Electrolysis optimization via arbitrary wave forms - open source project

[oldway]

It is not beyond the bounds of possibility that periodic brief polarity reversals may aid stripping the gas molecules formed at the electrodes from the electrode surface, thus maximising the effective electrode area and minimising the area current density, which would reduce the over-potential required to maintain a particular current, and thus the wasted energy due to Joule heating of the electrolyte...

I would like to know how a periodic brief polarity reversal would help stripping the gas molecules formed at the electrodes ? In my opinion, that's impossible.
The solutions are to recirculate the electrolyte (The movement of the electrolyte detaches the gas bubbles) and to reduce current density.
I wrote that:
Some recommend in order to make an hobbyist electrolysis cell for HHO (Brown's gas) production:
- Current per cm2: less than 0.1A / cm²
- Electrolyte: distilled water with 15 to 25% KOH (NaOH is also useful but KOH s better)
- Distance from the plates: the more near the better but that can cause problem with gaz output. Thus, better not less than 5mm
- Plates: stainless steel.
Multicell is better, with neutral plates.

[Ian.M]

I agree that flowing electrolyte is a far more effective method of detaching the bubbles.  However, it would take a lot of detailed experimental work to conclude that pulsing the current has NO effect on their adhesion.

[RIS]

you know that the water is slightly polar molecule and by-product of that is capacitor and by-product of that is sensitivity to any frequency you want.

[oldway]

I agree that flowing electrolyte is a far more effective method of detaching the bubbles.  However, it would take a lot of detailed experimental work to conclude that pulsing the current has NO effect on their adhesion.

Pulsing current has a high RMS value therefore increases power losses in the electrolyte and reduces efficiency.
In every case, it is not an acceptable solution.
It may also affect the purity of hydrogen....industrial electrolyser need an Hydrogen Purity >99.998%

[dmills]

I worked on a hydrogen powered car project at one time professionally, the stuff is not a good road fuel....

Firstly you have the storage problem, it actually has an amazingly low volumetric energy density as a gas at any pressure you might care to use, so big tanks or 5,000 psi your choice. The other two options also have issues, cryogenic slush has horrible overall efficiency due to the energy you have to expend on liquification, and metal hydrides add weight to the volume problem.
Then you get into the fun of hydrogen embrittlement of steels....

Hydrogen is the fuel of choice only when you need a low molecular weight exhaust and can engineer your way around all of the pain (Hydrogen embrittlement of metals, highly mobile gas, possible cryogenics), basically high Isp rockets if you are government funded.

Now there are other, probably better options, sewage sludge into an anaerobic environment (a big tank) will give off methane as the microbiology feeds, and that is a useful fuel gas, wood and coal gas, water gas (H2/CO mix from a endothermic redox reaction between steam and carbon) if you have a good source of heat to start with. In fact a diesel engine will often run quite happily on vegetable oil if you heat it a bit (run the engine cooling water thru a heat exchanger).

Incidentally the cheap way to make H2 is that water gas reaction, steam + natural gas + carefully metered air, the natural gas plus air begets more steam plus CO, the heat drives the redox reaction between the steam and the natural gas getting you H2 + CO, separate the CO and burn it with more air to add heat, exhaust the CO2, cool and compress the H2 for storage.   

Long term of course cars make little sense without some pretty major infrastructure support, you need lube oil and hydraulic fluids apart from anything else, give me a couple of heavy horses and a few ox in a preppers wet dream situation any day, self replicating transport that can pull a plough.   

To the OP, first learn the differences between Heat and Temperature, Power and Energy and what 'power factor' means in AC circuits, understanding these things will equip you to understand a lot of the utter bollocks on youtube.

Regards, Dan.

[SeanB]

Firstly you have the storage problem, it actually has an amazingly low volumetric energy density as a gas at any pressure you might care to use, so big tanks or 5,000 psi your choice. The other two options also have issues, cryogenic slush has horrible overall efficiency due to the energy you have to expend on liquification, and metal hydrides add weight to the volume problem.
Then you get into the fun of hydrogen embrittlement of steels....

Hydrogen is the fuel of choice only when you need a low molecular weight exhaust and can engineer your way around all of the pain (Hydrogen embrittlement of metals, highly mobile gas, possible cryogenics), basically high Isp rockets if you are government funded.

Rockets can solve that, big tanks, insulate the crap out of it and keep filling with the slush till just before launch when you stop refilling and removing the boiled off gas for safe burning really far away. The embrittlement is easy, just use it once and throw it away, or crack test the crap out of it and have a competition to find the best welders to weld up all those cracks, closing them and also boiling off the gas inside. Both things done by NASA, though the second option was a lot more expensive and took a lot of time.

Incidentally the cheap way to make H2 is that water gas reaction, steam + natural gas + carefully metered air, the natural gas plus air begets more steam plus CO, the heat drives the redox reaction between the steam and the natural gas getting you H2 + CO, separate the CO and burn it with more air to add heat, exhaust the CO2, cool and compress the H2 for storage.   

Long term of course cars make little sense without some pretty major infrastructure support, you need lube oil and hydraulic fluids apart from anything else, give me a couple of heavy horses and a few ox in a preppers wet dream situation any day, self replicating transport that can pull a plough.   

To the OP, first learn the differences between Heat and Temperature, Power and Energy and what 'power factor' means in AC circuits, understanding these things will equip you to understand a lot of the utter bollocks on youtube.

Regards, Dan.

The good old days of town gas, that was made from coking coal, but which was later replaced ( at some cost) by the availability of plentiful natural gas from oil fields. The only advantage of LNG is that it is not a silent killer like the old town gas, but storage is hard, you need really large gas reservoirs and water seals to keep a constant low pressure, as the 2 components have such a wide variation in boiling point.