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Identifiers | |
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ChemSpider |
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UNII | |
CompTox Dashboard (EPA) | |
Properties | |
Appearance | Straw-colored liquid |
Density | 775-840 g/L |
Melting point | −47 °C (−53 °F; 226 K) |
Boiling point | 176 °C (349 °F; 449 K) |
Hazards | |
NFPA 704 (fire diamond) | |
Flash point | 38 °C (100 °F; 311 K) |
210 °C (410 °F; 483 K) | |
Safety data sheet (SDS) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Jet fuel or aviation turbine fuel (ATF, also abbreviated avtur) is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is colorless to straw-colored in appearance. The most commonly used fuels for commercial aviation are Jet A and Jet A-1, which are produced to a standardized international specification. The only other jet fuel commonly used in civilian turbine-engine powered aviation is Jet B, which is used for its enhanced cold-weather performance.
Jet fuel is a mixture of a variety of hydrocarbons. Because the exact composition of jet fuel varies widely based on petroleum source, it is impossible to define jet fuel as a ratio of specific hydrocarbons. Jet fuel is therefore defined as a performance specification rather than a chemical compound. [1] Furthermore, the range of molecular mass between hydrocarbons (or different carbon numbers) is defined by the requirements for the product, such as the freezing point or smoke point. Kerosene-type jet fuel (including Jet A and Jet A-1, JP-5, and JP-8) has a carbon number distribution between about 8 and 16 (carbon atoms per molecule); wide-cut or naphtha-type jet fuel (including Jet B and JP-4), between about 5 and 15. [2] [3]
Fuel for piston-engine powered aircraft (usually a high-octane gasoline known as avgas) has a high volatility to improve its carburetion characteristics and high autoignition temperature to prevent preignition in high compression aircraft engines. Turbine engines (like diesel engines) can operate with a wide range of fuels because fuel is injected into the hot combustion chamber. Jet and gas turbine (turboprop, helicopter) aircraft engines typically use lower cost fuels with higher flash points, which are less flammable and therefore safer to transport and handle.
The first axial compressor jet engine in widespread production and combat service, the Junkers Jumo 004 used on the Messerschmitt Me 262A fighter and the Arado Ar 234B jet recon-bomber, burned either a special synthetic "J2" fuel or diesel fuel. Gasoline was a third option but unattractive due to high fuel consumption. [4] Other fuels used were kerosene or kerosene and gasoline mixtures.
Most jet fuels in use since the end of World War II are kerosene-based. Both British and American standards for jet fuels were first established at the end of World War II. British standards derived from standards for kerosene use for lamps—known as paraffin in the UK—whereas American standards derived from aviation gasoline practices. Over the subsequent years, details of specifications were adjusted, such as minimum freezing point, to balance performance requirements and availability of fuels. Very low temperature freezing points reduce the availability of fuel. Higher flash point products required for use on aircraft carriers are more expensive to produce. [3] In the United States, ASTM International produces standards for civilian fuel types, and the U.S. Department of Defense produces standards for military use. The British Ministry of Defence establishes standards for both civil and military jet fuels. [3] For reasons of inter-operational ability, British and United States military standards are harmonized to a degree. In Russia and the CIS members, grades of jet fuels are covered by the State Standard (GOST) number, or a Technical Condition number, with the principal grade available being TS-1.
Jet A specification fuel has been used in the United States since the 1950s and is usually not available outside the United States [5] and a few Canadian airports such as Toronto and Vancouver, [6] whereas Jet A-1 is the standard specification fuel used in the rest of the world other than Russia and the CIS members where TS-1 is the most common standard. Both Jet A and Jet A-1 have a flash point higher than 38 °C (100 °F), with an autoignition temperature of 210 °C (410 °F). [7]
The primary difference is the lower freezing point of A-1: [5]
The other difference is the mandatory addition of an anti-static additive to Jet A-1.
Jet A trucks, storage tanks, and plumbing that carry Jet A are marked with a black sticker with "Jet A" in white printed on it, adjacent to another black stripe.
