Many of us get a kick out of quasi-scientific and anti-scientific "proofs" in which the experimenter is "hoisted by his own petard." One of our members brought to my attention a "proof" of this sort regarding using oxyhydrogen ("HHO", Brown's) gas to "improve" the performance of a motor scooter. As most people who are familiar with combustion science and chemistry can attest, there is no reason to think that generating oxyhydrogen on board a motor scooter and then feeding the gas to the engine would improve performance. The expectation would be that performance would be reduced, because more energy is required to split the water into H2 and O2 than can be recovered by burning the mixture.* In fact, because the typical internal combustion engine is 25% efficient, and a typical alternator is 65-70% efficient, simply breaking even would require that the electrolysis process be 500% efficient: clearly impossible to anyone outside the over-unity fringe group.
Promoters of these "fuel from water" scams come up with all sorts of fanciful reasons for why such schemes should work. It's hard to know how many of the people who profess such beliefs are truly scammers, and how many are simply gullible and uneducated in the chemistry and physics involved. Quite a large number are true scammers, and some of the more famous (like Dennis Lee and Stan Meyer) have been successfully prosecuted for fraud. In my experience looking over perhaps 20 websites promoting various electrolysers, every single promoter is an active, knowing scammer. For example, on one site, an old 6 cylinder pickup truck is shown running at idle, both with the electrolyser switched on and switched off. The "fuel consumption" at idle in both cases is several times higher than it would be in an ordinary engine running at idle: the engine supposedly sucks down 8 ounces of fuel extremely quickly. The "baseline" performance is so far from reality that nothing can be believed. It is as if the promoter is saying "This Honda Civic was getting 4 miles per gallon before HHO, and now gets 25 mpg with HHO!!" Plausible?
The amount of oxyhydrogen produced is infinitesimal, in all cases: 10 amps alternator draw is typical in these scams, so even at 100% electrolysis efficiency we'd be getting 120 watts worth of oxyhydrogen. In an engine of 100,000 to 200,000 watts output, you would not expect to measure any difference at all: you'd expect a net loss, but even on a dynamometer, a loss of .1% cannot be measured reliably. Scammers, however, claim magic at this point: that there is something about HHO** that "improves combustion". They even claim that large portions (15%, 20%, 30%) of the fuel going into an engine is not burned in the cylinder – which is completely untrue. Other scammers claims over-unity gas production by electrically "fracturing" water, rather that splitting it by "brute force" (However, splitting water at over unity has never, ever been demonstrated… and try as we may, there has never been any indication that it is possible to get more energy out of a system than we put in.) Engines are not inefficient because part of the fuel burns does not burn; they are inefficient because most of the heat is wasted. Injecting an infinitesimally small amount of H2, oxyhydrogen or dynamite will not change that.
The scammers say: "Prove it". Odd, because ordinarily it's the extraordinary claim that requires extraordinary proof. But it turns out that we now have one of the scammers inadvertently offering proof that his device does not work. The test is on a motor scooter, which is perfect because if there could be any effect, it would show up here, on an engine 1/100 the size of many American V8s. A motor scooter can easily generate 3 amps at 12 volts, to supply 36 watts worth of oxyhydrogen. The particular scooter in the test is tiny and slow, with about 4 HP, or 3000 watts. Thus the oxyhydrogen produced could have an energy value of about 1/100 the engine output. So we'd still not expect to be able to measure the change on any but the most sensitive dynamometers -- but if there were any change, we'd be about 10 times more likely to see it here than in any car or truck.
The scooter is also a great test vehicle, because the throttle can safely be held open all the time, meaning the engine is always at very near full output. (The test scooter will do about 60 kM/h – 37 mph.) Even the CVT drive train helps, because as load increases, the ratio automatically changes to help the engine run near its HP peak. Hills and headwinds are filtered out because the scooter slows but the engine continues run at its full output. We would want to measure fuel consumption in lb/hp/hr, just as engineers do, rather than distance per volume (mpg) because if one test run was against a head wind and the other with a tail wind, the distances and speeds would be different, but the time at full out put would be the same.
So… if you wanted a simple, reasonably valid test, running a scooter at full throttle for as long as it takes to consume a particular amount of fuel would be a good method. (You obviously cannot do this safely with a car – unless you are on a chassis dyno.) This is just what our scammer/tester does. He apparently lies about the distance (he claims the odometer is broken) because if you watch the speedometer, you can see that the top speed varies, in both runs, in similar ways. However, it is possible that one run was into a head wind, and the other with a tailwind (and the experimenter is just gullible, thinking the difference was a valid measure). But the important thing to measure is time, which is little influenced by headwind/tailwind, uphill/downhill provided the operator runs at full throttle, as he promises to do.
An oxyhydrogen generator on a car cannot be expected to have any measurable performance reduction (the energy consumption and oxyhydrogen production are far too small). Even on a scooter, the amount of energy consumed is too small to be able to reliable measure a performance reduction. But at least our scammer's test shows convincingly that there is no measurable difference with and without "HHO" injection. The running times are essentially identical, within just a couple seconds out of about 300.
The "without HHO" scooter test:
http://www.youtube.com/watch?v=_fg5MYRht4U&feature=user
The "with HHO" scooter test:
http://www.youtube.com/watch?v=3TwFMOIyYnw&feature=related
A post from a related thread where this scooter test came up:
http://cr4.globalspec.com/comment/236473/Re-Saving-MPG-with-Brown-Gas-Generator
* There is nothing special about water and hydrogen in this respect. Any reversible reaction gives off energy in one direction and consumes it in the other. Imagine if that were not the case. Our energy woes would have been eliminated years ago, if we could get heat out of a reaction in one direction and then get heat our again when it runs in the other direction. (Rust iron to make heat. Unrust iron to make more heat.)
** HHO is often said (by the fringe) to be "atomic" hydrogen and oxygen, rather than the mixture of H2 and O2 that it really is. There is no evidence that an electrolyser gives off anything but the common, expected mixture (assuming you don't do the usual, safer, gathering of the gases seperately) . How would one H stay separate from another H?
Comments rated to be Good Answers:
Comments rated to be "almost" Good Answers: