Na + H2O2 (50%) -> H2?

[charliew2]

Don, apparently ZHEN doesn't yet realize that with pure water and sodium,
you get hydrogen. You DON'T want excess oxygen when this happens.
Translation - dumping sodium into hydrogen peroxide is indeed INSANELY
DANGEROUS.

 

[Don Lancaster]

Don, apparently ZHEN doesn't yet realize that with pure water and sodium,
you get hydrogen. You DON'T want excess oxygen when this happens.
Translation - dumping sodium into hydrogen peroxide is indeed INSANELY
DANGEROUS.

The trick is to use a flask made of lithium borohydride when you do
this.

--
Many thanks,

Don Lancaster
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
voice: (928)428-4073 email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[The Phantom]

An individual can easily buy concentrated sodium.
An individual is prohibited from buying concentrated H2O2.

Here in the Seattle area some health food stores sell so called "food
grade" 35% H2O2. The 35% stuff is plenty strong enough to severely
damage skin and eyes, and if it comes into contact with an appropriate
catalyst such as fine divided metals, it can decompose fast enough to
cause thermal burns.

They sell it as a food additive, to "oxygenate" your blood, a function
that I find is fulfilled adequately by breathing.

 

[David Harper]

Where did you get such a silly idea?

1 pound of CONTAINED terrestral hydrogen does not have remotely the
same energy density as 1 pound of contained gasoline.

I was basing it off the statement made by Bob. I assumed his statement was correct.

 

[David Harper]

You have shown examples where individuals lack an understanding of the
potential applications. Hydrogen doesn't fit here.

To speak of hydrogen as the wonder fuel of the future is like saying
nuclear fusion would be 'the' energy source of the next decade back in
the 50s.

When did I ever say hydrogen was a "wonder fuel" and will be the fuel
of the 2010's? I only made the statement that saying 'hydrogen will
never be viable energy source due to cost' was short sighted.

Hydrogen as a 'fuel' has serious physical limitation. One of the biggest
is that it is not an energy source.

What?! What about fuel cells? The shuttle main engines? Sure, you
need oxygen too, but saying it's not a source of energy...???

And what physical limitations are you talking about? The only one I
can think of is volume when it's not cryogenic.

And to imply that this can be
overcome by 'vision' means you would have to defy nature, which is not
the case in the examples you have posted above.

Best, Dan.

How would using hydrogen as a fuel "defy" nature? Afterwards, you
might want to inform NASA that their shuttle doesn't work.

Dave

 

[David Harper]

You forgot the old saw that if man was meant to fly, God would have given
him wings. That facts are than many things deemed impossible or impractical
still are, your examples not with standing. Carnot efficiency in a
thermodynamic engine comes to mind as does the various perpetual motion
ideas that come up from time to time.

Sure, but we're not discussing engine efficiencies or compression
ratios (which you could improve with hydrogen, BTW). We were only
discussing the fuel source for those engines.

Just because some bozo thought the
telephone was impractical does not mean that hydrogen is practical.

Today, that statement is correct. My contention is that in the future
that statement may proove false. When? I don't know.

Hydrogen
has many negatives that have been discussed here and elswhere ad nausium.

Correction: Hydrogen CURRENTLY has many negatives that have been
discussed here and elswhere ad nausium.

Do
yourself a favor and find out what the negatives are then propose what has
to happen to get around them. If you can find solutions, you could become a
very rich man, indeed.
Bob

Exactly. Figure out what has to be done to get around them... again,
my point wasn't that hydrogen is a viable option today. It was that
it is possible in the future. How this will happen? I don't know.
When? I don't know.

But saying hydrogen will always be the "fuel of the future" implies it
will never be practical.

 

[G. R. L. Cowan]

When did I ever say hydrogen was a "wonder fuel" and will be the fuel
of the 2010's? I only made the statement that saying 'hydrogen will
never be viable energy source due to cost' was short sighted.


What?! What about fuel cells? The shuttle main engines? Sure, you
need oxygen too, but saying it's not a source of energy...???

And what physical limitations are you talking about? The only one I
can think of is volume when it's not cryogenic.


How would using hydrogen as a fuel "defy" nature? Afterwards, you
might want to inform NASA that their shuttle doesn't work.

If he does, it might not be their first clue ...

