Water-fuelled car
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A water-fuelled car is a hypothetical motor car that uses ordinary water as its fuel.
This is not the same concept as a steam engine. A steam engine uses water to transmit energy from the fire or other heat source to the pistons that do the work of turning the engine.
This is not the same concept as a hydrogen car, though it often incorporates some of the same elements. To fuel a hydrogen car from water, energy from a power plant is used to generate hydrogen from electrolysis, which is then either burned in the car's engine or merged with oxygen to create water via a semipermeable membrane. Both methods produce energy which is output to create motion. The car ultimately receives its energy from the power plant, with the hydrogen acting as an energy carrier.
The water-fuelled car, on the other hand, would have to create or extract energy from the water itself with no other energy input.
Water fuelled cars have featured in urban legends since the 1930s. The story is usually that a lone inventor invents an engine that runs on water but the idea is suppressed by either Big Oil or automakers in order to safeguard their profits. Claims for water fuelled power sources are often used to fraudulently extract money from gullible investors.
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[edit] Chemical energy content of water
The burning of conventional fuels such as petrol (gasoline), wood and coal releases energy, which converts the fuel into substances with less energy. In the case of most fossil fuels, one of the waste products is water. This is because water is at a lower energy state than the original fuel.
Chemical processes do not create energy, they merely store and release it in the form of bond energy between the atoms. Water is a stable and abundant chemical compound in part because it is already at a very low energy level. Where water takes part in a reaction that produces energy, the material it is reacting with contains the chemical energy that is being released. For example, mixing water with sodium produces a vigorous reaction which generates heat and generates hydrogen which can be burned in air. But in that case, sodium is being converted into a lower energy state, making sodium the source of the energy — not the water.
[edit] Nuclear energy content of water
It is theoretically possible to extract energy from water by nuclear fusion, and indeed, all naturally occurring water contains trace amounts of heavy water molecules in which one of the hydrogen atoms is deuterium (an isotope of hydrogen) which is useful in nuclear fusion reactions. However, there is no suggestion that any motor, small or large, has yet been proposed that can achieve this — indeed, practical nuclear fusion power plants are not yet technologically feasible even on large scales. For further discussion, see Cold fusion.
[edit] Electrolytic designs
- See also: Electrolysis
Where designs that claim to be water fuelled engines have been made public, they often involve obtaining hydrogen from water by electrolysis. The usual scheme is to use electricity (from a battery) to split water into hydrogen and oxygen — then to burn the hydrogen in a more or less conventional engine — then use some of the power of that engine to recharge the battery and thus electrolyse more water. The end result would once again be water because that is what you get when you burn hydrogen in air. In effect, you'd have a perpetual motion machine.
In practice, none of the processes involved are 100% efficient. This means that some electricity is wasted in the electrolysis stage, some heat is wasted in burning the hydrogen in the engine and some of the power of the engine is lost in generating electricity. This means that the amount of power available for recharging the battery is considerably less than the amount of electricity needed for continued electrolysis — and the engine rapidly comes to a halt when the battery runs out of charge.
When the hydrogen is burned, the heat it creates can be converted into work by a conventional piston engine (car engine), but the efficiency of such engines is limited by the second law of thermodynamics and is likely to be of the order 30%. Because a conventional electric motor does not use heat, it can theoretically have an efficiency close to 100% and 80% efficient motors are commonplace.
A variation of the electrolytic design is the water fuel cell where it is claimed that hydrogen and oxygen are produced by a mysteriously efficient form of electrolysis. This design also reduces to a perpetual motion machine and violates the first law of thermodynamics.
[edit] The gasoline pill
Some sources claim that you can fill your car up with water and then add a small pill to convert the water into usable fuel. Because, as described above, water itself cannot contribute significant energy regardless of what you do to it or what you mix it with, the tablet would have to contain all the energy of a full fuel tank. This would require that the tablet was a safe object that contained, weight for weight, approximately 100,000 times the energy of previously known explosives such as TNT. While this might not be impossible, it would certainly be exceedingly unstable and dangerous. In any event, the result would be a car fuelled by the substances in the gasoline pill and not a car fuelled by water.
[edit] Specific reports
[edit] Garrett electrolytic carburettor
Henry Garrett from Dallas, Texas allegedly demonstrated a water fuelled car in 1935 which was reported on September 8, 1935 in The Dallas Morning News. The car generated hydrogen by electrolysis as can be seen by examining Garrett's patent: U.S. Patent 2,006,676
US patent number 02006676 was filed on July 1st 1932 by Charles H Garrett. The patent was granted on 2nd July 1935. This patent includes drawings which show a carburettor similar to an ordinary float type carburettor but with electrolysis plates in the lower portion, and where the float is used to maintain the level of the water.
There appears to be nothing shown in the patent that could provide a new source of energy unknown to conventional science so it is likely that the energy in the electricity from the car battery would be converted to hydrogen at between 50% and 70% efficiency [1], the hydrogen would be converted to rotational kinetic energy by the motor at around 25% to 30% efficiency and that could be used to generate electricity at around 80% efficiency. Hence only between 10% to 15% of the energy taken from the battery for electrolysis would be available to recharge the battery even if the vehicle were standing still. Whilst the vehicle might run for a while, after a short time the battery would discharge to the point where electrolysis could no longer be maintained and the car would stop. Simply using the battery to drive an electric motor would have been far more efficient.
[edit] New Scientist
An article in New Scientist in July 2006 that described an engine running on water had a misleading headline.[1] New Scientist later published a letter criticizing them for making "outrageous claims", and pointing out that the engine actually used boron as its fuel.[2]
[edit] Suppressing useful inventions
It is a frequent claim of inventors of water fuelled engines that the technology has existed for a long time and is being suppressed by conventional fuel suppliers such as oil companies.[3] This is unlikely because once any useful invention becomes technically possible it is likely to be invented independently several times. This makes the suppression of a useful invention for any length of time impossible in practice. Patenting an invention does not suppress it because the contents of all patents are publicly available for inspection.
[edit] See also
[edit] References
- ^ Adam, David (2006-07-29). "A fuel tank full of water". New Scientist: p. 35. Retrieved on 2007-03-01. "Forget cars fuelled by alcohol and vegetable oil. Before long, you might be able to run your car with nothing more than water in its fuel tank. It would be the ultimate zero-emissions vehicle."
- ^ Wilkins, Lucas (2006-08-12). "Water is no fuel". New Scientist: p. 19. Retrieved on 2007-03-01. "Why is it deemed necessary to put such outrageous claims in the titles and beginnings of articles? Saying that the car discussed in the article runs on water is equivalent to saying that the internal combustion engine runs on air. ... The fuel is boron."
- ^ http://waterpoweredcar.com/stanmeyer.html site promoting many conspiracy theories including that water-fuelled cars have been suppressed
