JP-8

Last updated

JP-8, or JP8 (for "Jet Propellant 8"), 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.

Contents

A kerosene-based fuel, JP-8 is projected to remain in use at least until 2025. It was first introduced at NATO bases in 1978. Its NATO code is F-34.

Usage

The United States Air Force replaced JP-4 with JP-8 completely by the end of 1995, to use a less flammable, less hazardous fuel for better safety and combat survivability. [1]

JP-8 is formulated with an icing inhibitor, corrosion inhibitor lubricants, and antistatic agents, and contains less benzene (a carcinogen) and n-hexane (a neurotoxin) than JP-4. However, it also smells stronger than JP-4. JP-8 has an oily feel to the touch, while JP-4 feels more like a solvent.

The United States Navy uses a similar formula, JP-5. JP-5 has an even higher flash point of > 140 °F (60 °C), but also a higher cost, though the U.S. Navy Seabees still use JP-8 in their construction and tactical equipment.

Single-fuel concept

JP-8 was specified in 1990 by the U.S. government as a replacement for government diesel fueled vehicles. This is in the wider context of the 1986 NATO Single-Fuel Concept agreement, in which F-34 (JP-8) is to replace F-54 (diesel fuel) in land vehicles and F-40 (JP-4) in land-based turbine aircraft to simplify logistics. [2] It is also used as coolant in engines and some other aircraft components.

Beyond use in vehicles from trucks to tanks [3] to planes, JP-8 is used in U.S. Army heaters and stoves. [4] [5]

Problems and health concerns

Diesel problems

When used in highly supercharged diesel engines with the corresponding low compression ratio of about only 14:1 or below, JP-8 causes troubles during cold start and idling due to low compression temperatures and subsequent ignition delay because the cetane index is not specified in MIL-DTL-83133G to 40 or higher. Because lubricity to the BOCLE method is not specified in MIL-DTL-83133G, modern common-rail diesel engines can experience wear problems in high-pressure fuel pumps and injectors. Another problem in diesel engines can be increased wear to exhaust valve seats in the cylinder heads, because a maximum sulfur content is not specified in MIL-DTL-83133G. Sulfur in fuel normally contributes to a build-up of soot layers on these valve seats. According to the notes in this standard, it is intended to include a cetane index value in one of the next releases.[ citation needed ] MIL-DTL-83133J sets the maximum sulfur content at 0.30%. It however only requires a cetane number of 40 after addition of FT-SPK (synthetic jet fuel). [6]

The use of jet fuel in diesel engines has caused some minor issues, none of which were discovered in the Fort Bliss test with JP-8. During Desert Shield and Desert Storm, commercial Jet A1 was used as the single-fuel and failed engines with Stanadyne fuel-injection pumps missing an elastomer insert retrofit. [7] Other than that, JP-8 slightly reduces torque and fuel economy due to its lower density and viscosity compared to diesel fuel. Engine modification can offset this issue. [8]

Health concerns

Workers have complained of smelling and tasting JP-8 for hours after exposure. As JP-8 is less volatile than standard diesel fuel, it remains on the contaminated surfaces for longer time, increasing the risk of exposure. [9] JP-8 exposure has also been linked to hearing problems, but rather than being unable to hear sounds, the brain has a hard time deciphering the message. Dr. O'neil Guthrie, a research scientist and clinical audiologist with the United States Department of Veterans Affairs Loma Linda Healthcare System in California, has compared the central auditory processing disorder to dyslexia for the ears. [10]

In 2001, Texas Tech University's Institute of Environmental and Human Health and the United States Air Force conducted an 18-month study of the health effects of JP-8 on 339 active duty personnel at six US Air Force installations. The study found that Air Force workers who were exposed to JP-8 were no more likely to seek medical attention than workers who were not exposed to JP-8 on the job. Personnel in the high- and moderate-exposure categories self-reported greater amounts of symptoms such as headaches, dizziness, difficulty breathing, general weakness, trouble concentrating, forgetfulness, and trouble gripping things. [11]

