Hydrogen fuel cell vehicles use an electric motor (or motors) to propel the vehicle. The motors are powered by a stack of "fuel" cells that generate powerer by passing Hydrogen gas over one side of a special membrane that allows Oxygen to pull the positive ions through but not the negative electrons, the oxygen and hydrogen combine to form water, and the electrons are forced to pass along the outside of the membrane and electron flow = voltage. The generated voltage is then used by the motors.

 

Here is info on Hydrogen combustion. Note that it the a/f ratio for Hydrogen combustion is 34.33:1 more than twice that of gasoline, and that is why adding Hydrogen generated from an "HHO generator" does next to nothing for your gasoline powered engine.

The theoretical or stoichiometric combustion of hydrogen and oxygen is given as:
2H2 + O2
= 2H2O
Moles of H2 for complete combustion
= 2 moles
Moles of O2 for complete combustion
= 1 mole
Because air is used as the oxidizer instead oxygen, the nitro-gen in the air needs to be included in the calculation:
Moles of N2 in air
= Moles of O2 x (79% N2 in air / 21% O2 in air)
= 1 mole of O2 x (79% N2 in air / 21% O2 in air)
= 3.762 moles N2
Number of moles of air
= Moles of O2 + moles of N2
= 1 + 3.762
= 4.762 moles of air
Weight of O2
= 1 mole of O2 x 32 g/mole
= 32 g
Weight of N2
= 3.762 moles of N2 x 28 g/mole
= 105.33 g
Weight of air
= weight of O2 + weight of N (1)
= 32g + 105.33 g
= 137.33 g
Weight of H2
= 2 moles of H2 x 2 g/mole
= 4 g
Stoichiometric air/fuel (A/F) ratio for hydrogen and air is:
A/F based on mass:
= mass of air/mass of fuel
= 137.33 g / 4 g
= 34.33:1

 

Wow, this thread is probably already too far gone to do any good, but I'll try anyway...

The addition of hydrogen and oxygen to the engine process through electrolysis does not help mileage simply due to the added energy contained in the hydrogen. If the added hydrogen/oxygen (hydroxy) were merely re-burned, you'd nave a net result of less than you started with; most good electrolyzers are merely 85% efficient, and most that you buy on the 'net are a bit less efficient than that.

HOWEVER

The introduction of hydroxy gas into the chamber has more of an effect to combustion than the hydrogen's net energy content would have you believe. The hydroxy has a dual effect that helps increase the thermal efficiency of the engine, neither of which have much to do with the energy released by burning the hydrogen.

These are:

1) Reduce lean-burn misfire.

Since the hydrogen is extremely light and is in a gaseous state, it is very evenly distributed throughout the combustion chamber. Since there will always be hydroxy gas close to the spark plug, there is a much better chance of the plug firing off the mix to commence combustion.

2) Catalyze the oxidation of gasoline.

Since the hydrogen is so well mixed throughout the combustion chamber, the hydrogen molecules aren't always sitting right next to an oxygen molecule. However, they're almost always sitting next to either an oxygen molecule, or a gasoline molecule. That means they can combine with either oxygen and simply be burned, or combine with the gasoline and catalyze the oxidation process. As an example from "simple high school chemistry."

A single hydrogen atom is called a hydrogen free radical, which is just as important as the free oxygen in the burning of the gasoline. The hydrogen doesn't automatically seek out the free oxygen in the mixture, especially if that hydrogen atom happens to be sitting right next to a nice long gasoline molecule. The hydrogen atoms help to break up the longer chained molecules, which then oxidize more readily. Shorter chains oxidize much more quickly than longer ones; the shorter chained molecules have a much lower boiling point than the longer ones do.

C8H18 + 2H + Heat = C4H10 + C4H10 <-- Shorter chains are much "lighter" and evaporate much more easily, and therefore can contact oxygen much more effectively.

The hydrogen doesn't automatically chop all of the molecules in half, though. For example, C8H18 + H2 might turn into CH4 + C7H16. Both molecules are "lighter" than the original, however, and support more quick and efficient combustion.

Therefore, if you haven't realized by now, flame speed is the key to the increase in gas mileage and thermal efficiency that can be seen with the introduction of hydroxy gas. If you talk to any competent engine builder, he'd tell you that once they get as much air/fuel crammed into the chamber as possible, the next step is to get it all to burn as quickly as possible. Crankshaft geometries dictate that you want peak BMEP by around 13° after top dead center on the power stroke. If you can get away with less needed ignition advance to achieve that goal, your engine is, by definition, more efficient. The introduction of hydroxy gas into the combustion chamber helps increase the flame speed and therefore less ignition advance is required.

 

I've volunteered for testing of a hydrogen unit. My first experience was two weeks ago. My particular drive unit is a Lexus with the V6. First run with no unit added, I was not impressed with the car at all. Fuel mileage was around the 22.0 mpgs mark. With the unit added, the mileage and power remained exactly the same. This unit also incorporates a different PCM programming to supposedly account for the reduced BTUs of the hydrogen. They have since worked on the car and have made some changes. Yesterday, the car ran with better power but the mpgs was still around the same. The bad news is that the car is now not emmissions compliant and zero increase in fuel mileage. You can't use a fuel of less BTUs and use less of it and expect to gain efficiency- simple physics folks. This particular unit is not on the market and I doubt it ever will be. Projected cost on your car is $1600.00. You can buy a lot of gas for that kinda money even at todays prices. Considering there is technology out there to produce diesel from landfill garbage, there is zero political pressure on garbage unlike water, diesel technology is already here and so is distribution, this is the future fuel. Now if somebody would just be smart enough to put a small diesel electric car together- we'd be set to tell the Arabs and Wall Street to shove it.

