Alternative fuel vehicle

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.

Car classification
The classification of new energy vehicles is roughly as follows. The three major schemes of electric vehicles, alternative fuel vehicles, and hybrid vehicles are the mainstream, but others have developed other solutions:

Driven by electricity
Because of its simple structure, it is more suitable for cars in the city, but in the case of long-distance driving, it may be necessary to use microwave power during driving. Larger cars can operate in trolleybus mode.

Wireless power supply
The fuel cell

Driven by alternative fuel
Such a scheme is to continue to use internal combustion engines, but to switch to other cheaper and lower carbon-emitting fuels, which also competed with gasoline vehicles in the late 19th and early 20th centuries. The advantage of being a new energy vehicle is that it is more suitable for heavy vehicles that are not suitable for electric vehicles.

Ethanol, such as the Ford Model T, initially had a version that used alcohol fuel, but since the person who bought the car had a low income, it would only stop buying a lower-priced gasoline version.
Compressed natural gas (CNG)
Liquefied petroleum gas (LPG)
liquified natural gas
Wood gas was popular before and after World War II, such as the Japanese charcoal bus.

Driven by hybrid
Hybrid (a car that uses two or more sources of energy).

Other low-emission carbon dioxide and high energy conversion options.

Nuclear energy does not require refueling and no exhaust gas throughout its life, but the resolution of nuclear waste and radiation problems will be possible only after the success of the fourth generation reactor.
Solar energy converts solar energy into an electric drive that drives cars.
Mechanical energy Using tools like compressed air and clockwork or flywheels can convert nearly 100% of energy.
Steam engine The earliest car solution, but because of the huge boiler and the problem of water consumption and water loss in evaporation, but the energy conversion efficiency is almost 100%, it is possible to achieve the Stirling engine.
Six-stroke or eight-stroke engines Although still an internal combustion engine, the combustion efficiency is much higher than that of modern four-stroke engines, and it is close to the main structure of modern cars, so it is also a promising solution.

Single fuel source

Engine Air Compressor
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 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.

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.

Dimethyl ether fuel
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, NOx, 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
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.


Bioalcohol and ethanol
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.

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.

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.

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 CO2 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.

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.

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.

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.

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 CO2 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.

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.

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.

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
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:

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.


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.

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; Ford Motor Corporation with over 424 thousand hybrids sold in the United States through June 2015, of which, around 10% are plug-in hybrids; Hyundai Group with cumulative global sales of 200 thousand hybrids as of March 2014, including both Hyundai Motors and Kia Motors hybrid models; and PSA Peugeot Citroën with over 50,000 diesel-powered hybrids sold in Europe through December 2013.

The Elantra LPI Hybrid, launched in the South Korean domestic market in July 2009, is a hybrid vehicle powered by an internal combustion engine built to run on liquefied petroleum gas (LPG) as a fuel. The Elantra PLI is a mild hybrid and the first hybrid to adopt advanced lithium polymer (Li–Poly) batteries.

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. 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.

As of December 2015, about 500,000 highway-capable plug-in hybrid electric cars had been sold worldwide since December 2008, out of total cumulative global sales of 1.2 million light-duty plug-in electric vehicles. As of December 2016, the Volt/Ampera family of plug-in hybrids, with combined sales of about 134,500 units is the top selling plug-in hybrid in the world. Ranking next are the Mitsubishi Outlander P-HEV with about 119,500, and the Toyota Prius Plug-in Hybrid with almost 78,000.

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
According to a recent comparative exergy and environmental analysis of the vehicle fuel end use (petroleum and natural gas derivatives & hydrogen; biofuels s.a. ethanol and 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.

Source from Wikipedia