather hope things have improved some in the
last eight years, but I wouldn't bet the mortgage on it.

>> [argument relying on the use of fossil fuel and nuclear energy deleted]
>
>> If you want to use the hydrogen floating in the oceans, one can grasp the
>> difficulty of extracting it by thinking of water as rusted hydrogen. ( a
>> thought I learned from an unknown Princeton physics professor about 20
>> years ago)
>
>Nice analogy, but irrelevant. The point is that you produce the
>hydrogen where solar energy is abundant (e.g. north africa) and then
>transport it to wherever you need it - just the same way as oil is
>being shipped around the world.

There are major safety concerns with that plan.  There is not a single port
in the entire world that would let a tanker filled with hydrogen dock
anywhere near them.  Gasoline tankers give ports the willies, and you are
proposing putting a *far* more flammible gas in their facilities.  Good
luck.

>I don't deny that there are technical difficulties involved, but
>simply dismissing hydrogen in a knee-jerk response is definitly not
>going to solve the very real problem of global warming and fossil fuel
>depletion.

No one is dismissing hydrogen as a knee-jerk response.  There are a lot
of very talented, and very well informed engineers who have studied this
possibility, and it just doesn't stack up against fossil fuels.  So, unless
something major changes in the near future, don't expect to see any
hydrogen powered aircraft.

>I maintain that the reasons why this isn't happening yet are mostly
>political.

There are two major reasons why nothing major is being done.  Economics and
airplane performance.  If it were merely political, your whining would have
some hope of eventually succeeding.  As it is, there is no pressing
economic argument to change fuels.  The cost of developing a totally
separate fuel infrastructure, one for hydrogen, is staggering.  The cost,
quite literally, would be in the hundreds of billions of dollars.  At that,
we'd be getting off cheap just doing the jet transports, which by the way,
contribute less than 5% of all your global warming gases, IIRC.

The lower energy density of gaseous hydrogen fuel has a severe effect on
airplane range.  The weight penalty for insulation to handle the liquid
hydrogen fuel would have much the same effect.  Or did you have in mind
something like metallic hydrogen?  Not that anyone knows how to store,
ship, or handle metallic hydrogen fuel.  And we haven't even brought up
design standards or the test data to back them up.

Jet fuel in the United States runs less than $0.60 per US gallon.  What
would your hydrogen fuel cost?  Who will pay for it?  Who will pay for and
maintain hydrogen fuel tanks at airports all around the world?  What about
turboprops?  Do they have to use hydrogen fuel, too?

In closing, I'd like to say that moving to a hydrogen fuel *someday* sounds
like a promising idea.  However, the technology is not here yet.  Moreover,
there needs to be some pressing need to develop the technology, and there
isn't one.

Terry
--
Terry
drinkard@bcstec.ca.boeing.com
"Anyone who thinks they can hold the company responsible for what I say has
more lawyers than sense."