Jet A-1 fuel must meet:
Jet A fuel must reach ASTM specification D1655 (Jet A). [8]
Jet A-1 | Jet A | |
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Flash point | 38 °C (100 °F) | |
Autoignition temperature | 210 °C (410 °F) [7] | |
Freezing point | −47 °C (−53 °F) | −40 °C (−40 °F) |
Max adiabatic burn temperature | 2,230 °C (4,050 °F) open air burn temperature: 1,030 °C (1,890 °F) [10] [11] [12] | |
Density at 15 °C (59 °F) | 0.804 kg/L (6.71 lb/US gal) | 0.820 kg/L (6.84 lb/US gal) |
Specific energy | 43.15 MJ/kg (11.99 kWh/kg) | 43.02 MJ/kg (11.95 kWh/kg) |
Energy density | 34.7 MJ/L (9.6 kWh/L) [13] | 35.3 MJ/L (9.8 kWh/L) |
Jet B is a naphtha-kerosene fuel that is used for its enhanced cold-weather performance. However, Jet B's lighter composition makes it more dangerous to handle. [8] For this reason, it is rarely used, except in very cold climates. A blend of approximately 30% kerosene and 70% gasoline, it is known as wide-cut fuel. It has a very low freezing point of −60 °C (−76 °F), and a low flash point as well. It is primarily used in some military aircraft. It is also used in northern Canada, Alaska, and sometimes Russia, because of its low freezing point.[ citation needed ]
TS-1 is a jet fuel made to Russian standard GOST 10227 for enhanced cold-weather performance. It has somewhat higher volatility than Jet A-1 (flash point is 28 °C (82 °F) minimum). It has a very low freezing point, below −50 °C (−58 °F). [14]
The DEF STAN 91-091 (UK) and ASTM D1655 (international) specifications allow for certain additives to be added to jet fuel, including: [15] [16]
As the aviation industry's jet kerosene demands have increased to more than 5% of all refined products derived from crude, it has been necessary for the refiner to optimize the yield of jet kerosene, a high-value product, by varying process techniques.
New processes have allowed flexibility in the choice of crudes, the use of coal tar sands as a source of molecules and the manufacture of synthetic blend stocks. Due to the number and severity of the processes used, it is often necessary and sometimes mandatory to use additives. These additives may, for example, prevent the formation of harmful chemical species or improve a property of a fuel to prevent further engine wear.
It is very important that jet fuel be free from water contamination. During flight, the temperature of the fuel in the tanks decreases, due to the low temperatures in the upper atmosphere. This causes precipitation of the dissolved water from the fuel. The separated water then drops to the bottom of the tank, because it is denser than the fuel. Since the water is no longer in solution, it can form droplets which can supercool to below 0 °C (32 °F). If these supercooled droplets collide with a surface they can freeze and may result in blocked fuel inlet pipes. [19] This was the cause of the British Airways Flight 38 accident. Removing all water from fuel is impractical; therefore, fuel heaters are usually used on commercial aircraft to prevent water in fuel from freezing.
There are several methods for detecting water in jet fuel. A visual check may detect high concentrations of suspended water, as this will cause the fuel to become hazy in appearance. An industry standard chemical test for the detection of free water in jet fuel uses a water-sensitive filter pad that turns green if the fuel exceeds the specification limit of 30 ppm (parts per million) free water. [20] A critical test to rate the ability of jet fuel to release emulsified water when passed through coalescing filters is ASTM standard D3948 Standard Test Method for Determining Water Separation Characteristics of Aviation Turbine Fuels by Portable Separometer.
Military organizations around the world use a different classification system of JP (for "Jet Propellant") numbers. Some are almost identical to their civilian counterparts and differ only by the amounts of a few additives; Jet A-1 is similar to JP-8, Jet B is similar to JP-4. [21] Other military fuels are highly specialized products and are developed for very specific applications.
