I think he is just saying that using such a system to improve the efficiency of an ICE is possible, though it would require a very heavy redesign of the engine to actually work properly. However, most people take this theoretical concept and attempt to practice it by just throwing a kit on some random car and hoping the equation will balance itself.
This, I think, is in line with what Tony, a very respected individual, has to say about it:
Quote:
More subtly, other systems claim that the hydrogen is used as a combustion enhancer. The idea is that adding quite small amounts of hydrogen to the fuel/air mixture cause improvements to the burn, which in turn leads to better economy and reduced emissions.
In principle this is a sound idea. Several reputable studies have been done into the idea, and there is no doubt that adding hydrogen to a petrol / air mix gives the following benefits:
* Better ignitability (leaner mixtures can be ignited)
* Higher flame speed (leaner mixture will burn reliably)
* Reduced tendency to knock (so higher compression ratio can be used)
If an engine is designed and optimised to take advantage of these altered properties, then substantial improvements in power and economy can be obtained - ArvinMeritor claim up to 20-30% (full article here).
So, this is a great technology and we should all rush out and bolt hydrogen generators onto our cars? Well, no. The problem is that the rest of the engine needs to be optimised as well to get the benefits. To take advantage of the higher octane rating, the compression ratio must be raised by redesigning the cylinder head or pistons. More critically, the ability to burn a leaner mixture is only useful if the engine ECU is configured to inject a very lean air/fuel ratio, and manage the required variations in spark timing and fuelling (which current production vehicles, without exception, are not). Simply speeding up the burn, even if theoretically advantageous, is likely to make economy worse if the ignition timing is not adjusted to suit.
As a result of these considerations, I am highly sceptical about the use of hydrogen generators as an aftermarket fuel "saving" device, and will remain so until the makers produce some good results.
Many devices that produce hydrogen via on-board electrolysis feed not pure hydrogen, but a mixture of hydrogen and oxygen, to the engine. This mixture (two parts hydrogen to one part oxygen) is commonly known as Brown's Gas. Various semi-magical properties are claimed for this gas, but these are widely disputed and should be considered with scepticism.
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http://fuelsaving.info/hydrogen.htm