From Wikipedia, the free encyclopedia
An
alternative fuel vehicle is a vehicle that runs on a fuel other than traditional
petroleum fuels (
petrol or
Diesel fuel); and also refers to any technology of powering an engine that does not involve solely
petroleum (e.g.
electric car,
hybrid electric vehicles, solar powered). Because of a combination of factors, such as environmental concerns, high oil prices and the potential for
peak oil,
development of cleaner alternative fuels and advanced power systems for
vehicles has become a high priority for many governments and vehicle
manufacturers around the world.
Hybrid electric vehicles such as the
Toyota Prius
are not actually alternative fuel vehicles, but through advanced
technologies in the electric battery and motor/generator, they make a
more efficient use of petroleum fuel. Other research and development efforts in alternative forms of power focus on developing
all-electric and
fuel cell vehicles, and even the stored energy of compressed air.
An environmental analysis extends beyond just the operating efficiency and emissions. A
life-cycle assessment of a vehicle involves production and post-use considerations. A
cradle-to-cradle design is more important than a focus on a single factor such as the type of fuel.
Global outlook
As of 2017, there were more than 1.4 billion
motor vehicles on the world's roads,
compared with just more than 116 million alternative fuel and advanced
technology vehicles that had been sold or converted worldwide at the end
of 2016 and consisting of:
Brazil is the world's leader in flexible-fuel car sales, with cumulative sales totalling 25.5 million units as of June 2015 .
- About 55 million flex fuel automobiles, motorcycles and light duty trucks manufactured and sold worldwide by mid 2015, led by Brazil with 29.5 million by mid 2015, followed by the United States with 17.4 million by the end of 2014, Canada with about 1.6 million by 2014, and Sweden with 243,100 through December 2014. The Brazilian flex fuel fleet includes over 4 million flexible-fuel motorcycles produced since 2009 through March 2015.
- 22.7 million natural gas vehicles as of August 2015, led by China (4.4 million) Iran with 4.00 million, followed by Pakistan (3.70 million), Argentina (2.48 million), India (1.80 million) and Brazil (1.78 million).
- 24.9 million LPG powered vehicles by December 2013, led by Turkey with 3.93 million, South Korea (2.4 million), and Poland (2.75 million).
- More than 12 million hybrid electric vehicles have been sold worldwide. As of April 2016,
Japan ranked as the market leader with more than 5 million hybrids
sold, followed by the United States with cumulative sales of over
4 million units since 1999, and Europe with about 1.5 million hybrids
delivered since 2000. As of January 2017, global sales are by Toyota Motor Company with more than 10 million Lexus and Toyota hybrids sold, followed by Honda Motor Co., Ltd. with cumulative global sales of more than 1.35 million hybrids as of June 2014. As of January 2017, global hybrid sales are led by the Prius family, with cumulative sales of 6.1 million units. The Toyota Prius liftback is the world's top selling hybrid electric car with cumulative sales of 3.985 million units through January 2017.
- 5.7 million neat-ethanol only light-vehicles built in Brazil since 1979, with 2.4 to 3.0 million vehicles still in use by 2003. and 1.22 million units as of December 2011.
- More than 4 million highway-legal plug-in electric passenger cars and light utility vehicles had been sold worldwide at the end of September 2018. Cumulative global sales of all-electric cars and vans passed the 1 million unit milestone in September 2016. As of September 2018, the Nissan Leaf
is the world's all-time top selling highway-capable plug-in electric
car, with global sales of over 350,000 units since its inception. As of December 2016, ranking second was the all-electric Tesla Model S with about over 158,000 units, followed by the Chevrolet Volt
plug-in hybrid, which together with its sibling the Opel/Vauxhall
Ampera has combined global sales of about 134,500 units, and the Mitsubishi Outlander P-HEV, with global sales of about 119,500 units.
- As of September 2018, China has the world's largest stock of
highway legal plug-in electric passenger cars with cumulative sales of
almost 2 million units. Among country markets, the United States ranks second with 1 million plug-in electric cars sold through September 2018.Cumulative sales of highway legal plug-in electric cars and vans in Europe achieved the one million unit milestone in June 2018. As of September 2018, sales in the European light-duty plug-in electric segment are led by Norway with almost 275,000 units registered.
China is the world's leader in the plug-in heavy-duty segment,
including electric all-electric buses, and plug-in commercial and
sanitation trucks. The stock of new energy vehicles sold in China
totaled 2.21 million units up until September 2018. As of December 2015, China was the world's largest plug-in electric bus market with a stock of almost 173,000 vehicles.
Single fuel source
Engine Air Compressor
The Peugeot 2008 HYbrid air prototype replaced conventional hybrid batteries with a compressed air propulsion system
The air engine is an emission-free piston engine that uses compressed
air as a source of energy. The first compressed air car was invented
by a French engineer named
Guy Nègre.
The expansion of compressed air may be used to drive the pistons in a
modified piston engine. Efficiency of operation is gained through the
use of environmental heat at normal temperature to warm the otherwise
cold expanded air from the storage tank. This non-adiabatic expansion
has the potential to greatly increase the efficiency of the machine.
The only exhaust is cold air (−15 °C), which could also be used to air
condition the car. The source for air is a pressurized carbon-fiber
tank. Air is delivered to the engine via a rather conventional injection
system. Unique crank design within the engine increases the time during
which the air charge is warmed from ambient sources and a two-stage
process allows improved heat transfer rates.
Battery-electric
Battery electric vehicles
(BEVs), also known as all-electric vehicles (AEVs), are electric
vehicles whose main energy storage is in the chemical energy of
batteries. BEVs are the most common form of what is defined by the
California Air Resources Board (CARB) as
zero emission vehicle
(ZEV) because they produce no tailpipe emissions at the point of
operation. The electrical energy carried on board a BEV to power the
motors is obtained from a variety of battery chemistries arranged into
battery packs. For additional range genset trailers or pusher trailers
are sometimes used, forming a type of hybrid vehicle. Batteries used in
electric vehicles include "flooded" lead-acid, absorbed glass mat, NiCd,
nickel metal hydride, Li-ion, Li-poly and zinc-air batteries.
