And now the google ads at the bottom of the page are advertising sites that claim to run cars on water - ie total scams. Is there any way of reporting these scam ads to TPTB at the Straight Dope? Or should the motto be changed to “profiting from scam ads since 2006”??
That loop will lose energy, absolutely true. But it oversimplifies the situation.
If a small hydrogen addition, say 0-10% of the total fuel usage, can increase the efficiency of the engine operation, that could overwhelm the energy lost producing it. If a little hydrogen somehow lets you send more of the gasoline’s energy through the piston face into the crankshaft, and less of it out the exhaust pipe, it may be worthwhile.
For example, the ideal Otto cycle models a spark ignition engine as having instantaneous combustion, at constant volume. Real spark-ignition engines burn their fuel over a finite time, starting BEFORE the piston is at top dead centre. An engine still runs if you spark at or after TDC, but the efficiency goes right down. There’s a benefit in getting the flame front to propagate faster.
The paper below describes lab results on hydrogen supplementation of a methane-burning engine.
http://society.kisti.re.kr/~Eksae/_notes/data/pdf/v2n3_1.pdf
Adding from 10-40% hydrogen as a percentage of total heat output, combustion is faster, reaching peak pressure earlier, see figure 5. The results are progressively less significant with falling hydrogen content, and even the 10% test was nothing to get excited about, but those experiments were in a fixed combustion chamber starting at atmospheric pressure. Results in compressed mixtures with turbulent swirl would be more applicable to an engine. Check out the high speed photography results in figure 13 though, with 20% hydrogen supplementation! Interesting stuff.
Personally I doubt that tiny hydrogen additions are going to do anything at all, let alone give 20-40% efficiency improvements, but I’m not going to dismiss the possibility completely.
Nice! I had inferred that a potential effect of adding hydrogen was an increase in combustion speed, but couldn’t find any reliable data to that effect. Not that I looked that hard, but…
Exactly my thinking.
Unfortunately it can’t. Even that would violate the first law of thermodynamics. Just imagine that you could then take the excess energy you produced and use it to electrolyze more water. yo9u would have a free energy machine.
As imaginative as that is, it doesn’t. The load electrolysis puts on the engine will always take more energy than you get out of burning the hydrogen.
Hopefully, your engine is already timed for the flame propegation of the octane rated gasoline you are using. It’s probably not timed for hydrogen.
Well I hope you don’t imagine that this paper supports this garbage. At no place in the paper do they mention that they are producing the hydrogen by electrolysis in order to gain that electrolysis energy back. Worse yet, it has nothing to do with burning gasoline. Hell, if all I have to do is dial in my combustion mixture I’d probably choose all Hydrogen. Unfortunately, electrolysis of water takes an enormous amount of energy. That’s exactly why hydrogen is such a good fuel.
Any efficiency you get back is lost in the electrolysis. It’s worth dismissing completely.
That would most certainly NOT violate the first law of thermodynamics.
A “real” combustion cycle is a sight less efficient than an “ideal” combustion cycle, for a variety of reasons, one if which is that combustion isn’t instantaneous. The hypothesis here is that some amount of hydrogen added to gasoline would increase the speed of combustion (making it closer to the “ideal”), which would then increase the overall efficiency of the engine. Now maybe it does and maybe it doesn’t, but one thing it’s NOT is a “free energy machine.” It no more violates the first law of thermodynamics than optimizing the spark timing (which costs nothing!) would.
No it wouldn’t. The first law of thermodynamics could only be violated if the efficiency of the engine goes over 100%. If adding a tiny bit of hydrogen raised the efficiency of the engine from, say, 10% to 20%, due to quicker combustion, it could easily be an overall net gain. I’m pretty sure this is impossible, especially since last I read it took 10 times the energy to split water as you get from burning it, but there are no basic violations of physics here. If we could raise the efficiency of electrolysis, which I’ve heard scientists are working on by using a catalyst and UV light, net gains in engine efficiency could become a possibility. Of course you’d reach a point where no more gains can be realized by injecting more hydrogen.
