High strength fibers for high pressure tubes.
Robert Clark
The pressure a pipe can resist is given by the Barlow formula P =
2*S*t/d, with P the pressure, S the tensile strength of the pipe
material, t the pipe wall
thickness, and d the inner diameter.
I want to get maximum pressure resistance for the weight of the tube
for my
application. However, if the tube is made of wound fibers such as
carbon fibers, Kevlar fibers, S-glass fibers etc., you won't have the
same tensile strength of the pipe wall material as that of the fibers
in longitudinal tension, which can be in the range of 1,000,000 psi.
This is because the fibers have to be bound together with epoxy which
will reduce the tensile strength of the pipe wall against burst
pressures (BTW, how much is this reduction in comparison to the
longitudinal tensile strength of the fiber?)
So I was thinking, has anyone tried drilling through these fibers
longitudinally to create tubes? Since the fibers are quite thin this
would
create quite thin tubes, but that's alright for my application as I can
just
bind them together to get more fluid flow.
The question is would the tensile strength circumferentially be the
same as
the tensile strength for the fibers tensed longitudinally?
A couple of ideas occur to me. While forming the fiber you could have
it form around a thin rod covered with some type of lubricating
material so
that after the fiber forms, you could slide out the rod to get a hollow
fiber.
Or you could have this rod have a much lower melting or sublimation
temperature than your fiber and raise the temperature so the rod will
melt or
sublimate then flush the melted or gaseous rod material from within the
fiber.
Secondly, to test the fibers circumferential tensile strength without
having
to make the fibers be hollow, you could drill a small hole cross-wise
through
the fiber. Then send a high pressure fluid through the small hole. You
could
deduce the cross-wise tensile strength from the Barlow formula by
seeing how
high the pressure can be before the fiber fails cross-wise.
Top view:
-----------------------------------------------
___ ^
/ \ |
| | Cross-wise tensile strength to be tested.
\___/ |
v
-----------------------------------------------
Tensile strength<------------->known high lengthwise.
Side view:
Hole drilled downwards through fiber this way:
|
| And high pressure fluid sent downwards through
hole.
v
-----------------------------------------------
^
|
Cross-wise tensile strength to be tested.
|
v
-----------------------------------------------
(Hole drilled cross-wise, so not visible from side.)
In addition to the application I'm considering which is aerospace
related,
a potentially very important application to this would be in hydrogen
storage.
Hydrogen fueled automobiles have been given high priority by the US
government. A key problem that needs to be solved is the storing of the
hydrogen in low weight systems within the vehicles. The US government
has set
a benchmark of 6.5% weight hydrogen to the storage system weight for
hydrogen
fueled vehicles to be competitive with gasoline vehicles.
Liquid hydrogen requires expensive and heavy cryogenics. And gas
hydrogen
storage requires the gas to be kept at high pressures.
In the case of gas storage clearly you want the density to be as high
as
possible while at the same time saving weight in the storage system.
This is
why high tensile strength materials would be useful.
Carbon nanotubes have been a key area of research in this regard.
There were
some early reports that high storage density was achieved but these
results
were not repeatable:
Carbon nanostructures: An efficient hydrogen
storage medium for fuel cells?
http://www.fuelcelltoday.com/FuelCellToday/FCTFiles/FCTArticleFiles/Article_433_Carbon%20Nanostructures.pdf
In addition to the high strength non-metallic fibers mentioned above
there is also
a high strength steel wire marketed known as Scifer wire. This steel
wire can
be up to 5.5 Gpa strong in tension. As is the case with the other
fibers this strength
holds in longitudinal tension for thin wires: the Scifer wire may be
only 8 microns
wide. However, interestingly there is micromaching being done actually
at the
*submicron* scale. Here's a review article by Clark-MXR, Inc. (no
relation) :
Clark-MXR, Inc. Femtosecond Lasers Micromachining Handbook.
http://www.cmxr.com/Industrial/Handbook/Introduction.htm
The key facet that makes this possible is that ultrafast laser pulses
are
used. This prevents the thermal energy from spreading beyond the area
that
needs to be machined.
This method clearly would suffice for creating a small hole cross-wise
in
8 micron wide wires or wider fibers, which would allow tests to be
made of their
cross-wise tensile strength.
In regard to producing tubes from the wire, the method may also work
if the
wire is kept very straight. Also, an interesting advantage of using
ultrafast
pulses is that the heated material moves away quickly from the
illuminated
area because it turns into a highly ionized plasma. We might also help
this
process by using a high pressure suction to remove this material or
high
magnetic fields.
Still another facet of these ultrafast lasers is that they can
actually be
tuned to focus *inside* the material. That is, the exterior of the
material
is left unheated and the laser energy is concentrated inside.
We can get an estimate of the storage weight density of hydrogen we
can achieve using
Scifer steel tubes assuming they are able to maintain their 5.5 Gpa =
55,000
bar tensile strength radially. At very high pressure hydrogen like all
gases
no longer obeys the ideal gas law. I found this page that computes
hydrogen
properties given temperature and pressure:
Hydrogen Properties Package.
http://www.inspi.ufl.edu/data/h_prop_package.html
Lets say we store the hydrogen at 2200 bar. Then at 200K the density is
62.4
kg/m^3. Use the Barlow formula to see how thick the Scifer steel tube
would
have to be to hold a gas at 2200 bar pressure: P = 2*S*t/d, t =
P*d/(2*S) =
2200*d/110000 = d/50 . Since the outside diameter = 8 microns = d +
2*t, this
results in t = .154 microns and d = 7.7 microns. For say a 1 meter long
tube
the volume of the steel would be Pi*(.000008^2-.0000077^2)/4 =
3.7*10^(-12)
cubic meters. At 7800 kg per cubic meter density for steel this would
weigh
2.89*10^(-8) kg.
Now the hydrogen inside the tube would have volume Pi*.0000077^2/4 =
46.57*10^(-12) cubic meters and at 62.4 kg/m^3 density would weigh
2.91*10^(-9) kg. So the ratio of the hydrogen to the steel would be
2.91*10^(-9)/28.9*10^(-9) = .1, which exceeds the benchmark required
for
hydrogen car viability.
Actually looking at the density numbers returned by the "Hydrogen
Properties
Package" we could do better than this by choosing a lower pressure for
the
hydrogen. And indeed the pressure probably doesn't have to be
exorbitant. But
the key factor is of the thinness of the Scifer steel or other high
strength fiber
that would be required to hold it.
Bob Clark
G. R. L. Cowan
For tiny tubes with walls that ought to be fairly strong,
see http://www.caer.uky.edu/energeia/PDF/vol6-3.pdf ,
figure 6.
--- Graham Cowan, former hydrogen fan
http://www.eagle.ca/~gcowan/Paper_for_11th_CHC.html --
boron: how individual mobility gains nuclear cachet
Uncle Al
[snip]
> Since the fibers are quite thin this
> would
> create quite thin tubes, but that's alright for my application as I can
> just
> bind them together to get more fluid flow.
[snip]
Unclear on the concept. Viscous conductance varies as (radius)^4.
> We can get an estimate of the storage weight density of hydrogen we
> can achieve using
> Scifer steel tubes
[snip]
Hopeless idiot. The H*Y*D*R*O*G*E*N car is bullshit. The densest
storage of hydrogen, atoms/liter, is diesel - and you can do that in
an open bucket without paying for /_\PV.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
Philip Holman
"Robert Clark" <rgrego...@yahoo.com> wrote in message
news:1114198033.4...@g14g2000cwa.googlegroups.com...
>I have interest in an application involving a very high pressure tube.
> The pressure a pipe can resist is given by the Barlow formula P =
> 2*S*t/d, with P the pressure, S the tensile strength of the pipe
> material, t the pipe wall
> thickness, and d the inner diameter.
> I want to get maximum pressure resistance for the weight of the tube
> for my
> application. However, if the tube is made of wound fibers such as
> carbon fibers, Kevlar fibers, S-glass fibers etc., you won't have the
> same tensile strength of the pipe wall material as that of the fibers
> in longitudinal tension, which can be in the range of 1,000,000 psi.
> This is because the fibers have to be bound together with epoxy which
> will reduce the tensile strength of the pipe wall against burst
> pressures (BTW, how much is this reduction in comparison to the
> longitudinal tensile strength of the fiber?)
Hoop stress is double longitudinal stress for a pressurized tube. High
pressure hoses have bias plies at an angle of ~65deg. to the
longitudinal axis. This way the plies are not in shear. Car and bicycle
tires are at 45 deg. to constrict the wheel on inflation. Inflating a
tubular tire to max pressure off the rim will damage the tire.
Phil H
Robert Clark
Uncle Al wrote:
> Robert Clark wrote:
> ...
> Hopeless idiot. The H*Y*D*R*O*G*E*N car is bullshit. The densest
> storage of hydrogen, atoms/liter, is diesel - and you can do that in
> an open bucket without paying for /_\PV.
>
> --
> Uncle Al
"Dr. Strange Al, or how I learned how to stop worrying and love
pollution."
Reading Al's posts on this topic you get the feeling he doesn't WANT
cars to run on pure hydrogen even if it is feasible to do so.
Bob Clark
G. R. L. Cowan
http://www.hydrogen.org/h2cars/overview/main01.html
That's a lot of prototypes, and a lot of years, for zero sales.
Robert Clark
G. R. L. Cowan wrote:
>...
> For tiny tubes with walls that ought to be fairly strong,
> see http://www.caer.uky.edu/energeia/PDF/vol6-3.pdf ,
> figure 6.
>
>
> --- Graham Cowan, former hydrogen fan
> http://www.eagle.ca/~gcowan/Paper_for_11th_CHC.html --
> boron: how individual mobility gains nuclear cachet
I couldn't get that link to open. Is it still up?
Bob Clark
Dan Bloomquist
Robert Clark wrote:
> Uncle Al wrote:
>
>>Robert Clark wrote:
>>...
>>Hopeless idiot. The H*Y*D*R*O*G*E*N car is bullshit. The densest
>>storage of hydrogen, atoms/liter, is diesel - and you can do that in
>>an open bucket without paying for /_\PV.
>
> "Dr. Strange Al, or how I learned how to stop worrying and love
> pollution."
>
> Reading Al's posts on this topic you get the feeling he doesn't WANT
> cars to run on pure hydrogen even if it is feasible to do so.
Feasible and practical are not the same concept. Arnold Schwarzenegger
gets 50 miles of range with his new H2 Hummer. (And I'll bet he has to
keep his foot out of it for even that.) How much did that vehicle and
fuel cost? And the big question that never seems to get addressed,
'Where does the hydrogen come from?'
> Bob Clark
Best, Dan.
Robert Clark
Feasible, practical, cost effective, cheaper. Dr. Strange Al still
wouldn't like it as long as it *didn't* create pollution.
Bob Clark
Dan Bloomquist
Robert Clark wrote:
> Dan Bloomquist wrote:
>
>>Robert Clark wrote:
>>>
>>> Reading Al's posts on this topic you get the feeling he doesn't
>
> WANT
>
>>>cars to run on pure hydrogen even if it is feasible to do so.
>>
>>Feasible and practical are not the same concept. Arnold
>
> Schwarzenegger
>
>>gets 50 miles of range with his new H2 Hummer. (And I'll bet he has
>
> to
>
>>keep his foot out of it for even that.) How much did that vehicle and
>
>
>>fuel cost? And the big question that never seems to get addressed,
>>'Where does the hydrogen come from?'
>>
> Feasible, practical, cost effective, cheaper. Dr. Strange Al still
> wouldn't like it as long as it *didn't* create pollution.
You didn't answer my question. It goes directly to the 'create
pollution' issue. Where does the hydrogen come from? Answer this instead
of making claims about what Uncle Al would like.
Making a case based on your feelings has no credibility on a sci group.
> Bob Clark
Best, Dan.
CWatters
"Robert Clark" <rgrego...@yahoo.com> wrote in message
news:1114198033.4...@g14g2000cwa.googlegroups.com...
> longitudinally to create tubes? Since the fibers are quite thin this
> would create quite thin tubes,
Wouldn't you loose a lot of energy getting anything to go through tubes that
small?
mme...@cars3.uchicago.edu
delusions of enthusiasts notwithstanding.
Mati Meron | "When you argue with a fool,
me...@cars.uchicago.edu | chances are he is doing just the same"
G. R. L. Cowan
Robert Clark
Really, Mati? We already have light-weight tanks that can hold 10,000
psi. And we have materials that can withstand 1,000,000 psi at least in
one direction. Does it really seem so unimaginable that we can increase
this pressure to 30,000 in light-weight tanks or find materials that
have 1,000,000 psi strength isotropically as a technical problem? Like
trying to find the answer to nuclear fusion?
Note also that we already have methods for creating gem-quality
diamonds in millimeter sized amounts and diamond probably has strength
isotropically at least 1 Mbars = 15,000,000 psi. The methods for
creating these large-sized diamonds can clearly be scaled up so as a
technical problem it is feasible.
No, in reading his posts the implication you draw is that he doesn't
like any idea that was specifically designed to *reduce* pollution.
Bob Clark
Robert Clark
Short answer: I don't know. I am not a hydrogen "enthusiast". I was
only giving a proposed solution to a problem that is having millions of
dollars world-wide spent yearly on it.
Bob Clark
Robert Clark
Good question. It *might* be that the increased pressures you can hold
will allow you to maintain high flow-rates. Another consideration is
that the friction/viscosity reduction is dependent on the smoothness of
the material. This is unknown for holes drilled through the centers of
these high strength fibers/wires.
Bob Clark
G. R. L. Cowan
Maybe I missed something, but I believe Arnold has still converted
zero Hummers. GM converted one, and staged a mockery of a travesty
of a sham where a hose was put in this hummer, connected to a dummy
hydrogen pump, held by an actor playing the governor. No hydrogen
was transferred.
jbuch
Scientific American recently ran an article on the unlikelyhood of the
HYDROGEN economy showing up for quite a while.
Do you read any such technical appraisals ... ? Or do you just read the
HYDROGEN WILL SAVE US .... sorts of things.
I think it was Fortune magazine that just last month had an article on
the General Motors thrust to HYDROGEN as one ofthe future ways to save
the company, and it described the many problems to this ever being realized.
Popular Science magazine is famous for the flying car-airplane articles
from the 1950's and 1960's as well as the personal helicopter articles
of the same period.
They also were big on air conditioning based merely on clever
compression and expansion of the air with no refrigerant fluid, also
forecast in the 1950's and 1960's.
So we have high pressure tanks. Big -------- Deal. That is only a tiny
and impractical step.
jbuch
Aren't you the guy that wanted to build a "Skyhook" tower based upon
pressurized structural tubes?
Wasn't the paper you based your proposal upon flawed and inappropriate,
as discussed briefly by the original author?
Your focus on PRESSURE is noted.
--
...............................
Keepsake gift for young girls.
Unique and personal one-of-a-kind.
Builds strong minds 12 ways.
Guaranteed satisfaction
- courteous money back
- keep bonus gifts
Robert Clark
jbuch wrote:
> Robert Clark wrote:
>
>
> Aren't you the guy that wanted to build a "Skyhook" tower based upon
> pressurized structural tubes?
>
> Wasn't the paper you based your proposal upon flawed and
inappropriate,
> as discussed briefly by the original author?
>
> Your focus on PRESSURE is noted.
> --
> ...............................
>
The application I'm considering is for carrying very high pressure
fluids vertically to kilometer altitudes. That proposal was not
dependent on the Landis paper. Reference to that was only to get the
formula online for taper ratio to height for high altitude towers. This
is a well-known formula available in many papers. The Landis paper had
it in an online source.
Bob Clark
jbuch
are looking for PROBLEMS that it will solve.
The Skyhook and now the HYDROGEN ECONOMY.
It isn't unnatural, some great things have come from this seeming dogged
focus on a "solution". But, on balance, a lot of such efforts have been
merely mildly interesting efforts focused on a solution looking for a
problem.
Robert Clark wrote:
Uncle Al
>
> Uncle Al wrote:
> > Robert Clark wrote:
> > ...
> > Hopeless idiot. The H*Y*D*R*O*G*E*N car is bullshit. The densest
> > storage of hydrogen, atoms/liter, is diesel - and you can do that in
> > an open bucket without paying for /_\PV.
> "Dr. Strange Al, or how I learned how to stop worrying and love
> pollution."
>
> Reading Al's posts on this topic you get the feeling he doesn't WANT
> cars to run on pure hydrogen even if it is feasible to do so.
"Ye canna' break the laws of physics." Yer screwed, Clarke - starting
with where you mine the hydrogen - as assuredly as the E*L*E*C*T*R*I*C
car was dead dead dead one business day after Federal subsidies
terminated.
The H*Y*D*R*O*G*E*N car is bullshit. Are you going to have a 10,000
psi storage tank the volume of a car's trunk? A 2000 lb tank of
metal matrix storage (e.g., HYSTOR) that is poisoned by trace CO or
SO2? 500 lbs of single wall carbon nanotubes for adsorption? Build
national distribution and storage networks?
Hey stooopid, how many gas stations are there in the US?
Get this through your thick insane head: By a huge margin (even on a
log-axis), the densest storage of hydrogen - atoms/liter - is diesel.
You can do that in an uncovered $1.50 bucket from K-Mart. Diesel
comes out of the ground for no more than $2.00/bbl amortized cost as
petroleum. Not cost per gallon, jackass, cost per barrel. That is
what Arabian crude production costs. They cap and forget any well
that is not a gusher.
Uncle Al
[snip]
> We already have light-weight tanks that can hold 10,000
> psi.
A 400 liter 10,000 psi tank of hydrogen contains less here-to-there
than my VW Golf's modest gasoline tank. The hydrogen tank also
contains
(400 liters)(680 atmospheres)(101.235 J/l-atm) =
27.5 megajoules of /_\PV energy. That is the energy of detonation of
14.5 lbs of TNT after a minor rear-ender. KA-FUCKING-BOOM!
(Apologies tendered to readers for author's inability to display
sufficiently bold and large font in 7-bit Usenet.) Add ignition as
pleases you.
BTW, jackass, that is the energy you must INPUT to pressurize the
tank. It is unrecoverable upon discharge. How much gasoline must you
burn to run the compressor to fill your 10,000 psi hydrogen tank? Oh,
wait! You'll burn HYDROGEN! Idiot.
Uncle Al
Hey stooopid, viscous laminar flow varies as (radius)^4. Going from a
10 mm ID to a 0.5 mm ID gives you 1/160,000 the flow for the same
pressure drop. You don't have high pressure, jackass, you are
disharging the storage volume. If you have high pressure flow
maintained you get turbulence and you STILL don't get any flow. If
you try to push supersonic the bore chokes. You STILL don't get any
flow.
Hey stooopid, what length of 0.5 mm bore must you accumulate to store
400 liters of volume? Will the H*Y*D*R*O*G*E*N car pull a 16-wheel
trailer? Oh yeah, every bend screws your flow rate big time.
mme...@cars3.uchicago.edu
"cost is not an object" situation) can be "clearly" be scaled to
arbitrary large size, at arbitrarily small cost, is one of the
hallmarks of a deluded enthusiasm. And the belief that somebody just
wants to have more polution is a hallmark of utter stupidity. I think
that my sig is giving me a clear signal here. So long.
The Ghost In The Machine
<Uncl...@hate.spam.net>
wrote
on Sat, 23 Apr 2005 09:52:32 -0700
<426A7D50...@hate.spam.net>:
> Robert Clark wrote:
> [snip]
>
>> We already have light-weight tanks that can hold 10,000
>> psi.
>
> A 400 liter 10,000 psi tank of hydrogen contains less here-to-there
> than my VW Golf's modest gasoline tank.
45 MJ/liter gasoline. Assuming 30 mpg = 7.925 miles/liter
= 12.754 km/liter, that's 3.529 * MJ/km. Assuming a 15 gallon
= 56.87 liter gas tank that's a cruising range of 450 miles
or 725 km, though one might want to allow for error.
Total energy: 2.559 gigaJoules.
10000 psi = 69 megaPascal.
400 liter = 0.4 m^3.
n = PV/(RT) = 6.9*10^7 * 0.4 / (8.314472 * 300) = 1.107 * 10^4 moles.
Reaction: H2 + 1/2 O2 = H2O + 285.8 kJ/mole H2.
Total energy: 3.164 gigaJoules.
Of course, that Golf probably won't be able to hold a 400 liter
hydrogen gas tank. :-) I'm also curious as to the weight of the
tanks per megaJoule; I've not accounted for acceleration to
cruising speed, which for a 2 metric tonne car accelerating to
30 m/s = 67.1 km/hr is .9 megaJoule right there. Every extra
kg requires 450J in the budget -- and then one has to worry
about breaking.
But never mind that, hydrogen cars are the future! If only because
Bush & Co. say so -- assuming anyone believes them at this point.
> The hydrogen tank also
> contains
>
> (400 liters)(680 atmospheres)(101.235 J/l-atm) =
>
> 27.5 megajoules of /_\PV energy. That is the energy of detonation of
> 14.5 lbs of TNT after a minor rear-ender. KA-FUCKING-BOOM!
> (Apologies tendered to readers for author's inability to display
> sufficiently bold and large font in 7-bit Usenet.) Add ignition as
> pleases you.
14.5 lbs TNT = 30 MJ = about 16.7x the energy of a head-on collision
between two metric tonne vehicles both moving at 30 m/s (67.1 mph).
# # # ###### ####### ####### # #
# # # # # # # # # # ## ##
# # # # # # # # # # # # # #
### # # ###### # # # # # # #
# # ####### # # # # # # # #
# # # # # # # # # # # #
# # # # ###### ####### ####### # #
Fortunately for most of the rest of us, gasoline doesn't
explode all that readily and gas tanks are well protected.
(Except in '74 Pintos. I don't know regarding Golfs. :-) )
Hydrogen might be even safer, were it not for the pressure.
Presumably, that's the killer, here.
>
> BTW, jackass, that is the energy you must INPUT to pressurize the
> tank. It is unrecoverable upon discharge. How much gasoline must you
> burn to run the compressor to fill your 10,000 psi hydrogen tank? Oh,
> wait! You'll burn HYDROGEN! Idiot.
>
The tank pressurization energy should be partially recoverable though
I'm not sure exactly how, but prototype liquid nitrogen cars have
been suggested by a Webpage somewhere; I'd have to find it now.
Of course, they're far worse than hydrogen, mileage-wise.
I am not so naive to think we can recover all of it, of course, and
I doubt that significant recovery is even possible, as the regulator
(the bit that actually releases the gas) will probably freeze up.
<mode voice="habshi"> Of course we might be able to convert that
into air conditioning. </mode> :-)
--
#191, ewi...@earthlink.net
It's still legal to go .sigless.
Uncle Al
That is a nice set of numbers you have there! A 400 liter 10,000 psi
hydrogen tank will give the same driving range as a tank of gasoline
in a VW Golf, if it is weightless and threads to fill the entire
underside volume of the car. If it ruptures the /_\PV energy release
is 16X the energy of a 70 mph head-on collision between two luxury
cars... the same amount of energy being needed each time to fill it at
pressure.
