Electrolysis using Displacement current?

[Narayanan KR]

The figure shows two insulated metal electrodes kept in pure water with a small gap between them.

When sufficiently large voltage pulses applied between electrodes, there is a flow of displacement current through the insulators and water, but will this split the water molecules because of the E field ?

all your answers are welcomed !

 

[anorlunda]

Normally, electrolysis occurs at the anode and cathode, not in the water in the middle. Your diagram shows an insulation layer that prevents contact of the water from the anode and cathode.

What kind of electrolysis reaction are you expecting? The reduction reaction (see below) require electrons, but the number of free electrons in pure water due to displacement current will be exceedingly small. You should be able to calculate the energy needed for an oxidation reaction, and compare that with energy available from the displacement current in the immediate vicinity of an H2O molecule.

It sounds difficult to make that work. But you did not specify the voltage level, and if we keep increasing the voltage pulse magnitude eventually something(?) should happen. Neither did you specify how much electrolysis is needed to declare success (a single molecule or more?).

https://en.wikipedia.org/wiki/Electrolysis_of_water

In pure water at the negatively charged cathode, a reduction reaction takes place, with electrons (e−) from the cathode being given to hydrogen cations to form hydrogen gas (the half reaction balanced with acid):

Reduction at cathode: 2 H+(aq) + 2e− → H2(g)
At the positively charged anode, an oxidation reaction occurs, generating oxygen gas and giving electrons to the anode to complete the circuit:

Oxidation at anode: 2 H2O(l) → O2(g) + 4 H+(aq) + 4e−

 

[CWatters]

Pretty sure the short answer is no...

http://[URL [/url]

Displacement current has the units of electric c

urrent density, and it has an associated magnetic field just as actual currents do. However it is not an electric current of moving charges, but a time-varying electric field.

More..


Edit: Sorry about the formatting of this post. For some reason the editor is preventing me fix it.

 

[Narayanan KR]

well folks, this idea is nothing about chemical electrolysis that involve oxidation and reduction , its simply a "dielectric break down" of water due to strong electric field.

I called electrolysis because it produces similar effects of separating H2O molecule.

 

[anorlunda]

http://physics.stackexchange.com/qu...ter-not-used-as-a-dielectric-in-the-condenser

Dielectric breakdown (which is 60-70 Mega Volt / m for Distilled water

It would take a very very strong field.

 

[Narayanan KR]

Valuable Information @anorlunda...

65 MV/meter is 65 KV / millimeter, we can use Flyback transformer.

Plus heat and frequency will lower the Breakdown voltage.

 

[anorlunda]

I'm not sure if there is a distinction between "pure water" and "distilled water" , if yes it might make a big difference. You should research it more for pure water.

 

[CWatters]

Is the "strong electric field" across the water or across the insulators?

 

[Narayanan KR]

across the water

 

[CWatters]

For that to be true the water would need to have a higher impedance than the insulators.

 

[Windadct]

In general - dielectric breakdown yield a plasma, and a plasma underwater would at least be a steam explosion and considering you are separating into Hydrogen and Oxygen - and then you have a plasma (ignition source), really does not seem practical to do this. Part of the benefit of traditional electrolysis is the Oxygen and Hydrogen are generated at different locations. Distilled or De-ionized Water - ether may "work" if you measure the conductivity first.

And then - As CW points out you still have the electrodes insulation - so as the water approaches a breakdown (effectively lowering the resistance of the water) then the the voltage applied will be across the electrodes' insulation.

 

[Narayanan KR]

well ...i thought insulating the electrode will prevent the flow of Real Current (Amps), so that all we need for electrolysis will be Voltage... but as You say it sounds difficult to achieve.

 

[CWatters]

You cannot electrolyse water with just voltage or just current. It takes power/energy.