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Hydrogen vehicle
Car Show
Hydrogen vehicle
A hydrogen vehicle is an
automobile which uses
hydrogen as its primary source of power for locomotion. These cars generally use the hydrogen in one
of two methods: combustion or fuel-cell conversion. In combustion, the
hydrogen is "burned" in engines in fundamentally the same method as
traditional gasoline cars. In fuel-cell conversion, the hydrogen is
turned into electricity through fuel cells which then powers electric
motors. With either method, the only byproduct from the spent hydrogen
is water.
Hydrogen can be obtained from decomposition of
methane (natural gas) or from water using electricity (electrolysis). A primary
benefit of using pure hydrogen as a power source is that it uses oxygen from the
air to produce only water vapor as exhaust (and very little nitrogen oxides from
the nitrogen in the air when burning at high temperatures, moving the source of
atmospheric pollution from many cars back to a single power plant, where it can
be more easily dealt with. (The hydrogen car has absolutely nothing to do with
fusion of hydrogen.)
Hydrogen is not a pre-existing source of
energy like fossil fuels, but a carrier, much like a battery. It is renewable in
a realistic time scale, unlike fossil fuels which can take millions of years to
replenish. The largest apparent advantages are that it could be produced and
consumed continuously as well as cleanly using solar, wind and nuclear power for
electrolysis. However, hydrogen production methods currently utilizing
hydrocarbons would actually be more pollutive than direct consumption of the
fossil fuels. To reduce pollution and reliance on fossil fuels, sustainable
methods of hydrogen production would have to be invested in.
Some hydrogen cars currently exist, and a significant amount of research is
underway to make the technology more viable. The common
internal combustion engine, usually fueled with gasoline (petrol) or diesel
liquids, can be converted to run on gaseous hydrogen. However, the most
efficient use of hydrogen involves the use of fuel cells and electric motors
instead of a traditional engine. Hydrogen reacts with oxygen inside the fuel
cells, which produces electricity to power the motors. One primary area of research is hydrogen
storage, to try to increase the range of hydrogen vehicles while reducing the
weight, energy consumption, and complexity of the storage systems. Two primary
methods of storage are metal hydrides and compression.
High speed cars, buses, submarines, and space rockets
already run on hydrogen, in various forms. There is even a working toy model car
that runs on solar power, using a reversible fuel cell to store energy in the
form of hydrogen and oxygen gas. It can then convert the fuel back into water to
release the solar energy.
[1]
Hydrogen fuel cell
While fuel cells are potentially highly efficient, and working prototypes
were made by
Roger E. Billings in the late 1960s, three major obstacles exist in the
development of a fuel cell-powered hydrogen car. The first problem is that
hydrogen has a very low density. Even when the fuel is stored as a liquid in a
cryogenic tank or in a pressurized tank as a gas, the amount of energy that can
be stored in the space available is limited, and hydrogen cars therefore have
limited range compared to their conventional counterparts. Some research has
been done into using special crystalline
materials to store hydrogen at greater densities and with margins.
Instead of storing
molecular hydrogen on-board, some have advocated using hydrogen reformers to
extract the hydrogen from more traditional fuels including methane, gasoline,
and ethanol. Many environmentalists are irked by this idea, as it promotes
continued dependence on fossil fuels (at least in the case of gasoline). However, given an efficient
reforming process, vehicles using reformed gasoline or ethanol to power fuel
cells would still be more efficient than vehicles running internal combustion
engines.
The second major problem that used to plague hydrogen fuel cells involves the
high cost of making reliable fuel cells that would provide electric power in a
hydrogen car. Scientists are also working hard to figure out how to produce
inexpensive fuel cells that are also robust enough to survive the bumps and
vibrations that all automobiles have to handle. Furthermore freezing conditions
have to be handled because fuel cells do produce water and utilise moist air
with varying water content. Most fuel cell designs are fragile and can't survive
in such environments. Also, many designs require rare substances such as
platinum as a catalyst
in order to work properly, and the catalyst can be contaminated by impurities in
the hydrogen supply. However, within the past few years, a nickel-tin catalyst
has been developed which drastically lowers the cost of a hydrogen fuel cell car
to make it an economically viable car.
The third "problem" is due to the fact that while hydrogen can be used as an
energy carrier, it is not an energy source. It still must be
produced from
fossil fuels, or from some other energy source, with a net loss of energy (since
the conversion from energy to hydrogen storage and back to energy is not 100%
efficient). Hydrogen is nearly twice as efficient than traditional combustion
engines, which only have an efficiency of 15-25%. Hydrogen has a thermodynamic
efficiency of 50-60%. The percentage will never be 100% because of the second
law of thermodynamics.