Attempts at building viable, modern
battery-powered electric vehicles began in the 1950s with the introduction of the first modern (
transistor controlled) electric car – the
Henney Kilowatt,
even though the concept was out in the market since 1890. Despite the
poor sales of the early battery-powered vehicles, development of various
battery-powered vehicles continued through the mid-1990s, with such
models as the
General Motors EV1 and the
Toyota RAV4 EV.
The Nissan Leaf
is the world's top selling highway-capable all-electric car in history.
The Leaf achieved the milestone of 250,000 units sold globally in
December 2016.
Battery powered cars had primarily used
lead-acid batteries and
NiMH batteries.
Lead-acid batteries' recharge capacity is considerably reduced if
they're discharged beyond 75% on a regular basis, making them a
less-than-ideal solution. NiMH batteries are a better choice, but are considerably more expensive than lead-acid.
Lithium-ion battery powered vehicles such as the
Venturi Fetish and the
Tesla Roadster
have recently demonstrated excellent performance and range, and
nevertheless is used in most mass production models launched since
December 2010.
As of December 2015, several
neighborhood electric vehicles,
city electric cars and
series production highway-capable
electric cars and utility vans have been made available for retails sales, including Tesla Roadster,
GEM cars,
Buddy,
Mitsubishi i MiEV and its rebadged versions Peugeot iOn and Citroën C-Zero,
Chery QQ3 EV,
JAC J3 EV,
Nissan Leaf,
Smart ED,
Mia electric,
BYD e6,
Renault Kangoo Z.E.,
Bolloré Bluecar,
Renault Fluence Z.E.,
Ford Focus Electric,
BMW ActiveE,
Renault Twizy,
Tesla Model S,
Honda Fit EV,
RAV4 EV second generation,
Renault Zoe,
Mitsubishi Minicab MiEV,
Roewe E50,
Chevrolet Spark EV,
Fiat 500e,
BMW i3,
Volkswagen e-Up!,
Nissan e-NV200,
Volkswagen e-Golf,
Mercedes-Benz B-Class Electric Drive,
Kia Soul EV,
BYD e5, and
Tesla Model X. The world's all-time top selling highway legal electric car is the
Nissan Leaf, released in December 2010, with global sales of more than 250,000 units through December 2016. The
Tesla Model S, released in June 2012, ranks second with global sales of over 158,000 cars delivered as of December 2016. The
Renault Kangoo Z.E. utility van is the leader of the light-duty all-electric segment with global sales of 25,205 units through December 2016.
Solar
Nuna team at a racecourse.
Nuna solar powered car, which has travelled up to 140km/h (84mph).
A solar car is an electric vehicle powered by solar energy obtained
from solar panels on the car. Solar panels cannot currently be used to
directly supply a car with a suitable amount of power at this time, but
they can be used to extend the range of electric vehicles. They are
raced in competitions such as the World Solar Challenge and the North
American Solar Challenge. These events are often sponsored by Government
agencies such as the United States Department of Energy keen to promote
the development of
alternative energy
technology such as solar cells and electric vehicles. Such challenges
are often entered by universities to develop their students engineering
and technological skills as well as motor vehicle manufacturers such as
GM and Honda.
Trev's battery lasts over 250,000 kilometres.
The
North American Solar Challenge
is a solar car race across North America. Originally called Sunrayce,
organized and sponsored by General Motors in 1990, it was renamed
American Solar Challenge in 2001, sponsored by the United States
Department of Energy and the National Renewable Energy Laboratory.
Teams from universities in the United States and Canada compete in a
long distance test of endurance as well as efficiency, driving thousands
of miles on regular highways.
Nuna
is the name of a series of manned solar powered vehicles that won the
World solar challenge in Australia three times in a row, in 2001 (Nuna 1
or just Nuna), 2003 (Nuna 2) and 2005 (Nuna 3). The Nunas are built by
students of the Delft University of Technology.
The
World solar challenge
is a solar powered car race over 3,021 kilometres (1,877 mi) through
central Australia from Darwin to Adelaide. The race attracts teams from
around the world, most of which are fielded by universities or
corporations although some are fielded by high schools.
Trev (two-seater
renewable energy
vehicle) was designed by the staff and students at the University of
South Australia. Trev was first displayed at the 2005 World Solar
Challenge as the concept of a low-mass, efficient commuter car. With 3
wheels and a mass of about 300 kg, the prototype car had maximum speed
of 120 km/h and acceleration of 0–100 km/h in about 10 seconds. The
running cost of Trev is projected to be less than 1/10 of the running
cost of a small petrol car.
Dimethyl ether fuel
Installation of BioDME synthesis towers at Chemrec's pilot facility
Dimethyl ether (DME) is a promising fuel in
diesel engines,
petrol engines (30% DME / 70% LPG), and
gas turbines owing to its high
cetane number, which is 55, compared to diesel's, which is 40–53.
Only moderate modification are needed to convert a diesel engine to
burn DME. The simplicity of this short carbon chain compound leads
during combustion to very low emissions of particulate matter, NO
x,
CO. For these reasons as well as being sulfur-free, DME meets even the
most stringent emission regulations in Europe (EURO5), U.S. (U.S. 2010),
and Japan (2009 Japan).
Mobil is using DME in their
methanol to gasoline process.
Ammonia fuelled vehicles
The X-15 aircraft used ammonia as one component fuel of its rocket engine
Ammonia
is produced by combining gaseous hydrogen with nitrogen from the air.
Large-scale ammonia production uses natural gas for the source of
hydrogen. Ammonia was used during World War II to power buses in
Belgium, and in engine and solar energy applications prior to 1900.
Liquid ammonia also fuelled the
Reaction Motors XLR99 rocket engine, that powered the
X-15
hypersonic research aircraft. Although not as powerful as other fuels,
it left no soot in the reusable rocket engine and its density
approximately matches the density of the oxidizer, liquid oxygen, which
simplified the aircraft's design.
Ammonia has been proposed as a practical alternative to
fossil fuel for
internal combustion engines. The calorific value of ammonia is 22.5 MJ/kg (9690
BTU/lb),
which is about half that of diesel. In a normal engine, in which the
water vapour is not condensed, the calorific value of ammonia will be
about 21% less than this figure. It can be used in existing engines with
only minor modifications to
carburettors/
injectors.
If produced from coal, the CO2 can be readily sequestered (the combustion products are nitrogen and water).
Ammonia engines or ammonia motors, using ammonia as a
working fluid, have been proposed and occasionally used. The principle is similar to that used in a
fireless locomotive,
but with ammonia as the working fluid, instead of steam or compressed
air. Ammonia engines were used experimentally in the 19th century by
Goldsworthy Gurney in the UK and in
streetcars in New Orleans. In 1981 a Canadian company converted a 1981 Chevrolet Impala to operate using ammonia as fuel.
Ammonia and GreenNH3 is being used with success by developers in Canada,
since it can run in spark ignited or diesel engines with minor
modifications, also the only green fuel to power jet engines, and
despite its toxicity is reckoned to be no more dangerous than petrol or
LPG.
It can be made from renewable electricity, and having half the density
of petrol or diesel can be readily carried in sufficient quantities in
vehicles. On complete combustion it has no emissions other than nitrogen
and water vapour. The combustion chemical formula is 4 NH3 + 3 O2 → 2
N2 + 6 H2O, 75% water is the result.
Biofuels
Bioalcohol and ethanol
The Ford Model T was the first commercial flex-fuel vehicle. The engine was capable of running on gasoline or ethanol, or a mix of both.
The first commercial vehicle that used
ethanol as a fuel was the
Ford Model T, produced from 1908 through 1927. It was fitted with a
carburetor with adjustable jetting, allowing use of gasoline or ethanol, or a combination of both. Other car manufactures also provided engines for ethanol fuel use. In the United States, alcohol fuel was produced in corn-alcohol
stills until
Prohibition criminalized the production of alcohol in 1919. The use of alcohol as a fuel for
internal combustion engines, either alone or in combination with other fuels, lapsed until the
oil price shocks
of the 1970s. Furthermore, additional attention was gained because of
its possible environmental and long-term economical advantages over
fossil fuel.
Both
ethanol and
methanol have been used as an automotive fuel. While both can be obtained from petroleum or natural gas, ethanol has attracted more attention because it is considered a
renewable resource, easily obtained from sugar or
starch in crops and other agricultural produce such as
grain,
sugarcane, sugar beets or even
lactose.
Since ethanol occurs in nature whenever yeast happens to find a sugar
solution such as overripe fruit, most organisms have evolved some
tolerance to
ethanol, whereas
methanol is toxic. Other experiments involve
butanol,
which can also be produced by fermentation of plants. Support for
ethanol comes from the fact that it is a biomass fuel, which addresses
climate change and
greenhouse gas emissions, though these benefits are now highly debated, including the heated 2008
food vs fuel debate.
Most modern cars are designed to run on gasoline are capable of
running with a blend from 10% up to 15% ethanol mixed into gasoline (
E10-E15). With a small amount of redesign, gasoline-powered vehicles can run on ethanol concentrations as high as 85% (
E85), the maximum set in the United States and Europe due to cold weather during the winter, or up to 100% (
E100) in Brazil, with a warmer climate. Ethanol has close to 34% less energy per volume than gasoline,
consequently fuel economy ratings with ethanol blends are significantly
lower than with pure gasoline, but this lower energy content does not
translate directly into a 34% reduction in mileage, because there are
many other variables that affect the performance of a particular fuel in
a particular engine, and also because ethanol has a higher octane
rating which is beneficial to high compression ratio engines.
For this reason, for pure or high ethanol blends to be attractive
for users, its price must be lower than gasoline to offset the lower
fuel economy. As a
rule of thumb,
Brazilian consumers are frequently advised by the local media to use
more alcohol than gasoline in their mix only when ethanol prices are 30%
lower or more than gasoline, as ethanol price fluctuates heavily
depending on the results and seasonal harvests of sugar cane and by
region. In the US, and based on EPA tests for all 2006
E85 models, the average fuel economy for E85 vehicles was found 25.56% lower than unleaded gasoline. The EPA-rated mileage of current American flex-fuel vehicles
could be considered when making price comparisons, though E85 has
octane rating of about 104 and could be used as a substitute for premium
gasoline. Regional retail E85 prices vary widely across the US, with
more favorable prices in the
Midwest region, where most corn is grown and ethanol produced. In August 2008 the US average spread between the price of
E85 and gasoline was 16.9%, while in
Indiana was 35%, 30% in
Minnesota and
Wisconsin, 19% in
Maryland, 12 to 15% in California, and just 3% in
Utah. Depending of the vehicle capabilities, the break even price of E85 usually has to be between 25 and 30% lower than gasoline.
E85 fuel sold at a regular gasoline station in Washington, D.C..
