Water-fuelled car
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A water-fuelled car is a hypothetical motor car that uses water as its fuel or produces fuel from water on-board, with no other energy input.
The water-fuelled car is not related to any of these:
- The steam engine: A steam engine uses water to transmit energy from the fire or other heat source to the pistons or turbine that do the work of turning the engine.
- The Crower six stroke, which adds two extra strokes to the customary internal combustion engine four stroke Otto cycle, to produce and exhaust steam from water, while venting heat from the engine.
- water injection which is a method for cooling the combustion chambers of engines by adding water to the incoming fuel-air mixture, allowing for greater compression ratios and reduced engine knocking (detonation).
- The hydrogen car, although 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 by electrolysis. The resulting hydrogen is then either burned in the car's engine or merged with oxygen to create water via a fuel cell. The car ultimately receives its energy from the power plant, with the hydrogen acting as an energy carrier.
- Hydrogen fuel enhancement systems.
The water-fuelled car, on the other hand, purports to create or extract energy from water itself, which would be the basis of a perpetual motion machine. Water-fuelled cars have been mentioned in history books, newspaper and popular science magazines, and urban legends since the 1800s. Many accounts describe engines that run on water, frequently claiming suppression by government or private interests to explain delays in production.[1] There are currently no commercially available products based on these technologies, and several have been shown in court to have been fraudulently used to solicit investment funds.[2] [3]
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[edit] Chemical energy content of water
The burning of conventional fuels such as petrol (gasoline), wood, and coal converts the fuel into substances with less energy (see enthalpy of formation). Energy is released. In the case of most fossil fuels, combustion can be represented with the following chemical equation:
Water is a waste product.
Spontaneous chemical processes do not create energy, they release it by converting unstable bonds into more stable bonds and/or by increasing entropy. Water is such an abundant chemical compound in part because it has very stable bonds that resist most reactions. In order for water to participate in a reaction that produces energy, high energy compounds must be added. For example, it is possible to generate the combustible fuel acetylene by adding calcium carbide to water. However, the calcium carbide, a high energy material, is the 'fuel,' not water.
It is theoretically possible to extract energy from water by nuclear fusion, but fusion power plants of any scale remain impractical, much less on an automotive platform.
[edit] Electrolytic designs
- See also: Electrolysis
Claimed water fuelled engines often obtain hydrogen by electrolysis of water. The electrolysis cell must be powered electrically. The hydrogen and oxygen obtained by this electrolysis can then be burned but more energy is required to drive the electrolysis cell than can be extracted from the resulting hydrogen-oxygen mixture. Otherwise, such a system would be equivalent to a perpetual motion machine.
When hydrogen is burned, the heat it creates can be converted into work by a conventional Otto cycle car engine, but the efficiency of such engines is limited by the second law of thermodynamics and is likely to be around 20%.[4][5] Because a conventional electric motor does not use heat, it can theoretically have an efficiency close to 100%. 94% efficient motors of sufficient power to drive a car are commonplace.[6]
A variation on the water-fuelled car hoax is Stanley Meyers' 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] Garrett electrolytic carburetor
Henry Garrett from Dallas, Texas allegedly demonstrated a water-fuelled car, which was reported on September 8, 1935 in The Dallas Morning News.[citation needed] The car generated hydrogen by electrolysis as can be seen by examining Garrett's patent, issued that same year.U.S. Patent 2,006,676 This patent includes drawings which show a carburetor similar to an ordinary float-type carburetor but with electrolysis plates in the lower portion, and where the float is used to maintain the level of the water.
Garrett's patent fails to identify a new source of energy, so it is likely that the energy in the car battery would be used to electrolyze water into hydrogen, which in turn is combusted. Hydrogen can be obtained from water by electrolysis at 50 - 70% efficiency.[1] Combustion of the hydrogen would be converted to rotational kinetic energy by the motor at 25 - 30% 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. Although the vehicle might run for a while, after a short time the battery would discharge to the point that electrolysis would cease, and the car would stop. Simply using the battery to drive an electric motor would have been far more efficient, as is currently practiced in battery-powered cars. Such cars however require recharging.
[edit] The gasoline pill and related additives
Related to the water-fuelled car hoax are claims that additives, often a pill, convert the water into usable fuel. Recall that in a carbide lamp, a high-energy additive produces the combustible fuel. This gasoline pill has been allegedly demonstrated on a full-sized vehicle, as reported in 1980 in Mother Earth News. Once again, water itself cannot contribute any energy to the process, the additive or the pill is the fuel.
A popular science article in New Scientist in July 2006 described a new type of engine under the misleading headline "A fuel tank full of water".[7] New Scientist later published a letter criticizing them for making "outrageous claims" and pointing out that the engine actually used boron as its fuel.[8] In this case, the fuel is sodium borohydride, a high energy compound that releases hydrogen upon contact with water:
- NaBH4 + 4 H2O → NaB(OH)4 + 2 H2
Hydrogen burns in air (to produce water):
- 2 H2 + O2 → 2 H2O
A number of chemical compounds combine with water to release hydrogen, but in all cases the energy required to produce such compounds exceeds the energy obtained upon their combustion.
[edit] Claims of suppressed inventions
"Inventors" of water-fuelled engines often claim that the technology has long existed but is suppressed internationally by conventional fuel suppliers such as oil companies.[9] Patenting an invention does not suppress it because the contents of all patents are publicly available for inspection.
[edit] In popular culture
Like Water for Octane, season 1, episode 4 of The Lone Gunmen, a fictional TV series and spin-off from the X-files,[10] is based on a "water powered" car that character Melvin Frohike saw with his own eyes back in 1962.[11]
The Water Engine, a David Mamet play, made into a television film in 1994, tells the story of Charles Lang inventing an engine that runs using water for fuel. The plot centers on the many obstacles the inventor must overcome to patent his device.[12]
[edit] See also
[edit] References
- ^ See, for example, claims regarding Stanley Meyer
- ^ Edwards, Tony. "End of road for car that ran on Water", The Sunday Times, Times Newspapers Limited, 1996-12-01, p. Features 12. Retrieved on 2007-05-16.
- ^ State of New Jersey Department of Law and Public Safety press release, November 9, 2006
- ^ Physics In an Automotive Engine
- ^ Improving IC Engine Efficiency
- ^ Washington University Extension Energy Solutions Database
- ^ Adam, David (2006-07-29). "A fuel tank full of water". New Scientist: p. 35. "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. "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."
- ^ WaterPoweredCar.com — site promoting many conspiracy theories, including the suppression of water-fuelled car technology
- ^ "The Lone Gunmen - Plot Summary." _IMDB_. 2007. Internet Movie Database Inc. Accessed 18-11-2007.
- ^ "The Lone Gunmen - Like Water for Octane (2001) - Overview - Plot Outline." _IMDB_. 2007. Internet Movie Database Inc. Accessed 18-11-2007.
- ^ "The Water Engine - Plot Summary for" _IMDB_. 2007. Internet Movie Database Inc. Accessed 17-03-2008.