Since all energy sources have drawbacks, a shift into hydrogen powered
vehicles may require difficult political decisions on how to produce this
energy. The US Energy Department has already announced a plan to produce
hydrogen directly from
Generation IV reactors. These nuclear powerplants would be capable of
producing hydrogen and electricity at the same time. Recently, alternative
methods of creating hydrogen directly from sunlight and water through a metallic
catalyst have been announced. This may provide a cheap, direct conversion of
solar energy into hydrogen, a very clean solution.
[2]
Sodium boro hydride (NaBH4) a chemical compound may hold future
promise due to the ease at which hydrogen can be stored under normal atmospheric
pressures in automobiles that have fuel cells.
United States President George W. Bush is optimistic that these problems
could be overcome with research. In his 2006 State of the Union address, he
announced the U.S. government's hydrogen fuel initiative, which complements the
President's existing FreedomCAR initiative for safe and cheap hydrogen fuel cell vehicles.
Moving the world economy toward the use of alternative (i.e. non-fossil fuel)
energy sources, of which creating economically feasible hydrogen vehicles with
perfomance comparable to current gasoline powered vehicles is an important part,
may help to alleviate a great deal of the world's political problems. For
instance, dramatically reducing the United States' dependence on oil would
eliminate its main strategic interest in the Middle East allowing it to withdraw
both U.S. troops and U.S. aid to repressive regimes in the region (such as Saudi
Arabia, Egypt, Pakistan, and Israel) thereby depriving anti-American terrorists
of one of their most valuable recruiting tools. Moreover, the economic
marginalization of oil that would occur in as the world moved away from oil as
its primary fuel would create dramatic changes in the political and economic
dynamics of oil producing states. The declining price of oil would help to
alleviate the so-called "Dutch Disease" that afflicts major oil exporters in
which the oil industry soaks up most of the investment and caused currency
appreciation that undermine the competiveness other industries working in
tradable goods. The immense oil wealth of these states (think Saudi Arabia or
the UAE) also prevents the formation of important political institutions and
removes the government's dependence on the people for revenue thereby depriving
the people of any ability to hold the government accountable. Without the huge
revenues provided by oil the government would have to rely on the people for
revenue meaning that the state would likely be forced to make important
concessions to the people in the fields of political rights and civil liberties.
The bottom line is that the United States may be able to decrease Muslim
anti-Americanism, bring home troops, and promote reform in the Muslim world by
moving toward alternative energies such as the hydrogen powered vehicle. This
may also help to relieve other geopolitical tensions by removing an area over
which great powers have traditionally competed and still compete today. (For
more information on the corosive effects of oil look for "Dutch Disease" in
almost any economics textbook and check out "Saving Iraq From Its Oil" by Nancy
Birdsall and Arvind Subramanian in the July/August 2004 issue of Foreign
Affairs)
Hydrogen internal combustion
Hydrogen internal combustion engine cars are different from hydrogen fuel
cell cars. The hydrogen internal combustion car is a slightly modified version
of the traditional
gasoline internal combustion engine car. Hydrogen internal combustion cars burn
hydrogen directly, with no other fuels and produce pure water vapor exhaust. The
problem with these cars is the hydrogen fuel that can be stored in a normal size
tank is used up rapidly. A full tank of hydrogen, in the gaseous state, would
last only a few miles before the tank is empty. However, methods are being
developed to reduce tank space, such as storing condensed (liquid) hydrogen or
using metal hydrides in the tank.
In 1807,
Franηois Isaac de Rivaz built the first hydrogen-fueled internal combustion
vehicle. However, the design was very unsuccessful.
It's estimated that more than a thousand hydrogen powered vehicles were
produced in Germany before the end of the WWII prompted by
the acute shortage of oil.
BMW's CleanEnergy internal combustion hydrogen car has more power and is
faster than hydrogen fuel cell electric cars. A BMW hydrogen car ( H2R[3]) broke
the speed record for hydrogen cars at 300 km/h (186 mi/h), making automotive
history. Mazda has developed Wankel engines to burn hydrogen. The Wankel uses a
rotary principle of operation, so the hydrogen burns in a different part of the
engine from the intake. This reduces intake backfiring, a risk with hydrogen fueled piston engines.
However the major car companies like
DaimlerChrysler and General Motors Corp, are investing in the slower, weaker, but more efficient
hydrogen fuel cells instead.
An existing conventional car sleeps in a converter to run on hydrogen, or a
mixture of hydrogen and other gasses as produced in a reforming process. Since
hydrogen can burn in a very wide range of air/fuel mixtures, a small amount of
hydrogen can also be used to ignite various liquid fuels in existing
internal combustion engines under extremely lean burning conditions. This
process requires a number of modifications to existing engine air/fuel and
timing controls. Roy McAlister of the American Hydrogen Association has been
demonstrating these conversions. Other renewable energy sources, like biodiesel, are also practical for existing automobile conversions, but come with their own
host of problems.
Some claim to have devices that convert water to hydrogen gas directly in the
car using the engine's output, making a car that runs only on water and produces
water as exhaust. Since this is a closed loop exhibiting net energy output (perpetual
motion), it is widely regarded as a hoax.