Reacting to the high price of oil and its growing dependence on imports, in 1975
Brazil launched the
Pro-alcool program,
a huge government-subsidized effort to manufacture ethanol fuel (from
its sugar cane crop) and ethanol-powered automobiles. These
ethanol-only vehicles were very popular in the 1980s, but became
economically impractical when oil prices fell – and sugar prices rose –
late in that decade. In May 2003
Volkswagen built for the first time a commercial ethanol
flexible fuel car, the
Gol
1.6 Total Flex. These vehicles were a commercial success and by early
2009 other nine Brazilian manufacturers are producing flexible fuel
vehicles:
Chevrolet,
Fiat,
Ford,
Peugeot,
Renault,
Honda,
Mitsubishi,
Toyota,
Citroën, and
Nissan. The adoption of the flex technology was so rapid, that flexible fuel cars reached 87.6% of new car sales in July 2008. As of August 2008, the fleet of "flex" automobiles and light commercial vehicles had reached 6 million new vehicles sold, representing almost 19% of all registered light vehicles.
The rapid success of "flex" vehicles, as they are popularly known, was
made possible by the existence of 33,000 filling stations with at least
one ethanol pump available by 2006, a heritage of the
Pro-alcool program.
In the United States, initial support to develop alternative fuels by the government was also a response to the
1973 oil crisis,
and later on, as a goal to improve air quality. Also, liquid fuels were
preferred over gaseous fuels not only because they have a better
volumetric energy density but also because they were the most compatible
fuels with existing distribution systems and engines, thus avoiding a
big departure from the existing technologies and taking advantage of the
vehicle and the refueling infrastructure. California led the search of sustainable alternatives with interest in
methanol.
In 1996, a new FFV
Ford Taurus was developed, with models fully capable of running either methanol or ethanol blended with gasoline. This ethanol version of the Taurus was the first commercial production of an E85 FFV.
The momentum of the FFV production programs at the American car
companies continued, although by the end of the 90's, the emphasis was
on the FFV E85 version, as it is today.
Ethanol was preferred over methanol because there is a large support in
the farming community and thanks to government's incentive programs and
corn-based ethanol subsidies.
Sweden
also tested both the M85 and the E85 flexifuel vehicles, but due to
agriculture policy, in the end emphasis was given to the ethanol
flexifuel vehicles.
Biodiesel
Bus running on soybean biodiesel
The main benefit of Diesel combustion engines is that they have a 44%
fuel burn efficiency; compared with just 25–30% in the best gasoline
engines. In addition diesel fuel has slightly higher
Energy Density by volume than gasoline. This makes Diesel engines capable of achieving much better fuel economy than gasoline vehicles.
Biodiesel
(Fatty acid methyl ester), is commercially available in most
oilseed-producing states in the United States. As of 2005, it is
somewhat more expensive than fossil diesel, though it is still commonly
produced in relatively small quantities (in comparison to petroleum
products and ethanol). Many farmers who raise oilseeds use a biodiesel
blend in tractors and equipment as a matter of policy, to foster
production of biodiesel and raise public awareness. It is sometimes
easier to find biodiesel in rural areas than in cities. Biodiesel has
lower
Energy Density
than fossil diesel fuel, so biodiesel vehicles are not quite able to
keep up with the fuel economy of a fossil fuelled diesel vehicle, if the
diesel injection system is not reset for the new fuel. If the injection
timing is changed to take account of the higher Cetane value of
biodiesel, the difference in economy is negligible. Because biodiesel
contains more oxygen than diesel or
vegetable oil fuel,
it produces the lowest emissions from diesel engines, and is lower in
most emissions than gasoline engines. Biodiesel has a higher lubricity
than mineral diesel and is an additive in European pump diesel for
lubricity and emissions reduction.
Some
Diesel-powered cars can run with minor modifications on 100% pure
vegetable oils.
Vegetable oils tend to thicken (or solidify if it is waste cooking
oil), in cold weather conditions so vehicle modifications (a two tank
system with diesel start/stop tank), are essential in order to heat the
fuel prior to use under most circumstances. Heating to the temperature
of engine coolant reduces fuel viscosity, to the range cited by
injection system manufacturers, for systems prior to 'common rail' or
'unit injection ( VW PD)' systems. Waste vegetable oil, especially if it
has been used for a long time, may become hydrogenated and have
increased acidity. This can cause the thickening of fuel, gumming in the
engine and acid damage of the fuel system. Biodiesel does not have this
problem, because it is chemically processed to be PH neutral and lower
viscosity. Modern low emission diesels (most often Euro -3 and -4
compliant), typical of the current production in the European industry,
would require extensive modification of injector system, pumps and seals
etc. due to the higher operating pressures, that are designed thinner
(heated) mineral diesel than ever before, for atomisation, if they were
to use pure vegetable oil as fuel. Vegetable oil fuel is not suitable
for these vehicles as they are currently produced. This reduces the
market as increasing numbers of new vehicles are not able to use it.
However, the German Elsbett company has successfully produced single
tank vegetable oil fuel systems for several decades, and has worked with
Volkswagen on their TDI engines. This shows that it is technologically
possible to use vegetable oil as a fuel in high efficiency / low
emission diesel engines.
Biogas
Compressed Biogas may be used for Internal Combustion Engines after
purification of the raw gas. The removal of H2O, H2S and particles can
be seen as standard producing a gas which has the same quality as
Compressed Natural Gas. The use of biogas is particularly interesting
for climates where the waste heat of a biogas powered power plant cannot
be used during the summer.
Charcoal
In the 1930s
Tang Zhongming made an invention using abundant
charcoal
resources for Chinese auto market. The Charcoal-fuelled car was later
used intensively in China, serving the army and conveyancer after the
breakout of World War II.
Compressed natural gas (CNG)
High-pressure
compressed natural gas,
mainly composed of methane, that is used to fuel normal combustion
engines instead of gasoline. Combustion of methane produces the least
amount of CO
2 of all fossil fuels. Gasoline cars can be retrofitted to CNG and become bifuel
Natural gas vehicles (NGVs) as the gasoline tank is kept. The driver can switch between CNG and gasoline during operation.
Natural gas vehicles (NGVs) are popular in regions or countries where natural gas is abundant. Widespread use began in the
Po River Valley of
Italy, and later became very popular in
New Zealand by the eighties, though its use has declined.