Interestingly, in the first few miles of each of its flights,
when it was flying, more than half the Shuttle's power
came from aluminum combustion. You might be interested in
the following thought experiment:


(1) Take a serious hydrogen car such as the recent BMW 750.
Like every such car it has a combustion motor
and a cryogenic liquid hydrogen tank.
Remove most of this tank's guts -- the vacuum
superinsulation, the heater, the 140-L inner tank.
Keep only the 175-L outer steel shell;
if you want, change it to aluminum.

(2) Put 63 litres of aluminum pellets into it.

(3) Replace -- this is a difficult step, but it's all the
same price to think about -- the hydrogen burner motor
with an aluminum-burning one.

As proof that such motors can exist, I offer the
space shuttle's SRBs. When the shuttle was flying,
the first 10 miles or so of every flight was
principally aluminum combustion-powered.

(4) Run the vehicle until all the aluminum has burned.
Pressed into small briquettes, the resulting oxide
should fill up about 96 litres of space, so it can
go back in the tank. In fact, it can have its own
compartment there.

(5) Note how far you drove: well over a thousand km,
over three times as far as is possible using the
same space for hydrogen.


--- Graham Cowan
http://www.eagle.ca/~gcowan/Paper_for_11th_CHC.doc --
How individual mobility gains nuclear cachet.
Link if you want it to happen

 

[MH]

One seemingly too much neglected problem with small consumer vehicles with
hydrogen engines is really the problem with H2 storage; Cryogenic storage is
not a real option (either you drive a lot or let the hydrogen boil into air-
I suppose that a real tank in a real car would boil out within a week as
best) or then you use high pressure bottles, whose capacity/weight ratio
wouldn't be very impressive. Both are dangerous in crash situations; Leaking
liquid hydrogen freezes everything nearby and/or is a fire hazard (at least
some special material maintaining its ductility in very low temperatures to
resist rupture should be used in the tank and its weldings), compressed gas
bottles are prone to explode in fires or collisions making rescue workers'
days bad.

I believe that instead of using raw hydrogen, the cars of future will be
burning different alcohols- they are easy to produce even from hydrogen,
handle and store. Further, they can be used in most normal combustion
engines normally burning gasoline after some adjusting.

Regards, Matti

 

[Sam Goldwasser]

If he does, it might not be their first clue ...

Interestingly, in the first few miles of each of its flights,
when it was flying, more than half the Shuttle's power
came from aluminum combustion. You might be interested in
the following thought experiment:


(1) Take a serious hydrogen car such as the recent BMW 750.
Like every such car it has a combustion motor
and a cryogenic liquid hydrogen tank.
Remove most of this tank's guts -- the vacuum
superinsulation, the heater, the 140-L inner tank.
Keep only the 175-L outer steel shell;
if you want, change it to aluminum.

(2) Put 63 litres of aluminum pellets into it.

(3) Replace -- this is a difficult step, but it's all the
same price to think about -- the hydrogen burner motor
with an aluminum-burning one.

As proof that such motors can exist, I offer the
space shuttle's SRBs. When the shuttle was flying,
the first 10 miles or so of every flight was
principally aluminum combustion-powered.

(4) Run the vehicle until all the aluminum has burned.
Pressed into small briquettes, the resulting oxide
should fill up about 96 litres of space, so it can
go back in the tank. In fact, it can have its own
compartment there.

(5) Note how far you drove: well over a thousand km,
over three times as far as is possible using the
same space for hydrogen.

Now calculate how much energy was needed to extract the aluminum
in the first place!

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header is ignored.
To contact me, please use the feedback form on the S.E.R FAQ Web sites.

 

[David Harper]

If he does, it might not be their first clue ...

Interestingly, in the first few miles of each of its flights,
when it was flying, more than half the Shuttle's power
came from aluminum combustion. You might be interested in
the following thought experiment:


(1) Take a serious hydrogen car such as the recent BMW 750.
Like every such car it has a combustion motor
and a cryogenic liquid hydrogen tank.
Remove most of this tank's guts -- the vacuum
superinsulation, the heater, the 140-L inner tank.
Keep only the 175-L outer steel shell;
if you want, change it to aluminum.

(2) Put 63 litres of aluminum pellets into it.

(3) Replace -- this is a difficult step, but it's all the
same price to think about -- the hydrogen burner motor
with an aluminum-burning one.