![]() | This section may be confusing or unclear to readers.(July 2014) |
Jet fuel is very similar to diesel fuel, and in some cases, may be used in diesel engines. The possibility of environmental legislation banning the use of leaded avgas (fuel in spark-ignited internal combustion engine, which usually contains tetraethyllead (TEL), a toxic substance added to prevent engine knocking), and the lack of a replacement fuel with similar performance, has left aircraft designers and pilot's organizations searching for alternative engines for use in small aircraft. [33] As a result, a few aircraft engine manufacturers, most notably Thielert and Austro Engine, have begun offering aircraft diesel engines which run on jet fuel which may simplify airport logistics by reducing the number of fuel types required. Jet fuel is available in most places in the world, whereas avgas is only widely available in a few countries which have a large number of general aviation aircraft. A diesel engine may be more fuel-efficient than an avgas engine. However, very few diesel aircraft engines have been certified by aviation authorities. Diesel aircraft engines are uncommon today, even though opposed-piston aviation diesel powerplants such as the Junkers Jumo 205 family had been used during the Second World War.
Jet fuel is often used in diesel-powered ground-support vehicles at airports. However, jet fuel tends to have poor lubricating ability in comparison to diesel, which increases wear in fuel injection equipment.[ citation needed ] An additive may be required to restore its lubricity. Jet fuel is more expensive than diesel fuel but the logistical advantages of using one fuel can offset the extra expense of its use in certain circumstances.
Jet fuel contains more sulfur, up to 1,000 ppm, which therefore means it has better lubricity and does not currently require a lubricity additive as all pipeline diesel fuels require.[ citation needed ] The introduction of Ultra Low Sulfur Diesel or ULSD brought with it the need for lubricity modifiers. Pipeline diesels before ULSD were able to contain up to 500 ppm of sulfur and were called Low Sulfur Diesel or LSD. In the United States LSD is now only available to the off-road construction, locomotive and marine markets. As more EPA regulations are introduced, more refineries are hydrotreating their jet fuel production, thus limiting the lubricating abilities of jet fuel, as determined by ASTM Standard D445.
Fischer–Tropsch (FT) Synthesized Paraffinic Kerosene (SPK) synthetic fuels are certified for use in United States and international aviation fleets at up to 50% in a blend with conventional jet fuel. [34] As of the end of 2017, four other pathways to SPK are certified, with their designations and maximum blend percentage in brackets: Hydroprocessed Esters and Fatty Acids (HEFA SPK, 50%); synthesized iso-paraffins from hydroprocessed fermented sugars (SIP, 10%); synthesized paraffinic kerosene plus aromatics (SPK/A, 50%); alcohol-to-jet SPK (ATJ-SPK, 30%). Both FT and HEFA based SPKs blended with JP-8 are specified in MIL-DTL-83133H.
Some synthetic jet fuels show a reduction in pollutants such as SOx, NOx, particulate matter, and sometimes carbon emissions. [35] [36] [37] [38] [39] It is envisaged that usage of synthetic jet fuels will increase air quality around airports which will be particularly advantageous at inner city airports. [40]
Chemist Heather Willauer is leading a team of researchers at the U.S. Naval Research Laboratory who are developing a process to make jet fuel from seawater. The technology requires an input of electrical energy to separate Oxygen (O2) and Hydrogen (H2) gas from seawater using an iron-based catalyst, followed by an oligomerization step wherein carbon monoxide (CO) and hydrogen are recombined into long-chain hydrocarbons, using zeolite as the catalyst. The technology is expected to be deployed in the 2020s by U.S. Navy warships, especially nuclear-powered aircraft carriers. [43] [44] [45] [46] [47] [48]
On February 8, 2021, the world's first scheduled passenger flight flew with some synthetic kerosene from a non-fossil fuel source. 500 liters of synthetic kerosene was mixed with regular jet fuel. Synthetic kerosene was produced by Shell and the flight was operated by KLM. [49]