Buses powered with CNG are common in the United States.
As of December 2012, there were 17.8 million
natural gas vehicles
worldwide, led by Iran with 3.30 million, followed by Pakistan (2.79
million), Argentina (2.29 million), Brazil (1.75 million), China (1.58
million) and India (1.5 million). As of 2010, the Asia-Pacific region led the global market with a share of 54%. In Europe they are popular in Italy (730,000), Ukraine (200,000), Armenia (101,352), Russia (100,000) and Germany (91,500), and they are becoming more so as various manufacturers produce factory made cars, buses, vans and heavy vehicles. In the United States CNG powered buses are the favorite choice of several
public transit agencies, with an estimated CNG bus fleet of some 130,000. Other countries where CNG-powered buses are popular include India, Australia, Argentina, and Germany.
CNG vehicles are common in South America, where these vehicles are mainly used as
taxicabs
in main cities of Argentina and Brazil. Normally, standard gasoline
vehicles are retrofitted in specialized shops, which involve installing
the gas cylinder in the trunk and the CNG injection system and
electronics. The Brazilian GNV fleet is concentrated in the cities of
Rio de Janeiro and
São Paulo. Pike Research reports that almost 90% of NGVs in Latin America have
bi-fuel engines, allowing these vehicles to run on either gasoline or CNG.
In 2006 the Brazilian subsidiary of
FIAT introduced the
Fiat Siena Tetra fuel, a four-fuel car developed under
Magneti Marelli of
Fiat Brazil. This automobile can run on 100% ethanol (
E100),
E25
(Brazil's normal ethanol gasoline blend), pure gasoline (not available
in Brazil), and natural gas, and switches from the gasoline-ethanol
blend to CNG automatically, depending on the power required by road
conditions. Other existing option is to
retrofit an ethanol
flexible-fuel vehicle to add a natural gas tank and the corresponding injection system. Some
taxicabs in
São Paulo and
Rio de Janeiro,
Brazil, run on this option, allowing the user to choose among three
fuels (E25, E100 and CNG) according to current market prices at the
pump. Vehicles with this adaptation are known in Brazil as "tri-fuel"
cars.
HCNG or Hydrogen enriched Compressed Natural Gas for automobile use is premixed at the
hydrogen station.
Formic acid
Formic acid is used by converting it first to hydrogen, and using that in a
fuel cell. Formic acid is much easier to store than hydrogen.
Hydrogen
Hydrogen fueling station in California.
The Toyota Mirai
is one of the first hydrogen fuel-cell vehicles to be sold commercially
to retail customers, initially, only in Japan and California.
A
hydrogen
car 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, however during combustion
with air
NOx can be produced.
Honda introduced its fuel cell vehicle in 1999 called the
FCX and have since then introduced the second generation
FCX Clarity.
Limited marketing of the FCX Clarity, based on the 2007 concept model,
began in June 2008 in the United States, and it was introduced in Japan
in November 2008. The FCX Clarity was available in the U.S. only in
Los Angeles Area,
where 16 hydrogen filling stations are available, and until July 2009,
only 10 drivers have leased the Clarity for US$600 a month. At the 2012
World Hydrogen Energy Conference,
Daimler AG, Honda, Hyundai and Toyota all confirmed plans to produce
hydrogen fuel cell vehicles for sale by 2015, with some types planned to
enter the showroom in 2013.
[96] From 2008 to 2014, Honda leased a total of 45 FCX units in the US.
A small number of prototype 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. Some
believe that hydrogen cars will never be economically viable and that
the emphasis on this technology is a diversion from the development and
popularization of more efficient hybrid cars and other alternative
technologies.
A study by
The Carbon Trust for the UK
Department of Energy and Climate Change
suggests that hydrogen technologies have the potential to deliver UK
transport with near-zero emissions whilst reducing dependence on
imported oil and curtailment of renewable generation. However, the
technologies face very difficult challenges, in terms of cost,
performance and policy.
Buses,
trains,
PHB bicycles,
canal boats,
cargo bikes,
golf carts,
motorcycles,
wheelchairs,
ships, airplanes,
submarines, and
rockets can already run on hydrogen, in various forms.
NASA used hydrogen to launch
Space Shuttles into space. A working toy model car runs on
solar power, using a
regenerative 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.
BMW's Clean Energy internal combustion hydrogen car has more
power and is faster than hydrogen fuel cell electric cars. A limited
series production of the 7 Series Saloon was announced as commencing at
the end of 2006. A BMW hydrogen prototype (H2R) using the driveline of
this model 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 pre-detonation, a problem with hydrogen fueled
piston engines.
The other major car companies like Daimler, Chrysler, Honda,
Toyota, Ford and General Motors, are investing in hydrogen fuel cells
instead. VW, Nissan, and Hyundai/Kia also have fuel cell vehicle
prototypes on the road. In addition, transit agencies across the globe
are running prototype fuel cell buses.
Fuel cell vehicles, such as the new Honda Clarity, can get up to 70 miles (110 km) on a kilogram of hydrogen.
The
Hyundai ix35 FCEV fuel cell vehicle is available for lease in the U.S. In 2014, a total of 54 units were leased. Sales of the
Toyota Mirai to government and corporate customers began in Japan on December 15, 2014. Toyota delivered the first market placed Mirai to the
Prime Minister's Official Residence and announced it got 1,500 orders in Japan in one month after sales began against a sales target of 400 for 12 months.
Deliveries to retail customers began in California in October
2015. A total of 57 units were delivered between October and November
2015. Toyota scheduled to release the Mirai in the
Northeastern States in the first half of 2016. The market launch in Europe is slated for September 2015.
