Water electrolysis and heating with AC

[PhysicsProf]

   Been busy; but I have a question about Water electrolysis and heating with AC...

Let's start with 60 Hz 120 V from the mains, two electrodes in tap water.  How much electrolysis into H2 and O2 will there be?  how much heating?

Now I've done experiments with "Davey sonic bells" just like this -- two bells, one connected to the hot line and one to return/ground.  I observe slow heating from room temp -- not many bubbles indicating electrolysis.  There are some small bubbles, but I think this is due to dissolved air coming out of the water... not sure.
Further, the heating agrees with what I expect for simple resistive heating of the water -- watts in, hot water as the result.

Q (Joules) =  Cp * mass * (change in temperature)

The specific heat (Cp) of water is 1 calorie/gram °C = 4.186 joule/gram °C.

Distilled water heats very slowly -- very high resistance.  (Water from the store -- there will be some ions even if from CO2 dissolving from air into the water.)


Next let's go to higher Freq, say 20 KHz.  I haven't done the experiment with water; but I expect no significant electrolysis again.

I'm here to learn -- is this right,  no significant electrolysis  compared to resistive heating, with AC in tap water?

I'm particularly curious about using this method to measure output power in a blocking-oscillator circuit, with the output AC used to directly heat water...

Comments welcomed.



 

[Paul-R]

Now I've done experiments with "Davey sonic bells" just like this -- two bells, one connected to the
hot line and one to return/ground.

The essence of Davey is that the bells are tuned to the frequency of the mains or an octave.

What was the error in tuning, i.e. the heterodyning frequency?

[PhysicsProf]

I selected bells that oscillate at approx. 480 Hz, 8 x 60 Hz.  I did not attempt fine-tuning.

But back to the main point of the thread -- does anyone wish to comment on"

--> is this right,  no significant electrolysis  compared to resistive heating, with AC in tap water?

[Paul-R]

I selected bells that oscillate at approx. 480 Hz, 8 x 60 Hz.  I did not attempt fine-tuning.

In that case, your experiment was not a Davey experiment. This is why you did not
get any special heating effect.

[Paul-R]

no significant electrolysis  compared to resistive heating, with AC in tap water?[/b][/i]

Since the electrodes are constantly changing polarity, i.e. 60 times a second, both poles
will be getting hydrogen and oxygen and I suspect that they recombine to form water
again, the only end product being heat.

[GibbsHelmholtz]

The energy for breaking water is 118kcal/ 36 grams.  That's 3.27 kcal per gram of water lost.  Even though we do not see significant electrolysis, we still could produce/consume a large amount of energy.  I think we must be careful.

[exnihiloest]

Since the electrodes are constantly changing polarity, i.e. 60 times a second, both poles will be getting hydrogen and oxygen and I suspect that they recombine to form water again, the only end product being heat.

I share this view. With cc, the positive and negative ions have much time to move toward their respective electrodes and to concentrate around.
With ac, the two species remain mixed together around the electrodes and so, they should recombine.
From my own experiments, I never saw significative bubbles with ac. Only heat is produced.

[muDped]

Even when DC is applied to the electrodes within an electrolyte
to perform electrolysis the bubbles do not arise instantly.  There
is a brief delay before bubbles begin to form at the electrodes.

The ions in solution move rather sluggishly when subjected to
electric fields.

[exnihiloest]

Even when DC is applied to the electrodes within an electrolyte to perform electrolysis the bubbles do not arise instantly.  There is a brief delay before bubbles begin to form at the electrodes.
...

I said to myself the same thing yesterday! There is a noticeable delay when DC is applied. This means that the time for the ions to move towards the electrodes is much more than 9 or 10 ms of the half-period of a 60 or 50 Hz current, during which the electric field remains of same polarity. This confirms the radically different behavior of ions in presence of AC and DC: in 9 or 10ms, the ions can't attain the same equilibrium position as with DC.

[EMdevices]

this is an interesting paper that explored electolysis cell impedance using pulsed DC of various frequencies, much like Stanley Myers, which probably drove this investigation.

The results obtained show a 15% improvement in power consumption, when pulsed at the correct frequency (see figure)

http://www.electrochemsci.org/papers/vol7/7043466.pdf

EM

[muDped]

That is a rather interesting paper EM.  How did you happen to
find this gem?

The first question which comes to mind is "Why Aluminum?"

Aluminum wouldn't normally be used as electrode material in
an electrolytic cell (exception: Electrolytic Capacitor) designed
for the electrolysis of water with a basic electrolyte.

