Naked Science Forum

On the Lighter Side => New Theories => Topic started by: Egon Phillips on 12/02/2009 10:30:01

Title: Could the heat from car exhaust make more efficient electrolysis to generate hydrogen?
Post by: Egon Phillips on 12/02/2009 10:30:01
Egon Phillips  asked the Naked Scientists:
   
Dear Sir or Madame,

A few months ago I noticed several videos on Youtube where inventors, amateur scientist, hobbyist, and others claim that they are able to use water for fuel or an mileage enhancing admixture in conventional gasoline (internal combustion) engines.  There are numerous kits and books for sale.  And, of course plenty of folklore has sprung up around the concept.

Is it possible to use the combination of a Car Battery and the Heat generated from an internal combustion engine exhaust to produce enough hydrogen from water electrolysis to significantly improve gas mileage? The maximum internal combustion exhaust temperature is approximately 1450 degrees C.

The concept calls for gasoline to be used as a primer to raise the temperature of the engine exhaust to reduce the energy required for electrolysis of water.  After-which, the engine would burn hydrogen produced from the electrolysis of water, or a combination of hydrogen and gasoline.  Burning hydrogen, or a combination of hydrogen and gasoline would then maintain the temperature of the exhaust at sufficient levels for electrolysis to continue.

A similar design would work for virtually any fuel Natural Gas or Coal or Bio Fuel, whatever.

Basically once the exhaust of an energy generating process (internal combustion engine, coal fired power plant, nuclear power station) gets hot enough, the energy contained within the exhaust can be used to liberate Hydrogen from water, which is then used as either the primary fuel or as an admixture.

You concluded that Electrolysis of H20 can't produce the amount of hydrogen required to significantly improve gas millage.  But, during the shows introduction, you state several times that only a trickle of hydrogen is required.  How much is a trickle?  It has been claimed that a 5% hydrogen mixture is required to produce a boost.  

Now the heat of the exhaust of a gasoline engine is between 700 C - 1400 C.  And, it is claimed that temperatures between 100 C and 850 C will significantly increase the efficiency of electrolysis.  So the exhaust from a gasoline engine can provide the energy required for much more efficient electrolysis.

Apparently, when water is heated to produce steam, and electrolysis of the steam is used to produce HHO gas (AKA Brown's gas, used for welding), the HHO gas functions as a catalyst.  Since, catalysts are theoretically not changed during a chemical reaction, once the required concentration of hydrogen is reached - the amount required to increase the efficiency of gasoline combustion - only trace amounts of hydrogen would be required for the reaction to continue.

Would you be willing to try a high-temperature electrolysis in say, part 2, or part 3 of DIY Hydrogen for More MPG?

What do you think?
Title: Could the heat from car exhaust make more efficient electrolysis to generate hydrogen?
Post by: Vern on 12/02/2009 12:26:49
Quote from: Egon Phillips
Is it possible to use the combination of a Car Battery and the Heat generated from an internal combustion engine exhaust to produce enough hydrogen from water electrolysis to significantly improve gas mileage? The maximum internal combustion exhaust temperature is approximately 1450 degrees C.
That idea has been beat upon a whole lot in these forums. It generally comes down to the fact that you can't separate water into its constituent elements by any means that requires less energy than you get by recombining the elements.

I'm not a chemist, but I don't think there's any method that could use H as a catalyst. There is a way to use Boron as a catalyst, however. Edit: Maybe catalyst is the wrong word. Boron is a participant in the reaction.

Quote from: Boron Paper.
Tareq Abu-Hamed, now at the University of Minnesota, and colleagues at the Weizmann Institute of Science in Rehovot, Israel, have devised a scheme that gets round these problems. By reacting water with the element boron, their system produces hydrogen that can be burnt in an internal combustion engine or fed to a fuel cell to generate electricity. "The aim is to produce the hydrogen on-board at a rate matching the demand of the car engine," says Abu-Hamed. "We want to use the boron to save transporting and storing the hydrogen." The only by-product is boron oxide, which can be removed from the car, turned back into boron, and used again. What's more, Abu-Hamed envisages doing this in a solar-powered plant that is completely emission-free.
Title: Could the heat from car exhaust make more efficient electrolysis to generate hydrogen?
Post by: Egon Phillips on 23/02/2009 16:21:31
Sorry, I don't know what took the Naked Scientist long to post my message. I discussed this via email with BMW, Patrick Norton and others in January / February of 2008, and posted it to the Naked Science forum in order to generate some discussion, and get some feedback.  Way back then in Jan / Feb 2008 Patrick mentioned that there were many hybrid gas/water/hydrogen electrolysis systems but none that he was aware of used exhaust heat to reduce the delta H, delta E of the electrolytic reaction; which was intended to be the focus of the discussion.

Kind of disappointing that Naked Scientist would wait so long, and that I missed the discussions.

Sorry about that.

EGON
Title: Could the heat from car exhaust make more efficient electrolysis to generate hydrogen?
Post by: Vern on 23/02/2009 19:31:24
It's not too late; this can still be discussed. If you do a search you will find the subject of using water as a fuel and / or as an additive has been discussed exhaustively.