Variants

JP-8+100 (F-37) is a variant of JP-8 augmented with the additive Spec-Aid 8Q462, also known as Aeroshell Performance Additive 101, created by BetzDearborn (now GE Betz). [12] The additive increases the thermal stability of JP-8 by 100 °F (37.8 °C), hence the designation "+100". Spec-Aid 8Q462 was introduced in 1994 to reduce choking and fouling in engine fuel systems and is a combination of a surfactant, metal deactivator, and an antioxidant. It is added to JP-8 at a ratio of 256 ppm to create JP-8+100, at an added cost of $5 per 1000 gallons of fuel. [13] Commercially, this additive is used in police helicopters in Tampa, Florida.[ citation needed ] JP-8+100 is also used for Canadian Forces CP-140 Aurora, CC-130 Hercules, CF-18 Hornet and the CC-115 Buffalo.

F-35 is a variant without icing inhibitor. The only requried additive is a static dissipater. [6]

JP-8+100LT is a variant of JP-8+100, with additives to facilitate low-temperature performance. It is considered as a logistically friendly low-cost replacement of the JPTS fuel for the Lockheed U-2 airplane. [13]

F-24 is commercial Jet A fuel (ASTM D1655) with the additive package required for JP-8 (SDA, CI/LI, FSII) added by the military. [14] The intention is to lower costs by using commercially-available fuel. The resulting fuel has identical properties to JP-8, save for a higher freezing-point specification. [15] The U.S. military has switched to F-24 in domestic (excluding Alaska) sites in 2012. [16] In 2018, it was found that the F-24 mixture could deteriorate during transport causing much reduced thermal stability, but addition of the +100 (8Q462) additive was enough to salvage degraded fuel. [17]

F-27 is F-24 with the +100 additive package. [14]

JP-8+225 is a planned variant of JP-8 that increases thermal stability by 225 °F (125 °C). Such a fuel would match the thermal stability of JP-7 and become a lower-cost replacement should it exist. [18]

See also

Related Research Articles

<span class="mw-page-title-main">Gasoline</span> Liquid fuel, also called petrol, derived from petroleum

The terms gasoline, petrol, or simply gas identify and describe the petrochemical product characterized as a transparent, yellowish, and flammable liquid, which is used as a fuel for spark-ignited, internal combustion engines. As the fuel for gasoline engines, gasoline is chemically composed of organic compounds derived from the fractional distillation of petroleum, and later is chemically enhanced with gasoline additives.

<span class="mw-page-title-main">Diesel fuel</span> Liquid fuel used in diesel engines

Diesel fuel, also called diesel oil or historically heavy 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.

<span class="mw-page-title-main">Avgas</span> Aviation fuel

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 without lead since the 1970s to allow the use of catalytic converters for pollution reduction, the most commonly used grades of avgas still contain tetraethyl lead, a toxic substance used to prevent engine knocking. There are ongoing efforts to reduce or eliminate the use of lead in aviation gasoline.

An antifreeze is an additive which lowers the freezing point of a water-based liquid. An antifreeze mixture is used to achieve freezing-point depression for cold environments. Common antifreezes also increase the boiling point of the liquid, allowing higher coolant temperature. However, all common antifreeze additives also have lower heat capacities than water, and do reduce water's ability to act as a coolant when added to it.

<span class="mw-page-title-main">GE Aerospace</span> American Aircraft Engine Manufacturer

GE Aerospace is an aircraft engine supplier, headquartered in Evendale, Ohio, outside Cincinnati. Not only does GE Aerospace manufacture engines under its umbrella, it also partners with other manufacturers. CFM International, the world’s leading supplier of aircraft engines and GE’s most successful partnership, is a 50/50 joint venture with the French company Safran Aircraft Engines. As of 2020, CFM International holds 39% of the world's commercial aircraft engine market share. GE Aerospace's main competitors in the engine market are Pratt & Whitney and Rolls-Royce.

