Our New Hydrogen Bomb

The New York Times ^ | February 21, 2003 | NICHOLAS D. KRISTOF

[Brian Allen]

<< That is the kind of energy source that only a government could love. >>

A gummint, that is -- and its subsidised to way past the eyeballs corn-growing New Welfare Rich -- the "American" farmer.

[MainFrame65]

Gasoline is highly flammable, but not explosive. Gasoline VAPOR is explosive IN AIR, within a particular range of mixture, but it has to be pretty warm to reach a sufficient vapor pressure. I don't know the numbers, but lets guess it is something like 15 to 30 percent. Hydrogen is ONLY a gas at conceivable temperatures and pressures, so it will always mix with air. But Hydrogen mixed with air is explosive over a much wider range of mixture - perhaps 10 to 70 percent. (No, I don't have real numbers)

As far as a tank exploding, a filled, sealed gas tank will not - no Oxygen. Same for a tank of Hydrogen, at ambient pressure. But as the gas tank empties, the air above it forms a mixture that is almost certainly explosive, although not very large. As a PRESSURIZED tank of Hydrogen empties, its content remains pure Hydrogen, so it would not become explosive - as long as you ignore the problem of extremely high pressure gas of ANY kind.

[Toskrin]

One figure I've heard is that for the USA to convert fully to ethanol from gasoline, 98% of the America's land would be planted in corn.

But, rather than fermenting corn, some researchers are studying ethanol production from the fermentation of garbage.

Garbage - America's ultimate renewable resource.

[MainFrame65]

Using rough numbers, actually about six times the area of Texas, irrigated (but where would the water come from?) and tended (we would have to resurrect a whole lot of farmers.)

In 1999 we produced 9.5 billion bushels of corn on 70.5 million acres. Corn yields about 2.5 gallons of alcohol per bushel. That amounts to about 8 barrels (42 gallon) per acre. Texas is about 171 million acres.

In the year 2000 we consumed about 7.5 billion barrels of crude oil. Some of it became heating oil, diesel, jet fuel, and chemical feedstocks. But around 35% became gasoline, I think.

[chaosagent]

Capricorn One was about a fake Mars landing, not a fake Moon landing.

[greasepaint]

Hydrogen storage technology is old.
Fuel cell technology, what little there is of it, is old.
Nothing new here.
Move along.

[Boiler Plate]

Bill,

I do not believe that the cost of hydrogen is the problem here. As pointed out in the article the problem is the cost of fuel cells. There was a good article in the Washington Times auto section today dealing specifically with the cost of fuel cell production. At present fuel cells use platinum and need about a 100 grams of the stuff. At $600 an ounce that's $2100 just for the platinum. If these things go into mass production you can expect the price to skyrocket. In short a 70kW (100HP) fuel cell is about $200,000. I'd put money on diesel, check out the Audi A2 TDI and VW Lupo TDI.

Regards,
Boiler Plate

[Boiler Plate]

by building submarine-like power barges in a shipyard. Each power barge would be the same overall size as a U.S. Navy nuclear sub, but would have no crew quarters, weapons, or propulsion equipment; instead, each barge would contain two identical computer-contryolled naval-type PWR nuclear reactors, with associated machinery and generator sets.

B-Chan,

Do you have any idea what the real cost of operating Navy sub reactor is? A sub reactor is only 60 MegaWatts whereas a General Electric MK 6 BWR commercial reactor is 1300 MegaWatts. Anything sitting in salt water is a maintenance nightmare and then how do you provide security?

I don't want to sound to harsh, but this sounds like a Popular Mechanics article.

Regards,
Boiler Plate

[noslogans]

nope...that's backwards. Hydrogen has 3 TIMES
the energy per pound as gasoline....something like
147 megajoule/kg for H2 vs 47 for gasoline and similar
for diesel and propane.