As proof that such motors can exist, I offer the
space shuttle's SRBs. When the shuttle was flying,
the first 10 miles or so of every flight was
principally aluminum combustion-powered.

(4) Run the vehicle until all the aluminum has burned.
Pressed into small briquettes, the resulting oxide
should fill up about 96 litres of space, so it can
go back in the tank. In fact, it can have its own
compartment there.

(5) Note how far you drove: well over a thousand km,
over three times as far as is possible using the
same space for hydrogen.


--- Graham Cowan
http://www.eagle.ca/~gcowan/Paper_for_11th_CHC.doc --
How individual mobility gains nuclear cachet.
Link if you want it to happen

Yes, you could use aluminum (or many others), although it would
"probably" need to be atomized before it got to the engine. Also, the
engines would experience extreme problems with aluminum oxide deposits
(as it would be molten), and removing it from the cylinders might
proove difficult, as would the extreme wear you'd get in the cylinders
and pistons. Not that this couldn't be worked around, but I don't see
it being as easily renewable as hydrogen could be (anytime soon).

Also, the first few miles (up to 200k or so feet) of the shuttle
launch = 2 minutes. The remaining 6 or 7 are all H2+O2. But your
point is valid.

Dave

 

[Fred B. McGalliard]

....

So, hydrogen would have to come from some non fossil source to be a fuel
of the future, and that source is non existent.

Let us suggest that oil is suddenly way too hard to find and costs over $40
per barrel. We still have a lot of cars, trucks, tanks, and bombers that
need fuel. What do we do? Right now I would build a large coal to oil plant.
You might want to remember that coal to oil is around 40-60% efficient (as I
recall), and unless we add nuclear or natural gas energy and hydrogen from
these sources we generally add water and belch out a lot of extra CO2, to
provide the energy to crack H2 from water with the very coal supply we are
making fuel from. In this case, hydrogen, except for it's poor properties as
a transportation fuel, is energetically about the same as oil and is a
fossil fuel (or a fossil derived fuel anyway), just like oil. In a dense
city, we already know what lots of oil burners does. H2 has some advantage
then, for local pollution, even if the greenhouse gas emissions is not
helped. And if we are making oil or H2 from the same sources, it is a
max-nix (doesn't make any difference). Look at the problem closely. You will
notice that any argument that H2 is a bad fuel because of the source of the
energy, in the end, becomes exactly the same argument against fuel oil made
from these same sources.
This implies some engineering solutions that should be discussed openly as
part of the conclusion.

 

[Fred B. McGalliard]

...
(2) Put 63 litres of aluminum pellets into it.

(3) Replace -- this is a difficult step, but it's all the
same price to think about -- the hydrogen burner motor
with an aluminum-burning one.

As proof that such motors can exist, I offer the
space shuttle's SRBs.

OK. You could have an aluminum air battery with replaceable plates (or some
kind of rolling sheet plate). You can just burn the aluminum and make an
external combustion heat engine. You can burn the aluminum with water, take
the hot hydrogen and run a more normal IC engine. The battery energy density
is apparently not so hot, and the mechanism rather complex. The external
combustion engine is very very large and heavy. This would undoubtedly work
for a train, but not so much for a passenger car. The H2 conversion would
probably work OK, but the product has a lot more volume and you do have to
find a way to use the large heat released in the fuel reforming tank. The
process is interesting, but you have to figure out how to make it practical.

 

[Bob Eldred]

But saying hydrogen will always be the "fuel of the future" implies it
will never be practical.

Bingo! I believe that because there are always many alternatives to
hydrogen that do not carry the limitations, are cheaper, more convienient
and practical. That is true today and should continue to be true in the
future. One has to ask: why hydrogen? The only answer is its percieved
cleanliness and low polution coupled with potential reduction of CO2
emissions. Of course, if it is made from a carbon source, coal, methane,
etc. the CO2 issue is a red herring. Furthermore low polution can be
obtained in other, more convienient ways. Biofuels will answer the CO2
question. All of the issues that make hydrogen attractive are and will
continue to be answered by more convenient, cheaper, safer alternatives.
Even in the case of fuel cells, methanol will most likely become the fuel of
choice. That's why hydrogen will always be "the fuel of the future."
Bob

 

[Dan Bloomquist]

When did I ever say hydrogen was a "wonder fuel" and will be the fuel
of the 2010's? I only made the statement that saying 'hydrogen will
never be viable energy source due to cost' was short sighted.

