Jet Fuel, JP-5, JP-8 & DFM: Properties, Chemical Composition & Toxicokinetics

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In summary, the conversation discusses various types of aviation fuels, including specialty fuels JP-9 and JP-10 used for missile applications. These fuels are formulated with high-density naphthenes and have high volumetric energy content. Other military fuels mentioned are JP-5, JP-8, and DFM, which contain a complex mixture of hydrocarbons and additives. The physical and chemical properties of these fuels are described, including freezing point, boiling point, flash point, viscosity, and composition. The conversation also briefly touches on the potential toxicity of fuel vapors and the challenges of predicting the toxicokinetics of various hydrocarbons in these fuels.
  • #1
Astronuc
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I found some interesting stuff while doing some research and thought it might be useful.

http://www.chevron.com/products/prodserv/fuels/bulletin/aviationfuel/toc.shtm
http://www.chevron.com/products/prodserv/fuels/bulletin/aviationfuel/1_at_fuel_intro.shtm
http://www.chevron.com/products/prodserv/fuels/bulletin/aviationfuel/4_at_fuel_comp.shtm

Naphthalene (Aromatic) C10H8
n-Dodecane (n-Paraffin) C12H26

Hydrocarbon Missile Fuels

JP-9 and JP-10 are specialty fuels that have been developed for demanding applications, such as aircraft-launched missiles. The required properties are: maximum volumetric energy content, clean burning, and good low-temperature performance. To achieve these properties, the fuels are formulated with high-density naphthenes in nearly pure form. These fuels only are used in limited volumes and in situations where price is a minor consideration.

JP-10 is essentially a single hydrocarbon exo-tetrahydrodicyclopentadiene. It has a minimum volumetric heat content of 39,434 MJ/m3 (141,500 Btu/gal). For comparison, Jet A or JP-8 has a volumetric energy content of about 35,000 MJ/m3 (125,800 Btu/gal), about 11 percent lower. JP-9 is a blend of three hydrocarbons: methylcyclohexane, perhydronorbornadiene dimer, and exo-tetrahydrodicyclopentadiene (JP-10). JP-9 has a minimum volumetric heat content of 39,573 MJ/m3 (142,000 Btu/gal).

-------------------
Sinclair Oil Co. MSDS-
SPECIFIC GRAVITY (g/ml): 0.77-0.84
VAPOR DENSITY (air=1): 4.5
-------------------

Physical and Chemical Properties of Military Fuels - National Academies Press
Jet fuels and diesel fuel marine (DFM) are complex mixtures of hydrocarbons produced by distillation of crude oil. They contain hundreds of hydrocarbons as well as many additives. The actual composition of any given fuel varies depending upon source of the crude oil, refinery processes, and product specifications. The hydrocarbons in jet and diesel fuels are less volatile than those in gasoline. JP-5 is a high-flash-point jet fuel developed by the Navy. JP-5 is a specifically refined type of kerosene consisting of C9-C16 paraffins (53%), cycloparaffins (31%), aromatics (16%), and olefins (0.5%). The aromatic content of JP-5 might vary from less than 2.5% to greater than 22% by volume. The benzene content of JP-5 is typically less than 0.02% (Dollarhide, 1992), and a small amount of polycyclic aromatic hydrocarbons might be present in JP-5. Because water contamination in aviation fuels is a serious problem, a fuel-system icing inhibitor is added to the fuel to eliminate the formation of ice in aircraft systems. JP-8 is similar to commercial jet A-1 fuel. JP-8 was developed for the Air Force to provide a safe kerosene-based jet fuel that would still have adequate reliability and an acceptable freezing point. DFM is a blend of diesel fuel that is basically the same as kerosene to which high-boiling-point fractions and high-boiling-point residual oils have been added. Diesel fuels consist primarily of C9-C20 hydrocarbons. For DFM, these are roughly 13% paraffins, 44% aromatics, and 44% naphthalenes. DFM might also contain less than 10% polycyclic aromatic hydrocarbons.

In considering the potential toxicity of the fuel vapors, it is important to note that many compounds in the fuel do not exist in the vapors (Bishop, 1982). The toxicity of the more-volatile fractions of the fuel is considered in this report and not the toxicity of the total fuel. The composition of the vapors from the three fuels under consideration are expected to be similar since the fuels are made by mixing kerosene with different amounts of low-boiling-point distillates.

The physical and chemical properties of military fuels JP-5, JP-8, and DFM are described below.

Molecular weight: ˜185

Synonyms: Jet fuel JP-5, MIL-T-5624M, AVCAT

Freezing point, maximum: -46°C

Boiling point: 156-293°C

Initial point: 182°C (156-191°C)

10% evaporated: 199°C ( 180-211°C)
20% evaporated: 207°C (199-213°C)
50% evaporated: 220°C (212-229°C)
90% evaporated: 246°C (236-275°C)

End point: 166°C (248-293°C)

Flash point, minimum: 60°C

Vapor pressure:
0.52 mm Hg (10°C) 1.8 mm Hg (28°C)

Specific gravity, kg/L, 15°C,
Minimum: 0.788
Maximum: 0.834

Heating value, Btu/lb, minimum: 18,300

Autoignition temperature: 246°C

Viscosity, maximum at -20°C: 8.5

Composition:
C9–C16 paraffins, vol % ˜ 53%;
cycloparaffins, vol % ˜ 31%;
aromatics, vol % ˜ 16%;
olefins, vol % ˜ 0.5%.

Aromatics typical of cracked gasoline and kerosene include benzene, alkyl benzenes, toluene, xylene, indenes, naphthalenes. Benzene content = 0.02%.

========================
JET-PROPULSION FUEL 8
Molecular weight: ˜180

Synonyms: Jet fuel JP-8, MIL-T-83133B, AVTUR

Freezing point, maximum: -47°C

Boiling point: 175-300°C

10% recovered, maximum: 205°C

End point, maximum: 300°C

Flash point, minimum: 38°C

Vapor pressure: 0.52 mm Hg (10°C) 1.8 mm Hg (28°C)

Specific gravity, kg/L, 15°C,
Minimum: 0.775
Maximum: 0.840

Heating value, Btu/lb, minimum: 18,400

Viscosity, maximum at -20°C: 8

Composition:
C8– C9 aliphatic hydrocarbons, vol % ˜ 9%
C10–C14 aliphatic hydrocarbons, vol % ˜ 65%;
C15–C17 aliphatic hydrocarbons, vol % ˜ 7%;
aromatics, vol % ˜ 18%. Aromatics typical of cracked gasoline and kerosene include benzene, alkyl benzenes, toluene, xylene, indenes, naphthalenes.

Conversion factors at standard temperature and pressure:
1 ppm = 8.0 mg/m3, 1 mg/m3 = 0.12 ppm
===================================

Toxicokinetics of Military Fuels
It is not possible to fully describe the toxicokinetics of the individual volatile hydrocarbons that are present in JP-5, JP-8, and diesel fuel marine (DFM). However, toxicoldnetic data are available for the most toxic chemicals in each of the major classes of these fuels. For example, the n-paraffin group includes n-hexane, a human neurotoxicant. In the branched paraffin group, the chemical 2,2,4-trimethylpentane is thought to be responsible for the development of kidney-specific nephropathy and carcinogenicity in gasoline-exposed male rats. The aromatic group contains benzene (a human hematotoxicant and leukemogen) as well as toluene and the o-, m-, and p-xylenes. Finally, methoxyethanol, an important deicing additive in fuels, is a known developmental and reproductive toxicant. Thus, one of the major challenges in describing the behavior of the various hydrocarbons in these fuels is predicting the effect of other present hydrocarbons on the toxicokinetics of each highly toxic chemical.
 
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  • #2
I have a copy of that Chevron book as well as CRC's handbook of aviation fuels on my desk. They are good sources that cover a wide range of topics. I am my company's designated fuels coordinator (lucky me). It is a rather interesting area. Too bad I'm not a chemist so I can delve into the really serious aspects of the area.

I get the lovely opportunity to work with JETA, JP8 and JP10 on a daily basis. JETA and JP8 are very very similar and darned near the same fuel. There are a couple of slight differences between them. If anyone needs data or specs I'd be more than happy to help.
 
  • #3
Can you give me some information about jp-10 ?

FredGarvin said:
I have a copy of that Chevron book as well as CRC's handbook of aviation fuels on my desk. They are good sources that cover a wide range of topics. I am my company's designated fuels coordinator (lucky me). It is a rather interesting area. Too bad I'm not a chemist so I can delve into the really serious aspects of the area.

I get the lovely opportunity to work with JETA, JP8 and JP10 on a daily basis. JETA and JP8 are very very similar and darned near the same fuel. There are a couple of slight differences between them. If anyone needs data or specs I'd be more than happy to help.

I have to do some homework about jp-10 , can you help me ? Thank you very much ! << e-mail address deleted by berkeman >>
 
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  • #4
FredGarvin said:
I have a copy of that Chevron book as well as CRC's handbook of aviation fuels on my desk. They are good sources that cover a wide range of topics. I am my company's designated fuels coordinator (lucky me). It is a rather interesting area. Too bad I'm not a chemist so I can delve into the really serious aspects of the area.

