From: Christian Weisgerber (naddy@mips.inka.de)
Date: Fri Jan 31 2003 - 17:11:48 MST
<Spudboy100@aol.com> wrote:
> <<The "hydrogen economy" has been promoted for years by environmental
> activists and alternative-energy gurus like Amory Lovins. But hydrogen is not
> a source of energy, something which hydrogen advocates either don't
> understand or refuse to acknowledge.
This throws in the Luddites with those people who *do* understand.
The idea behind hydrogen as an intermediate fuel is to go from a
large number of small poluters to a small number of large poluters
that can be turned into not quite so large poluters or even
non-poluters.
> Since hydrogen does not exist in geological reservoirs it must
> be extracted from fossil-fuel feedstocks or water.
The former. Looking at the followups, everybody here seems to be
thinking electrolysis of water. See below.
> The process of extracting hydrogen uses energy, which means that using
> hydrogen is less efficient that burning fossil fuels.
This does not follow. There is a chain of efficiencies involved
that you need to add up (multiply, actually). The final outcome
is not trivially obvious. A modern fossil fuel power plant is far
closer to the thermodynamic limits than a measly car engine. Economy
of scale comes into play big time here. And besides we are talking
about other processes anyway.
> As a recent energy-technology review in Science magazine pointed
> out last November, "Per unit of heat generated, more CO2 is produced
> by making H2 [hydrogen] from fossil fuel than by burning the fossil
> fuel directly."
You need to quote the conditions and assumptions that went into
that as well.
Here's something you probably want to start looking into:
--------------->
From: schillin@spock.usc.edu (John Schilling)
Newsgroups: rec.arts.sf.science
Subject: Re: Is the fuel cell car going to make it soon?
Date: 31 Jan 2003 12:31:03 -0800
Message-ID: <b1eme7$2rh$1@spock.usc.edu>
derekl1963@yahoo.com (Derek Lyons) writes:
[...]
>Nope. What all the proponents of a hydrogen economy try frantically
>to steer attention away from is the need to generate energy to
>manufacture the hydrogen. And for the foreseeable future, that source
>is oil.
Actually, the source is coal and/or natural gas. You can make hydrogen
from oil, but it's at the bottom of the list of fossil fuels you'd use
for the purpose.
But all of the fossil fuels are way above solar or nuclear electrolysis.
You want hydrogem, you *don't* use electricty, which can be generated
with only mediocre efficiency, to try and strip hydrogen from the most
tightly bound of its common compounds, water. Heat and chemistry work
much better.
[...]
<---------------
-- Christian "naddy" Weisgerber naddy@mips.inka.de
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