According to their tabulated data there does indeed seem to
be some sort of "resonance" at work.

[exnihiloest]

...
http://www.electrochemsci.org/papers/vol7/7043466.pdf
...

In this setup, it is pulsed current, not AC. Pulsed current is equivalent to a DC + AC superposition. Here, AC is a square signal.
So we have a real mean DC current that polarizes and electrolyzes the electrolyte, and an AC current that can have a resonant effect onto the ions.
Their result (only 15% gain) shows that the interest is very limited except for the industry.

I asked me if we could polarized the electrolyte with HV in isolated electrodes each side of the solution, and use two other electrodes, each one near the first ones but in contact with the solution, with AC for the electrolysis current.
This would be a real AC electrolysis, but with each electrode in a bath of different ions, depending on the polarity of the HV which separates positive and negative ions and attracts them towards each side. The interest is that no power is required for the HV polarization due to the absence of current.

[Farrah Day]

I asked me if we could polarized the electrolyte with HV in isolated electrodes each side of the solution, and use two other electrodes, each one near the first ones but in contact with the solution, with AC for the electrolysis current.
This would be a real AC electrolysis, but with each electrode in a bath of different ions, depending on the polarity of the HV which separates positive and negative ions and attracts them towards each side. The interest is that no power is required for the HV polarization due to the absence of current.

This is more or less the principle of operation behind my Closed-Loop Electrolyser.

[Paul-R]

The energy for breaking water is 118kcal/ 36 grams. 

It must depend on how  you do it. Bob Boyce and Dave Lawton get superior results using
a very sharply square DC pulse at Keely's 42.8Khz, and Keely is supposed to have done it
using an audio signal at that frequency.

[Farrah Day]

It must depend on how  you do it. Bob Boyce and Dave Lawton get superior results using
a very sharply square DC pulse at Keely's 42.8Khz, and Keely is supposed to have done it
using an audio signal at that frequency.

Things are never as clear-cut as many would like to think. It would be a grave mistake simply to take the things you read on the internet as gospel.  

I have never seen any real science or figures to back up any of these claims. Most of this stuff is just fantasy and wishful thinking. This stuff has been knocking around cyberspace for donkey's years. It is extremely difficult to make accurate in/out energy measurements at the best of times - start pulsing DC and it becomes even more difficult.  Playing about on a small bench in a garage without the correct equipment or methodology and results are all pretty meaningless. Lack of knowledge and understanding can always produce 'incredible' results, particularly if you don't have a clue what you are doing or how to interpet what is happening.

I used to converse with Dave Lawton, he was a genuine guy, doing some interesting work, but you have to bear in mind that his facilities were limited. From what I understand some of the gas evolving from his electrolyser set up may have been down to cavitation occurring. I've only read what is available on the internet about Keely, but no one to my knowledge has ever successfully reproduced his work.

You have to remember that in order for things not to simply be considered as wild speculation and conjecture, these claims have to be independently corroborated and reproduceable.

Boyce is probably the biggest bullshitter out there - and trust me I know him a lot better than most. For all his past talk of running his car on water, building electrolysers that produce 10x-18x over-Faraday gas output, no one has yet replicated his designs and neither he nor anyone else has had his designs independently tested. Boyce and his mindlessly devoted fanclub reside solely in a fantasy world. Not once, anywhere have any of his claims even come close to being corroborated by a reliable independent source.

It's quite laughable really because people seem to simply believe anything Boycie says, irrelevant of the utter nonsense he is continually spouting, or the total lack of anything coming close to proof. I'm sorry but the fact that some people talk about Bullshit Boycie like he is some HHO guru, when the reality of it is he has never actually shown the world anything, really riles me.  

But by all means provide a link to research or experiments that supports all Boycies wild claims.

[Paul-R]

Boyce is probably the biggest bullshitter out there - and trust me I know him a lot better than most. For all his past talk of running his car on water, building electrolysers that produce 10x-18x over-Faraday gas output, no one has yet replicated his designs

I don't accept a word of your post.

I was offered a development model of his 101 plate units on the presumption that I lived in the States.
Unfortunately, I don't. They wanted  beta volunteers reasonably close to hand. The gear is fragile
and would probably have been knocked out of true by the transportation, and the cost of freight would
have been ruinous.

[Farrah Day]

I don't accept a word of your post.

lol, fine by me. If you're happy to put your faith in unsubstantiated claims and untrustworthy people, then that's your prerogative - each to their own.  

They wanted  beta volunteers reasonably close to hand.

Who are they???

