Can anyone tell me how much energy is needed
to produce about a litre of hydrogen?
(or whatever amount you wish to use for calculations)
Be it in watts, amps or whatever of both is needed?

Can anyone tell me how much energy is needed
to produce about a litre of hydrogen?
(or whatever amount you wish to use for calculations)
Be it in watts, amps or whatever of both is needed?

Pretty Please.
PS: I can not do the math for such so please don't show
me a link for such, nor the math itself, unless it also has
the answer.
:)

--
James M Driscoll Jr
Spaceman

On Jun 25, 8:46 pm, "Spaceman" <space... at (no spam) yourclockmalfunctioned.duh
wrote:
Can anyone tell me how much energy is needed
to produce about a litre of hydrogen?
(or whatever amount you wish to use for calculations)
Be it in watts, amps or whatever of both is needed?

Pretty Please.
PS: I can not do the math for such so please don't show
me a link for such, nor the math itself, unless it also has
the answer.
:)

--
James M Driscoll Jr
Spaceman

Sorry James that in the existing 46 posts in this thread, no once has
actually addressed your original question, which suggests that every
respondent to your question is either illerate in trivial
electrochemistry, is reading compromised, or has their head up their
rectum.

The answer to your question is rather simple. It takes a Faraday of
electricity to though electrolysis liberate a mole equivaent weight of
gas or gasses.. Now a Faraday of electricity is defined as 96,500
Coulombs, and a Coulomb is defined as the amount of electrical charge
transfered by the passage of an electric current through a conductor
or electrolyte during one second.

So far are you with me?

Now here is where it become a bit more complex, and where most readers
other than educated science professional will move on the the next
thread. Here is another definition: A mass equal to the atomic weight
divided by the valence is called an 'equalvalent weight.' In turn, if
you electrolyse water, this defines how much of that Faraday of
electricity produces hydrogen at the cathode of the cell, or oxygen at
the anode.

I'm quite sure that I lost a few readers at this juncture, so maybe
it's time to summarize.

Faraday's law of electrolysis simply states that is simply that the
number of gram-equivalent-weights of a substance deposited, liberated,
or reacted at an electrode is equal the number of Faradays of
electricity transferred though the electrolyte.

As Don L. can assure you, no exceptions to Faraday's law of
electrolysis have ever been observed. OK, James, now cutting to the
chase, it takes 96,600 Ampere-Seconds of electrical charge transfer to
liberate to liberate electrolytically hydrogen an oxygen from a water
molecule.

Now still again the complexity of what is going on increases still.
Assuming that you have thought very carefully about the above, you now
understand how much electrical current is involved, and specific ratio
hydrogen and oxygen this will produced. but nothing about how much
volume the gas will occupy, or how much energy is cosumed in the
process.

Thus far, you only know that 96,500 coulombs of electrical charge, or
96,500 Ampere seconds, but how many Watts of electrical energy are
condumed in the next questions, and things get more complex still.
Here we enter the mysterious world of voltage drop, and other rather
curious circumstances,

Let me know if this post is worth continuing for anyone.

Also, please feel free to correct me on anything in which I err. No
offense will be taken, since I'm an old fart and have in the past been
told that I've already forgotten more than most people will ever
know. I'm personally not very sure about that, but I do know beyond
having retired from 50 or so years in physics and engineering, I've
still pretty good at rebuilding a 1950s engine or repairing/restoring
a TV set of that era.

I believe are all here to help the next generation.

Harry C.

p.s. I realize that I have not reached an answer to Jame's original
question, but I try to explain how to get to that answer, which sadly
no other poster has yet attempted to do.

p.s. I realize that I have not reached an answer to Jame's original
question, but I try to explain how to get to that answer, which sadly
no other poster has yet attempted to do.

hhc314 at (no spam) yahoo.com wrote:

So far are you with me?

Yes surprisingly I am.
But I do have a question because I learned that that is how I learn,
by asking questions.
Would different conductors or electrolytes (materials)
make any difference that would change the Coulumb
amount?
It sounds like it would.

hhc314 at (no spam) yahoo.com wrote:

p.s. I realize that I have not reached an answer to Jame's original
question, but I try to explain how to get to that answer, which sadly
no other poster has yet attempted to do.

Oh actually someone did but I don't think he liked the answer.

Spaceman wrote:

hhc314 at (no spam) yahoo.com wrote:

So far are you with me?