On August 8, 2007, Air Force Secretary Michael Wynne certified the B-52H as fully approved to use the FT blend, marking the formal conclusion of the test program. This program is part of the Department of Defense Assured Fuel Initiative, an effort to develop secure domestic sources for the military energy needs. The Pentagon hopes to reduce its use of crude oil from foreign producers and obtain about half of its aviation fuel from alternative sources by 2016. With the B-52 now approved to use the FT blend, the USAF will use the test protocols developed during the program to certify the Boeing C-17 Globemaster III and then the Rockwell B-1B Lancer to use the fuel. To test these two aircraft, the USAF has ordered 281,000 US gal (1,060,000 L) of FT fuel. The USAF intends to test and certify every airframe in its inventory to use the fuel by 2011. They will also supply over 9,000 US gal (34,000 l; 7,500 imp gal) to NASA for testing in various aircraft and engines.[ needs update ]
The USAF has certified the B-1B, B-52H, C-17, Lockheed Martin C-130J Super Hercules, McDonnell Douglas F-4 Phantom (as QF-4 target drones), McDonnell Douglas F-15 Eagle, Lockheed Martin F-22 Raptor, and Northrop T-38 Talon to use the synthetic fuel blend. [50]
The U.S. Air Force's C-17 Globemaster III, F-16 and F-15 are certified for use of hydrotreated renewable jet fuels. [51] [52] The USAF plans to certify over 40 models for fuels derived from waste oils and plants by 2013. [52] The U.S. Army is considered one of the few customers of biofuels large enough to potentially bring biofuels up to the volume production needed to reduce costs. [52] The U.S. Navy has also flown a Boeing F/A-18E/F Super Hornet dubbed the "Green Hornet" at 1.7 times the speed of sound using a biofuel blend. [52] The Defense Advanced Research Projects Agency (DARPA) funded a $6.7 million project with Honeywell UOP to develop technologies to create jet fuels from biofeedstocks for use by the United States and NATO militaries. [53]
In April 2011, four USAF F-15E Strike Eagles flew over the Philadelphia Phillies opening ceremony using a blend of traditional jet fuel and synthetic biofuels. This flyover made history as it was the first flyover to use biofuels in the Department of Defense. [54]
The air transport industry is responsible for 2–3 percent of man-made carbon dioxide emitted. [55] Boeing estimates that biofuels could reduce flight-related greenhouse-gas emissions by 60 to 80 percent. One possible solution which has received more media coverage than others would be blending synthetic fuel derived from algae with existing jet fuel: [56]
Solazyme produced the world's first 100 percent algae-derived jet fuel, Solajet, for both commercial and military applications. [64]
Oil prices increased about fivefold from 2003 to 2008, raising fears that world petroleum production is becoming unable to keep up with demand. The fact that there are few alternatives to petroleum for aviation fuel adds urgency to the search for alternatives. Twenty-five airlines were bankrupted or stopped operations in the first six months of 2008, largely due to fuel costs. [65]
In 2015 ASTM approved a modification to Specification D1655 Standard Specification for Aviation Turbine Fuels to permit up to 50 ppm (50 mg/kg) of FAME (fatty acid methyl ester) in jet fuel to allow higher cross-contamination from biofuel production. [66]
Worldwide demand of jet fuel has been steadily increasing since 1980. Consumption more than tripled in 30 years from 1,837,000 barrels/day in 1980, to 5,220,000 in 2010. [67] Around 30% of the worldwide consumption of jet fuel is in the US (1,398,130 barrels/day in 2012).
Article 24 of the Chicago Convention on International Civil Aviation of 7 December 1944 stipulates that when flying from one contracting state to another, the kerosene that is already on board aircraft may not be taxed by the state where the aircraft lands, nor by a state through whose airspace the aircraft has flown. However, there is no tax regulation in the Chicago Convention to refuel the aircraft before departure. The Chicago Convention does not preclude a kerosene tax on domestic flights and on refueling before international flights. [68] : 16
Kerosene tax can be levied throughout the European Union on domestic flights and between Member States according to the 2003 Energy Taxation Directive. [69] In the United States, most states tax jet fuel.
