Pulse electrolysis is an alternate electrolysis method that utilises a pulsed direct current to initiate non-spontaneous chemical reactions. By utilising conventional pulse width modulation PMW , multiple dependent variables can be altered, including the type of waveform, typically a rectangular pulse wave , and the duty cycle , which determines the waveform frequency. Currently, there has been a focus on theoretical and experimental research into PDC electrolysis in terms of the electrolysis of water to produce hydrogen. Past research has demonstrated that there is a possibility it can result in a higher electrical efficiency in comparison to DC electrolysis. PDC electrolysis is not only confined to the electrolysis of water.
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Pulse electrolysis is an alternate electrolysis method that utilises a pulsed direct current to initiate non-spontaneous chemical reactions. By utilising conventional pulse width modulation PMW , multiple dependent variables can be altered, including the type of waveform, typically a rectangular pulse wave , and the duty cycle , which determines the waveform frequency.
Currently, there has been a focus on theoretical and experimental research into PDC electrolysis in terms of the electrolysis of water to produce hydrogen. Past research has demonstrated that there is a possibility it can result in a higher electrical efficiency in comparison to DC electrolysis. PDC electrolysis is not only confined to the electrolysis of water. Uses in industry such as electroplating and electrocrystallisation are also undergoing research due to the wider range of properties that can be achieved.
The various and alterable effects of using intermittent pulses in PDC electrolysis has resulted in an area of interest that could benefit industry. However, as it is still being researched and has produced conflicting results, a consistent and reliable answer to how dependent electrolysis efficiency is on the properties of an electrical pulse has not been determined,  hence, other forms of electrolysis such as polymer electrolyte membrane and alkaline water electrolysis are being used in industry.
PDC electrolysis was first considered theoretically in ,  and experimental research began as early as however it was originally focused on its technical applications to industry and the possibilities of improving the quality and rate of metal deposition. The first instance it was considered to initialise the electrolysis of water was from the perspective of magnetolysis in , where high strength magnets, or in this case electromagnets , are used in conjunction with homopolar propellers.
A current density ratio of 2. Since hydrogen gas cannot be collected in its free form, and it can be used to provide a source of renewable and clean energy through fuel cells ,   discovering an electrolysis method with the greatest efficiency is valued. With early experimental and theoretical success, many patents began to be developed until as recent as ,  but since , it has only been researched intermittently with varying levels of success.
With the perspective that the current use of non-renewable fuel sources is a main cause of global environmental problems,  hydrogen is being viewed as a possible renewable fuel source replacement. When a voltage is applied to an electrolysis cell, immediately following this an Electric Double Layer EDL , or a diffusion layer , is theoretically formed. This can can create a capacitance , or can cause the electrolyser to act as a capacitor. Electrolysers require high currents produced by very low voltages.
Using a magnetic field of 0. The disc needed a rotation speed of rpm to reach the correct electrical potential for electrolysis. The difference between Faraday's original model and Bockris and Ghorogchian's is that their disc will only rotate when it is in contact with an electrolyte.
They encountered one large problem, a viscous force created by the electrolyte, that slowed down the motion of the disc. The two ways they could fix this is to rotate the disc and solution together or increase the magnetic field used. The latter being most practicable, the required magnetic field was calculated according to the power consumption rate or producing a cubic meter of hydrogen. It was discovered a magnetic field of 11T was needed for effective electrolysis,  more than 16 times greater than what was originally used.
Since superconducting magnets would be required, and they can become too expensive to justify their use, ruling this out as a possible method. Their final decision was to use a homopolar generator as an external source of power. This follows Faraday's method more closely. In this method, a pulse potential was created to take advantage of previous studies that give an effectiveness factor of 2 when either a nickel electrode  or a Teflon-bonded platinum electrode was used.
The generator was constructed with a magnetic flux density of 0. Pulses of V that were sustained for 1ms were achieved. This was the first instance of a successful application of pulse electrolysis for the production of hydrogen. However, it still presents its own limitations in the possibility for it to be used in industry. Mazloomi et al.
A simplified electrolysis model was used, to which a 'metal oxide semiconductor field effect transistor' MOSFET  was applied. An example test showing a positive response is with a 1. Further experimentation found the optimal frequency changed depending on the size of the electrodes, the molarity of the electrolyte and the distance between the electrodes. A comparison between a pulsed and non-pulsed dc current electrolysers was explored in by Shaaban, that demonstrated a non-pulsed current used the least electrical power.
This opposes the previous and future works conducted. The experimental electrolyser separated the anolyte and catholyte compartments and used a Naflon membrane to allow the ion exchange. The distance between the anode, made with platinum coated titanium, and the cathode, stainless steel, was 3mm and was immersed in a 10 weight percent sulfuric acid electrolyte.
He conducted tests under several different frequencies that included '0. Initial observations revealed that the off-period resulted in a reversal in polarity, causing the reaction to reverse. This effected the cathode, which displayed a 2g loss after experimentation. However, the cell was prevented from dropping to 0 V during the off-period, maintaining a higher value of 2. This further impacted the experiment, distorting the square wave produced by the function generator Shaaban used, as the electrical potential provided needed to overcome the cell voltage of 2.
Calculating the power consumption, it was determined a non-pulsed current had power demand losses of 3. The possible increased effect a pulsed current will have on the corrodibility of metals was first looked at by de la Rive in A pulsed current can be varied in many ways that increases the possible outcomes and can vary the properties of deposited metals during eletroplating.
These effects were first researched on zinc by Coehn. In theoretical electrolysis of water, a voltage of only 1. Minimising the EDL formed during pulse electrolysis is advantageous, as it can reduce the thermo-neutral voltage and the energy input required, increasing energy efficiency.
Whilst the method of PDC electrolysis has been proven by Ghoroghichian and Bockris in and to work extremely well in theory, it is difficult to replicate with consistently positive results in practical experimentation. Hence, the many mechanisms that have been patented are unable to be repeated and used in industry. According to Shabaan, during the pulse-off period, if the electrolytic cell is not constructed properly, the current polarity can reverse.
This can cause the cathode to deteriorate. Any loss in mass can reduce the speed and effectiveness of the electrolytic reaction, reducing the overall efficiency of the pulse electrolysis method. Shaaban also states that due to expected internal losses, such as through heat, the current density required will increase, which increases the required voltage.
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Bibcode : IJHE Energy Conversion and Management. Technology in Society. Nano Letters. Bibcode : NanoL.. Performance of teflon bonded Pt black electrodes for H2 evolution". Electrochimica Acta.
International Journal of Electrochemical Science. Renewable Energy. Physical Review Letters. Bibcode : PhRvL. Comptes Rendus. Transactions of the IMF. Science China Chemistry. Categories : Chemical processes Electrolysis Electrochemistry.
US7552702B2 - Water fueled engine - Google Patents
Magnet doubles hydrogen yield from water splitting
This application claims the benefit of the priority filing date of provisional application No. Portions of the disclosure of this patent document contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office file or records, but otherwise reserves all copyright rights whatsoever. The third product has the same atomic and molecular constituents as the fuel and oxidizer.
Can electrolysis be powered by magnets?