The solution? Fuel cells! Why a child could have thought of it -
preferably one pre-arithmetic.
CWatters
How big are carbon fibres? I found this abstract that suggests "large
diameter fibres" are 15-60 microns!
Dan Bloomquist
G. R. L. Cowan wrote:
> Dan Bloomquist wrote:
>>
>>Feasible and practical are not the same concept. Arnold Schwarzenegger
>>gets 50 miles of range with his new H2 Hummer. (And I'll bet he has to
>>keep his foot out of it for even that.) How much did that vehicle and
>>fuel cost? And the big question that never seems to get addressed,
>>'Where does the hydrogen come from?'
>
> Maybe I missed something, but I believe Arnold has still converted
> zero Hummers. GM converted one, and staged a mockery of a travesty
> of a sham where a hose was put in this hummer, connected to a dummy
> hydrogen pump, held by an actor playing the governor. No hydrogen
> was transferred.
I read it a few weeks ago. I'm not surprised if it was a sham.
> --- Graham Cowan, former hydrogen fan
Best, Dan.
Jonathan Barnes
> >> We already have light-weight tanks that can hold 10,000
> >> psi.
> >
> > A 400 liter 10,000 psi tank of hydrogen contains less here-to-there
> > than my VW Golf's modest gasoline tank.
Doing a little thinking out loud,
the most efficient pressure tank is a sphere.
for 400 l capacity
0.4 = 4/3 x pi x r^3 gives a diameter of 915 mm
cross section of tank = 0.915 ^2 / 4 x pi = 0.657 m^2
pressure is 10,000 psi = 67 MPa
strength of steel = 430 MPa
area of tank wall = pi x 0.915 x t = 2.87 x t
If we had a safety factor of 2.5, wall stress is 172 MPa
172 x 2.87 x t = 0.657 x 67
wall of tank is t = 90 mm ( thin wall assumption " pushed " )
tank wall volume = pi x 0.915^2 x 0.09 = 0.270 m^3
density of steel = 7.81 tonnes / m^3
weight of tank = 2.1 tonnes
When your fuel tank weighs a couple of tons you need a big vehicle which
needs a lot of fuel..... :-)
--
Jonathan
Barnes's theorem; for every foolproof device
there is a fool greater than the proof.
To reply remove AT
Robert Clark
You said feasible not cost effective. Anyways the benchmark set by the
U.S. government is 6.5% storage by weight and we're already close to
that. A company called Quantum claims 6% storage at 10,000 psi gas
pressure with carbon composite tanks. This is hardly the difficulty
level of creating controlled nuclear fusion or even going to the Moon.
You should read Uncle Al's post more carefully. Anything whose
*purpose* is reduce pollution incurs his wrath.
Bob Clark
G. R. L. Cowan
>
> > >> We already have light-weight tanks that can hold 10,000
> > >> psi.
> > >
> > > A 400 liter 10,000 psi tank of hydrogen contains less here-to-there
> > > than my VW Golf's modest gasoline tank.
>
> Doing a little thinking out loud,
>
> the most efficient pressure tank is a sphere.
>
> for 400 l capacity
> 0.4 = 4/3 x pi x r^3 gives a diameter of 915 mm
>
> cross section of tank = 0.915 ^2 / 4 x pi = 0.657 m^2
>
> pressure is 10,000 psi = 67 MPa
>
> strength of steel = 430 MPa
>
> area of tank wall = pi x 0.915 x t = 2.87 x t
>
> If we had a safety factor of 2.5, wall stress is 172 MPa
>
> 172 x 2.87 x t = 0.657 x 67
> wall of tank is t = 90 mm ( thin wall assumption " pushed " )
>
> tank wall volume = pi x 0.915^2 x 0.09 = 0.270 m^3
>
> density of steel = 7.81 tonnes / m^3
>
> weight of tank = 2.1 tonnes
>
> When your fuel tank weighs a couple of tons you need a big vehicle which
> needs a lot of fuel..... :-)
Two tonnes of tank wall, 13 kg of payload.
Instead of weighing as much as a regular car,
an automotive hydrogen tank can cost as much as one:
the carbon filament-wound tanks in the GM Hy-Wire and Sequel
vehicles, if they exist. At 5,000 psi, 2 kg H2 is contained
in only 75 kg of tank.
Or it can be a Dewar and not have the PV bomb feature,
and be much more compact, and so score a much lower mass ratio --
http://www.visionengineer.com/env/h2_liquid.shtml ,
http://www.magnasteyr.com/automobilentwicklung/1342_1354_ENG_HTML.asp --
on the order of 15, but I don't know how expensive.
Not as bad as a carbon fibre tank, I guess.
--- Graham Cowan, former hydrogen fan
G. R. L. Cowan
IIRC, hybrids don't.
Jonathan Barnes
"Uncle Al" <Uncl...@hate.spam.net> wrote in message
> Hey stooopid, what length of 0.5 mm bore must you accumulate to store
> 400 liters of volume? Will the H*Y*D*R*O*G*E*N car pull a 16-wheel
> trailer? Oh yeah, every bend screws your flow rate big time.
>
Hay Uncle Al
I'm happy to call a bend radius of twice the pipe diameter as low
restriction, so your 0.5 mm bore pipe should be O.K. with 1 mm radius
bends....
Uncle Al
>
1) "Two tonnes of tank wall, 13 kg of payload." All you need is an
engineering staff, some workstations, and optimization algorithms.
Reality cannot stand before political convenience.
2) What makes you think organics would hold 10,000 psi hydrogen
against diffusion? Ever see a fiberglas Corvette 24 hrs after a minor
fender ding? The whole body crazes. Pumping up and discharging an
organic wall tank to 10,000 psi 50 times/year for five years is not a
clever idea.
3) Housewife + liquid hydrogen = TV sitcom.
4) A hydrogen-burning engine would be a major NOx polluter. A fuel
cell car would be an expensive joke.
5) The densest hydrogen storage modality - atoms/liter - is diesel
fuel in a bucket. We already have both, plus distribution networks in
place.
Uncle Al
>
> "Uncle Al" <Uncl...@hate.spam.net> wrote in message
>
> > Hey stooopid, what length of 0.5 mm bore must you accumulate to store
> > 400 liters of volume? Will the H*Y*D*R*O*G*E*N car pull a 16-wheel
> > trailer? Oh yeah, every bend screws your flow rate big time.
> >
> Hay Uncle Al
>
> I'm happy to call a bend radius of twice the pipe diameter as low
> restriction, so your 0.5 mm bore pipe should be O.K. with 1 mm radius
> bends....
It's not bore crimping that kills gas conductance, it's the bend
itself even if it is perfect. Momentum! Every bend is death, every
stopcock is death, every through-fitting and jog is a slap in the
face.
Uncle Al's vac line was really big bore tubing with big bore big
cryogenic traps (hooked up "backwards" so they worked without
clogging) with the largest greaseless screwdown stopock made leading
to a direct drive forepump. Down the hall was a very elegant
fairyland creation of mostly 7 mm Pyrex tubing and greaseless
connections swirled into a bouffant vac-do, ending in a huge forepump
backing a huge silicone vapor pump. The thing had huge bucks in it.
Big bad chemist, "Hey Al, bet you $20 my line pumps down faster than
your line."
Uncle Al, "Make that $100."
Stopwatch; pressure gauge at the far end of the line. My line could
not be expected to pull better than 5 microns. Open the line to air,
close. Flip the pump switch. The gauge dropped then oozed to about 6
microns over a few minutes and hung. Was Uncle Al out $100?
Stopwatch; pressure gauge at the far end of the line. His line could
be expected to pull better than 10^(-3) microns... eventually. Open
the line to air, close. Flip the forepump switch, then engage the
vapor pump when the pressure dropped. His line got to 6 microns at
the far end in more than double the time mine did - as every
greaseless connection in-between was outgassing just a teensy to put
icing on the cake.
It matters not how hard you suck at the near end. The far end is
kinetics not thermodynamics. I don't know what his vac line actually
did in his lab. Whatever it did it took a long time to do it if
non-condensable gas was being evolved. My vac line occasionally
explosively decompressed garden snails in the morning. POOF!
Partially frozen puffed snail. I hate snails.
rgrego...@yahoo.com
> The tank pressurization energy should be partially recoverable though
> I'm not sure exactly how, but prototype liquid nitrogen cars have
> been suggested by a Webpage somewhere; I'd have to find it now.
> Of course, they're far worse than hydrogen, mileage-wise.
>
> I am not so naive to think we can recover all of it, of course, and
> I doubt that significant recovery is even possible, as the regulator
> (the bit that actually releases the gas) will probably freeze up.
>
> <mode voice="habshi"> Of course we might be able to convert that
> into air conditioning. </mode> :-)
>
> --
> #191, ewi...@earthlink.net
> It's still legal to go .sigless.
You could use the high pressure gas to run a turbine and then on top
of that burn the hydrogen in an internal combustion engine.
To get an idea of the power that might be generated by the turbine, we
can calculate the speed achieved when the gas is released to ambient
pressure. For an incompressible gas approximation, the Bernoulli
formula implies v = (Pressure/density)^.5. For the 2200 bar pressure,
200 K temperature, 62.4 kg/m^3 density I originally suggested, this
would result in v = (2.2*10^8Pa/62.4kg/m^3)^.5 = 1877.7 m/s.
At 300K and 2200 bar, the "Hydrogen Properties Package" page gives the
density as 48.2 kg/m^3. Then the speed would be 2136.4 m/s.
Perhaps someone familiar with turbine engineering could calculate the
power that could be generated.
Bob Clark
rgrego...@yahoo.com
That's why I suggested the ultrafast laser approach:
Introduction to Micromachining Handbook.
http://www.cmxr.com/Industrial/Handbook/Introduction.htm
A very informative including some nice animations illustrating the
process.
Another posibility might be to use high pressure waterjets to cut
channels in the fibers. These can cut through steel with a combination
of pressure and velocity. The smallest diameter jets I've seen are
about .01" inches wide or 250 microns. It may be possible to reduce the
diameter of these jets to less than 10 micron diameter.
Keep in mind also that I don't know that any of these high strength
fibers maintain their longitudinal strength cross-wise or if they have
been tested yet.
Bob Clark
rgrego...@yahoo.com
> > >> We already have light-weight tanks that can hold 10,000
> > >> psi.
> > >
> > > A 400 liter 10,000 psi tank of hydrogen contains less
here-to-there
> > > than my VW Golf's modest gasoline tank.
>
> Doing a little thinking out loud,
>
> the most efficient pressure tank is a sphere.
>
> for 400 l capacity
> 0.4 = 4/3 x pi x r^3 gives a diameter of 915 mm
>
> cross section of tank = 0.915 ^2 / 4 x pi = 0.657 m^2
>
> pressure is 10,000 psi = 67 MPa
>
> strength of steel = 430 MPa
>
> area of tank wall = pi x 0.915 x t = 2.87 x t
>
> If we had a safety factor of 2.5, wall stress is 172 MPa
>
> 172 x 2.87 x t = 0.657 x 67
> wall of tank is t = 90 mm ( thin wall assumption " pushed " )
>
> tank wall volume = pi x 0.915^2 x 0.09 = 0.270 m^3
>
> density of steel = 7.81 tonnes / m^3
>
> weight of tank = 2.1 tonnes
>
> When your fuel tank weighs a couple of tons you need a big vehicle
which
> needs a lot of fuel..... :-)
>
>
I'm proposing using materials whose tensile strength is more than 10
times 430 Mpa. If the Scifer steel does have 5.5 Gpa tensile strength
cross-wise then the thickness will only have to be 430/5500 as big and
therefore the mass will also decrease by this factor to 430/5500 *
2100kg = 164kg.