<span class="mw-page-title-main">Aviation fuel</span> Fuel used to power aircraft

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.

<span class="mw-page-title-main">Liquid fuel</span> Liquids that can be used to create energy

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.

Shell V-Power is the brand name given to Shell's enhanced high specification fuels for road motor vehicles including Shell V-Power Nitro+ and Shell V-Power Diesel. Introduced in Italy in 2001, Shell relaunched the fuel in March 2008, under the name Nitrogen-Enriched Shell V-Power, with nitrogen-containing detergents.

Cetane number is an indicator of the combustion speed of diesel fuel and compression needed for ignition. It plays a similar role for diesel as octane rating does for gasoline. The CN is an important factor in determining the quality of diesel fuel, but not the only one; other measurements of diesel fuel's quality include energy content, density, lubricity, cold-flow properties and sulphur content.

<span class="mw-page-title-main">Jet fuel</span> Type of aviation fuel

Jet fuel or aviation turbine fuel 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.

<span class="mw-page-title-main">JP-7</span> Special jet fuel for supersonic aircraft and beyond

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.

Fuel system icing inhibitor (FSII) is an additive to aviation fuels that prevents the formation of ice in fuel lines. FSII is sometimes referred to by the registered, genericized trademark Prist. Jet fuel can contain a small amount of dissolved water that does not appear in droplet form. As an aircraft gains altitude, the temperature drops and the fuel's capacity to hold water is diminished. Dissolved water can separate out and could become a serious problem if it freezes in fuel lines or filters, blocking the flow of fuel and shutting down an engine.

JP-4, or JP4 was a jet fuel, specified in 1951 by the United States Department of Defense (MIL-DTL-5624). Its NATO code is F-40. It is also known as avtag.

<span class="mw-page-title-main">Metal deactivator</span>

Metal deactivators, or metal deactivating agents (MDA) are fuel additives and oil additives used to stabilize fluids by deactivating metal ions, mostly introduced by the action of naturally occurring acids in the fuel and acids generated in lubricants by oxidative processes with the metallic parts of the systems. Fuels desulfurized by copper sweetening also contain a significant trace amounts of copper.

<span class="mw-page-title-main">Charcoal lighter fluid</span> Aliphatic petroleum solvent used in lighting charcoal in a barbecue grill

Charcoal lighter fluid is a flammable fluid used to accelerate the ignition of charcoal in a barbecue grill. It can either be petroleum based or alcohol based. It can be used both with lump charcoal and briquettes. Lighter-fluid infused briquettes, that eliminate the need for separate application of lighter fluid, are available. The use of lighter fluid is somewhat controversial as the substance is combustible, harmful or fatal if swallowed, and may impart an unpleasant flavor to food cooked upon fires lit with it.

Cetane index is used as a substitute for the cetane number of diesel fuel. The cetane index is calculated based on the fuel's density and distillation range. There are two methods used, ASTM D976 and D4737. The older D976, or "two-variable equation" is outdated and should no longer be used for cetane number estimation. It is, however, still required by the United States Environmental Protection Agency (EPA) as an alternative method for satisfying its aromaticity requirement for diesel fuel. D4737 is the newest method and is sometimes referred to as "the four-variable equation". D4737 is the same method as ISO 4264. Cetane index in some crude oil assays is often referred to as Cetane calcule, while the cetane number is referred to as Cetane measure.

Jet Propellant Thermally Stable (JPTS) is a jet fuel originally developed in 1956 for the Lockheed U-2 reconnaissance aircraft.

A cetane improver [′sē‚tān im′prüv·ər] is a chemical which has the effect of increasing a diesel fuel's cetane number. A few examples are nitrates, nitroalkanes, nitrocarbonates and peroxides.