[Paul-R]

lol, fine by me. If you're happy to put your faith in unsubstantiated claims and untrustworthy people, then that's your prerogative - each to their own.   
  Who are they???

Do you imagine that I have nothing better to do?

[exnihiloest]

...The gear is fragile and would probably have been knocked out of true by the transportation
...

It reminds me the Steorn hoax. According to the alleged cause they gave, their motor didn't work because the ball bearing heated... 
There are always good reasons preventing the perpetual machines from working and people from duplicating them.
Could the gear have been sabotaged by the oil industry?

[Farrah Day]

Do you imagine that I have nothing better to do?

No, I just think that you need to do your homework. You might then have second thoughts about simply accepting what you read on the internet.

[Farrah Day]

this is an interesting paper that explored electolysis cell impedance using pulsed DC of various frequencies, much like Stanley Myers, which probably drove this investigation.

The results obtained show a 15% improvement in power consumption, when pulsed at the correct frequency (see figure)

http://www.electrochemsci.org/papers/vol7/7043466.pdf

EM

It is an interesting paper, but for the life of me I can not understand why they would use aluminium electrodes instead of something more inert.

Aluminium electrodes will themselves react in an alkaline solution. The protective aluminium oxide coating will get eaten away and the exposed aluminium will react with water to produce aluminium oxide and hydrogen, and this reaction in itself may cast doubt on their conclusions. It may well be that the reaction of the aluminium electrodes is what is decreasing the voltage overpotential.

You should note that this is a polar opposite of what Meyer was trying to achieve. Here they are simply trying to reduce the voltage overpotential to make standard Faraday electrolysis more power efficient. And for this to show any power efficiencies, the voltage across the cell (or cells) would need to be reduced accordingly. Ie, if you have a cell that will work effectively at 1.1 volts, you will not see any power efficiency from running it at 1.2 volts.

Meyer, on the other hand, claimed to be doing something completely different. He was using high voltages so voltage overpotential was not really an issue.

[Paul-R]

It reminds me the Steorn hoax. According to the alleged cause they gave, their motor didn't work because the ball bearing heated...

There is no excuse for overheated bearings. They should read the manufacturers' spec sheets.

Bob Boyce's device consists of 101 plates, about 1mm apart in an precision milled slotted
case. Each of the 100 cells must be insulated from the others. This is NOT electrolysis.
The water is fractured in a different way to electrolysis.

Each plate is at the nill point of a standing wave system (i.e. where the wave value is
at zero. (Like Dave Lawton's system, the gases are liberated BETWEEN the plates, and not
at the plates). But I would imagine that if the box is dropped 12 inches on to a hard surface,
then the whole thing would go out of kilter. See Patrick's Chapter 10 for a better explanation.

Bob's solid state electronic variant is a very exciting project.

[Farrah Day]

Bob Boyce's device consists of 101 plates, about 1mm apart in an precision milled slotted
case. Each of the 100 cells must be insulated from the others. This is NOT electrolysis.
The water is fractured in a different way to electrolysis.
 

Perhaps in your world and Boycie's this is not electrolysis, but why then does he still require a standard voltage overpotential for it to work?

And remember I said about doing your homework?  Well if you actually took it upon yourself to research what you are talking about you would realise the absurdity of this statement:

Each plate is at the nill point of a standing wave system (i.e. where the wave value is
at zero.

It is down to uneducated and gullible people like yourself that this kind of misiinformation and pseudoscience is constantly being banded about as fact and promoted on the internet and indeed forums like this. Just like our old friend Chet, you appear to blindly support the claims of people you do not know and science of which you have neither any knowledge or understanding whatsoever.  

Sadly, just repeating some nonsense you have read on the internet won't make it any more real.

[exnihiloest]

...
This is NOT electrolysis.
The water is fractured in a different way to electrolysis.
...
Each plate is at the nill point of a standing wave system (i.e. where the wave value is
at zero. (Like Dave Lawton's system, the gases are liberated BETWEEN the plates, and not
at the plates).
...

A standing wave of what? Pressure? Electric? How the standing wave can be maintained while the gases are liberated, changing the properties of the resonating medium? Why a standing wave would fracture the water?
The principle seems very doubtful and there is no experimental evidence.

[exnihiloest]

This is more or less the principle of operation behind my Closed-Loop Electrolyser.

Not exactly the same principle. In yours there is two concentric containers isolated from one another at the position of the AC electrode. No DC can flow from one to the other. In mine there is only one. I don't understand what are the yellow disks with a cross, in the bottom picture.