I saw a while back a YouTube video that appears to show a news report of a man who patented technology to turn water into "HHO".
The video makes some big claims — 161 km (100 mi.) on 0.1 L (4 oz.) of gas, developing water-powered Hummers, something "as hot as the surface of the sun", etc. but I haven't seen anything to officially refute it.
Is there an official verdict on this?
The technology he demonstrates for welding is well known and understood (see this patent from 1962), and is generally called an oxyhydrogen electrolytic torch or water torch. Water is decomposed into Oxygen and Hydrogen on demand. This has some benefits in difficult environments (e.g. underwater) and others where you wouldn't want to have cylinders of compressed flammable gas, as well as for some other niche applications. It's not commonly used today.
The core problem with his "100ml of water for 160km" claim (not that that's impressive, he just re-captures the water after the combustion) and similar efficiency claims is that the splitting of H2O into "HHO" (actually 2H₂O → 2H₂+O₂) requires energy. The combustion of "HHO" produces energy, but there is always a net loss - heat, friction (as in a car engine), and losses in the original splitting. His claim is that he has refined this process to get more energy out than is put in, which puts his claims in the realms of perpetual motion machines, and breaks a lot of very well understood laws of physics. Without making a more specific claim - a special catalyst he uses or some new technology, this is not even a claim worth investigating.
The electrolysis of water is well understood, as it is widely performed on a commercial scale. Most plants have overall efficiency of less than 70%.
as hot as the surface of the sun
Yeah, they like to claim self-contradicting things like this:
HHO produces a 279 degree flame, that can sublimate tungsten in seconds at over 10,000 degrees.
If this were really sublimating tungsten (boiling point of 5555 °C = 10031 °F), then yes, it would be hotter than the surface of the sun (5780 K = 9940 °F). But it's not true. Whenever you see them demonstrating this feat, they're aiming the torch at tungsten rods in air.
Tungsten doesn't sublimate in air. It burns, reacting with atmospheric oxygen to form tungsten trioxide, which then melts (at 1473 °C) or vaporizes (1700 °C) and is blown away by the torch, exposing a layer of fresh tungsten, which burns, etc.:
When a tungsten specimen is heated, its surface becomes covered with crystals which melt when the melting point of tungsten trioxide is reached, the liquid oxide flowing to the lower (frontal) part of the specimen and forming a drop which then separates. Melting of the oxide coating is accompanied by rapid self-heating of the specimen with transition to the combustion regime. - Ignition and combustion of high-melting metals (tungsten, molybdenum, boron)
The particles that are blown away form smoke, which you can see in the video.
This is why light bulbs are bulbs, and not just tungsten filaments hanging around in the air. They need to be surrounded by an oxygen-free atmosphere in order to take advantage of their high boiling point. When the bulb breaks, they burn up.
"HHO gas" doesn't exist. It's just a hoax name for conventional oxyhydrogen gas (2× H2 gas mixed with 1× O2 gas), as produced by a conventional "water torch" or "water welder", which burns at 2800 °C, plenty hot to turn tungsten into smoke. All their other claims are equally sloppy and unscientific.
The whole report is mixing a lot of stuff up, making it very confusing to understand what is actually claimed. I'll go ahead with the claim that they developed a car that can run on water as a fuel.
To make it short, basic thermodynamics tell us that water cannot be a fuel in the way described in that report. If you pay attention to the video, he says that he uses "water and electricity", using electrolysis to split the water into hydrogen and oxygen gas, and then burning this gas mixture which results in water again. So you start from water and end up with water again. Energy is conserved, you can neither create it nor destroy it, so going from water back to water cannot provide you with any energy out of the water.
Where the energy that actually drives the car from is the electricity used to split the water into hydrogen and oxygen. A hydrogen/oxygen gas mixture contains a lot more energy than water, and this energy is released when you burn the mixture, the end result is water. But to get from water to hydrogen/oxygen gas you have to put more energy into it than you'll get out in the end.
