Re: Hydrogen heroes

On Mon, 24 Jul 2006 19:13:12 GMT, Dan Bloomquist
<public21@xxxxxxxxxxx> wrote:



Josh Hill wrote:

On Mon, 24 Jul 2006 15:25:52 GMT, Dan Bloomquist
<public21@xxxxxxxxxxx> wrote:

Josh Hill wrote:

On Sun, 23 Jul 2006 22:59:34 -0700, "AKA Gray Asphalt"
<goodidea1950@xxxxxxxxxxxxxxxx> wrote:

I'm not far along enough to have numbers. Why don't you provide some? I'm
still wondering why so many people say that hydrogen is a dangerous item to
transport and store and at the same time other people are saying that it is
nor more dangerous than gasoline. I could use some numbers.


Suggest you do a search on hydrogen + safety: there are some
informative reports online. The consensus among those who have
actually studied the issue seems to be that, on balance, hydrogen is
no more hazardous than gasoline.

What is the point of this if you don't have a source of hydrogen.

One or another of wind, fission, syngas, and biofuels...

You have talked past the issue of displacing coal and the economic
implications before. I'm sure you will continue.

This wasn't a discussion of coal, but of gasoline. I doubt very much
that hydrogen will replace coal, although it may have a role in power
generation at remote locations and peak storage.

If, OTOH, you're interested in the cost of hydrogen from various
sources as it compares to gasoline, you'll find an interesting table
here:

http://darwin.nap.edu/books/0309091632/html/51.html

Note that when made from natural gas and coal, hydrogen is projected
to cost about the same on a mileage equivalent as gasoline, even with
sequestration, but that it is projected to cost significantly more
when made from biofuels and wind

If we had been talking about displacing coal in power generation, I
would have referred you to the table I posted of power costs from
various sources, including coal, natural gas, nuclear power, and wind
at up to 20% penetration. I would also have have pointed you to the
MIT study's estimate of the current cost of electricity from fusion --
again, I have posted the URL here. Of course, when extrinsic costs are
taken into account, the actual costs of burning this filthy fuel are
higher, as are the actual costs of nuclear generation. One doesn't
have to be a whiz, though, to see that the effect on our economy of
replacing coal with cleaner sources would be trivial. For one thing,
there is the example of France, which has generated most of its
electricity from nuclear power for years and had a GDP per capita of $
27,700 in 2003, essentially the same as that of its European
neighbors:

http://www.worldfactsandfigures.com/gdp_country_desc.php

The real questions, I think, are whether the next government will be
honest enough to do what's best for the country and the world rather
than what's best for its campaign contributors, and, from my
perspective, whether it would be technically and economically feasible
to use renewables at close to 100% penetration, or at least as close
as we need to before fusion comes on line. Assuming, of course, that
sequestration proves impractical.

At that, have you ever been near a fuel air explosion?

http://www.chem.agilent.com/cag/servsup/psnews/h2safety.html

In practice, though, it's apparently very difficult to make hydrogen
explode in open air, since being lighter than air it dissipates
rapidly...

In addition to what Graham wrote.

I've thrown matches into my burn barrel with gas fumes oozing about and
don't have a problem with it. The wave front at atmospheric pressure is
never more than a whoosh.

Do the same with just two or three cubic feet of hydrogen air, 'at your
own risk!' Personally, I wouldn't have anything to do with filling a
test bag except remotely. (that's got to hurt)

My eighth grade science teacher did the same with a smaller quantity
of hydrogen in a beaker: made a thump. Conversely, a fellow blew up a
townhouse in New York City last week with natural gas. Russian
partisans needed only gasoline, a bottle, and a rag to blow up tanks.
And it seems that there were 129 grain dust explosions in the United
States between 1987 and 1997, half of them involving corn.

Which is to say that this all seems to me nothing more than anecdote:
most fuels have a risk factor, even logs, which can catch fire or fall
on your foot. What does matter is what happens in the real world with
real world safety precautions. As far as I know, when that's the case,
you're no likelier to die in a car accident involving hydrogen than
one involving gasoline, which is stored in a more fragile tank,
ignites at a lower temperature, and forms a puddle and a vapor cloud.

--
Josh

[Truly] I say to you, [...] angel [...] power will be able to see that [...]
these to whom [...] holy generations [...]. After Jesus said this, he departed.

- The Gospel of Judas
.

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