Yes surprisingly I am.
But I do have a question because I learned that that is how I learn,
by asking questions.
Would different conductors or electrolytes (materials)
make any difference that would change the Coulumb
amount?
It sounds like it would.

Dammit I'll have to answer ....

That's a bit like saying if you 'cheated' and made a pint glass a bit
bigger (say by 50%) , if you poured a standard pint of liquid into it
it would still fill it to the top.

I wasn't responsive to the question earlier - I guess I didn't read it
fully.

To run an engine takes 5 litres per second at typical air pressure and
temps. That's 10/147th the mass of a liter of air. A liter of air
contains 1.26 grams of air - so 5 liters of hydrogen at the same temp
and pressure as air contains 431 milligrams of hydrogen.

At stoichiometric ratio this requires 3.45 grams of oxygen - and, at
20% oxygen/nitrogen - that means 17.26 grams of air - which is 13.6
liters of AIR per second - so this is the air fuel mix by volume.

13.6 liters of air per second
5.0 liters of hydrogen per second.

all at the same temp and press.

AS you can see the amount of air exceeds the amount of hydrogen by
volume at these pressures and temps.

Now, a liter of LIQUID hydrogen contains 70 grams per liter - so,
using the engine heat to vaporize liquid hydrogen at a rate of 431
milligrams per second - means that you use your LIQUID hydrogen at a
rate of a liter of liquid hydrogen per 2.7 minutes.

So, to run an engine at this rate per minute for 120 minutes (2 hours)
you need 44.33 liters of liquid. A manageable size.

Highly compressed hydrogen contains 30 grams per liter - so, from a
compressed hydrogen tank 1.16 minutes are needed to discharge this
rate from a 1 liter tank. So, to run an engine at this rate per
minute for 120 minutes you need 103.45 liter compressed hydrogen
tank.

Larger, but still manageable.

For comparison, gasoline contains 120 Megajoules per gallon - and 431
milligrams of hydrogen contain 61.6 kilojoules - so, this is
equivalaent to a gasoline use rate of 1.85 gallons per hour - or 3.7
gallons for two hours. At 50 mph - this is 27 miles per gallon
equivalent.

The thing I don't understand is Eeyore's comment that the volume of
hydrogen is HUGE - its no more huge than the volume of gasoline VAPOR,
or air pulled through the engine - so, I don't understand what he's
getting at by saying that.

Obviously, if you have an electrical source to make hydrogen to run
your engine on the fly, you can use that source to drive an electric
motor.

Equally obviously, you can use a stationary electrical generator to
use nuclear power or sunlight to produce hydrogen at very low cost,
then distribute that hydrogen to fill tanks that then run gasoline
engines converted from gasoline to hydrogen - by adding a hydrogen
tank an fuel line - with controllers.

This is what BMW has done

http://en.wikipedia.org/wiki/Hydrogen_7

All that's missing is a low-cost source of hydrogen adequate to our
needs.

The world uses

23.8 billion barrels of liquid fuels
5.5 billion tons of coal
2.1 billion tons of natural gas

All this is replaced directly, with very minor changes in
infrastructure, with

3.4 billion tons of hydrogen

made from 30 billion tons water and 140 billion megawatt-hours of DC
electricity - generated from sunlight or nuclear power - at
sufficiently low cost.

Solar panels operate only 1700 hours per year. Nuclear power plants
operate 8700 hours per year. So, this means that 83 trillion watts
of panels are needed, or 16 trillion watts of nuclear plants are
needed.

The world in 2007 spent $4 trillion on primary energy. This
translates to a $1,200 per ton of hydrogen - delivered cost. This is
equivalent to buying gasoline at $1.20 per gallon.

Assuming venture capital rates of return - say 40% per year - for
investors - requires that the entire system cost less than $10
trillion. According to the Merrill Lynch World Wealth Report there
are 9.5 million millionaires in the world, and they possess $38
trillion in 2007. Backed by appropriate government bonds and so
forth, with 30% to 40% ROI - they would likely cut loose with $10
trillion fairly quickly.

Dividing this $10 trillion by the wattage needed for each system we
obtain target prices for the generator systems - including all balance
of system costs - of;

$0.12 per peak watt - solar
$0.62 per peak watt - nuclear

The cost of conventional nuclear reactors is $5 per peak watt.
The cost of conventional solar panels is $7 per peak watt.