Liquid nitrogen car
Liquid nitrogen (LN2) is a method of storing energy. Energy is used
to liquefy air, and then LN2 is produced by evaporation, and
distributed. LN2 is exposed to ambient heat in the car and the resulting
nitrogen gas can be used to power a piston or turbine engine. The
maximum amount of energy that can be extracted from LN2 is 213
Watt-hours per kg (W·h/kg) or 173 W·h per liter, in which a maximum of
70 W·h/kg can be utilized with an isothermal expansion process. Such a
vehicle with a 350-liter (93 gallon) tank can achieve ranges similar to a
gasoline powered vehicle with a 50-liter (13 gallon) tank. Theoretical
future engines, using cascading topping cycles, can improve this to
around 110 W·h/kg with a quasi-isothermal expansion process. The
advantages are zero harmful emissions and superior energy densities
compared to a
Compressed-air vehicle as well as being able to refill the tank in a matter of minutes.
Liquefied Natural Gas (LNG)
Liquefied natural gas is natural gas that has been cooled to a point at which it becomes a
cryogenic
liquid. In this liquid state, natural gas is more than 2 times as dense
as highly compressed CNG. LNG fuel systems function on any vehicle
capable of burning natural gas. Unlike CNG, which is stored at high
pressure (typically 3000 or 3600 psi) and then regulated to a lower
pressure that the engine can accept, LNG is stored at low pressure (50
to 150 psi) and simply vaporized by a heat exchanger before entering the
fuel metering devices to the engine. Because of its high energy density
compared to CNG, it is very suitable for those interested in long
ranges while running on natural gas.
In the United States, the LNG supply chain is the main thing that
has held back this fuel source from growing rapidly. The LNG supply
chain is very analogous to that of diesel or gasoline. First, pipeline
natural gas is liquefied in large quantities, which is analogous to
refining gasoline or diesel. Then, the LNG is transported via semi
trailer to fuel stations where it is stored in bulk tanks until it is
dispensed into a vehicle. CNG, on the other hand, requires expensive
compression at each station to fill the high-pressure cylinder cascades.
Autogas (LPG)
LPG or
liquefied petroleum gas
is a low pressure liquefied gas mixture composed mainly of propane and
butane which burns in conventional gasoline combustion engines with less
CO
2 than gasoline. Gasoline cars can be retrofitted to LPG
aka Autogas and become bifuel vehicles as the gasoline tank stays. You
can switch between LPG and gasoline during operation. Estimated 10
million vehicles running worldwide.
There are 17.473 million LPG powered vehicles worldwide as of
December 2010, and the leading countries are Turkey (2.394 million
vehicles), Poland (2.325 million), and South Korea (2.3 million). In the U.S., 190,000 on-road vehicles use propane,
and 450,000 forklifts use it for power. Whereas it is banned in
Pakistan(DEC 2013) as it is considered a risk to public safety by OGRA.
Steam
A steam car is a car that has a
steam engine. Wood, coal,
ethanol, or others can be used as
fuel. The fuel is burned in a
boiler and the heat converts water into
steam. When the water turns to steam, it expands. The expansion creates
pressure. The pressure pushes the
pistons back and forth. This turns the
driveshaft to spin the wheels forward. It works like a coal-fueled
steam train, or
steam boat. The steam car was the next logical step in independent transport.
Steam cars take a long time to start, but some can reach speeds over 100 mph (161 km/h) eventually. The late model
Doble Steam Cars
could be brought to operational condition in less than 30 seconds, had
high top speeds and fast acceleration, but were expensive to buy.
A steam engine uses
external combustion, as opposed to internal combustion. Gasoline-powered cars are more efficient at about 25–28%
efficiency. In theory, a
combined cycle steam engine in which the burning material is first used to drive a
gas turbine can produce 50% to 60% efficiency. However, practical examples of steam engined cars work at only around 5–8% efficiency.
The best known and best selling steam-powered car was the
Stanley Steamer.
It used a compact fire-tube boiler under the hood to power a simple
two-piston engine which was connected directly to the rear axle. Before
Henry Ford
introduced monthly payment financing with great success, cars were
typically purchased outright. This is why the Stanley was kept simple;
to keep the purchase price affordable.
Steam produced in
refrigeration also can be use by a
turbine in other vehicle types to produce electricity, that can be employed in electric motors or stored in a battery.
Steam power can be combined with a standard oil-based engine to
create a hybrid. Water is injected into the cylinder after the fuel is
burned, when the piston is still superheated, often at temperatures of
1500 degrees or more. The water will instantly be vaporized into steam,
taking advantage of the heat that would otherwise be wasted.
Wood gas
Wood gas can be used to power cars with ordinary internal combustion engines if a
wood gasifier
is attached. This was quite popular during World War II in several
European and Asian countries because the war prevented easy and
cost-effective access to oil.
Herb Hartman of Woodward, Iowa currently drives a wood powered
Cadillac. He claims to have attached the gasifier to the Cadillac for
just $700. Hartman claims, “A full hopper will go about fifty miles
depending on how you drive it,” and he added that splitting the wood was
“labor-intensive. That’s the big drawback.”
Multiple fuel source
Dual Fuel
Dual
fuel vehicle is referred as the vehicle using two types of fuel in the
same time (can be gas + liquid, gas + gas, liquid + liquid) with
different fuel tank.
Diesel-CNG Dual Fuel is a system using two type of fuel which are
diesel and Compressed Natural Gas (CNG) at the same time. It is because
of CNG need a source of ignition for combustion in diesel engine.
Flexible fuel
Six typical Brazilian full flex-fuel models from several carmakers, popularly known as "flex" cars, that run on any blend of ethanol and gasoline(actually between E20-E25 to E100).
