Text 34326, 126 rader
Skriven 2009-07-07 09:09:28 av Robert Bashe (2:2448/44)
  Kommentar till text 34314 av Roy Witt (1:397/22)
Ärende: Hydrogen
================
Roy Witt wrote to Robert Bashe on Monday July 06 2009 at 12:05:

RW> "Car and Driver.com

Instead of quoting pages of text, it would make things easier to just quote the
essence. But in this case there was no "essence" except:

RW> What happens if you crash it?

RW> They never said anything about that...

I'll just bet ;-)

RW>>> If the tank springs a leak, the gas harmlessly dissapates into the
RW>>> air. Unless there's a means to ignite it, which is taken care of by
RW>>> laws that keep propane and now hydrogen containers free from damage.

RB>> Except for the fact that hydrogen has a different explosion range
RB>> than propane, escapes more easily because of the smaller atomic size,
RB>> dissipates differently and also has a different ignition point.

RW> And the people who know these things are also the people who build the
RW> systems.

And another page-long quote with the essence:

RW> Training Required

...with regard to fueling the car with hydrogen...

RW> A Multi-Step Process

...with regard to convenience...

RW> All of this sounds complicated, but in practice, it only requires one
RW> extra step-connecting the communicator-compared with filling up a car
RW> with gas or diesel. Once we became familiar with it, the process wound
RW> up taking maybe 30 seconds longer than inserting a credit card,

... for people who use computers on a day-to-day basis and are familiar with
technical things...

RW> Now, at this point, just how long you get to sit back and relax after
RW> connecting everything depends on a few things: how much pressure the
RW> vehicle's tank is designed to handle-the Equinox's can handle up to
RW> 10,000 psi, and the FCX Clarity's takes 5000 psi-and the type of pump
RW> you've pulled up to.

...which only confirms the pressures I mentioned...

RW> At this point, refueling can take anywhere between five minutes and an
RW> eternity.

...which is naturally an "advantage" to the normal driver...

RW> Sadly, in our test car, we watched the distance-to-empty readout in
RW> the gauge cluster plummet faster than GM's recent stock prices when we
RW> climbed hills or suffered through L.A.'s infamous traffic jams.

...demonstrating how "practical" such things are even in short-run, big city
environments...

RW> Unlike gas, hydrogen for fuel-cell purposes might not have to be
RW> shipped or trucked in but rather is captured and packaged on site,
RW> extracted from the station's supply of water (as is the case with the
RW> West L.A. station) or from natural gas.

...Layman's language for cracking, electrolysis or reforming...

RW> The equipment required for this, of course, is not cheap for station
RW> owners, with costs ranging between $500,000 and $5,000,000 per
RW> installation.

...which is the _real_ nitty-gritty... who pays? ...

RW> But beyond these initial efforts, many of which are the result of
RW> local government initiatives (read "heavily subsidized"), we don't
RW> expect the hydrogen infrastructure to spread much farther, at least
RW> not until fuel-cell vehicles themselves become available in
RW> significant numbers and a market price for hydrogen is established.

...oh, yes: "heavily subsidized"...

RW>>> There's no liquid hydrogen storage involved in this program, yet.

RB>> The information I found was different, but I'll take your word for
RB>> that.

RW> You don't have to. If you've read the above article, you already know
RW> that the Shell station I mentioned and the one in the article are one
RW> and the same...

... do I? Sorry, Roy, I'm still not a mindreader, but thanks for the
information.

RW> ... and is producing hydrogen gas on the spot and not a liquid.

Presumably by electrolysis, compressing it and then waiting for a customer, as
I already mentioned. Not by any means the "generate as you wait" operation you
described, and not just "snapping your fingers" at a glass of water, which
proceeds to dissolve into Hydrogen and oxygen.

RW>>> Yeup...living in the dark ages alright.

RB>> OK, then you tell me what you're thinking of, since this was the
RB>> alternative mentioned to tanks of hydrogen on site. If you have some
RB>> "secret", out with it or stop the hinting without anything to back it
RB>> up.

RW> See above.

Nothing there except for laymen's descriptions of cracking, electrolysis and
reforming. Nothing new for me, maybe for you.

Roy, I accept your enthusiasm, but don't get carried away. The generation,
transportation and storage problems are real and won't disappear by just
wishing - and there is still the safety question, which I would consider a
major factor once these vehicles are common enough (if that ever is the case)
to be involved in crashes like the "Unsafe at Any Speed" Corvair. Maybe you
aren't worried, but I don't want to be in a vehicle with a hydrogen tank under
700 bar pressure when some SUV rams it from behind.

Cheers, Bob

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