General health hazards associated with exposure to jet fuel vary according to its components, exposure duration (acute vs. long-term), route of administration (dermal vs. respiratory vs. oral), and exposure phase (vapor vs. aerosol vs. raw fuel). [70] [71] Kerosene-based hydrocarbon fuels are complex mixtures which may contain up to 260+ aliphatic and aromatic hydrocarbon compounds including toxicants such as benzene, n-hexane, toluene, xylenes, trimethylpentane, methoxyethanol, naphthalenes. [71] While time-weighted average hydrocarbon fuel exposures can often below recommended exposure limits, peak exposure can occur, and the health impact of occupational exposures is not fully understood. Evidence of the health effects of jet fuels comes from reports on both temporary or persisting biological from acute, subchronic, or chronic exposure of humans or animals to kerosene-based hydrocarbon fuels, or the constituent chemicals of these fuels, or to fuel combustion products. The effects studied include: cancer, skin conditions, respiratory disorders, [72] immune and hematological disorders, [73] neurological effects, [74] visual and hearing disorders, [75] [76] renal and hepatic diseases, cardiovascular conditions, gastrointestinal disorders, genotoxic and metabolic effects. [71] [77]
Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from Greek: κηρός (keros) meaning "wax", and was registered as a trademark by Canadian geologist and inventor Abraham Gesner in 1854 before evolving into a generic trademark. It is sometimes spelled kerosine in scientific and industrial usage. The term kerosene is common in much of Argentina, Australia, Canada, India, New Zealand, Nigeria, and the United States, while the term paraffin is used in Chile, eastern Africa, South Africa, Norway, and in the United Kingdom. The term lamp oil, or the equivalent in the local languages, is common in the majority of Asia and the Southeastern United States. Liquid paraffin is a more viscous and highly refined product which is used as a laxative. Paraffin wax is a waxy solid extracted from petroleum.
Gasoline or petrol is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. On average, U.S. refineries produce, from a barrel of crude oil, about 19 to 20 gallons of gasoline; 11 to 13 gallons of distillate fuel ; and 3 to 4 gallons of jet fuel. The product ratio depends on the processing in an oil refinery and the crude oil assay. A barrel of oil is defined as holding 42 US gallons, which is about 159 liters or 35 imperial gallons.
Contrails or vapor trails are line-shaped clouds produced by aircraft engine exhaust or changes in air pressure, typically at aircraft cruising altitudes several miles above the Earth's surface. Contrails are composed primarily of water, in the form of ice crystals. The combination of water vapor in aircraft engine exhaust and the low ambient temperatures that exist at high altitudes allows the formation of the trails. Impurities in the engine exhaust from the fuel, including sulfur compounds provide some of the particles that can serve as nucleation sites for water droplet growth in the exhaust. If water droplets form, they might freeze to form ice particles that compose a contrail. Their formation can also be triggered by changes in air pressure in wingtip vortices or in the air over the entire wing surface. Contrails, and other clouds directly resulting from human activity, are collectively named homogenitus.
Diesel fuel, also called diesel oil, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a result of compression of the inlet air and then injection of fuel. Therefore, diesel fuel needs good compression ignition characteristics.
An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years many small UAVs have used electric motors.
Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. Biofuel can be produced from plants or from agricultural, domestic or industrial biowaste. The climate change mitigation potential of biofuel varies considerably, from emission levels comparable to fossil fuels in some scenarios to negative emissions in others. Biofuels are mostly used for transportation, but can also be used for heating and electricity. Biofuels are regarded as a renewable energy source.
Avgas is an aviation fuel used in aircraft with spark-ignited internal combustion engines. Avgas is distinguished from conventional gasoline (petrol) used in motor vehicles, which is termed mogas in an aviation context. Unlike motor gasoline, which has been formulated since the 1970s to allow the use of platinum-content catalytic converters for pollution reduction, the most commonly used grades of avgas still contain tetraethyllead (TEL), a toxic substance used to prevent engine knocking. There are ongoing experiments aimed at eventually reducing or eliminating the use of TEL in aviation gasoline.
A hydraulic fluid or hydraulic liquid is the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water. Examples of equipment that might use hydraulic fluids are excavators and backhoes, hydraulic brakes, power steering systems, automatic transmissions, garbage trucks, aircraft flight control systems, lifts, and industrial machinery.
