Lets talk Hydrogen Injection - PeachParts Mercedes-Benz Forum

patbob · #1 10-19-2007, 02:53 AM

This recent poke at the ludicrous claims of an ebay car seller (Running on plain Water and WVO??? Only at ebay!) got me to reading up on hydrogen injection (sometimes called hydrogen fumigation) systems.

Synopsis:
Onboard electrolysis of water to get H2 & O2 gas, feed them into the air intake. Supposedly provides about 10% better fuel economy, more power, lower emissions, and lower EGTs.

Obviously, thermodynamically speaking, it's a crock -- TANFL. Current theory seems to be that it achieves this benefit despite the negative thermodynamics by causing all the diesel to actually combust, and do so in a way that allows more energy to be extracted as useful work. No perpetual motion machine or anything.. just squeezing work out of that last bit of incompletely combusted diesel.

What do you all think -- total crock or interesting technology?

#2 10-19-2007, 05:13 AM

Running on plain Water and WVO??? Only at ebay!

It does not in any way "extract" more power from the fuel. It's simply an ADDITIONAL fuel.

One more thing to think about: Hydrogen embrittlement.

vstech · #3 10-19-2007, 09:57 AM

well, it does add in pure Oxygen too... so in theory it COULD aid in combustion, also, the h2 Gas may help raise the temp of the burn making the Diesel burn more complete.

Graminal95 · #4 10-19-2007, 11:06 AM

I can't see how adding hydrogen could aid in the economy of the engine.

If you are forming H2 and 02 on board, then you have to put energy in the form of e- to break the O-H bond, and then some of the potential energy from O- and H+ floating around is lost when H2 and O2 is formed. Its like perpetual motion, you can't get more energy out then you put in.

If you were taking just the O2 and putting into the engine then you should be able to achieve a more efficient burn but still not close to enough to make up for the electrolysis. With both the H2 and the O2 all you are getting is the energy you put in to make them from water in the form of heat. This heat may aid in the combustion of the diesel, but I can't imagine its much.

So the extra energy you get out will be lost in the production of e- at about 50% efficiency (thats a high estimate) from the alternator, then another 5-10% as heat/resistance in the wires to the electrolysis machine, then I have no idea how much is lost in that process.

If there was a way to make H2 and O2 efficiently using the engine as a power source, then we all would be driving around with H2/O2 internal combustion engine and a tank of water, instead of hydrocarbons.

Just my thoughts on the subject.

vstech · #5 10-19-2007, 12:12 PM

for sure there is no efficient way to drive on H2O, however, it is possible that the gases may increase combustion efficiency. however, I am not going to try it.

ConnClark · #6 10-19-2007, 12:23 PM

Electrolysis of water is not a very energy efficient process. So any device that splits water molecules on the fly from power taken from your engine isn't going to give you back any more energy.

That said there my be a use for stored hydrogen as a power booster on a diesel.

It was researched for use in airships

go here
http://ntrs.nasa.gov/search.jsp

search for
NACA-TR-535

lutzTD · #7 10-19-2007, 01:21 PM

so Im no chemist but this isnt completely a perpetual motion machine scheme is it? What about the gobs of energy being sent out of the tail pipe? At best the comustion process is 20-30% efficient for moving the car, what about all of that lost heat energy? If that lost energy in the form of heat could be used to make H and O to increase the efficiency of the engine from 25% to 35% say, wouldnt that give you a huge net milage increase?

Graminal95 · #8 10-19-2007, 02:08 PM

I am a Chemist

, and this has to do with thermodynamics and physical chemistry. Think about it this way, if there was an easy way to make hydrogen using say heat pumps to collect energy from the exhaust stream then we would see it on every car or at least new cars. The fact of the matter is there is just no efficient way to make H2/O2 using lost energy from an internal combustion engine (exhaust heat), or from electricity generated.

Currently the extra energy in the form of heat from the exhaust is being used to run a turbo (increased efficiency) and to catalyze the stuff not burn in the cylinder, so we can and are using the wasted energy to an extent.