Nuclear power plants scale as 1/t raised to the fourth power - so, to
obtain $0.62 per peak watt requires that temps be raised by 68% - in
absolute terms - from 600F to 1350F - to achieve this price point.
This reactor technology was proposed since 1950s to displace fossil
fuels in a big way. It has never been acted upon - despite its
ability to create power that is 'too cheap to meter' - and is the
basis of DOE Generation 4 reactor slated for 2040 introduction. This
is very similar to classified reactors of the 1950s (project Pluto and
Rover achieved temperatures in excess of this), and nearly identical
to high temp reactors proposed by AEC/DOE throughout the 1960s 70s and
80s... but never acted on in a meaningful way.

Solar power plants can use concentrated photovoltaics to reduce PV
costs, and reduce costs overall, providing optics and other balance of
system costs are held in check through careful design. I have done
this and produced a system that costs less than $0.07 per peak watt -
which is 1% of the conventional panels, and allows the introduction of
a hydrogen economy based on solar derived hydrogen.

Sources of low cost pollution free hydrogen may be used in conjunction
with carbon to create liquid fuels readily used by the market without
change. Up to 15% of the energy may be supplied by hydrogen mixed in
with natural gas - with zero changes of infrastructure. Hydrogen
may be used to upgrade coal to liquids, or upgrade residual oil to
high grade products. Oxygen may be used to increase yeilds of both,
and convert natural gas to liquid fuels.

This forms an obvious interim step.

What is saved is the construction of a vast network of hydrogen
distribution and storage, and the conversion of every power plant that
uses hydrocarbons and carbon - to hydrogen alone.

5.5 billion tons of coal converted to 39.6 billion barrels of
liquid fuels
by the application of 0.6 billion tons of hydrogen

2.2 billion tons of methane converted to 21.5 billion barrels of
liquid fuels
by the application of 2.2 billion tons of oxygen

While replacing

5.5 billion tons of coal burned with 0.9 billion tons of hydrogen
burned
2.2 billion tons of methane burned with 0.9 billion tons of
hydrogen burned.

This creates a world where oil output becomes;

28.3 billion barrels of liquid fuels extracted
39.6 billion barrels of liiquid fuels from coal
21.5 billion barrels of liquid fuels from natural gas

89.4 billion barrels of liquid fuels total

Which implies an increase of 375% which at 4% per annum growth rate
- would take humanity 34 years - with zero increase in carbon
footprint.

Hydrogen becomes 50% of the market at that time and can grow to 100%
of the market in 34 years following - allowing a reduction of carbon
output over the 68 year period - despite increasing energy use.

This closely matches the expected declines in natural gas and oil
reserve outputs over this period, while also slowly reducing coal mine
output over this period as well. Large surface mine operations need
not be reduced in value, since they form natural locations for solar
collector sites, or nuclear reactor sites - to reclaim the land - from
which their stockholders may maintain a revenue stream equal to that
of a fully producing mine.

All fossil fuel producers could participate in a 'buy-in' that allows
them to improve their credit rating to maintain their vaibility even
as their production and the value of conventional reserves fall over
this period.

Fact is properly managed - our energy supply infrastructure should be
able to last us another generation - and using these sources of
primary energy - nuclear and solar at low-cost - to produce hydrogen -
and first converting existing coal to oil - and displacing stationary
uses of carbon with hydrogen first - provides a clear way to maintain
strong growth in energy use, reduction in fuel prices, and conversion
over a generation or two to low cost hydrogen fuel.

Appropriate research dollers, appropriate bonding, at a $400 billion
per year rate - would cost governments very little - and resolve our
energy problem AND our carbon emissions problems - such as it is -
over the next generation - while maintaining the value of stocks in
fossil fuel companies even while their output and the value of
reserves decline.

That is, at a discount rate of say 4% - the $10 trillion in assets
convert to a $100 trillion asset based on revenues discounted at this
rate. Maintaining the same income - over a 68 year period, combined
with natural inflation of currency values over this same period - re-
establishes the decline in energy costs relative to the rest of the
economy that was present for most of the industrial era from 1870 to
1970.

Spaceman posted a very basic questin of how much energy is required to
produce a litre of hydrogen gas, which has absolutely nothing to do
with how to strore, transport, the hydrogen, or if it is at all useful
as a transportations fuel. None of this has anything at all to do with
the OP's simple question

I merely was starting an explanation to James as to how to obtain an
anwer to his question. I believe that I carried that explanation from
the point of Faraday's law to the evolution of hydrogen and oxygen
from a water based electrolyte, but at that point left his question
only half way though a final explantion.