Carbon fibers have comparable strength but only 1/5th the weight so
the mass would be 164kg/5 = 33kg.
Bob Clark
rgrego...@yahoo.com
> ...
> Get this through your thick insane head: By a huge margin (even on a
> log-axis), the densest storage of hydrogen - atoms/liter - is diesel.
> You can do that in an uncovered $1.50 bucket from K-Mart. Diesel
> comes out of the ground for no more than $2.00/bbl amortized cost as
> petroleum. Not cost per gallon, jackass, cost per barrel. That is
> what Arabian crude production costs. They cap and forget any well
> that is not a gusher.
>
> ...
Unless you're going to use this diesel fuel in a reformer to convert
it into hydrogen, this is irrelevant to the issue at hand. You remember
reformers, right Al? Their PURPOSE is to reduce POLLUTION.
But since they use diesel fuel should like them right?
Bob Clark
rgrego...@yahoo.com
Uncle Al wrote:
> Robert Clark wrote:
> [snip]
>
> > We already have light-weight tanks that can hold 10,000
> > psi.
>
> A 400 liter 10,000 psi tank of hydrogen contains less here-to-there
> than my VW Golf's modest gasoline tank. The hydrogen tank also
> contains
>
> (400 liters)(680 atmospheres)(101.235 J/l-atm) =
>
> 27.5 megajoules of /_\PV energy. That is the energy of detonation of
> 14.5 lbs of TNT after a minor rear-ender. KA-FUCKING-BOOM!
> (Apologies tendered to readers for author's inability to display
I thought you said you couldn't get that energy added by the pressure
out again?
For a controlled use of this pressure, use a turbine.
Bob Clark
rgrego...@yahoo.com
> >
> > Uncle Al wrote:
> > > Robert Clark wrote:
> > > Hopeless idiot. The H*Y*D*R*O*G*E*N car is bullshit. The
densest
in
> > > an open bucket without paying for /_\PV.
> > >
> > > --
> > > Uncle Al
> >
> > "Dr. Strange Al, or how I learned how to stop worrying and love
> > pollution."
> >
> > Reading Al's posts on this topic you get the feeling he doesn't
WANT
> > cars to run on pure hydrogen even if it is feasible to do so.
>
>
> That's a lot of prototypes, and a lot of years, for zero sales.
>
>
These vehicles are still in the prototype stage, but look at the later
years here for more successful renditions:
H2Cars.
http://www.hydrogen.org/h2cars/overview/
Bob Clark
George Dishman
<rgrego...@yahoo.com> wrote in message
news:1114311725.7...@l41g2000cwc.googlegroups.com...
If your concern is to reduce CO2 production,
then consider a simpler alternative. If the
fuel recycles atmospheric carbon then there
is no net production:
http://www.absoluteastronomy.com/encyclopedia/B/Bi/Biodiesel.htm
or
http://www.absoluteastronomy.com/encyclopedia/B/Bi/Bioalcohol.htm
Check out what Brazil is doing.
George
Jonathan Barnes
<rgrego...@yahoo.com> wrote in message
news:1114310940.3...@l41g2000cwc.googlegroups.com...
Such as ??? Unidirectional louse carbon fibre is not a material you can
make a tank out of.
At best 35% of your material is the matrix, and you need strength in a plane
so you need twice as much as for a unidirectional material.
What is the density of the composite.. should be a lot less than steel thus
saving weight.
>If the Scifer steel does have 5.5 Gpa tensile strength
I think these " super " materials can only be fibers a few atoms thick..
Carbon fibres may be forty times the strength of steel on a weight for
weight basis, but for a carbon fibre bi directional composite it's a lot
less.
about 12 times might be realistic.
if we say the tank will be a metre in diameter and weigh 170 kg it's still a
problem to fit in a conventional car.
Jonathan Barnes
"Uncle Al" <Uncl...@hate.spam.net> wrote
> "G. R. L. Cowan" wrote:
> > Jonathan Barnes wrote:
> > >
> > > > >> We already have light-weight tanks that can hold 10,000
> > > > >> psi.
> > > > >
> > > > > A 400 liter 10,000 psi tank of hydrogen contains less
here-to-there
> > > > > than my VW Golf's modest gasoline tank.
> > >
> > >
> > > for 400 l capacity
> > > 0.4 = 4/3 x pi x r^3 gives a diameter of 915 mm
> > >
> > >
> > Two tonnes of tank wall, 13 kg of payload.
> >
> > Instead of weighing as much as a regular car,
> > an automotive hydrogen tank can cost as much as one:
> > the carbon filament-wound tanks in the GM Hy-Wire and Sequel
> > vehicles, if they exist. At 5,000 psi, 2 kg H2 is contained
> > in only 75 kg of tank.
> >
> against diffusion?
A coating of something needed ???
> Pumping up and discharging an
> organic wall tank to 10,000 psi 50 times/year for five years is not a
> clever idea.
I think you will have trouble with the matrix material at the high
pressures, but wound tanks do prefom well, but they are expensive, and there
is little on cost to be saved with volume production...
> 3) Housewife + liquid hydrogen = TV sitcom.
More a disaster movie I would think :-)
>
> 4) A hydrogen-burning engine would be a major NOx polluter. A fuel
> cell car would be an expensive joke
Fuel cell could improve drematicaly, but the hydrogen storage problem
remains.... methane powered cells look interesting... but they are to
complicated and thus are very expensive.
> 5) The densest hydrogen storage modality - atoms/liter - is diesel
> fuel in a bucket.
Can you supply the energy value ( Mj / kg ) for diesel and hydrogen ?
Robert Clark
> <rgrego...@yahoo.com> wrote in message
After a web search, these Scifer steel wires are about 10 microns
thick. The measured longitudinal tensile strength of these wires is 5.5
Gpa. Carbon fibers in use have longitudinal tensile strength about 7
Gpa.
Whether they can maintain this strength cross-wise is what I'm
suggesting should be investigated.
Quantum Technologies has in production carbon composite hydrogen tanks
that can hold 8 kg of hydrogen at 10,000 psi to fit in a standard size
car. This is enough to drive a prototype vehicle 300 miles, 480 km. The
carbon composite design makes these tanks much lighter than a
comparable steel tank:
GM launches latest stage of its hydrogen 'moonshot'.
Sequel concept is a five-seat SUV with a 300-mile range.
http://www.detnews.com/2005/autoshow/0501/09/-54837.htm
Bob Clark
G. R. L. Cowan
Has anyone outside GM seen it go one mile?
Robert Clark
> ...
> > GM launches latest stage of its hydrogen 'moonshot'.
> > Sequel concept is a five-seat SUV with a 300-mile range.
> > http://www.detnews.com/2005/autoshow/0501/09/-54837.htm
>
> Has anyone outside GM seen it go one mile?
>
>
Both GM and Ford demonstrated hydrogen prototype vehicles using
earlier versions of the Quantum tanks with storage at 5,000 psi:
Earth Day at the Pentagon Highlights An Array of Hydrogen Technologies.
http://www.hydrogenus.com/advocate/ad81day.asp
Bob Clark
daestrom
"Jonathan Barnes" <jbar...@btinternet.com> wrote in message
news:d4eo7b$kt$1...@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...
>
> "Uncle Al" <Uncl...@hate.spam.net> wrote in message
>
>> Hey stooopid, what length of 0.5 mm bore must you accumulate to store
>> 400 liters of volume? Will the H*Y*D*R*O*G*E*N car pull a 16-wheel
>> trailer? Oh yeah, every bend screws your flow rate big time.
>>
> Hay Uncle Al
>
> I'm happy to call a bend radius of twice the pipe diameter as low
> restriction, so your 0.5 mm bore pipe should be O.K. with 1 mm radius
> bends....
What I think Al is refering to is not a change in the internal dimensions
caused by bending (although very sharp bends do have this problem), but the
'secondary flow' of fluids flowing through tubing with bends in it. The
momentum of the fluid causes it to move to the outer edge of the tubing and
displace fluid around in a sort of 'eddy'. This transverse eddy flow robs
the fluid of energy causing a much larger pressure drop for a given flow
rate than would be expected by the viscous friction alone. If the relative
radius is optimized (experimental data suggests an r/d of aobut 4), then the
secondary flow effects in a 90 degree bend are equivalent to about 12
pipe-diameters more resistance than an equal length of straight tubing.
Most flow experimental data is with much larger bore though. Considering
the viscous boundry layer is a sizeable portion of your total bore, it may
behave more like laminar flow all the time. And that would mean the viscous
losses follow (diameter)^5 instead of (diameter)^4.
Some experiments in fluid flow around bends suggest there is an optimal
relative radius. When the bend radius is smaller, of course the flow
resistance rises. But what is surprising is that if the bend's relative
radius (r/d) is *increased* from the optimum, the flow resistance again
rises. For example, Davis found increases in flow resistance of the order
of 25% when increasing the relative radius from 4 to 14 tube diameters.
Balch found increases of over 100% in similar relative radius range. Even
with a relative radius bend of 20, the problem still exists. Not until you
get out past 50 r/d do 'secondary flow' effects drop off again. The low
point in flow resistance is with a relative radius of about 4 (2mm). So
either keep all bends to about 2mm, or larger than 25 mm to maximize the
flow rate.
With such a small bore tube, it would be difficult to get all the hydrogen
out in a timely manner if it were just one continuous length. Cutting the
tubing into much shorter lengths would seem in order (for a 0.5mm bore to
contain 400 liters, it would have to be over 2000 km long). So obviously
some sort of manifold would be needed to connect literally thousands of such
small bore tubes together. If each tube was 100 m long, that would take
over 20000 connections to such a manifold. This manifold, of course, would
be subject to the same pressures as the storage system.
Technologicly, making up some 20000 connections, and sealing them against
hydrogen leaks at 10000 psi sounds like quite a challenge.
daestrom
G. R. L. Cowan
It's interesting to look at energy-specific volumes.
10-kpsi hydrogen's is 980 litres per megawatt-hour
(tank internal volume only).
At the same pressure aluminum's is 45.5 L/MWh,
but its oxidation produces 58.2 L/MWh of alumina crystals.
So two non-space-sharing reservoirs for Al before
and Al after would need at least 103.6 L/MWh.
Space between bits of solid would put that up to ~200.
Conceivably these relatively small reservoirs' pressure could be reduced
to as little as 9900 psig. Heck, why not 9900 psia!
The challenge of burning Al and getting the Al2O3 into its bin,
plus converting some of the heat, may equal that of making
the lung-like ultra-high-pressure network daestrom mentions above.
But it's not as pointless, if zero-local-emission cars are what
you are after. People would *buy* Al-burners if they had the chance.
Hydrogen advocates sometimes say hydrogen is just as safe as
gasoline. Isn't it interesting that when you see boxes containing
rolled aluminum foil on grocery store shelves, they never have
that boast?
Robert Clark
Correction, using the incompressible fluid approximation Bernoulli
reads:
P1 + (1/2)*d*V1^2 = P2 + (1/2)*d*V2^2, P pressure, V velocity, d
density.
For P1 very high, the ambient air pressure P2 at 1 bar is small and
for the opening very small in relation to the tank size, V1 will be
very small in relation to V2, so the equation becomes,
P1 + 0 = 0 + (1/2)*d*V2^2, so V2 = (2*P1/d)^.5 . I left out the factor
of 2 inside the square-root as I first wrote it above.
Then those speeds should be 2655.5m/s at 200K and 3021.3m/s at 300K.
Bob Clark
Uncle Al
<http://www.findarticles.com/p/articles/mi_m0CYH/is_19_6/ai_91964920>
Let's do a quick calculation IGNORING the carbon energy output. Fact
has no place in Enviro-whiner dogma.