I wish there was a easy way to turn the left over heat/energy into chemical, electrical, or mechanical work (other then what has been stated above) that would greatly increase the efficiency of the engine. To my knowledge there are none yet, but with time comes innovations such as new catalysts and reaction paths that may turn these initial ideas into a viable reality.

patbob · #9 10-19-2007, 05:39 PM

Quote:

Originally Posted by ConnClark

It was researched for use in airships

go here
http://ntrs.nasa.gov/search.jsp

search for
NACA-TR-535

Thanks.. looks like an amusing paper.. I'll have to read it this weekend. Not that I'm terribly concerned with trimming my 4000 pound car for optimum aerodynamic drag or anything though

.

patbob · #10 10-19-2007, 06:02 PM

Quote:

Originally Posted by Graminal95

Currently the extra energy in the form of heat from the exhaust is being used to run a turbo (increased efficiency) and to catalyze the stuff not burn in the cylinder, so we can and are using the wasted energy to an extent.

I'd much rather figure out a way to finish burning the unburnt fuel that we're having to catalyze away presently. Burning it in the cylinder where we can extract useful work would be best. I'm intrigued by hydrogen injection because the credible sources seem to think it does just that.

Quote:

I wish there was a easy way to turn the left over heat/energy into chemical, electrical, or mechanical work (other then what has been stated above) that would greatly increase the efficiency of the engine. To my knowledge there are none yet, but with time comes innovations such as new catalysts and reaction paths that may turn these initial ideas into a viable reality.

I ran across a technology that purported to do just that. Some sort of nano-modified material that achieved a couple of orders of magnitude better conversion than the thermoelectric materials available today. They explicitly suggested extracting useable energy from the waste heat in automotive exhaust, but that was probably more dreamy-eyed-scientisting it to attract news publicity and investors, than being realistic. I'll post the link this weekend if I kept it.

SD Blue · #11 10-19-2007, 06:48 PM

Quote:

Originally Posted by Graminal95

I can't see how adding hydrogen could aid in the economy of the engine.............

If there was a way to make H2 and O2 efficiently using the engine as a power source, then we all would be driving around with H2/O2 internal combustion engine and a tank of water, instead of hydrocarbons.

I talked to these Canadian folks at the Great American Truck Show in Dallas, TX: www.hy-drive.com Granted, we should be skeptical but at least show a little consideration in the fact that there are commercial companies that have invested research into how hydrogen can boost economy and reduce emissions. They mentioned that their most promising research has been with diesel engines used in transportation and mining. By using an injection enhancement system, they no longer had to deal with storage and the explosion hazards involved with using hydrogen as a sole source of fuel.

Sure there are scam artists around that will jump on the "greenie" bandwagon with all kinds of wierd advertising stating "the government doesn't want you to know this"

or "the big oil companies are fighting to keep this a secret"

while trying to sell you a markedly inferior product that does nothing. Personally, anyone that uses such statements in their advertising is trying to sell you a "bill of goods"

and would be willing to bet that no one from the gov't or an oil company has ever approached them in such a manner. With this in mind, I am also very skeptical of the e-bay vehicle that makes no mention of the manufacturer of the HHO injection system and wants over $10k for a car that may be worth less than $2k.

dunl · #12 10-19-2007, 07:28 PM

If they can't increase economy without introducing another fuel (H2 in this case), they're simply not increasing the efficiency.

Cervan · #13 10-19-2007, 10:40 PM

ever seen the inside of an engine with a blown headgasket that was letting water into the combustion chambers? it was clean as a whistle huh?... maybe theres something there...

#14 10-20-2007, 05:26 AM

Quote:

Originally Posted by Cervan

ever seen the inside of an engine with a blown headgasket that was letting water into the combustion chambers? it was clean as a whistle huh?... maybe theres something there...

Yes, that can be done with a simple Surflo pump and water atomizing nozzle in the intake manifold.