A water-fuelled car is an automobile that supposedly derives its energy directly from water. Water-fuelled cars have been mentioned in newspapers, popular science magazines, local news coverage, and the internet; at least some of the claims were found to be tied to investment frauds. These vehicles may be claimed to produce fuel from water onboard with no other energy input, or may be a hybrid of sorts claiming to get energy from both water and a conventional source (such as gasoline). This article focuses on vehicles which claim to extract chemical energy directly from water, a process which would violate the first and/or second laws of thermodynamics.
What water-fuelled cars are not
A water-fueled car is not any of the following:
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.
Chemical energy content of water
See also: Enthalpy of combustion
Spontaneous chemical reactions do not create energy; they release it by converting unstable bonds into more stable bonds and/or by increasing entropy. The burning of conventional fuels such as petrol (gasoline), wood, and coal converts the fuel into substances with less energy, mostly water and carbon dioxide. In the combustion of fossil fuels water is a waste product, and the overall reaction can be represented with the following chemical equation:
CnHm + (n + m/4) O2 → n CO2 + m/2 H2O
Water is such an abundant chemical compound in part because it has very stable bonds that resist most reactions. For water to participate in a reaction that releases 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. Under conditions common on Earth, chemical energy cannot be extracted from water alone.[7][6] (It is theoretically possible to extract nuclear energy from water by fusion, but fusion power plants of any scale remain impractical, and no allegedly water-fuelled cars are claimed to be powered by fusion.)
Electrolysis
Many alleged water-fuelled cars obtain hydrogen or a mixture of hydrogen and oxygen (sometimes called "oxyhydrogen", "HHO", or "Brown's Gas") by the electrolysis of water, a process that must be powered electrically. The hydrogen or oxyhydrogen is then burned, supposedly powering the car and also providing the energy to electrolyse more water. The overall process can be represented by the following chemical equations:
2H2O → 2H2 + O2 [Electrolysis step]
2H2 + O2 → 2H2O [Combustion step]
Since the combustion step is the exact reverse of the electrolysis step, the energy released in combustion exactly equals the energy consumed in the electrolysis step, and—even assuming 100% efficiency—there would be no energy left over to power the car. In other words, such systems start and end in the same thermodynamic state, and are therefore perpetual motion machines, violating the first law of thermodynamics. And under actual conditions in which hydrogen is burned, efficiency is limited by the second law of thermodynamics and is likely to be around 20%.[9][10] More energy is therefore required to drive the electrolysis cell than can be extracted from burning the resulting hydrogen-oxygen mixture.
Hydrogen as a supplement
In addition to claims of cars that run exclusively on water, there have also been claims that burning hydrogen or oxyhydrogen in addition to petrol or diesel fuel increases mileage. Around 1970, Yull Brown developed technology which allegedly allows cars to burn fuel more efficiently while improving emissions. In Brown's design, a hydrogen oxygen mixture (so-called "Brown's Gas") is generated by the electrolysis of water, and then fed into the engine through the air intake system. Whether the system actually improves emissions or fuel efficiency is debated.[34] Similarly, Hydrogen Technology Applications claims to be able increase fuel efficiency by bubbling "Aquyen" into the fuel tank.
A common fallacy found in connection with this type of modification is the mistaken assumption that cars generate excess electricity via their alternators that normally goes to waste and therefore is available for electrolysis.
The amount of force required to turn an alternator or generator is directly proportional to the electrical resistance of the circuits it is supplying. If an electrolysis unit is added to a car,
the amperage it draws from the car's electrical system will make the alternator harder to turn, which will put additional drag on the engine. As a result more fuel will be required to maintain the same rotational speed (RPM.)
A number of websites exist promoting the use of oxyhydrogen (often called "HHO"), selling plans for do-it-yourself electrolysers or entire kits with the promise of large improvements in fuel efficiency. According to a spokesman for the American Automobile Association, "All of these devices look like they could probably work for you, but let me tell you they don't.