Petro-diesel is 0.84 g/cm^3, nominal composition (-CH2-)n, molecular
weight 14.027, 14.37 wt-% hydrogen. One liter of diesel therefore
contains
(1000 cm^3)(0.84 g/cm^3)(0.1437) = 120.7 grams of hydrogen.
One liter of liquid hydrogen, d= 0.070 g/cm^3 at 20.39 kelvin, is 70
grams of hydrogen. It's 58% of diesel - and diesel has all that
lovely carbon to be burned for energy, too (4x10^7 J/kg for pure
carbon oxidized to CO2), and doesn't need storage dewars or boil off
venting or cryogenic liquefaction in the first place, or ortho-para
spin isomer shifting... and petroleum comes out of the ground for free
(near enough).
One liter of 10,000 psi hydrogen is roughly
(10,000 psi)(1 atm/14.7 psi)[1/22.4 liters/mole)](2.016 g/mole) = 61
grams of hydrogen. It's crap; plus /_\PV work to compress it of
101.325 joules/liter-atmosphere.
The H*Y*D*R*O*G*E*N car. ha ha ha.
The Ghost In The Machine
<rgrego...@yahoo.com>
wrote
on 23 Apr 2005 18:31:18 -0700
<1114306278.1...@l41g2000cwc.googlegroups.com>:
A logical enough response, if one can afford the additional mass of
the turbine spindle, the turbine stationaries, the casing,
the gearing, etc. etc. Accelerating to 30 m/s (67.1 mph), one has
to account for 450 J per extra kg.
The power output of today's cars is about 80 - 120 kW,
full throttle. This necessitates a maximum chemical
hydrogen fuel flow of about 0.5 mole (1 gram) per second.
Any more than that would be wasted.
At 1877 m/s one gets a kinetic power of 1.8 kW. Sugar coating,
though it might help to power the electrical gear. (I'm wondering
which is more efficient: the traditional headlamp/light throwers,
spewing quintillions of photons onto the ground, or some sort
of infrared camera arrangement that uses passive viewing. Of
course that infrared camera is extra weight...hmm....)
There's also the issue of start-stop; many cars are used for
city driving.
BTW -- 200K is well below freezing. What's to keep the tank from
having problems as the car sits in a hot sunny mall parking lot? :-)
The Ghost In The Machine
<jbar...@btinternet.com>
wrote
on Sun, 24 Apr 2005 10:38:39 +0000 (UTC)
<d4fsvf$mo5$1...@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com>:
>
> "Uncle Al" <Uncl...@hate.spam.net> wrote
>> "G. R. L. Cowan" wrote:
>> > Jonathan Barnes wrote:
>> > >
>> > > > >> We already have light-weight tanks that can hold 10,000
>> > > > >> psi.
>> > > > >
>> > > > > A 400 liter 10,000 psi tank of hydrogen contains less
> here-to-there
>> > > > > than my VW Golf's modest gasoline tank.
>> > >
>> > > the most efficient pressure tank is a sphere.
>> > >
>> > > for 400 l capacity
>> > > 0.4 = 4/3 x pi x r^3 gives a diameter of 915 mm
>> > >
>> > > weight of steel tank ( approx ) = 2.1 tonnes
>> > >
>> > Two tonnes of tank wall, 13 kg of payload.
>> >
>> > Instead of weighing as much as a regular car,
>> > an automotive hydrogen tank can cost as much as one:
>> > the carbon filament-wound tanks in the GM Hy-Wire and Sequel
>> > vehicles, if they exist. At 5,000 psi, 2 kg H2 is contained
>> > in only 75 kg of tank.
>> >
>> 2) What makes you think organics would hold 10,000 psi hydrogen
>> against diffusion?
>
> A coating of something needed ???
A nice *thick* coating. Rocketry assumes that a minimum
of 3% must be used for just holding the propellant, which
in most rockets doubles as fuel. (A more reliable reading
suggests 5%-10%, in such engines as those used by the Saturn V
or the space muddle -- erm, shuttle.)
>
>> Pumping up and discharging an
>> organic wall tank to 10,000 psi 50 times/year for five years is not a
>> clever idea.
50? Depends on the driving habits; I'd surmise that there are those
who refill *daily*, with 200+-mile commutes. And then there's
the Fuller Brush salesmen (or their modern equivalents).
>
> I think you will have trouble with the matrix material at the high
> pressures, but wound tanks do prefom well, but they are expensive, and there
> is little on cost to be saved with volume production...
>
>> 3) Housewife + liquid hydrogen = TV sitcom.
>
> More a disaster movie I would think :-)
>>
>> 4) A hydrogen-burning engine would be a major NOx polluter. A fuel
>> cell car would be an expensive joke
>
> Fuel cell could improve drematicaly, but the hydrogen storage problem
> remains.... methane powered cells look interesting... but they are to
> complicated and thus are very expensive.
Unfortunately, methane is also a gas. An ethanol fuel cell might
be the Magic Bullet(tm), since ethanol (or at least a 95% ethanol/5%
water mixture) is generatable via fermentation, though
http://www.ucc.ie/ucc/depts/chem/dolchem/html/comp/ethanol.html
suggests that most of the ethanol is manufactured from ethene (C2H4).
I have no idea where the ethene comes from but suspect our favorite
villain, namely a byproduct of fractional distillation after
sucking some sticky black gooey stuff from somewhere... :-)
>
>> 5) The densest hydrogen storage modality - atoms/liter - is diesel
>> fuel in a bucket.
>
> Can you supply the energy value ( Mj / kg ) for diesel and hydrogen ?
>
Several problems.
[1] Hydrogen is a gas. Under STP the density of hydrogen is 41 moles
per cubic meter. At 69 megaPascal one gets 27,500 moles.
Gasoline/Diesel is quoted as 45 Megajoules per liter, or
45 Gigajoules per cubic meter. For various reasons 1 mole of
hydrogen can generate 237.13 kJ, in a fuel cell, with
48.7 kJ/mol of waste heat. This translates into a total
available energy of 6.52 gigaJoules.
http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/electrol.html
Granted, that diesel fuel will weigh about 870 kg or so.
The hydrogen will come in at a svelte 55 kg. The problem,
however, is not weight but volume.
[2] Hydrogen turns things brittle.
[3] Gasoline pipelines are already in service. Convering them to
hydrogen in light of [2] would make things rather interesting.
We already have issues with methane gas breaks; hydrogen
introduces the additional complication that any hydrogen leaked
during a pipeline rupture would probably be lost forever as
it floats up out of the atmosphere (bouyancy) and thence into
interplanetary space.
The Ghost In The Machine
<Uncl...@hate.spam.net>
wrote
on Sat, 23 Apr 2005 13:15:49 -0700
<426AACF5...@hate.spam.net>:
> The Ghost In The Machine wrote:
>>
>> <Uncl...@hate.spam.net>
>> wrote
>> on Sat, 23 Apr 2005 09:52:32 -0700
>> <426A7D50...@hate.spam.net>:
>> > Robert Clark wrote:
>> > [snip]
>> >
>> >> We already have light-weight tanks that can hold 10,000
>> >> psi.
>> >
>> > A 400 liter 10,000 psi tank of hydrogen contains less here-to-there
>> > than my VW Golf's modest gasoline tank.
>>
>> = 12.754 km/liter, that's 3.529 * MJ/km. Assuming a 15 gallon
>> = 56.87 liter gas tank that's a cruising range of 450 miles
>> or 725 km, though one might want to allow for error.
>> Total energy: 2.559 gigaJoules.
>>
>> 10000 psi = 69 megaPascal.
>> 400 liter = 0.4 m^3.
>> n = PV/(RT) = 6.9*10^7 * 0.4 / (8.314472 * 300) = 1.107 * 10^4 moles.
>> Reaction: H2 + 1/2 O2 = H2O + 285.8 kJ/mole H2.
>> Total energy: 3.164 gigaJoules.
>>
>> Of course, that Golf probably won't be able to hold a 400 liter
>> hydrogen gas tank. :-) I'm also curious as to the weight of the
>> tanks per megaJoule; I've not accounted for acceleration to
>> cruising speed, which for a 2 metric tonne car accelerating to
>> 30 m/s = 67.1 km/hr is .9 megaJoule right there. Every extra
>> kg requires 450J in the budget -- and then one has to worry
>> about breaking.
>>
>> But never mind that, hydrogen cars are the future! If only because
>> Bush & Co. say so -- assuming anyone believes them at this point.
>>
>> > The hydrogen tank also
>> > contains
>> >
>> > (400 liters)(680 atmospheres)(101.235 J/l-atm) =
>> >
>> > 27.5 megajoules of /_\PV energy. That is the energy of detonation of
>> > 14.5 lbs of TNT after a minor rear-ender. KA-FUCKING-BOOM!
>> > (Apologies tendered to readers for author's inability to display
>> > pleases you.
>>
>> 14.5 lbs TNT = 30 MJ = about 16.7x the energy of a head-on collision
>> between two metric tonne vehicles both moving at 30 m/s (67.1 mph).
>>
>> # # # ###### ####### ####### # #
>> # # # # # # # # # # ## ##
>> # # # # # # # # # # # # # #
>> ### # # ###### # # # # # # #
>> # # ####### # # # # # # # #
>> # # # # # # # # # # # #
>> # # # # ###### ####### ####### # #
>>
>> Fortunately for most of the rest of us, gasoline doesn't
>> explode all that readily and gas tanks are well protected.
>> (Except in '74 Pintos. I don't know regarding Golfs. :-) )
>>
>> Hydrogen might be even safer, were it not for the pressure.
>> Presumably, that's the killer, here.
>>
>> >
>> > BTW, jackass, that is the energy you must INPUT to pressurize the
>> > tank. It is unrecoverable upon discharge. How much gasoline must you
>> > burn to run the compressor to fill your 10,000 psi hydrogen tank? Oh,
>> > wait! You'll burn HYDROGEN! Idiot.
>> >
>>
>> The tank pressurization energy should be partially recoverable though
>> I'm not sure exactly how, but prototype liquid nitrogen cars have
>> been suggested by a Webpage somewhere; I'd have to find it now.
>> Of course, they're far worse than hydrogen, mileage-wise.
>>
>> I am not so naive to think we can recover all of it, of course, and
>> I doubt that significant recovery is even possible, as the regulator
>> (the bit that actually releases the gas) will probably freeze up.
>>
>> <mode voice="habshi"> Of course we might be able to convert that
>> into air conditioning. </mode> :-)
>
Pure theory, admittedly. :-) I'm mildly surprised regarding
the 10,000 PSI figure, as scuba tanks are only a third that.
Come to think of it, scuba tanks might be a good starting point
for computing the mass per megaJoule of hydrogen -- or I could
go the rocketry approach, I suppose.
> A 400 liter 10,000 psi
> hydrogen tank will give the same driving range as a tank of gasoline
> in a VW Golf, if it is weightless and threads to fill the entire
> underside volume of the car.
Hence my question earlier. Good point, that.
> If it ruptures the /_\PV energy release
> is 16X the energy of a 70 mph head-on collision between two luxury
> cars... the same amount of energy being needed each time to fill it at
> pressure.
>
> The solution? Fuel cells! Why a child could have thought of it -
> preferably one pre-arithmetic.
>
Actually, I for one would think one nice solution would
be a fusion accelerator unit -- and that's if someone's
solved a fair number of technical problems, beginning
with actually being able to reliably create fusion in a
car engine the size of a Hummer's or even a mine truck's,
never mind a Golf's. Fuel cells merely attack the engine
side of the problem. One might characterize the entire
problem as a conversion of something to mechanical energy;
fuel cells introduce electrical as an intermediate.