A
flexible-fuel vehicle (FFV) or dual-fuel vehicle (DFF) is an alternative fuel automobile or
light duty truck with a
multifuel engine that can use more than one
fuel, usually mixed in the same tank, and the blend is burned in the
combustion chamber together. These vehicles are
colloquially called
flex-fuel, or
flexifuel in Europe, or just flex in Brazil. FFVs are distinguished from
bi-fuel vehicles, where two fuels are stored in separate tanks. The most common commercially available FFV in the world market is the
ethanol flexible-fuel vehicle,
with the major markets concentrated in the United States, Brazil,
Sweden, and some other European countries. In addition to flex-fuel
vehicles running with
ethanol, in the US and Europe there were successful test programs with
methanol flex-fuel vehicles, known as
M85 FFVs, and more recently there have been also successful tests using
p-series fuels with E85 flex fuel vehicles, but as of June 2008, this fuel is not yet available to the general public.
Ethanol flexible-fuel vehicles have standard gasoline engines that are capable of running with
ethanol
and gasoline mixed in the same tank. These mixtures have "E" numbers
which describe the percentage of ethanol in the mixture, for example,
E85 is 85% ethanol and 15% gasoline. (See
common ethanol fuel mixtures for more information.) Though technology exists to allow ethanol FFVs to run on any mixture up to E100, in the U.S. and Europe, flex-fuel vehicles are optimized to run on
E85.
This limit is set to avoid cold starting problems during very cold
weather. The alcohol content might be reduced during the winter, to E70
in the U.S. or to E75 in Sweden. Brazil, with a warmer climate,
developed vehicles that can run on any mix up to
E100, though
E20-E25 is the mandatory minimum blend, and no pure gasoline is sold in the country.
About 48 million automobiles, motorcycles and
light duty trucks manufactured and sold worldwide by mid 2015, and concentrated in four markets, Brazil (29.5 million by mid 2015), the United States (17.4 million by the end of 2014), Canada (1.6 million by 2014), and Sweden (243,100 through December 2014). The Brazilian flex fuel fleet includes over 4 million flexible-fuel motorcycles produced since 2009 through March 2015. In Brazil, 65% of flex-fuel car owners were using ethanol fuel regularly in 2009, while, the actual number of American FFVs being run on
E85
is much lower; surveys conducted in the U.S. have found that 68% of
American flex-fuel car owners were not aware they owned an E85 flex. This is thought to be due to a number of factors, including:
Typical labeling used in the US to identify E85
vehicles. Top left: a small sticker in the back of the fuel filler
door. Bottom left: the bright yellow gas cap used in newer models. E85
Flexfuel badging used in newer models from Chrysler (top right), Ford (middle right) and GM (bottom right).
- The appearance of flex-fuel and non-flex-fuel vehicles is identical;
- There is no price difference between a pure-gasoline vehicle and its flex-fuel variant;
- The lack of consumer awareness of flex-fuel vehicles;
- The lack of promotion of flex-fuel vehicles by American automakers,
who often do not label the cars or market them in the same way they do
to hybrid cars
By contrast, automakers selling FFVs in Brazil commonly affix badges
advertising the car as a flex-fuel vehicle. As of 2007, new FFV models
sold in the U.S. were required to feature a yellow gas cap emblazoned
with the label "E85/gasoline", in order to remind drivers of the cars'
flex-fuel capabilities.
Use of E85 in the U.S. is also affected by the relatively low number of
E85 filling stations in operation across the country, with just over
1,750 in August 2008, most of which are concentrated in the
Corn Belt states, led by
Minnesota with 353 stations, followed by
Illinois with 181, and
Wisconsin with 114. By comparison, there are some 120,000 stations providing regular non-ethanol gasoline in the United States alone.
There have been claims that American automakers are motivated to produce flex-fuel vehicles due to a
loophole in the
Corporate Average Fuel Economy
(CAFE) requirements, which gives the automaker a "fuel economy credit"
for every flex-fuel vehicle sold, whether or not the vehicle is actually
fueled with E85 in regular use.
This loophole allegedly allows the U.S. auto industry to meet CAFE fuel
economy targets not by developing more fuel-efficient models, but by
spending between US$100 and US$200 extra per vehicle to produce a
certain number of flex-fuel models, enabling them to continue selling
less fuel-efficient vehicles such as
SUVs, which netted higher profit margins than smaller, more fuel-efficient cars.
In the United States,
E85
FFVs are equipped with sensor that automatically detect the fuel
mixture, signaling the ECU to tune spark timing and fuel injection so
that fuel will burn cleanly in the vehicle's internal combustion engine.
Originally, the sensors were mounted in the fuel line and exhaust
system; more recent models do away with the fuel line sensor. Another
feature of older flex-fuel cars is a small separate gasoline storage
tank that was used for starting the car on cold days, when the ethanol
mixture made ignition more difficult.
Modern
Brazilian flex-fuel technology enables FFVs to run an any blend between
E20-E25 gasohol and
E100 ethanol fuel, using a
lambda probe to measure the quality of combustion, which informs the
engine control unit as to the exact composition of the gasoline-alcohol mixture. This technology, developed by the Brazilian subsidiary of
Bosch in 1994, and further improved and commercially implemented in 2003 by the Italian subsidiary of
Magneti Marelli, is known as "
Software Fuel Sensor". The Brazilian subsidiary of
Delphi Automotive Systems developed a similar technology, known as "
Multifuel", based on research conducted at its facility in
Piracicaba,
São Paulo.
This technology allows the controller to regulate the amount of fuel
injected and spark time, as fuel flow needs to be decreased to avoid
detonation due to the high compression ratio (around 12:1) used by flex-fuel engines.
The first flex motorcycle was launched by
Honda in March 2009. Produced by its Brazilian subsidiary Moto Honda da Amazônia, the
CG 150 Titan Mix is sold for around US$2,700.
Because the motorcycle does not have a secondary gas tank for a cold
start like the Brazilian flex cars do, the tank must have at least 20%
of gasoline to avoid start up problems at temperatures below 15 °C
(59 °F). The motorcycle’s panel includes a gauge to warn the driver
about the actual ethanol-gasoline mix in the storage tank.
