Hydrogen/ oxygen added thru electrolisys, on board generator

[gpara]

I have found several hydrogen generators, by electrolysis, for sale, has anyone tried any of these devices????
I am looking at a unit that produces 1L/minute at 15 amp draw. They are claiming 20% min. fuel economy increase. I have ahd a chemist friend run the numbers and he says that they indeed can produce that much H and o-2/minute. It will run about 5 hours on 2 litres of water and both gases are fed into the intake air tube before the throttle plate.
Any idea how the oxygen sensor is going to respond to this extra fuel and will the block learn and integrator be able to adjust low enough to boost the economy.
If I install it I have a scan tool to monitor these para meters. Anyone interested in this project please contact me. The devise ia about $275.00, cheap if it works and the engine control system can tolerate the changes.
Gary

 

[Warpspeed]

That one litre a minute sounds about right to me too. And I fully agree with the conclusions of Mr Wizard.

The power to run the electrolyser will be far greater than anything you can get out of it. The surprisingly large amount of waste heat dissipated by the electrolyzer when it is running will be a clue to its inefficiency.

 

[patprimmer]

Here we go again, an increase by converting water to oxygen and hydrogen then converting it back to water.

You can gain energy by a one way chemical reaction, BUT YOU OBVIOUSLY CANNOT GET ENERGY OUT OF A REACTION THAT GOES ONE WAY AND IS THEN REVERSED.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[btrueblood]

15 amps at 12 volts = 180 watts. This is electrical energy that is put into splitting the water.

1L of H2/O2 combustion yields about 230 kJ/mol of free energy, or about (dividing by 22.8 mol/liter) 10 kJ per minute, or (divide by 60 seconds per minute) 167 watts in thermal energy. The engine is able to extract (oh, let's be generous and say 50% efficiency) 83 watts of that 167 watts as shaft power, and the alternator (again being generous with a 95% efficiency) gives back 79 watts of electrical power. So you had to burn an excess (180-79)=101 watts of fuel (gasoline) to run your magic mpg enhancer...

 

[GregLocock]

Although I agree that there is unlikely to be a net efficiency gain, there has been much research into the improvement in combustion efficiency that you get when you add hydrogen gas to a normal engine. The reason crudely is that hydrogen helps initiate the burn.

Seach for papers co-authored by Dr Harry Watson

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Warpspeed]

These electrolysers sound simple, but they are high maintenance and can be rather problematic.

Clean water will not work, because it will not conduct enough current to bring about any electrolysis action. So you need to add something to make the water highly conductive. Either an acid or an alkali will work. We used caustic soda, and I believe that is a fairly common choice.

Now the current flowing through the solution will generate a lot of heat, and that will boil the caustic solution very quickly unless a fairly effective cooling system is used. If it boils dry, then your caustic soda goes as hard as concrete and will need to be mechanically chiseled out of the reaction chamber to unblock it. This little mishap is rather easy to achieve.

If you can figure out a way to cool a standard 2.4Kw electric jug, and keep it from boiling dry, that is the sort of technology required to run your hydrogen electrolyser in your vehicle.

Now your cooling system will require a circulating pump and a radiator, and possibly a fan, all of which consume additional power.

Hooking something up to run for half an hour on the lab bench is one thing.

Designing something that will run for reasonably long periods without going wrong will be a much greater challenge. Certainly not impossible, but it will end up a lot more complex than the simplicity of the basic concept might suggest.

 

[oxilume]

gpara,

The focused R&D in your area of concern is for generation of hydrogen for direct injection into exhaust to reduce NOx.

Some individuals are claiming MPG gain when injected or blended with diesel prior to combustion. Yes, you will increase MPG due to the LEL and UEL of hydrogen. You can run leaner or extremely rich.

However, as the above individuals have told you more energy will be needed to produce the hydrogen then any gain in mileage.

However, there is a way around the net energy input vs net energy output. I'll disclose this after the patent application has been filed.

If you purchased a "Water Fuel" device for increasing mileage you just bought a dog that won't hunt!



Todd

http://www.oxilume.com

 

[GregLocock]

Actually that is not what I said. I don't know whether the increased efficiency of the entire combustion process, when hydrogen is used as an initiator, would compensate for the enrgy required to make the hydrogen. As I said, search for the papers.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[oxilume]

Greg,

I am the author of some of the papers. Hydrogen will increase fuel economy.

Why do you think there is so much interest in a hydrogen economy. It's not for reducing CO2 emissions if you are going to make H2 through steam reforming CH4. You still have to do something with the CO2.

You can blend hydrogen into diesel prior to injection and dramatically increase fuel economy.

But once again, where do you get the hydrogen from. Use a small plasmatron (see MIT's website) in lieu of electrolysis.



Todd

http://www.oxilume.com

 

[mattsooty]

Of course the addition of hydrogen will increase SFC in an engine. If one measures the SFC of an engine producing x kW then adds another, unmeasured, fuel into the combustion chamber hey presto a big gain in SFC!

As Greg says the amount of energy required to 'create' the hydrogen in the first instance will be higher than that which is liberated during combustion since combustion in an IC engine is a pretty inefficent process.

Besides which, using hydrogen as an initiator sounds like a ludicrous idea to me anyway - can you imagine the rate of pressure change within the chamber? The thing would sound like a machine gun and would be hosing out NOx like no ones business - so wouldnt really be that marketable.

Very interested in Oxilumes ambitions statement: -

"However, there is a way around the net energy input vs net energy output. I'll disclose this after the patent application has been filed"

Sounds like a rewrite of the laws of physics!

MS