As hydrogen is not an energy source, the cost of the source is
compounded by the losses in the hydrogen vector. The limitation is
physical, and vision doesn't change that.

What?! What about fuel cells?

What about them?

The shuttle main engines? Sure, you
need oxygen too, but saying it's not a source of energy...???

NASA's hydrogen comes from the energy source methane. Half the energy of
that perfectly good methane is lost in reformation. But if you think it
makes sense to convert one perfectly good fuel into another that is
harder to handle and loose half your energy in the process...

And what physical limitations are you talking about? The only one I
can think of is volume when it's not cryogenic.

That it is not an energy source. You must produce it from other energy
sources. And handling it cost you some 20 to 30 percent of the energy
content it carries.

How would using hydrogen as a fuel "defy" nature? Afterwards, you
might want to inform NASA that their shuttle doesn't work.

As long as you don't imply that it is a clean source of energy, no
problem. But it is neither clean nor a source. More than twice as much
CO2 is produced by using hydrogen rather than using methane directly.
Maybe more than three times as much if you consider the potential
mechanical net of using methane in a combined SOFC plant.

Dave

Best, Dan.

 

[David Harper]

So, hydrogen would have to come from some non fossil source to be a fuel
of the future, and that source is non existent.

Currently, yes.

At our present rate of
evolving the way we deal with energy, it will likely take 5 to 10
decades before hydrogen can be considered much less seriously implemented.

You know as well as I do that the first non fossil source of hydrogen
would have to come from a nuclear driven thermochemical processes.

And you're predicting this will be the first realistic way hydrogen
can be provided 50 to 100 years in advance? 50 to 100 years from now,
there may be many other methods that could surpass nuclear power as a
method to provide hydrogen.

Just to throw out a few "concepts":

1. Bateria genetically engineered to live off our millions of tons of
waste biomass that produce hydrogen.
2. Nanotech machines existing in large pools of water that use solar
energy to separate H2O into H2 and O2.
ex: 10% efficiency (which is worse than even bad solar cells) * 1000
W/m^2 (solar flux) * 8 hours sun per day = 2.9 Megajoules/m^2/day. A
1500m x 1500m "pool" could power 250,000 cars. (average car requires
4kW during an urban driving schedule * 1 hour driving / engine
efficiency = 28.8 MJ per car). Now just make a few dozen of these
pools per state.

Dave

 

[Dan Bloomquist]

...



Let us suggest that oil is suddenly way too hard to find and costs over $40
per barrel. We still have a lot of cars, trucks, tanks, and bombers that
need fuel. What do we do? Right now I would build a large coal to oil plant.
You might want to remember that coal to oil is around 40-60% efficient (as I
recall), and unless we add nuclear or natural gas energy and hydrogen from
these sources we generally add water and belch out a lot of extra CO2, to
provide the energy to crack H2 from water with the very coal supply we are
making fuel from. In this case, hydrogen, except for it's poor properties as
a transportation fuel, is energetically about the same as oil and is a
fossil fuel (or a fossil derived fuel anyway), just like oil. In a dense
city, we already know what lots of oil burners does. H2 has some advantage
then, for local pollution, even if the greenhouse gas emissions is not
helped. And if we are making oil or H2 from the same sources, it is a
max-nix (doesn't make any difference). Look at the problem closely. You will
notice that any argument that H2 is a bad fuel because of the source of the
energy, in the end, becomes exactly the same argument against fuel oil made
from these same sources.
This implies some engineering solutions that should be discussed openly as
part of the conclusion.

But Fred,
We could say what if there were no ocean, or some other what if. Real
world, oil is not going to suddenly be hard to find. Known reserves,
even if they are sand and tar oil, are enormous. Oil will get more
expensive. If something needs to be done today, it is about developing
new 'sources' of energy. Hydrogen does not address 'today's' challenges.

Best, Dan.

 

[Dan Bloomquist]

Currently, yes.




And you're predicting this will be the first realistic way hydrogen
can be provided 50 to 100 years in advance? 50 to 100 years from now,
there may be many other methods that could surpass nuclear power as a
method to provide hydrogen.

I said 'likely', i.e., my best guess. And yes, it may be economical
enough to do with solar and a thermo chemical process. We may have made
fusion work. But that's about it. But until you displace fossil as a
source of energy, it makes little sense to use hydrogen as a fuel.