But the extra energy that goes into the electrolysis could be countered by the more complete combustion of your main fuel.
Yes, but this could easily be adjusted.
Even if it doesn’t work for gasoline, or maybe any fuel at this time, with increases in the efficiency of electrolysis, it could work for some fuel some day as explained above. You’ll never get above 100% efficiency from an engine, but internal combustion engines are so far from that right now, it’s not unreasonable to imagine some day doubling or tripling the efficiency. Doing so with self-electrolyzed hydrogen injection is a theoretical possibility some day.
Not unless the kit also allows you to convert your gasoline-burning car to a hydrogen-burner, a problem engineers have been working on for years with only limited success, and that’s with building the car that way from scratch; never heard of even the possibility of a retrofit!
That’s not true at all. You can convert your car to running on hydrogen this book details how. The problem, however, is that hydrogen is not nearly as energy dense as gasoline, so to get the same level of performance as you would with gasoline, you need to burn lots of hydrogen (and control combustion to minimize emissions of things like NOx). That wouldn’t be a big issue, except for the fact that we presently have trouble storing hydrogen readily. A tank of liquid hydrogen the same size as your average gas tank would give the car a range of something like less than 100 miles between fill ups. A larger tank would be heavier and take up a lot more room. That’s why using things like boron and aluminum to liberate the hydrogen from water are such hot research topics.
See the following for more details:
http://www.greencarcongress.com/2007/08/pnnl-developing.html
http://www.peswiki.com/index.php/Directory:Hydrogen_from_Water_using_Boron
http://www.esquire.com/features/ESQ1206evianfuel
http://technology.newscientist.com/channel/tech/mg19125621.200-a-fuel-tank-full-of-water.html
http://www.greencarcongress.com/2007/08/purdue-research.html
Note that the folks investigating this stuff tend to be tied to large universities and research organizations, so it’s not just some crank in his garage claiming this stuff, but folks with degrees and who’re respected in their professions.
By the way, for reference, here are some previous threads substantially related to the subject:
Hydrogen power in a car, no fuel cell (6/04)
Isn’t this a perpetual motion machine? (11/05)
Motors running on water (6/06)
Please Settle the Daniel Dingle Debate (10/06)
Any validity to this? (H2O–>HHO power) (11/06)
Cheap hydrogen generation… is this bunk? (10/07)
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No, because the claim is that the gasoline is used more efficiently this way, not that energy is being created out of nothing.
Like others in the thread, I’m doubtful that the claim is supportable, but it’s not asking for physics to be rewritten to accommodate it.
There must be things that can be added to engines or engine design that will increase their fuel efficiency, without violating the laws of thermodynamics - if it were impossible to do this, we couldn’t ever have come this far.
I doubt this is one of those things, or that it works, but the basis on which you dismiss it is false.
It is true, that if the claim is that it causes engine efficiency to go up then there is some way to wiggle around the first law of thermodynamics. But automobiles are allready combusting their gasoline at nearly 100% efficiency. That is to say there is very little CO or unburned gas in the exhaust. The only place to improve is in the energy transfer to the piston. In order to take advantage of the new gas mixture you will basically have redesign the entire engine.
Also, you need to recognize exactly how low the energy density by volume that hydrogen has. Without a compressor you arern’t adding much in the way of combustible material. The 0.5 L in one minute mentioned above is simply laughable. If that stuff isn’t compressed, you will do just as good to inject nitrogen. It was also claimed above that it adds oxygen to the system. This is patently false. Since the hydrogen oxygen mixture is produced by electrolysis, you have a stoichiometric mixture and there is precisely enough oxygen in that system to burn all the hydrogen and nothing else.
