Re: Hydrogen cars, et al. A re-evaluation from several different perspectives.

Michael M. Butler (mbutler@comp*
Mon, 17 Nov 1997 01:53:44 -0800

Joe Suber wrote:

> Michael M. Butler wrote about hydrogen and fuel cells:
> > Re: pollution: Yes, and sort of, and no. Depends on what you mean by
> > pollution. Less airborne nitrox compounds, sure. But the carbon and
> > trace elements in the fuel have to go somewhere. And catalyst bed
> > contamination remains a serious problem. Further, as I mentioned before,
> > many "hydrogen economy" plans just move the pollution around, while
> > _increasing_ the sum. Examples: farmed-methanol, central-site
> > electrolysis with hydride storage, etc.
> Doesn't the central-site plan's polution impact depend on how you get the
> electricity to power the electrolysis? Wouldn't certain solar (or even
> nuclear fission) options net a lower total sum of polution? Or are you
> talking about the extra metals and chemicals that are needed to manufacture
> photovoltaics and storage devices? If so, is this a study or just a guess?

Fission isn't exactly popular these days, at least in the US. Yes, I am counting
infrastructure costs, including the cost of disposing of the nasties that
refining solar cell raw materials produces. Cost out a solar panel, cost out
tracking gear, figure out what that 1kW/M^2 turns out to in real life, then talk
to people who have tried it. Solar keeps beckoning, and the stage-to-stage
efficiencies keep killing you. For specialty applications, or if you're
well-off, solar is useful, especially compared with 9-volt 2U6 transistor radio
batteries. But the ROI is slim slim slim. Today.

I made earlier comments in a post some time ago. It's hard to beat the energy
stored by all those plants collecting all that light long ago, then squooshed
and heated by the Earth since the Carboniferous. Neither a study nor a guess, I
priced the components and talked to experienced people (including Don
Lancaster). Maybe someday the costs will go down. As I said, I believe that's
unlikely in the short (predictable) term. Now, if you count hydro as solar
(something has to evaporate all that ocean water to make the precipitation that
fills the reservoirs)... we're already using solar.

Re: alternative energy: If you nose around, you might find some
relevant stuff.

> I am under the impression that hydrogen gas could be distributed on the same
> kinds of pipelines in use for natural gas today. I also have read that
> hydrogen has an energy density 3 times that of gasolene, by mass (not by
> normal volume, of course). Good enough that a strong liquid hydrogen tank
> could give you gasolene-like range (even given internal combustion
> efficiency) while venting less than 10% of its hydrogen storage per day to
> keep the contents cool.

Hydrogen is *cold* in liquid form. And have you ever heard of "hydrogen
embrittlement"? Many things are possible. Their being possible doesn't make them

> > Now, hypothetical complex-organic fuel cell catalysts (verging on
> > enzymes in complexity) *might* solve these problems. I devoutly wish
> > for them. But evidence of their actual commercial-quantity appearance
> > remains sketchy at the present time--even though I built a
> > bacteria-powered fuel cell twenty years ago. IMHO, bulk nano is the most
> > likely way to produce such--by which time _everything else changes too_.
> What is the differences/advantages between engineered bacteria and "bulk
> nano?" Also, could you tell us more about the bacteria-powered fuel cell?

Well, they do blur together, rather, and I spoke loosely. I think it's possible
that something bacterial could be developed that might be able to crank out the
needed catalyst(s) in tank-car lots. Bulk nano, as I use the term, means
building dumb structures (say of not much more complexity than modern
composites; stupider than a living tree) at a very high rate. The difference as
I envision it is that bulk nano might be able to extrude entire fuel cell
elements in one step. I envision slightly more advanced bulk-like nano as being
able to provide mechanisms for recovering the stuff that usually contaminates
fuel cell electrodes (Sulfur, for one).

To a first approximation, "Bulk Nano"=="no information processing required".
This still makes bulk nano potentially more versatile than bacteria.

Re: bacterial battery: Nope, I purged that info out of my memory banks. I am
pretty sure it's still floating around as a science fair project. I'll see what
I can dig up.

> > AFAIK, all published fuel cell chemistries that use hydrocarbons
> > function in exactly the way I describe, by reforming the fuel at point
> > of use: the fuel cell. Methanol is expensive for reasons mentioned
> > previously. The issue isn't purely one of how efficent the _fuel cell_
> > is; it's a _systems_ concern.
> If we are going to have fossil-fuels at the point-of-use, then we might as
> well use internal combustion


> you can fart and roll down your window and do more damage
> than the new car you are driving.

Heh. Care to guess what the amount of fuel vapor you (anyone, not picking on you
specifically) release when you vent your tank to fill up corresponds to in
"dirty" miles driven? It's remarkable.

That said, I drive an '85 beater. I think we're in violent agreement here.

> My first post to this great mailing list!
> -Joe Suber

Best wishes!


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