As it turned out, Spaceman asked a very interesting question, and the
total explanation is not exactially trivial. So, if you have your own
axe to grind on peripheral issues, I would suggest that you begin a
new thread.

Now with respect to Spaceman (James), I hesitate to venture even a
guess as to how much knowledge this poster already has strored in his
head. He somtimes post silliness, but also asks questions far beyond
the capacity of many posters to grasp. Your poster Spaceman has
knowledge of some serious shit. and I believe he is simply now filling
in the gaps in his knowledge. Lest we forget, here is the question
that began this thread.

"Can anyone tell me how much energy is needed
to produce about a litre of hydrogen?
(or whatever amount you wish to use for calculations)
Be it in watts, amps or whatever of both is needed? "

It puzzles me why almost all of the responsed to this well phased
questions are going in all directions, except to answer the posted
query? It's a pretty fundamental question, clearly stated, so why all
of the arm waving and tangential subject responses? Good Lord, I'm a
physicist specializing in classical mechanics and electromagnetic
field theory, but it seems as though I know more about
electrochemistry than all of you other posters combined, because no
one except me has liftend a hand to try and answer Spacemans's
original question.

For shame on all of you! I've posted half of the answer, and
identified the fact that electrolysis is based on on the current flow
though the electrolyte, and the relationship of this with Faradays Law
of Electrolysis. Still, that only responds to to part of Spaceman's
questions. That part is pretty much textbook. The more complex part
of the answer is deducing the volume hydrogen gas produced, and an
evaluaton of the energy loss in the electrolysis cell.

Nobody but Spaceman appears interested in these details, so why should
I waste my time on throwing pearls of knowdge to pigs who need to have
everything handed to them.

Now I have never met James, although it seems that we both live in the
same area, and we both do our dumpster diving for automotive parts in
the same junkyards, I know him only though his Usenet posts. In fact,
Spaceman could be anywhere between 15 and 90 for all I know, but we
both live in the Greater Boston area, and for some unexplained
reasons, Boston seems to breed some very interesting people from all
walks of life. Strange area, which is why many people are attracted to
it. Boston itself is largely a focus for tourists, and the financial
and commercial crowd. The teckies and artists tend to gravitate to
Cambridge, across the Charles River from Boston.

What to me personally that seems interesting, is the fact that often
many of the members of a class that you are lecturing to at MIT or
Harvard, you meet at the MIT Ham Radio flea market, and Jack's Used
Auto Parts (reads junkyard) in Billerica. You tend to meet the same
people at "Tadmuck" in Westford. Frankly, I cannot imagine this
happening anywhere in Califoria, where appearance is everything. Then
too, in Massachustts, the prevailing concept seem to be, if you can
fix it yourself and need wheels, it makes no difference if you drive
an old Chevy, a BMW or a Mercedes, if you can locate a $300 part for
$10, its worth the effort. Right, I know, people in New England are
very strange.

Brad, you like others are going off on a tangent to the origital
posters question.

Spaceman posted a very basic questin of how much energy is required to
produce a litre of hydrogen gas, which has absolutely nothing to do
with how to strore, transport, the hydrogen, or if it is at all useful
as a transportations fuel. None of this has anything at all to do with
the OP's simple question

I merely was starting an explanation to James as to how to obtain an
anwer to his question. I believe that I carried that explanation from
the point of Faraday's law to the evolution of hydrogen and oxygen
from a water based electrolyte, but at that point left his question
only half way though a final explantion.

*It takes roughly 4 watt hours to produce one litre of hydrogen.*

4.4 kilowatt-hours of electricity
converts 1 liter of water into
1.59 liters of liquid hydrogen
0.79 liters of liquid oxygen

However the discussion then foundered on the shouls of his belief that
he can get the energy needed out of an alternator with no demands on
the engine.

Robert Adsett wrote:
However the discussion then foundered on the shouls of his belief that
he can get the energy needed out of an alternator with no demands on
the engine.

I never stated such.
I stated my hand could not feel the difference when a load
was placed on the alternator.

Spaceman wrote:

Robert Adsett wrote:
However the discussion then foundered on the shouls of his belief
that he can get the energy needed out of an alternator with no
demands on the engine.

I never stated such.
I stated my hand could not feel the difference when a load
was placed on the alternator.

For god's sake stick it in the belt, chop your hand off and we won't
have to put up with your ignorant blather any more.

Never heard engine rpm drop when a heavy electrical load is switched
on ?