Aircraft engine performance refers to factors including thrust or shaft power for fuel consumed, weight, cost, outside dimensions and life. It includes meeting regulated environmental limits which apply to emissions of noise and chemical pollutants, and regulated safety aspects which require a design that can safely tolerate environmental hazards such as birds, rain, hail and icing conditions. It is the end product that an engine company sells.

References

  1. "The History of Jet Fuel". archive.org. BP. 18 October 2012. Archived from the original on October 18, 2012. Retrieved 21 December 2014.
  2. "Chapter 15: Fuels, Oils, Lubricants and Petroleum Handling Equipment: Military Fuels and the Single Fuel Concept" . Retrieved 19 May 2023.
  3. the M1 Abrams series of battle tanks uses JP fuel in its gas turbine engine
  4. Modern Burner Units Archived 2011-07-16 at the Wayback Machine , JP-8 is used by Army Food Service Specialists (cooks) to fuel MBUs, in accordance with U.S. Army Field Feeding Manual FM 10-23
  5. Babington Airtronic Burner Archived 2014-02-26 at the Wayback Machine burns JP-8 and other distillate fuels, and is the current common heat source for Marine Corps food service equipment.
  6. 1 2 MIL-DTL-83133J.
  7. "The Reality of the Single-Fuel Concept". www.globalsecurity.org.
  8. McKee, Heather; Fernandes, Gerald; Fuschetto, Jerry; Filipi, Zoran; Assanis, Dennis (2005-12-07). "Impact of Military JP-8 Fuel on Heavy Duty Diesel Engine Performance and Emissions #ADA573594".
  9. Day, Dwayne A. "Aviation Fuel". U.S. Centennial of Flight Commission. Retrieved 21 December 2014.
  10. "Exposure to jet fuel, not just noise, contributes to hearing problems". United States Department of Veterans Affairs . March 20, 2014. Archived from the original on March 18, 2021. Retrieved April 18, 2021.
  11. Ronald K. Kendall; Ernest Smith; Leslie B. Smith; Roger L. Gibson (August 2001). "JP-8 Final Risk Assessment" (PDF). Texas Tech University . Archived (PDF) from the original on March 27, 2020. Retrieved April 18, 2021.
  12. MIL-DTL-83133F DETAIL SPECIFICATION TURBINE FUEL, AVIATION, KEROSENE TYPE, JP-8 (NATO F-34), NATO F-35, and JP-8+100 (NATO F-37). From https://quicksearch.dla.mil/Transient/19C031269152438C816A666C97F37F4A.pdf
  13. 1 2 Simms, Christian G. (March 2001). "JP-8+100LT: A low cost replacement of JPTS as the primary fuel for the U-2 aircraft?" (PDF). Defense Technical Information Center. Archived (PDF) from the original on September 27, 2013.
  14. 1 2 MIL-STD-3004-1 w/CHANGE 1, available from https://quicksearch.dla.mil/Transient/230B5DB336074B18A1E558D105636331.pdf
  15. "USMC POLICY ON CONVERTING CONUS AVIATION AND GROUND/TACTICAL EQUIPMENT FROM JP-8 TO F-24". www.marines.mil.
  16. Paul J. Kern; Walker Mills; Erik Limpaecher; Matt Santoli; Ben Flanagan (29 June 2021). "An Albatross Around the US Military's Neck: The Single Fuel Concept and the Future of Expeditionary Energy". Modern War Institute.
  17. Morris, Robert W. Jr; Shardo, James R.; Marcum, Grady; Lewis, William K.; Wrzesinski, Paul J.; Bunker, Christopher E. (2018-01-01). "Characterization of an On-Spec, Commercial Grade, Jet A and A Near-Off-Spec Military F-24; Evaluation of +100 Thermal Stability Package". Defense Technical Information Center.
  18. Edwards, Tim (13 July 1998). Prospects for JP-8+225, a stepping stone to JP-900. 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit. doi:10.2514/6.1998-3532.