In 2005 an Israeli company claimed it succeeded in conquering most of the
problems related to producing Hydrogen internal combustion engine by using a
device called a Metal-Steam combustor that separate Hydrogen out of heated
water. A tip of a
Magnesium or Aluminum coil is inserted into the small Metal-Steam combustor
together with water where it is heated to very high temperatures. The metal
atoms bond with the Oxygen from the
water, creating metal oxide. As a result, the Hydrogen molecules become free,
and are sent into the engine alongside the steam. The solid waste product of the
process, in the form of metal oxide, will later be collected in the fuel station
and recycled for further use by the metal industry
[4]
Automobile and bus makers
Many companies are currently researching the feasibility of building hydrogen
cars. Funding has come from both private and government sources. In addition to
the BMW and Mazda examples cited above, many automobile manufacturers have begun
developing cars. These include:
A fuel cell powered vehicle from
GM
- BMW 7 series (auxiliary power), based on
UTC Power fuel
cell technology
- DaimlerChrysler F-Cell, a hydrogen fuel cell vehicle based on
the
Mercedes-Benz A-Class.
- Ford Focus FCV a hydrogen fuel cell modification of the Ford
Focus
- General Motors multiple models of fuel cell vehicles including
Hy-wire
and the HydroGen3
- Honda is experimenting with a variety of alternative fuels and fuel
cells with experimental vehicles based on the
Honda EV Plus
- Hyundai Santa Fe FCEV, based on
UTC Power fuel
cell technology
- Mazda - RX-8,
with a dual-fuel (hydrogen or gasoline) rotary-engine
[5]
- Nissan X-TRAIL FCV, based on
UTC Power fuel
cell technology
- Volkswagen and Toyota also have hydrogen fuel cell cars in development.
A few bus companies are also conducting hydrogen fuel cell research. These
include:
- DaimlerChrysler, based on
Ballard fuel cell technology
- Thor Industries (the largest maker of buses in the U.S.), based on
UTC Power fuel
cell technology
- Irisbus, based on
UTC Power fuel cell technology
Supporting these automobile and bus manufacturers are fuel cell and hydrogen
engine research and manufacturing companies. The largest of these is
UTC Power, a division of United Technologies Corporation, currently in joint
development with Hyundai, Nissan, and BMW, among other auto companies. Another
major supplier is Ballard Power Systems. The Hydrogen Engine Center is a supplier of
hydrogen-fueled engines.
Most, but not all, of these vehicles are currently only available in
demonstration models and cost a large amount of money. They are not yet ready
for general public use.
There are, however, fuel cell powered buses currently active or in
production, such as a fleet of Thor buses with
UTC Power fuel cells
in California, operated by SunLine Transit Agency
[6].
Perth is also participating in the trial with three fuel cell powered buses
now operating between Perth and the port city of
Fremantle. The trial is to be extended to other Australian cities over the
next three years.
Mazda leased two dual-fuel RX-8s to commercial customers in Japan in early
2006, becoming the first manufacturer to put a hydrogen vehicle in customer
hands. BMW has recently released to the media information of a new car that has
been manufactured and uses hydrogen or petrol and is completely clean. BMW also
plans to release its first publicly available hydrogen vehicle in 2008.
Fuel stations
Since the turn of the millennium,
filling stations offering hydrogen have been opening worldwide and hydrogen
stations. Among them:
- Some
fuel stations in Germany (among them, Aral), within the Clean Energy
Partnership, are offering hydrogen.
- Bus refueling stations in a small number of European cities as part of
the Clean Urban Transport for Europe programme.
- Iceland began opening stations in 2003 as part of
the country's initiative to implement a
hydrogen economy.[7]
- Stations in
California opened by the California Fuel Cell Partnership, and under
Governor Arnold Schwarzenegger's hydrogen highway program.
- The third hydrogen filling station in the world opened in
Dearborn, Michigan in 1999, sponsored by Ford.[8]
Planes
Smartfish is a revolutionary general aviation aircraft technology that is highly
innovative in terms of safety, economy and emotion. It uses hydrogen fuel.
References
-
↑
Thames & Kosmos kit,
Other educational materials, and
many more demonstration car kits.
-
↑
Hydrogen's Dirty Secret. URL accessed on
December 4, 2005.
-
↑
H2R. URL accessed on
December 4, 2005.
-
↑
IsraCast: THE CAR THAT MAKES ITS OWN FUEL.
-
↑
NEWS FROM MAZDA. URL accessed on
December 4, 2005.
-
↑
Hydrogen-filling station opens ... in Iceland
-
↑ Motavalli,
Jim (2001). Breaking Gridlock: Moving Towards Transportation That Works,
San Francisco: Sierra Club Books.
ISBN 1-57805-039-1.: p. 145.
See also
External links
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