25 MeV nuclear versus maybe 1 eV chemical. Then again,
almost all life depends on nuclear fusion anyway; it's
just that the reactor is about 150 gigameters away and
looks suspiciously like a star...
(This is not an original idea, BTW: Piers Anthony
postulates in _Hard Sell_ (1990) a vehicle going beyond
the speed of sound powered by a hydrogen fusion engine
-- driven by a guy who is barely conscious as he's
forgotten his medication. Erm.. excuse me, reality check
please... :-) )
One other solution (given no technological breakthrough
of some sort), is to go with a variant of Carter's fuel
synthesis program, creating gasoline from sunlight, water,
and carbon dioxide, if that's possible with some sort
of bioengineered bug. Failing that, we might go with
ethanol, if the modifications to car engines and fuel
delivery systems aren't too great. (There's also the
minor issue of denaturation. I'd also have to find out
if fermentation will be able to satisfy the thirst of a
billion cars. Hmm...what is the number of million-miles
driven yearly, worldwide?)
At least that way we go with the devil we know -- liquid
hydrocarbon fuels -- as opposed to exchanging it with
a devil that we really don't have that much experience
with (at least, not that much outside of the scientists
that work with hydrogen on a regular basis; but AIUI those
are relatively few compared to the motoring public, most
of whom might be able to figure out if a coolant hose is
leaking, but that's about it).
Or we can just have the Chinese build us a billion bicycles.
That's probably healthier, if the fuel used to power those
bicycles (I prefer pasta :-) ) can be reliably grown,
manufactured, etc. Can't be much cleaner than that, without
taking all of our clothes off and growing grass on the
current motorways (assuming said grass can survive being
trampled on by commuting feet; with our luck we'd have
to use AstroTurf(tm), which is petroleum-based).
Mark Thorson
> Yer screwed, Clarke - starting
> with where you mine the hydrogen
Get with the program, Al.
"Hydrogen" is a code word for Nuclear Power Is Back!
That's where you "mine" hydrogen.
Mitchell Jones
Uncle Al <Uncl...@hate.spam.net> wrote:
> Robert Clark wrote:
> [snip]
>
> > We already have light-weight tanks that can hold 10,000
> > psi.
>
> A 400 liter 10,000 psi tank of hydrogen contains less here-to-there
> than my VW Golf's modest gasoline tank. The hydrogen tank also
> contains
>
> (400 liters)(680 atmospheres)(101.235 J/l-atm) =
>
> 27.5 megajoules of /_\PV energy.
***{I didn't happen to have that 101.235 J/l-atm factoid floating around
in my head. Let's see: (400)(680) = V(1), so at 1 atmosphere the volume
will be 2.72x10^5 l, or 272 m^3. In effect, we raise a 1 m^2 piston a
distance of 271.6 m. Average pressure is 340 atm, which means the
average force on the 1 m^2 is [(14.7/2.2)(9.81)/(2.54^2)](100^2) =
1.02x10^5 N. Work done on expansion through a distance of 271.6 m is
therefore (271.6)(1.02x10^5) = 27.6x10^6 J. Good enough. --MJ}***
> That is the energy of detonation of
> 14.5 lbs of TNT after a minor rear-ender.
***{The combustion energy of TNT is 4.184 MJ/kg, or 1.9x10^6 J/lb. [See
http://en.wikipedia.org/wiki/Trinitrotoluene.] So we have 27.5/1.9 =
14.5 lbs of TNT. Right again. --MJ}***
> KA-FUCKING-BOOM!
> (Apologies tendered to readers for author's inability to display
> sufficiently bold and large font in 7-bit Usenet.) Add ignition as
> pleases you.
>
> BTW, jackass, that is the energy you must INPUT to pressurize the
> tank. It is unrecoverable upon discharge.
***{While I agree with your assessment of hydrogen powered cars and with
your generalized negative attitude toward environmentalism, you go too
far here: the fuel tank pressure is completely recoverable, inasmuch as
it will do the work that a fuel pump would otherwise have to do. With a
pressurized tank, all you need is a gate valve controlled by a pressure
sensor to feed fuel into your injectors. No fuel pump is required, and
thus the energy required to operate it is also not required. In effect,
the pump that pressurizes your fuel tank is also your fuel pump. --MJ}***
> How much gasoline must you
> burn to run the compressor to fill your 10,000 psi hydrogen tank?
***{Let's see, (20,750 Btu/lb)(6.152 lb/gal)(1055 J/Btu) = 1.35x10^8
J/gal. Therefore a normal 25% efficient gasoline engine would need to
burn (2.76x10^7/1.35x10^8)/.25 = .82 gal. to pressurize the hydrogen
tank from 1 atm to 680 atm. --MJ}***
> Oh,
> wait! You'll burn HYDROGEN! Idiot.
***{My main point vis-a-vis fossil fuel burning is this: CO2 is food for
plants. Hence the more CO2 that is freed up by fossil fuel burning and
released into the atmosphere, the larger the plant biomass that can
exist on Earth. That means the burning of fossil fuels does not result
in global warming, but in global greening--an expansion of greenbelt
toward the poles accompanied by rising water tables worldwide. Since
plants are mostly water, an expansion of greenbelt can allow Earth to
move to the midpoint of the present interglacial *without* sea levels
rising another 5 meters, as happened at the midpoint of the previous
interglacial. (See, for example,
http://www.ncdc.noaa.gov/paleo/arts/webmapper/data/huon_terrace_viia2_200
1.txt.) Bottom line: we should be cheering in support of those who burn
fossil fuels, rather than denouncing them as "polluters" and passing
legislation to restrict their activities. --MJ}***
bz
F04153.020...@spectator.sj.sys.us.xo.net:
> ***{My main point vis-a-vis fossil fuel burning is this: CO2 is food for
> plants. Hence the more CO2 that is freed up by fossil fuel burning and
> released into the atmosphere, the larger the plant biomass that can
> exist on Earth. That means the burning of fossil fuels does not result
> in global warming, but in global greening--an expansion of greenbelt
> toward the poles accompanied by rising water tables worldwide. Since
> plants are mostly water, an expansion of greenbelt can allow Earth to
> move to the midpoint of the present interglacial *without* sea levels
> rising another 5 meters, as happened at the midpoint of the previous
> interglacial.
One minor problem: at the same time we are increasing the CO2 content of
the air, we are doing away with much of the earth's plant life.
Paving over farm lands as urban sprawl takes place, turning rainforests
into farm lands by slash and burn, clear cutting timber lands, and creating
ocean dead zones.
All of these exacerbate the growth of CO2, rather than countering it.
Yeah, absent those, the CO2 growth MIGHT be 'self correcting', given
sufficient time.
We don't have that time.
--
bz
please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.
bz...@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
Mitchell Jones
bz <bz...@ch100-5.chem.lsu.edu> wrote:
> Mitchell Jones <mjo...@21cenlogic.com> wrote in news:mjones-
> F04153.020...@spectator.sj.sys.us.xo.net:
>
> > ***{My main point vis-a-vis fossil fuel burning is this: CO2 is food for
> > plants. Hence the more CO2 that is freed up by fossil fuel burning and
> > released into the atmosphere, the larger the plant biomass that can
> > exist on Earth. That means the burning of fossil fuels does not result
> > in global warming, but in global greening--an expansion of greenbelt
> > toward the poles accompanied by rising water tables worldwide. Since
> > plants are mostly water, an expansion of greenbelt can allow Earth to
> > move to the midpoint of the present interglacial *without* sea levels
> > rising another 5 meters, as happened at the midpoint of the previous
> > interglacial.
>
> One minor problem: at the same time we are increasing the CO2 content of
> the air, we are doing away with much of the earth's plant life.
***{The people who are burning fossil fuel aren't responsible for that,
so why criticize them?
For example, during ancient times the Middle East, most of North Africa,
most of Mongolia, and most of Australia were not deserts. Evidence: with
the exception of Australia, there are ruins of ancient cities, long
since abandoned, scattered all over those regions. The conventional
explanation of that state of affairs is climate change. However,
climatological explanations are strained, due to the fact that the only
obvious factors preventing rainfall in those areas are the massive, heat
generated thermals that perpetually stand over each of them. But the
thermals are an effect of the lack of vegetation, not a cause. When
sunlight falls on bare earth, its energy is converted into heat--which
means: it makes molecules bounce around faster. When sunlight falls on
vegetation, on the other hand, it is used, via photosynthesis, to
assemble molecules into larger structures--which means: to facilitate
plant growth. You either get growth, or you get heat, depending on
whether plant life is present. And, of course, if plant life covered the
worlds great deserts in ancient times, then the massive thermals that
stand over them today would have been absent. Since those thermals rise
upwards from the bare earth of present-day deserts and spread out at
higher altitudes like invisible mushroom clouds, the effect is to create
a wind at high altitudes blowing away from the desert--a wind that
pushes rainclouds away. But since those thermals were absent in ancient
times, the question is: what process denuded the surface of plant life,
and permitted the thermals to form?
The answer is nomadism. Nomadic tribes live, or lived until very
recently, on the edges of all of the world's great deserts, and, in
fact, created each of them. They accomplished that feat quite simply:
they stayed in an area until they had burned all the wood in their
campfires and their grazing animals had stripped away all the grass down
to bare earth, and then they packed up their tents and belongings and
moved on to another area, which they then proceeded to destroy in the
same way. Great deserts are simply the effect of thousands of small
tribes living in this way for thousands of years. Period. There is
nothing more to the process than that.
And, of course, the root cause is the fact that private property rights
are not protected in those areas. A person who wants to farm an area,
rotate his crops, let part of his land lie fallow during a portion of
the years, can't do it. The nomads will move in and destroy the land
that he is attempting to use responsibly, and the local government will
let them do it.
Bottom line: the people who are burning fossil fuels aren't the ones
denuding large portions of the Earth of vegetation. It is the nomads,
and the altruistic thieves in the West who are perpetuating their
defective lifestyle by shipping them food, who are doing that. One
solution is for the West to shut off the food and let them starve or
change their ways. Another would be to invade the shithole countries
that practice such insanity and set up proper governments, or, at least,
governments better than savages can set up.
Unfortunately, the West has opted in favor of shithole government
itself, and, before long, will be no better off than the countries that
presently need to be invaded.
--Mitchell Jones}***
> Paving over farm lands as urban sprawl takes place
***{In countries where landed property rights are more or less
respected, the improvement in crop yields has freed up thousands of
times as much land as has been consumed by urban sprawl. In the U.S. in
the last hundred years, for example, more former crop land has been
returned to forest than the area of the state of New Mexico. Result:
there is more forest in the U.S. today than there was in 1900. --MJ}***
> , turning rainforests
> into farm lands by slash and burn
***{If property rights are protected, the conversion of land from forest
to agriculture in some areas of the world is not a problem, since the
advancement of technology is turning farm land into forest in other
areas. People have to eat, and the world needs farm land to supply them
with food. Under free market conditions, if the agricultural areas get
too large, marginal farmers will go broke, and their land will be
returned to forest. Problems only arise if governments interfere with
free markets--e.g., by subdizing the inefficient farmers who ought to be
allowed to go broke. The main problem damaging the world's forests is
not conversion to farm land, but destruction by nomadic logging.
Itinerant loggers come into an area, cut down everything, and move on.
The predictable result, especially in high rainfall areas, is that all
of the topsoil is washed into the rivers, carried to the sea, and lost
forever. But such practices can't take place if the forest is privately
owned and the rights of the owners are protected. When such destruction
happens, it is a hallmark of a primitive society, nothing more and
nothing less. --MJ}***
> , clear cutting timber lands, and creating
> ocean dead zones.