Just to throw out a few "concepts":

1. Bateria genetically engineered to live off our millions of tons of
waste biomass that produce hydrogen.

Compare the available waste biomass of the world to the 70 million
barrels of oil a day we use. It hardly makes an impact. And because
biomass is carbon cycle neutral, why not make a fuel that is easily
handled like alcohol?

2. Nanotech machines existing in large pools of water that use solar
energy to separate H2O into H2 and O2.

Probably science fiction for another 5 or 10 decades.

ex: 10% efficiency (which is worse than even bad solar cells) * 1000
W/m^2 (solar flux) * 8 hours sun per day = 2.9 Megajoules/m^2/day. A
1500m x 1500m "pool" could power 250,000 cars. (average car requires
4kW during an urban driving schedule * 1 hour driving / engine
efficiency = 28.8 MJ per car). Now just make a few dozen of these
pools per state.

If you want to use solar, use it to start displacing coal on the grid.
If you use it to make hydrogen for vehicles, it is equivalent to getting
about 5% of the heating value of that coal to the wheels of a car. Seems
like a terrible waste to me.

Dave

Best, Dan.

 

[Teel Adams]

This is the most messages that sci.chem.engr has gotten in my memory.
Just to be silly, never forget that you can react Aluminum in water to
produce hydrogen. Not really that hard, and Aluminum does not explode on
contact with water.

As far as non-fossil fuel hydrogen. Bio-reaction/solar would appear to be a
rather good source. I believe the proteins are being produced in thin films
now?

 

[Fred B. McGalliard]

....

oil is not going to suddenly be hard to find. Known reserves,
even if they are sand and tar oil, are enormous. Oil will get more
expensive. If something needs to be done today, it is about developing
new 'sources' of energy. Hydrogen does not address 'today's' challenges.

Variations on a theme. Oil (and hydrogen) are made from raw energy sources.
Oil from crude oil, even oil sands, is just easier, cheaper, to make than
hydrogen. So what, of 'today's challenges', are addressed by hydrogen and
how about comparing these to the solution we have with oil?

Local pollution
H2 is way way way better than the lousy oil we burn. Big impact here, but
only with a major conversion of the whole transportation infrastructure..

The use of alternative energy sources (coal, nuclear, solar, etc)
H2 and fuel oils come out too close to call. For the pure thermal sources H2
might be slightly better.

Manufacture of alternative fuels (alcohols and light oils, perhaps methane
or propane)
Crude oil is more expansive than coal, coal works but is rather polluting,
nuclear, solar PV and thermal all work but are more expensive than we would
like. The fuel oils are one of these alternative fuels, and not a source.
Hydrogen is the core of this entire industry, but is not a fuel produced by
the industry because there is little demand for it except as a chemical
feedstock for the fuels it produces.

Hydrogen may address some of today's challenges. I just wouldn't go so far
as to suggest it as a suitable candidate for the fuel of the future. It's
performance is just too poor. But Hydrogen is likely to continue to be what
we will make, and make in vast quantities, in order to make the fuels of the
future.

As long as the coal lasts, we do not need a new fossil fuel in the USA, in
Russia, perhaps in China. In France? There seem to me to be a lot of
countries where depending on oil, or coal, from some outside community is
economically and militarily dangerous.

 

[Dan Bloomquist]

This is the most messages that sci.chem.engr has gotten in my memory.
Just to be silly, never forget that you can react Aluminum in water to
produce hydrogen. Not really that hard, and Aluminum does not explode on
contact with water.

The reaction is highly exothermic isn't it? This would represent a
considerable loss. As it is, electrolyses of water is some 70%
efficient. The issue is that either way, the source of the energy is
electrical. As most of our electricity is produced with coal at 30%
efficiency, it means getting 5% of the heating value of that coal to the
wheels of a vehicle under the best conditions. A battery powered car
would be 2 to 3 times as efficient.

As far as non-fossil fuel hydrogen. Bio-reaction/solar would appear to be a
rather good source. I believe the proteins are being produced in thin films
now?

Talk is that Bo diesel can be produce with algae at 5 to 7 percent solar
efficiency. And these farms would use the COO waste stream from coal
fired plants. With HEET technology, a coal fired plant can get better
than 50% efficiency. This combination may be 'an' answer.

Best, Dan.