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, similar to a carbide lamp, in which 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
Hydrogen on demand technologies
A hydrogen on demand vehicle uses some kind of chemical reaction to produce hydrogen from water. The hydrogen is then burned in an internal combustion engine or used in a fuel cell to generate electricity which powers the vehicle. While these may seem at first sight to be 'water-fuelled cars', they actually take their energy from the chemical that reacts with water, and vehicles of this type are not precluded by the laws of nature. Aluminium, magnesium, and sodium borohydride are substances that react with water to generate hydrogen, and all have been used in hydrogen on demand prototypes. Eventually, the chemical runs out and has to be replenished.[36][37][38] In all cases the energy required to produce such compounds exceeds the energy obtained from their reaction with water.[39]
One example of a hydrogen on demand device, created by scientists from the University of Minnesota and the Weizmann Institute of Science, uses boron to generate hydrogen from water. An article in New Scientist in July 2006 described the power source under the headline "A fuel tank full of water,"[39] and they quote Abu-Hamed as saying:
“ The aim is to produce the hydrogen on-board at a rate matching the demand of the car engine. We want to use the boron to save transporting and storing the hydrogen. ”
A vehicle powered by the device would take on water and boron instead of petrol, and generate boron trioxide. The chemical reactions describing the energy generation are:
4B + 6H2O → 2B2O3 + 6H2 [Hydrogen Generation Step]
6H2 + 3O2 → 6H2O [Combustion step]
The balanced chemical equation representing the overall process (hydrogen generation and combustion) is:
4B + 3O2 → 2 B2O3
As shown above, boron trioxide is the only net byproduct, and it could be removed from the car and turned back into boron and reused. Electricity input is required to complete this process which Al-Hamed suggests could come from solar panels
Closely following a sighting of a Hydrogen-powered 7 series during testing, BMW officially announced the Hydrogen 7 today. The car is touted as the first hydrogen-drive luxury performance automobile for everyday use. The BMW Hydrogen 7 will be built in a limited series, and sold to select customers in the U.S. and overseas in 2007. The engine in the Hydrogen 7, a derivative of the 7 series 12 cylinder engine, is capable of running on gasoline or hydrogen, and produces 260 hp. The car will accelerate from 0 to 62.1 mpg in 9.5 seconds. The ability to run on both gasoline and hydrogen gives the Hydrogen 7 a range of more than 400 miles. The high tech hydrogen storage tank has a capacity of approximately 17.6 lb of liquid hydrogen, giving the Hydrogen 7 a cruising range in hydrogen mode upwards of 125 miles. The gasoline mode accounts for an additional 300 miles of cruising range. The driver is the one who decides which fuel to use, with a smooth transition between both operating modes, since the engine power and torque remain identical regardless of the fuel used.
BMW Introduces 1st Production-based Hydrogen Car
31 May 2000
Munich, Germany - BMW presented the world's first production-based hydrogen
car in Berlin, the BMW 750hL. The luxurious sedans will be used as shuttles
for the entire duration of the EXPO 2000. These vehicles are built on the
same production line in Dingolfing as normal production 7 Series. They will
demonstrate to all who experience them thatthey meet the very highest
requirements for comfort, dynamics and utility value at market-appropriate
costs.
"And we will be the first automobile manufacturer in the world to offer series
production hydrogen cars," says Dr. Burkhard Göschel, Development
Director of the BMW Group.
Thousands of Hydrogen Cars and Adequate Infrastructure by 2010
Dr. Burkhard Göschel: "Our vision is to have a hydrogen fuel station
available in the vicinity of the branches of the BMW Group in Germany by the
11th of May 2005." BMW offers international energy companies close
cooperation for the development of a hydrogen fuel station network: "Our aim
is to have a sufficient network of hydrogen fuel stations all over Europe by
the year 2010," says the development chief. By then BMW has planned to have
sold several thousand hydrogen cars. The prices for the cars and for the
fuel are to be similar to those of conventional cars and fuels.
750hL: A Hydrogen Sedan For Everyday Use
The hydrogen technology used in the 12-cylinder sedans has already advanced
so far that it permits realistic planning for large series production. BMW
has extended its leading position in the development of the CleanEnergy car.
CleanEnergy is the generic term for the ecologically ideal, closed energy
cycle based on water.
Running on hydrogen, the 12-cylinder engine delivers 204-horsepower and
accelerates from standstill to 100 km/h in 9.6 seconds, while achieving a
top speed of 226 km/h. Fitted with the 140 liter Cryo fuel tank, the fully
equipped 7 Series has an additional range of 350 kilometers. The car
features a conventional fuel supply too, since the availability of hydrogen
fuel is limited. After the EXPO in Hanover is over, the sedans will drive
back to Munich on their own power using conventional fuel.
The engine itself differs mainly only with regard to the intake duct with
additional injection valves for the hydrogen. The production of the 750hL
was incorporated as much as possible into the normal production process.
The 12-cylinder engines were integrated into production in the Dingolfing plant
and assembled together with the conventional spark-ignition and diesel engines.
The hydrogen is stored cryogenically - i.e. in super-chilled and liquid form
- at a temperature of around minus 250 degrees Celsius in a double-walled
steel tank behind the rear seat-backs. Two safety valves ensure controlled
ventilation in the case of excess pressure. They are also part of the
comprehensive safety concept which proved its reliability in numerous crash
tests. Even in a massive rear-end collision in which the tank would be
affected in its protected area, the steel cylinder with its double
two-millimeter thick walls did not leak. Even greater deformations which
might cause a leak in the tank, would not cause it to explode. For an
explosion to occur, hydrogen and air would have to mix but due to the higher
inner pressure of the hydrogen, air cannot enter the tank.
The First Production-Based Cars With Fuel Cell
A number of the BMW hydrogen sedans are the first production-based cars to
feature a fuel cell for supplying on-board electricity. This "electrochemical"
battery takes on the function it does best: the production of electricity with
a very high degree of efficiency of up to 50 percent. The compact fuel cell
battery in the 7 Series with hydrogen drive is only as big as a conventional
lead-acid battery. However the five kilowatt unit outperforms the best of
these by far. The so-called fuel cell APU (Auxiliary Power Unit) not only
takes on the supply of all conventional electric components, but also allows
for new functions. The trailblazing 7 Series model features stationary air
conditioning which cools the interior even if the engine is turned off.