 

this thread sure was entertaining to read. I figure the laws of thermodynamics don't apply to everyone, that's how the HHO system works. I think I need to develop a low cost unit that looks as good as these HHO systems do, then i could market it and make money too

How about this: Use solar power to create the HHO gas, store it in a container, then run it in the car. I don't think using the vehicle's electrical system to create the gas is going to yield any net benefit due to energy losses.
Energy loss? Load up your electrical system, turn everything on. Run vehicle at idle. Wait about 5 minutes and touch the alternator. Is it hot? Heat is a form of energy (lost while producing the electrical energy).
Can we now develop a system where you can **** in the tank to fuel the vehicle?

 

Only if you have a very serious kidney disorder.

 

Google the GEET.

 

You completely missed my point. As I stated earlier, the MPG gains have absolutely nothing to do with the energy released through burning hydrogen. As has been said over and over and over and over, the energy taken to produce the hydrogen is greater than the energy from burning hydrogen.

Just like the physics professors above have stated, electrolyzers aren't anywhere near 100% efficient. However, just like most physics professors who generally have very little real-world experience (learned everything from their books), you're missing the other side of the equation (since it hasn't been given to you in your books).

Re-read my post and look more closely at the catalysis that takes place when fossil fuels are compressed, heated, and finally burned in the presence of hydrogen.

Now, take a look at the different types of chemicals that is in "gasoline" today. Maybe do an experiment... Fill a glass jar half-full with gasoline and let it sit outside with the lid open, allowing the lighter stuff to evaporate. After a few days in 100°F temps, come back and see what is left. Maybe try to run a small engine on the stuff. The result: the engine won't even run on the crap.

This is the "heavy" stuff that is in gasoline, and is the stuff that hydrogen likes to attack within the combustion chamber. The more of this crap that you can get vaporized, the more of it you will be able to burn. Heat it, pressurize it, and add hydrogen, and it will "crack" into smaller/lighter molecules that will much more readily burn.

Better yet, investigate the process that oil refineries use to break down long-chained fossil fuels into shorter ones. The abridged version: Heavy fossil fuels + pressure + heat + hydrogen = lighter fossil fuels.

 

Where does the energy to dissociate the long chain hydrocarbons come from? Or are they supposed to just fall apart?

 

Engine heat, compression pressure, and the presence of hydrogen all combine to help break down the long chain hydrocarbons. Also consider that when the spark plug fires, the flame front will consume the light hydrocarbons first. This creates more heat, which vaporizes the heavier stuff, which burn, which add heat, etc, etc, etc. The hydrogen simply speeds the process.

 

So Pinnhead, if I follow your post correctly, you could say that hydrogen works like a combustion accelerator/enhancer. A lot of folks used acetone for the same reasons and there was no net effect. If you have credible links to the info, I'd llike to read it. But breaking gasoline into shorter chain lengths is not even a sane comment. If you want shorter chain molecules, use a shorter chain fuel to begin with. We use 8 and 7 chain length molecules in our gas. It's called OCTane and HEPTane. Oct meaning 8 and Hept meaning 7. If you want shorter length chains, use butane, a two chain length molecule. But the Heptane is in the fuel already to serve the purpose of the claims of hydrogen- to help spread the flame front and assist in ignition. I fail to see where the hydrogen is going to do something different. But if you have links, I'm open to read.

 

MIT is working on it:

http://www.greencarcongress.com/2005...enenhance.html
Google "hydrogen enhanced engine" or "Hydrogen Enhanced Combustion"

Hydrogen Enhanced Combustion
http://georgepehli.googlepages.com/HEC_Presentation.pdf
There are numerous patents utilizing various methods of hydrogen enrichment. Some go so far as cracking and adding hydrogen to the fuel in a fuel reformer before it gets to the fuel rail (GEET and PICC are two examples).

Not to mention that I don't really need all of the "proof" on the internet for me to believe it works; it's working well enough in my F150.

 

Nobody wanted to do any investigating?

 

The Plasmatron by MIT was considered not feasible back in 1999 and there hasn't been much done with it since. There are loads of neat technologies out there that work great in a lab but aren't feasible in the public domain. The second link, it's hard to get past the blatant BS to glean any real info out of it. If you have any other links, I'm more than interested in investigating. We see all kinds of systems that "work" and see all kinds of claims but have yet to see one that yields any potential. The best one we think we've seen to date uses a potassium hydroxy which is why I volunteered to work this test. It also addresses the programming issues which few even consider. You can't just start putting hydrogen in any form down the manifold and expect results- it doesn't work like that. But this particular system has the potential of possibly raising the fuel mileage. By how much and at what cost and if it is feasible has yet to be determined. Frankly, considering the cost of the unit, the cost and availabilty of the hydroxy, I doubt it's feasible....even if it works.

 

http://www.japanprobe.com/?p=4888