RP-1 (alternatively, Rocket Propellant-1 or Refined Petroleum-1) is a highly refined form of kerosene outwardly similar to jet fuel, used as rocket fuel. RP-1 provides a lower specific impulse than liquid hydrogen (LH2), but is cheaper, is stable at room temperature, and presents a lower explosion hazard. RP-1 is far denser than LH2, giving it a higher energy density (though its specific energy is lower). RP-1 also has a fraction of the toxicity and carcinogenic hazards of hydrazine, another room-temperature liquid fuel.
Aviation fuels are petroleum-based fuels, or petroleum and synthetic fuel blends, used to power aircraft. They have more stringent requirements than fuels used for ground use, such as heating and road transport, and contain additives to enhance or maintain properties important to fuel performance or handling. They are kerosene-based for gas turbine-powered aircraft. Piston-engined aircraft use leaded gasoline and those with diesel engines may use jet fuel (kerosene). By 2012, all aircraft operated by the U.S. Air Force had been certified to use a 50-50 blend of kerosene and synthetic fuel derived from coal or natural gas as a way of stabilizing the cost of fuel.
Liquid fuels are combustible or energy-generating molecules that can be harnessed to create mechanical energy, usually producing kinetic energy; they also must take the shape of their container. It is the fumes of liquid fuels that are flammable instead of the fluid. Most liquid fuels in widespread use are derived from fossil fuels; however, there are several types, such as hydrogen fuel, ethanol, and biodiesel, which are also categorized as a liquid fuel. Many liquid fuels play a primary role in transportation and the economy.
Turbine Fuel Low Volatility JP-7, commonly known as JP-7 is a specialized type of jet fuel developed in 1955 for the United States Air Force (USAF) for use in its supersonic military aircraft, including the SR-71 Blackbird and the Boeing X-51 Waverider.
JP-8, or JP8 is a jet fuel, specified and used widely by the US military. It is specified by MIL-DTL-83133 and British Defence Standard 91-87, and similar to commercial aviation's Jet A-1, but with the addition of corrosion inhibitor and anti-icing additives.
JP-4, or JP4 was a jet fuel, specified in 1951 by the U.S. government (MIL-DTL-5624). Its NATO code is F-40. It is also known as avtag.
Aircraft engines produce gases, noise, and particulates from fossil fuel combustion, raising environmental concerns over their global effects and their effects on local air quality. Jet airliners contribute to climate change by emitting carbon dioxide, the best understood greenhouse gas, and, with less scientific understanding, nitrogen oxides, contrails and particulates. Their radiative forcing is estimated at 1.3–1.4 that of CO2 alone, excluding induced cirrus cloud with a very low level of scientific understanding. In 2018, global commercial operations generated 2.4% of all CO2 emissions.
Jet Propellant Thermally Stable (JPTS) is a jet fuel originally developed in 1956 for the Lockheed U-2 reconnaissance aircraft.
Sustainable biofuel is biofuel produced in a sustainable manner. It is not based on petroleum or other fossil fuels. It includes not using plants that are used for food stuff to produce the fuel thus disrupting the worlds food supply.
An aviation biofuel or bio-jet fuel or bio-aviation fuel (BAF) is a biofuel used to power aircraft and is said to be a sustainable aviation fuel (SAF). The International Air Transport Association (IATA) considers it a key element to reducing the carbon footprint within the environmental impact of aviation. Aviation biofuel could help decarbonize medium- and long-haul air travel generating most emissions, and could extend the life of older aircraft types by lowering their carbon footprint.
ISFuel Inc. is a United States company involved in research & development of synfuels. In particular, they research the use of coal and biomass to produce a fully synthetic fuel that can pass multiple fuel specifications, or “joint” fuel.
Worldwide commercial synthetic fuels plant capacity is over 240,000 barrels per day (38,000 m3/d), including indirect conversion Fischer–Tropsch plants in South Africa, Qatar, and Malaysia, and a Mobil process plant in New Zealand.