Pioneering Service Concept:
Permanent Checking Function via Radiotelematics
Like the Formula 1 racing cars, all 750hLs are radio-linked to the service
computer in the development workshop in Munich - 24 hours a day. This
enables the monitoring of all systems continually and facilitates reacting
instantly to any situation. Not only is all of the hydrogen data transmitted
and checked, but all the data processed by the standard bus system in the
7 Series, as well. "The workshop knows that something is wrong before the
driver does", explains Klaus Pehr, the BMW engineer responsible for hydrogen
cars. The insights gained are incorporated into the on-going improvement of
the hydrogen fleet. By means of a rotating deployment plan for the
environment-friendly 7 Series, all cars are brought up-to-date as quickly as
possible. After the world exhibition is over on October 31st, all vehicles
will have received the latest developments.
The telematic checking system has already proved its usefulness in the
development stage. Thanks to this system, the car check conducted every
evening in Hanover is reduced to a short operation in the branch where
mainly only the sensors have to be calibrated. There the 750hLs are also
refueled with hydrogen using a so-called mobile "Cryo-Can".
Hydrogen Engines: Lean-Burning Mixtures Prevent Emissions
Since the end of the seventies, BMW has been dealing with the topic of
hydrogen drive. Five generations of hydrogen cars have hit the road, each
based on the BMW 7 Series of the time.
Today too, the basic engine is a series-production engine, but the hydrogen
drive calls for some changes ranging from the fuel system to the mixture
formation process. An electronic mixture formation system has been
developed which precisely matches hydrogen injection and charge changes.
Combustion generally takes place with an excess of air. The additional air
in the combustion chamber absorbs heat and reduces the flame temperature to
below the critical level above which the mixture could ignite by itself. At
the same time the low combustion temperature also prevents the production of
nitric oxides (NOx), which have to be detoxified by catalytic converters in
petrol-engine cars. So even without additional exhaust emissions treatment,
the BMW hydrogen engines operate almost entirely without emissions. This
environment-friendly engine layout leads to a reduction in specific output.
However, this can be compensated for by means such as increasing the
displacement. Engines designed solely for hydrogen operation do not have to
make this compromise and are at least on par with spark-ignition or diesel
engines as far as specific output is concerned.
Refueling In Only Three Minutes
A further prerequisite for the introduction of hydrogen as fuel is a filling
system which must be no more complicated than filling a car today. The low
temperature of minus 250 degrees Celsius requires special refueling
technology.
In cooperation with its project partners, BMW has developed a fueling system
which can be used to fill vehicles with hydrogen as quickly, loss-free and
safely as with conventional fuels. The latest version of this technology is
currently being used by the world's first public robotic fuel station for
liquid hydrogen at the Munich airport. The fully automatic hydrogen fueling
operation takes less than three minutes and is a simple process for the
layman.
BMW Promotes Solar Electricity For Generating Hydrogen
Hydrogen can only be a sensible alternative to conventional fuels if the
electricity needed for generating it from water can be produced with
renewable energy sources. This can, for example, be achieved by means of
solar cells which produce electricity directly. Solar powerplants with
groove-shaped parabolic mirrors, which operate on the principle of the steam
turbine, are a promising alternative. Such a system is already in operation
in the California Mojave desert. In order to test such scenarios, BMW has
joined the solar hydrogen project in Neunburg vom Wald at an early stage,
where the photovoltaic generation of hydrogen and its use for different
purposes was studied. The aim is to produce sufficient amounts of hydrogen
economically using solar energy.
BMW Supports Practice-Oriented Hydrogen Initiatives
BMW supports initiatives at all levels that help to create the necessary
conditions for the introduction of hydrogen powered cars. The "European
Integrated Hydrogen Project" for example aims at harmonizing hydrogen
relevant regulations internationally. The goal is to provide lawmakers with
a sound basis for making decisions. Concepts for standardizing
infrastructure and vehicle components are being developed.
BMW has joined together with nine partners from the world of business and
research for this purpose. Work is running on two tracks: a top-down
process will analyze already existing hydrogen relevant laws in Europe. On
this basis suggestions for Europe-wide standardization are to be worked out.
The bottom-up analysis examines existing vehicles and infrastructures to
identify safety relevant aspects. They will then be used as a basis for
discussions with the authorities. With this project, BMW aims to bring
about general licensing for hydrogen powered vehicles.
HYFORUM 2000
To Strengthen International Alliance For Hydrogen
In addition BMW has been very active in bringing about the international
hydrogen conference HYFORUM 2000 which will take place in Munich in
September 2000. It is purposefully aimed at high-ranking decision-makers
from industry, finance, insurance and politics. Its goal is to bring
together important partners and to direct their attention to the topic of
hydrogen as an energy source. Wide-ranging cooperation is now called for in
order to pave the way for hydrogen to move from research to application. To
achieve this, not only are technical decisions needed, but political
decisions as well. It is expected that the HYFORUM 2000 will produce
answers to the energy question in the 21st century. As an international
forum, HYFORUM 2000 will send out signals to the entire world.
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