***{Itinerant fishermen, who linger in an area until the fish population
has been wiped out, and then move on, are just nomads of the sea. If
fishing rights in an area were privately owned, and the rights of the
owners were protected, it would not happen. --MJ}***
> All of these exacerbate the growth of CO2, rather than countering it.
>
> Yeah, absent those, the CO2 growth MIGHT be 'self correcting', given
> sufficient time.
>
> We don't have that time.
***{I repeat: those who burn fossil fuels are not the problem. The
problem is nomadism, in its various forms, all of which rest ultimately
on the denial of property rights in the affected areas. If you want to
do something constructive to actually deal with these problems, you
should advocate the protection of property rights in these areas of the
world, rather than advocate the placing of restrictions on those who
burn fossil fuels. They are not the problem. What they are doing
facilitates the greening of the Earth, and is a good thing. --MJ}***
bz
> ***{I repeat: those who burn fossil fuels are not the problem. The
> problem is nomadism, in its various forms, all of which rest ultimately
> on the denial of property rights in the affected areas. If you want to
> do something constructive to actually deal with these problems, you
> should advocate the protection of property rights in these areas of the
> world, rather than advocate the placing of restrictions on those who
> burn fossil fuels. They are not the problem. What they are doing
> facilitates the greening of the Earth, and is a good thing. --MJ}***
>
The "commons" problem is a problem for ALL humans.
Private property does not solve the problem, though it might if people
cared about long term consequences rather than short term gain.
It doesn't much matter who is responsible, we all partake of the
consquences.
It is better to fix problems than fix blame.
Past injustice does not justify future injustice.
The goal needs to be to minimize future injustice.
Saving the human race is a worthwhile goal.
rgrego...@yahoo.com
> ...
> ***{While I agree with your assessment of hydrogen powered cars and
with
> your generalized negative attitude toward environmentalism, you go
too
> far here: the fuel tank pressure is completely recoverable, inasmuch
as
> it will do the work that a fuel pump would otherwise have to do. With
a
> pressurized tank, all you need is a gate valve controlled by a
pressure
> sensor to feed fuel into your injectors. No fuel pump is required,
and
> thus the energy required to operate it is also not required. In
effect,
> the pump that pressurizes your fuel tank is also your fuel pump.
--MJ}***
>
percentage of this pressure- volume energy should be recoverable:
Compressed Air Energy Storage: Gaining Popularity as an Alternative
Energy Source.
"The Alabama Electric Cooperative CAES plant works like this: On nights
and weekends air is pumped underground and compressed using low-cost
electricity at pressures up to 1,078 pounds per square inch. Average
air pressure level at sea level is only 14.7 pounds per square inch.
During the day at peak times, air is released and heated using a small
amount of natural gas. The heated air flows through a turbine generator
to produce electricity."
http://www.aip.org/isns/reports/2001/025.html
In the case of the hydrogen fuel car, the natural gas used in CAES
could be replaced by the hydrogen itself.
Bob Clark
Mitchell Jones
rgrego...@yahoo.com wrote:
***{Come on, Bob, give it up. Al made one trivial mistake in a basically
correct analysis. Even if we ignore the question of what fuel we burn to
obtain the hydrogen, a hydrogen powered car is essentially a bomb on
wheels. It's a crazy idea. Worse, the supposed "problem" that the push
for hydrogen aims to solve--the release of CO2 into the atmosphere--is a
good thing. Remember, CO2 is food for plants, and is the means by which
sequestered carbon is recycled back into the biosphere. (Greenies like
plants and are in favor of recycling, right? :-) Bottom line: we live on
a world that is CO2 deficient, and we need more of it, not less. --MJ}***
Robert Clark
This assumes that all this energy would be immediately released all at
once (to have an explosion.)
Testing has shown this not to be likely:
Fill'er up-with hydrogen.
"Quantum verified the Tri-Shield's toughness by conducting a series of
rigorous tests under auspices of the European Union's European
Integrated Hydrogen Project. The tests were completed last November.
Manufacturers of storage cylinders must pass the tests to be able to
make and sell hydrogen storage cylinders in Europe.
"These tests included placing the cylinder in a crash car, firing
armor-piercing bullets at it, dropping the cylinder from six feet onto
a concrete surface, placing it in a diesel fire, cycling it thousands
of times, and subjecting the cylinder to extreme cold and to corrosive
liquids encountered in automotive environments, such as battery acids,
saltwater, brake oils, and methanols," explained Neel Sirosh, a
mechanical engineer and director of fuel storage systems at Quantum.
"The TriShield passed those tests as well as others for
vibration and shock. "These tests involved using accelerometers on test
vehicles to obtain the vibration profiles of on-the-road service,"
Sirosh said. "The vibration profiles were simulated by shake tables in
Quantum's testing labs upon which the tanks were mounted."
http://www.memagazine.org/backissues/feb02/features/fillerup/fillerup.html
The Quantum 10,000 psi tank has likewise received safety
certification.
I've never heard your theory before that more CO2 release would be
good for the planet. Do you have any references by biologists to
support that claim?
Bob Clark
Mitchell Jones
"Robert Clark" <rgrego...@yahoo.com> wrote:
***{Yes, and that will be the case if the tank is made of lightweight,
inexpensive materials.
You can, of course, enclose the tank within 3-inch thick, stainless
steel walls or something similar; but if you do so, the cost of the tank
will render the cost of the car prohibitive; and the fuel consumption
required to lug the tank around will render the car a fuel hog. And any
lightweigh alternative would require a materials science breakthrough of
some sort, would be utterly unproven by comparison to known fuel tank
materials due to lack of on-the-road testing, and would be prohibitively
expensive as well. All in all, that not a good prognosis, especially
given that the present gasoline and diesel powered vehicles are
perfectly satisfactory, have fuel distribution and repair systems in
place, are readily available, and, if the existing nutbar
environmentalist regs were repealed, would be readily affordable by
virtually everyone.
--Mitchell Jones}***
>Testing has shown this not to be likely
***{That's a generalization. As such, it is false. A true, and
unremarkable, statement would be:
"Testing has shown explosions to be unlikely FOR SOME VERY SPECIFIC TANK
DESIGNS."
Why is that unremarkable? Because there are other critical variables, as
noted above. It is a trivial achievement, from an engineering
standpoint, to produce a hydrogen tank that will not explode. What is
difficult is to produce a high capacity hydrogen tank that is
lightweight, compact, inexpensive, and will not explode.
Bottom line: it is meaningless to merely assert that a particular design
is non-explosive. For generalized vehicular use, it must also be
lightweight, compact, and inexpensive, or it is irrelevant to the point
we are discussing.
--Mitchell Jones}***
> Fill'er up-with hydrogen.
> "Quantum verified the Tri-Shield's toughness by conducting a series of
> rigorous tests under auspices of the European Union's European
> Integrated Hydrogen Project. The tests were completed last November.
> Manufacturers of storage cylinders must pass the tests to be able to
> make and sell hydrogen storage cylinders in Europe.
> "These tests included placing the cylinder in a crash car, firing
> armor-piercing bullets at it, dropping the cylinder from six feet onto
> a concrete surface, placing it in a diesel fire, cycling it thousands
> of times, and subjecting the cylinder to extreme cold and to corrosive
> liquids encountered in automotive environments, such as battery acids,
> saltwater, brake oils, and methanols," explained Neel Sirosh, a
> mechanical engineer and director of fuel storage systems at Quantum.
> "The TriShield passed those tests as well as others for
> vibration and shock. "These tests involved using accelerometers on test
> vehicles to obtain the vibration profiles of on-the-road service,"
> Sirosh said. "The vibration profiles were simulated by shake tables in
> Quantum's testing labs upon which the tanks were mounted."
> http://www.memagazine.org/backissues/feb02/features/fillerup/fillerup.html
>
> The Quantum 10,000 psi tank has likewise received safety
> certification.
***{Unless the Quantum 10,000 psi tank is compact (meaning it stores
approximately as much energy per unit volume as a gasoline or diesel
tank), lightweight (meaning it is comparable in weight to a gasoline or
diesel tank storing the same amount of energy), and inexpensive (meaning
it is comparable in cost to a diesel or gasoline tank storing the same
amount of energy), it is of no importance, insofar as generalized
vehicular use is concerned. Since the article you cited did not supply
any information that would allow a comparison to gasoline or diesel
tanks, it does not bear on the issue we are discussing at all. --MJ}***
> I've never heard your theory before that more CO2 release would be
> good for the planet.
>
> Do you have any references by biologists to
> support that claim?
***{I've never heard of a biologist denying that carbon-based life forms
need carbon, or that they obtain it, ultimately, from CO2 in the
atmosphere, so it would be essentially impossible to find a reference to
the contrary. However, since you ask, here is a good entrance point for
such information:
http://www.greeningearthsociety.org/Articles/2001/ga7.htm.
Next, for sheer fascination, try this:
http://www.thekrib.com/Plants/CO2/hurley-co2.html. This guy will explain
to you in vast detail how to maintain lush, beautiful plants in your
home aquarium--by bubbling in CO2 at a precisely controlled rate!
For those with lots of plants in the home:
http://www.bey-tech.com/CO2Blackbox.html. This company sells a fuel-cell
based CO2 generator which increases ambient CO2 concentrations in the
home up to 1500 ppm, to produce lush plant growth.
Additionally, a web search on "CO2 fertilization" ought to give you a
ton of hits. This is a topic that has been researched for at least a
hundred years, and is utterly non-controversial.
--Mitchell Jones}***
> Bob Clark
bush_au...@sbcglobal.net
> 'Where does the hydrogen come from?'
Modern thinking seems to have arrived at a consensus that when one
electron finds one proton, they join up and produce a hydrogen. Others
think that the Big Bang produced all the hydrogens there ever were or
ever will be.
I hope that answers your question, and you can quit clenching your
sphincter to the point of injuring yourself. Just like the troublesome
questions of how oil becomes gasoline, there's some technical problems
it is probably too late for you to learn this far in life and you
should leave those problems for the experts who know. All you need to
know is how to get off your wallet at the fill-up pump. As long as you
don't do anything POLITICALLY STUPID, like voting for oilmen, the
problem will take care of itself. Get ready for clean skies and
remember: NEVER vote for an oilman.
jbuch
What about voting for two oilmen?
G. R. L. Cowan
Anyone you vote into office will, at least temporarily,
become a civil servant; a disproportionate fraction of those
who have his ear will be civil servants. As such they inevitably --
http://www.opec.org/library/Special%20Publications/pdf/2004.pdf --
are oilmen.
Dan Bloomquist
bush_au...@sbcglobal.net wrote:
>>And the big question that never seems to get addressed,
>>'Where does the hydrogen come from?'
>
>
> Modern thinking seems to have arrived at a consensus that when one
> electron finds one proton, they join up and produce a hydrogen. Others
> think that the Big Bang produced all the hydrogens there ever were or
> ever will be.
>
> I hope that answers your question...
Nope.
Best, Dan.
Bret Cahill
surfboard.
A die grinder could then pump a water jet for a short burst of power
when taking off on really large waves.
The concern is, what would happen if a 10,000 psi tube burst?
Bret Cahill
Bret Cahill
Society" will get some new members.
Knotts Island has some drinkable wine from what I understand.
Bret Cahill
Oil Shale Guy
What if you could extract oil from shale using a clean coal plant as
well as creating electricity from that plant?
What if you could eliminate the popcorn effect present in the old oil
shale retort extraction methods.
What if you could do it with 1/4 of the water of old methods?
What if you could do this with no more CO2 emissions than a clean coal
plant?
What if you could refine the oil/kerogen in a distallation tower
straight out of the process without having to send the oil to a
refinery.
What if you could extract the oil for around $15Bbl US?