The problem with H2 is the VOLUMETRIC energy density;
i.e. btu/GALLON i.e. storage SPACE.

and no, using EXISTING engines on H2 is not "easy".
Propane is easy...LNG is harder but still sorta
"easy". H2 has a much different flame-speed and
gets a little funny in a production (today) car
engine...

best bet for H2 economy is to perfect 'formers';
i.e. conversion of H2 to methane or propane for
vehicles; and using process heat to run regular-type power-plants for fixed uses.

ps; as i recall, when gas hits $4/gal, oil-from-coal
becomes competitive. lotta ground dug up tho...

diff subject: it doesn't take more energy to grow
corn than the ethanol provides. In fact, it takes
zero energy to grow corn. Now, current mechanized
planting and harvesting methods do take a lot of
energy. But growing it is free. toss some corn
seed on your lawn and come back in the fall.
I'm not being facetious; if speed weren't an
issue, harvesting could be much less energy
intensive.


fyi; corn is one of the more efficient plants
on earth for turning sunlight into stored energy;
about 3% if I remember right. vast majority of
plants are under 1%. Best plants are around 8%...
some kind of algae i think.

Further; soy diesel is a better hit anyway....far
easier to process....with better yield of liquid
fuel per pound of input...it doesn't absorb
water like ethanol; and has a far higher energy/pound
(all oils are better than alcohols...think of alc's
as partially-burned oil...already contain some O2)

further; unless i'm very mistaken, the announced
'fuel cell' cars ARE hybrids. Fuel-cells typically
don't have much output...and have no 'peak load'
capacity at all. Batteries are almost always used
with them to provide short-term peak loads.

hybrids are best possible veh. for next 20-30
yrs....take advantage of the very high energy
density of hydrocarbon fuels...and the efficiency
of elec. motors for part-load ops; which is 99%
of a car's life. gas engines terrible efficiency
at part-load....diesel much better but still not
good.

further; fuel cells CAN turn "all the energy"
into electricity...say...up into the 90% range;
unlike IC-engines, fuel-cell isn't a Carnot
machine.

further; if i was going to choose a bio fuel, it'd
be wood...because it reproduces and grows just fine
without any 'farming'...and harvest can be pretty
cheap. I can bring a cord of wood out of the
forest, and section it, on less than a gallon of
gas in my Husky 55. That's 4,000 lbs...at about
1/3-1/2 the energy/pound as gasoline. Including
a quart of gas for the truck...about a 1000:1
energy gain.

[Godel]

The goal is to use wind energy to pluck hydrogen from water in the ocean,

Pretty silly, the only way to get hydrogen cheaply enough to make this viable is nuclear power.

[Robert_Paulson2]

bingo... and that is EXACTLY where this is headed.

[Robert_Paulson2]

When you reach a fork in the road... take it...

by that I mean... "do both" will be the option... not "either or," but "both and".

that's my guess.

[Moonman62]

When you reach a fork in the road... take it... by that I mean... "do both" will be the option... not "either or," but "both and". that's my guess.

I intended that as a rhetorical question since the decision has already been made. Many more votes can be bought with spending, rather than deregulation.

[O.C. - Old Cracker]

Correct! You get a cookie!

[nightdriver]

"It's called Hy-wire, and it's a one-of-a-kind prototype: a four-door sedan fueled by hydrogen, capable of speeds of 100 miles an hour, whisper-quiet, and emitting no pollution at all — only water vapor as exhaust. It looks like a spaceship, with glass all around and no pedals or steering wheel."

I'm unimpressed.

Show it to me after the state Highway Patrols have used it exclusively for a couple of years.

[Oztrich Boy]

What about ethanol? That is a re-newable resource and our farmers can grow plenty of whatever it takes to produce it.

What is takes to produce ethanol is energy and money. More energy than the energy the ethanol contains and more money than the market price of ethanol.

[MainFrame65]

I found some real numbers about explosive gas mixtures in air. the chart can be found at:

http://www.afcintl.com/pdf/combustibles.pdf

And the relevant numbers are:

LEL **** UEL **** Material

1.4% *** 7.6% *** Gasoline, 100 octane (vapor)

1.6% *** 8.4% *** Butane (gas)

3.3% ** 19.0% *** Ethanol (vapor)

6.0% ** 36.0% *** Methanol (vapor)

4.0% ** 75.0% *** Hydrogen (gas)

These are percentages by volume, at 1 atmosphere. LEL and UEL are LOWER and UPPER explosive limit, respectively.