Re: More hot hydrogen

[AJH <andrew.heggie@dtn.ntl.com>]

On Thu, 4 Jul 2002 18:03:22 -0600, "Ron Larson"
<ronallarson@qwest.net> wrote:

>(RWL):  Can you describe the general approach to your friend's hydrogen
>production?  I have several friends who have studied the hydrogen/engiine
>approach and have come away convinced that it is not cost effective to
>obtain one's hydrogen from methane .  The efficiency of that conversion is
>not good enough to compare even with fuel cell propulsion (but possibly
>justified for other reasons - such as 1) reducing emissions locally and 2)
>getting a hydrogen economy started that would be based on renewables at a
>later date.)  

If you wish to reduce local emissions then fuel cell or battery
electric cars will do so readily if the electricity is from a
thermonuclear plant. This is about the only route I see to producing
hydrogen as an energy carrier from an electric source. The
thermonuclear plant has great advantages in scaling and need for
constant loads, off peak usage for separating hydrogen will suit this
system. It's going to happen if the society indemnifies the operators
for their future decommissioning costs, it seems unlikely the private
insurance market will enter into this after recent scares. Even if
economic it will overall be a low return on the heat from fission.

I cannot see electrolysis of water (<50% conversion from the high
utility electricity) to hydrogen (a lower utility fuel with limits of
conversion back to electricity of ~75% by fuel cell and <60% by
thermal means), which has high storage and pumping costs, from an
unscheduled renewable source (wave, pv or wind) can possibly happen
until the renewable electricity source reaches the magic 20% limit for
unscheduled supplies. What is Non-Canadian North America's current
supply from these sources, as a percentage?

> They are not opposed to hydrogen in IC engines if the
>hydrogen is generated economically from electrolysis (wind?), biomass, etc.
>
I think Tom has pointed out, electrolysis may make hydrogen of high
quality, necessary to prevent contamination of fuel cell membranes to
give an operating life of the, typically, present few hundred hours
but it is wasteful to do so. Thermal systems co generating electricity
and hydrogen are inherently more efficient. IMO, with existing grids
for natural gas and electricity, biomass will make better sense in
local reformation to a local grid system, methane in this case would
be a better carrier, reformed from syngas. I guess it may be worth
starting to think about after we deplete coal reserves, maybe 2100?

>(RWL):  Can you give us his name?  Still interested in batteries?  A South
>African?  Does he still feel that zinc-air is best (compared to Lithium-ion,
>etc)?  Incidentally, I have been driving a Honda Insight hybrid for about 18
>months (60 mpg - almost 100 km/g - or about 25 km per liter) and can endorse
>it as a likely strong contender to be the approach of choice for most
>vehicles.  I wonder if your friend would agree that hybrids look appropriate
>in his approach (Amory Lovins does).

I envy your choice of car, I think it is a good first step but the
battery system is costly per Whr recovered and it is only recovering
fossil fueled motion, there is no option to charge and then boot the
motion up from a renewable source, though of course you could run it
on ethanol.

In fact the modern direct injection diesels offer better overall
performance unless there is a local zero emission 

>> Crispin the eye witness
>>
>(RWL):  What aspect of this energy train is he most working on now?
>
>    In the US much of the hydrogen emphasis is on fuel cells.  I am told
>that we are trying to catch up with good fuel cell progress in Europe and
>Japan.

We have a fuel cell running our local swimming baths, it is overhyped
and there are questions about its useful life.
>
>    On both the supply and applications side, the national hydrogen R&D
>headquarters is at the National Renwable Energy Laboratory (NREL), where Tom
>and I both worked (but well before they had started much Hydrogen work).  A
>furor is growing within the US RE community, because it appears that our US
>national emphasis is in the process to shifting to the natural gas, coal,
>and nuclear industries. 

One thing about your current administration is that they can plainly
see the writing on the wall and have already decided what they will
do.

> If your friend has something very new that can be
>reported (especially on renewables), I have friends who can help get a
>hearing.
>
>    Lastly, to bring this into the world of "stoves", there is little doubt
>that hydrogen would be a perfect household cooking fuel - if it could be
>supplied and stored cheaply.  I know of no-one making that claim now.
>
>    In the last two weeks, I have heard Amory Lovins give two talks on his
>"Hypercar" (hydrogen-fuel cell) approach.  An engineer who has worked on the
>project said the project has still not been picked up by any major auto
>firm - as they do not yet have a low enough means of producing and using the
>carbon fiber technology needed to get a low-weight, strong car body that
>will allow a smaller fuel cell and therefore a small enough on-board storage
>system. 

I think they are looking at the carbon fibres to store the fuel as
well. They consider that fullerine nanotube technology will enable
hydrogen storage in ultra high pressure, lightweight vessels. I will
use this when I settle on Mars for my retirement ;^).

There is a forthcoming conference by the carbon group where there is,
reputedly, to be a  discussion paper on nanotube fuel storage, I can
find details and expect it is UK.

> Any list member knowledgeable on carbon fiber production? 

A bit from gossip with someone I know quite well in the field ;-).

> (a nice
>place to use carbon from carbon-making stoves?) 

No

> Apparently now the carbon
>fibers are mostly coming from the sludge at the end of the diesel fuel
>production process.

Pitch? This has been used to form self lubricating pistons for use in
ceramic bores also.

The source for carbon fibres became polyacrylonitrile. This was
pyrolysed under tension between reels either side of the carboniser, I
imagine it was easier to knock out the nitrogen bonds than the C=>O
ones without disrupting the carbon chain.

AJH

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