Hybrids
Hybrid electric vehicle
A
hybrid vehicle uses multiple propulsion systems to provide motive power. The most common type of hybrid vehicle is the
gasoline-electric hybrid vehicles, which use gasoline (petrol) and electric batteries for the energy used to power
internal-combustion engines
(ICEs) and electric motors. These motors are usually relatively small
and would be considered "underpowered" by themselves, but they can
provide a normal driving experience when used in combination during
acceleration and other maneuvers that require greater power.
The
Toyota Prius
first went on sale in Japan in 1997 and it is sold worldwide since
2000. By 2017 the Prius is sold in more than 90 countries and regions,
with Japan and the United States as its largest markets.
In May 2008, global cumulative Prius sales reached the 1 million units,
and by September 2010, the Prius reached worldwide cumulative sales of 2
million units, and 3 million units by June 2013. As of January 2017, global hybrid sales are led by the
Prius family, with cumulative sales of 6.0361 million units, excluding its plug-in hybrid variant. The
Toyota Prius liftback is the leading model of the Toyota brand with cumulative sales of 3.985 million units, followed by the
Toyota Aqua/Prius c, with global sales of 1.380 million units, the
Prius v/α/+ with 671,200, the
Camry Hybrid with 614,700 units, the
Toyota Auris with 378,000 units, and the
Toyota Yaris Hybrid with 302,700. The best-selling
Lexus model is the
Lexus RX 400h/RX 450h with global sales of 363,000 units.
The
Honda Insight
is a two-seater hatchback hybrid automobile manufactured by Honda. It
was the first mass-produced hybrid automobile sold in the United States,
introduced in 1999, and produced until 2006.
Honda introduced the second-generation Insight in Japan in February
2009, and the new Insight went on sale in the United States on April 22,
2009. Honda also offers the
Honda Civic Hybrid since 2002.
As of January 2017, there are over 50 models of hybrid electric
cars available in several world markets, with more than 12 million
hybrid electric vehicles sold worldwide since their inception in 1997. As of April 2016,
Japan ranked as the market leader with more than 5 million hybrids
sold, followed by the United States with cumulative sales of over
4 million units since 1999, and Europe with about 1.5 million hybrids
delivered since 2000. Japan has the world's highest hybrid
market penetration. By 2013 the hybrid
market share accounted for more than 30% of new standard passenger car sold, and about 20% new passenger vehicle sales including
kei cars. The Netherlands ranks second with a hybrid market share of 4.5% of new car sales in 2012.
Plug-in hybrid electric vehicle
Until 2010 most
plug-in hybrids on the road in the U.S. were conversions of conventional hybrid electric vehicles,
and the most prominent PHEVs were conversions of 2004 or later Toyota
Prius, which have had plug-in charging and more batteries added and
their electric-only range extended. Chinese battery manufacturer and automaker
BYD Auto released the
F3DM to the Chinese fleet market in December 2008 and began sales to the general public in
Shenzhen in March 2010.
General Motors began deliveries of the
Chevrolet Volt in the U.S. in December 2010.
[149] Deliveries to retail customers of the
Fisker Karma began in the U.S. in November 2011.
During 2012, the
Toyota Prius Plug-in Hybrid,
Ford C-Max Energi, and
Volvo V60 Plug-in Hybrid were released. The following models were launched during 2013 and 2015:
Honda Accord Plug-in Hybrid,
Mitsubishi Outlander P-HEV,
Ford Fusion Energi,
McLaren P1 (limited edition),
Porsche Panamera S E-Hybrid,
BYD Qin,
Cadillac ELR,
BMW i3 REx,
BMW i8,
Porsche 918 Spyder (limited production),
Volkswagen XL1 (limited production),
Audi A3 Sportback e-tron,
Volkswagen Golf GTE,
Mercedes-Benz S 500 e,
Porsche Cayenne S E-Hybrid,
Mercedes-Benz C 350 e,
BYD Tang,
Volkswagen Passat GTE,
Volvo XC90 T8,
BMW X5 xDrive40e,
Hyundai Sonata PHEV, and
Volvo S60L PHEV.
Pedal-assisted electric hybrid vehicle
In
very small vehicles, the power demand decreases, so human power can be
employed to make a significant improvement in battery life. Two such
commercially made vehicles are the
Sinclair C5 and
TWIKE.
Comparative assessment of fossil and alternative fuels
Different
fuel pathways require different amounts of energy to drive 100 km. From
left to right: Coal to electricity to electrical car. Renewable energy
(e.g. wind or photovoltaics) to electrical car. Renewable energy to
hydrogen to hydrogen-powered car. Petroleum to diesel to internal
combustion engine.
According to a recent comparative energy and environmental analysis
of the vehicle fuel end use (petroleum and natural gas derivatives &
hydrogen; biofuels like ethanol or biodiesel, and their mixtures; as
well as electricity intended to be used in
plug-in electric vehicles),
the renewable and non-renewable unit energy costs and CO2 emission cost
are suitable indicators for assessing the renewable energy consumption
intensity and the environmental impact, and for quantifying the
thermodynamic performance of the transportation sector. This analysis
allows ranking the energy conversion processes along the vehicle fuels
production routes and their end-use, so that the best options for the
transportation sector can be determined and better energy policies may
be issued. Thus, if a drastic CO2 emissions abatement of the
transportation sector is pursued, a more intensive utilization of
ethanol in the Brazilian transportation sector mix is advisable.
However, as the overall exergy conversion efficiency of the sugar cane
industry is still very low, which increases the unit energy cost of
ethanol, better production and end-use technologies are required.
Nonetheless, with the current scenario of a predominantly renewable
Brazilian electricity mix, based on more than 80% of renewable sources,
this source consolidates as the most promising energy source to reduce
the large amount of greenhouse gas emissions which transportation sector
is responsible for.