Without some major improvements in electrode technology, there isn’t really a very good way to improve on the efficiency of electrolysis either. For one thing, if you are producing gas fast enough, the gas itself becomes an insulator that prevents further electrolysis. That means in order to generate enough hydrogen to be effective, you will need a huge surface area.
There might be specific advantages in being able to combust the fuel in a shorter time, or more evenly or something - same amount gets burned, but in such a way that the engine cycle can better make use of it (a bit like adjusting the timing, but making the firing part narrower, instead of moving it).
Again, not that I’m particularly inclined to believe this device does that, or at least does it to the extent claimed.
Yes, that is a fundamental error of logic - that doesn’t really bode well for everything else they’re claiming.
Of course. And if a trace of hydrogen acts as a fuel modifier that improves the flame propagation rate, it could do just that! Big if, though.
This abstract suggests that hydrogen accelerates the propagation of lean methane-ethane flames by producing more reactive intermediates. If I’m reading it right though, the hydrogen proportion was at least 30% by energy content, much more than you’d realistically be able to supply by electrolysis, and a huge energy sink even if you could.
This NASA paper from 1974 has an interesting abstract, but it isn’t available online: Feasibility demonstration of a road vehicle fueled with hydrogen-enriched gasoline I’d love to know how much hydrogen they actually added in that study!
I suspect I’m going to regret this, but this thread isn’t so old that I’ll get accused of reviving a zombie.
My wife sent me a link to this video on this topic.
I found this thread while trying to find an authoritative source that this video is pure bunk (interestingly, Snopes has nothing to say about this). My wife is not convinced.
I assume that the “welding torch” may be legitimate. It’s likely plugged into an electrical outlet providing the power necessary. May even have a compressor
But the car? Based on what I’ve read here – no way. But I post this link just in case someone else might be amused by the gullibility of local news.
One hundred miles on four ounces of water??? No effin way. None. Flat-out, physically impossible. Hydrogen has nowhere near the energy density of gasoline, and if you were able to drive 100 miles on four ounces of water, you could travel much, much, much farther on gasoline.
That’s quite possible. I was intrigued when they said the flame “feels slightly warm to the touch,” but the guy never ran it over his hand! It turned out he was talking about the temperature of the nozzle. “No other gas will do this,” he says. Well, that’s because most other flammable gases are hydrocarbons that will produce carbon dioxide as well as steam on combustion, and hot carbon dioxide radiates in the infra-red wavelengths a lot more than hot steam does. Any hydrogen-oxygen torch performs the same way, whether produced by electrolysis or not.
Well, this IS Fox News! You have to read between the lines. They didn’t really claim what they appear to claim.
"On a hundred mile trip, we use about 4 ounces of water." Sure. And four gallons of gasoline.
"Currently has it rigged as a ‘water and gasoline hybrid’ " That’s what I figured. See above.
"Can travel exclusively on water" Only if you have a LOT of batteries and a BIG electrolysis cell! But if he can do it, why isn’t he doing it?
That’s not the claim made. This is added to gasoline. It was speculated that a car could be run purely by the process but no system to date has been demonstrated.
I’ve been looking at this as of late and there are a number of systems out there being experimented on. None of them involve pure water. They all require an electrolytic catalyst. Some systems use tap water (for the minerals in it) but most of the people trying this use baking soda as a electrolytic agent. It’s not a pure electrolysis process, which would involve separating out the 2 gases. I don’t know if this changes the equation any.
There are many video’s of experimenters on you-tube and the goal is to get the best liter per minute per watt. You can figure out how to make one of the devices by watching the videos. It doesn’t require purchasing any of the books or equipment being sold.
From a practical standpoint the system cannot draw more than 30 amps on a car system which would be 360 watts. That would be slightly less than 1 hp drawn on an engine. Whatever amount of HHO that is produced would have to increase the fuel burn by more than 1 hp to make the process efficient.
[nitpick] Thirty amps is 420 watts as the nominal voltage with the engine running is 14 volts.[/nitpick]