What if you could address nearly all of the environmental groups
concerns?
What if you could use the spent shale as a cement extender?
With one economically viable plant the United States can declare all
1-2 trillion barrels of oil as reserves.
George Dishman
"Oil Shale Guy" <goo...@go5star.com> wrote in message
news:1116645625.0...@g49g2000cwa.googlegroups.com...
> What if you could make clean coal technology 50-60% efficient?
>
> What if you could extract oil from shale using a clean coal plant as
> well as creating electricity from that plant?
>
> What if you could eliminate the popcorn effect present in the old oil
> shale retort extraction methods.
>
> What if you could do it with 1/4 of the water of old methods?
>
> What if you could do this with no more CO2 emissions than a clean coal
> plant?
>
> What if you could refine the oil/kerogen in a distallation tower
> straight out of the process without having to send the oil to a
> refinery.
>
> What if you could extract the oil for around $15Bbl US?
All of the above add C)2 to the atmosphere
so are incompatible with the next:
> What if you could address nearly all of the environmental groups
> concerns?
You can, use biodeisel so you take out as
much CO2 as you put back. No net increase
and totally renewable for as long as the
Sun shines.
> What if you could use the spent shale as a cement extender?
>
> With one economically viable plant the United States can declare all
> 1-2 trillion barrels of oil as reserves.
Reserves aren't reserves if you extract
them ;) Declare them as reserves, then
leave them there.
George
Bret Cahill
That is affordable but the question is, how much can they produce?
Bret Cahill
Uncle Al
>
> Iowa veggie oil for biodiesel now sells for about $2.85/gallon.
>
> That is affordable but the question is, how much can they produce?
It does NOT sell for $2.85/gallon! That is the pump price. Add in
amortized government subsides. The proper question is "how little can
they produce?"
Mark Thorson
> What if you could address nearly all of the environmental
> groups concerns?
What if the one you can't address is extensive, irreversible
mixed hydrocarbon pollution of underground aquifers?
Oil Shale Guy
Gordon Couger
> "Uncle Al" <Uncl...@hate.spam.net> wrote
>
>>"G. R. L. Cowan" wrote:
>>
>>>Jonathan Barnes wrote:
>>>
>>>>>>>psi.
>>>>>>
>>>>>>A 400 liter 10,000 psi tank of hydrogen contains less
>
> here-to-there
>
>>>>>>than my VW Golf's modest gasoline tank.
>>>>
>>>>
>>>>for 400 l capacity
>>>>0.4 = 4/3 x pi x r^3 gives a diameter of 915 mm
>>>>
>>>>weight of steel tank ( approx ) = 2.1 tonnes
>>>>
>>>
>>>Two tonnes of tank wall, 13 kg of payload.
>>>
>>>Instead of weighing as much as a regular car,
>>>an automotive hydrogen tank can cost as much as one:
>>>the carbon filament-wound tanks in the GM Hy-Wire and Sequel
>>>vehicles, if they exist. At 5,000 psi, 2 kg H2 is contained
>>>in only 75 kg of tank.
>>>
>>
>> 2) What makes you think organics would hold 10,000 psi
hydrogen
>>against diffusion?
>
>
> A coating of something needed ???
>
>
>>organic wall tank to 10,000 psi 50 times/year for five years
is not a
>>clever idea.
>
>
high
> pressures, but wound tanks do prefom well, but they are
expensive, and there
> is little on cost to be saved with volume production...
>
>
>> 3) Housewife + liquid hydrogen = TV sitcom.
>
>
> More a disaster movie I would think :-)
>
>> 4) A hydrogen-burning engine would be a major NOx
polluter. A fuel
>>cell car would be an expensive joke
>
>
> Fuel cell could improve drematicaly, but the hydrogen storage
problem
> remains.... methane powered cells look interesting... but
they are to
> complicated and thus are very expensive.
>
>
is diesel
>>fuel in a bucket.
>
>
> Can you supply the energy value ( Mj / kg ) for diesel and
hydrogen ?
>
>
There is no hydrogen to burn for fuel.
There is no way to economically make hydrogen fuel.
There is no way to store hydrogen fuel that doesn't leak like a
sieve.
You can't use steel to store hydrogen because hydrogen make
steel brittle.
You can't put enough hydrogen in a car to go any where.
You can't fill up a hydrogen tank in a reasonable time.
It is not safe to store hydrogen in large amounts in town.
Bush needed to green wash his image and nothing is greener than
hydrogen. Just because its impossible to do means nothing to a
politician. Especial if it doesn't endanger his oil business.
Gordon Couger
Stillwater, OK
www.TakeThisOUTcouger.com/gcouger
Gordon Couger
more than half and do away with all the particulates.
I don't know how efficiently propane will burn because I have
never seen an engine with a high enough compression ratio to
take full advantage of it. But a good installation will equal
the gas millage in gallons and propane weighs 4 pounds to the
gallon and gasoline 7 pounds.
I don't think any states require any pollution controls at all
on propane powered vehicles and the whole industry and
infrastructure is there for it already.
Propane is not perfect but it is a lot better than anything else
we have.
Gordon Couger
> <rgrego...@yahoo.com> wrote in message
> news:1114311725.7...@l41g2000cwc.googlegroups.com...
>
>>Uncle Al wrote:
>>
>>>...
>>>Get this through your thick insane head: By a huge margin
(even on a
>>>log-axis), the densest storage of hydrogen - atoms/liter -
is diesel.
>>
>>>You can do that in an uncovered $1.50 bucket from K-Mart.
Diesel
>>>comes out of the ground for no more than $2.00/bbl amortized
cost as
>>>petroleum. Not cost per gallon, jackass, cost per barrel.
That is
>>>what Arabian crude production costs. They cap and forget
any well
>>>that is not a gusher.
>>>
>>>...
>>
>>Unless you're going to use this diesel fuel in a reformer to
convert
>>it into hydrogen, this is irrelevant to the issue at hand.
You remember
>>reformers, right Al? Their PURPOSE is to reduce POLLUTION.
>
>
> If your concern is to reduce CO2 production,
> then consider a simpler alternative. If the
> fuel recycles atmospheric carbon then there
> is no net production:
>
> http://www.absoluteastronomy.com/encyclopedia/B/Bi/Biodiesel.htm
>
> or
>
> http://www.absoluteastronomy.com/encyclopedia/B/Bi/Bioalcohol.htm
>
> Check out what Brazil is doing.
>
> George
>
>
Who ever sold the world on the circular logic that make bio fuel
nonpolluting makes Goebbels look like a beginner. If the land
is farmed and the fuel is burned the fact that it was made from
farm products does not reduce the pollution. It would be far
less polluting to raise no till crops and sell them for what
they are worth and bun oil for the few gallons of fuel that can
be made from the soil and let the not till framing tie up that
carbon and 2 or 3 times more carbon in the crop residue.
Gordon Couger
>
>>"Jonathan Barnes" <jbar...@btinternet.com> wrote in message
>>news:d4eo7b$kt$1...@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...
>>
>>>"Uncle Al" <Uncl...@hate.spam.net> wrote in message
>>>
>>>
>>>>Hey stooopid, what length of 0.5 mm bore must you
accumulate to store
>>>>400 liters of volume? Will the H*Y*D*R*O*G*E*N car pull a
16-wheel
>>>>trailer? Oh yeah, every bend screws your flow rate big time.
>>>>
>>>
>>>Hay Uncle Al
>>>
>>>I'm happy to call a bend radius of twice the pipe diameter
as low
>>>restriction, so your 0.5 mm bore pipe should be O.K. with 1
mm radius
>>>bends....
>>
>>What I think Al is refering to is not a change in the
internal dimensions
>>caused by bending (although very sharp bends do have this
problem), but the
>>'secondary flow' of fluids flowing through tubing with bends
in it. The
>>momentum of the fluid causes it to move to the outer edge of
the tubing and
>>displace fluid around in a sort of 'eddy'. This transverse
eddy flow robs
>>the fluid of energy causing a much larger pressure drop for a
given flow
>>rate than would be expected by the viscous friction alone.
If the relative
>>radius is optimized (experimental data suggests an r/d of
aobut 4), then the
>>secondary flow effects in a 90 degree bend are equivalent to
about 12
>>pipe-diameters more resistance than an equal length of
straight tubing.
>>
>>Most flow experimental data is with much larger bore though.
Considering
>>the viscous boundry layer is a sizeable portion of your total
bore, it may
>>behave more like laminar flow all the time. And that would
mean the viscous
>>losses follow (diameter)^5 instead of (diameter)^4.
>>
>>Some experiments in fluid flow around bends suggest there is
an optimal
>>relative radius. When the bend radius is smaller, of course
the flow
>>resistance rises. But what is surprising is that if the
bend's relative
>>radius (r/d) is *increased* from the optimum, the flow
resistance again
>>rises. For example, Davis found increases in flow resistance
of the order
>>of 25% when increasing the relative radius from 4 to 14 tube
diameters.
>>Balch found increases of over 100% in similar relative radius
range. Even
>>with a relative radius bend of 20, the problem still exists.
Not until you
>>get out past 50 r/d do 'secondary flow' effects drop off
again. The low
>>point in flow resistance is with a relative radius of about 4
(2mm). So
>>either keep all bends to about 2mm, or larger than 25 mm to
maximize the
>>flow rate.
>>
>>With such a small bore tube, it would be difficult to get all
the hydrogen
>>out in a timely manner if it were just one continuous length.
Cutting the
>>tubing into much shorter lengths would seem in order (for a
0.5mm bore to
>>contain 400 liters, it would have to be over 2000 km long).
So obviously
>>some sort of manifold would be needed to connect literally
thousands of such
>>small bore tubes together. If each tube was 100 m long, that
would take
>>over 20000 connections to such a manifold. This manifold, of
course, would
>>be subject to the same pressures as the storage system.
>>
>>Technologicly, making up some 20000 connections, and sealing
them against
>>hydrogen leaks at 10000 psi sounds like quite a challenge.
There will never be a automtive system that doesn't have major
leaks. A hydrogen atom is damned small and makes almost every
metal brittle.
Fortunately hydrogen is lighter than air and roof look like
chicken wire to it.
George Dishman
"Gordon Couger" <gcougerTa...@couger.com> wrote in message
news:kbXje.9883$Ri4.6854@okepread07...
> George Dishman wrote:
> >
> > If your concern is to reduce CO2 production,
> > then consider a simpler alternative. If the
> > fuel recycles atmospheric carbon then there
> > is no net production:
Ok, so "no net production" isn't stricly true
at the moment but it's fiarly close. ;-)
> Who ever sold the world on the circular logic that make bio fuel
> nonpolluting makes Goebbels look like a beginner. If the land is farmed
> and the fuel is burned the fact that it was made from farm products does
> not reduce the pollution.
Interesting, so what proportion of the carbon in
biodiesel do you think comes from atmospheric CO2
absorbed by the crops and how much from the soil?
I take it you realise that, to be sustainable, any
net removal of carbon from the soil would need to
be balanced by appropriate crop rotation.
> It would be far less polluting to raise no till crops and sell them for
> what they are worth and bun oil for the few gallons of fuel that can be
> made from the soil and let the not till framing tie up that carbon and 2
> or 3 times more carbon in the crop residue.
Any technique that digs up fossil carbon and
releases it into the atmosphere is a going to
change the balance, and we are deforesting so
fast there isn't a restoring mechanism at the
moment. Alcohol, diesel and propane are all
more practical than hydrogen but the key is
to bring the rate of release of fossil carbon
down to a sustainable level whichever fuel you
favour.
George
G. R. L. Cowan
>
>
> ... nothing is greener than
> hydrogen. Just because its impossible to do means nothing to a
That's what green *means*.