I get the lovely opportunity to work with JETA, JP8 and JP10 on a daily basis. JETA and JP8 are very very similar and darned near the same fuel. There are a couple of slight differences between them. If anyone needs data or specs I'd be more than happy to help.

I am a jet engine mechanic in the military and our tech data says our MEC's specific gravity can be adjusted from .76-.85. We use the CF6-50C2 GE engines. My question is: by changing the setting of SG on the MEC, what are we actually changing/telling in the MEC? Because we are not actually changing the density of the JP-8. << e-mail address edited out by berkeman >>
 
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  • #5
Essentially you are adjusting the energy content of the fuel. The fuel has a rating of X BTU/Lbm. By adjusting the SG you are really adjusting the density and thus the amount of energy available in the fuel.

As a note, the specific gravity for a fuel is not a constant. It is within a range. So depending on the load of fuel, the SG will change, especially with the seasons.
 
  • #6
I stayed in a house with an AGA stove running on kerosene. It was just about impossible to light - it usually took an hour of playing around a box of matches.

What is added to Jet-A to allow it to be ignited by an MP3 player, since I can't switch on electrical devices until inside the terminal because they are refuelling? This component only seems to be present in the UK - in the USA I can use a cell phone while the doors are open. :tongue:
 
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  • #7
We used to run our tent stoves on JP8 which is the military equivalent to JET-A. The carbuerators in the burner were really finicky as I recall too.

JET-A will not light with such a small energy content, especially in the liquid phase. For it to ignite in an engine, the igniters have a lot of energy and the fuel is atomized. You can drop a match in a pool of JET-A and it will snuff out the match. Of course, vapors are what one needs to be leery of. I think I have a study that was done to specify the minimum energy required for combustion of certain fuels. I'll see if I can find it.
 
  • #8
FredGarvin said:
Essentially you are adjusting the energy content of the fuel. The fuel has a rating of X BTU/Lbm. By adjusting the SG you are really adjusting the density and thus the amount of energy available in the fuel.

As a note, the specific gravity for a fuel is not a constant. It is within a range. So depending on the load of fuel, the SG will change, especially with the seasons.

ok so we are changing the SG of the fuel. I always thought it was constant. How does it actually change the SG?
 
  • #9
You're not altering the fuel physically. If I understand what you are doing correctly, you are adjusting the fuel control for the engine, or am I mistaken?
 
  • #10
Yes all we are doing is adjusting the fuel control, especially when we deploy to the desert. The EGT gets too high because of the high TATs, so the book says to adjust accordingly.
 
  • #11
FredGarvin said:
I have a copy of that Chevron book as well as CRC's handbook of aviation fuels on my desk. They are good sources that cover a wide range of topics. I am my company's designated fuels coordinator (lucky me). It is a rather interesting area. Too bad I'm not a chemist so I can delve into the really serious aspects of the area.

I get the lovely opportunity to work with JETA, JP8 and JP10 on a daily basis. JETA and JP8 are very very similar and darned near the same fuel. There are a couple of slight differences between them. If anyone needs data or specs I'd be more than happy to help.

I HAVE A COPY OF THE EXXON JET FUEL BIBLE I CAN FORWARD YOU ON EMAIL.

I AM WORKING ON A PROCESS TO CONVERT SOY BASED BIODIESEL TO COMMERCIAL JET FUEL.

<< e-mail address deleted by berkeman >>

HRH
 
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  • #12
Does anyone know the dielectric constants for JP8, JP5 and Jet A?
 
  • #13
FredGarvin said:
I have a copy of that Chevron book as well as CRC's handbook of aviation fuels on my desk. They are good sources that cover a wide range of topics. I am my company's designated fuels coordinator (lucky me). It is a rather interesting area. Too bad I'm not a chemist so I can delve into the really serious aspects of the area.

I get the lovely opportunity to work with JETA, JP8 and JP10 on a daily basis. JETA and JP8 are very very similar and darned near the same fuel. There are a couple of slight differences between them. If anyone needs data or specs I'd be more than happy to help.

I am beginning a new research project concerning JP-10. Can you help me to inquire some data ? I can use everything you can throw at me concerning JP-10. So please really everything what you have on JP-10 (specs, ppt's, experimental data,...the whole lot) is very usefull for me.

Thanks in advance!
Maarten

PS: I can't send private messages to you (otherwise I gave you my emailadres right away)
 
  • #14
We have approval from the Hazmat department to buy JP-10, but they say it will take them 10-17 days to get us a 55 gallon drum. Any suggestions for 1-2 day delivery sources?
 
  • #15
FredGarvin said:
We used to run our tent stoves on JP8 which is the military equivalent to JET-A. The carbuerators in the burner were really finicky as I recall too.

JET-A will not light with such a small energy content, especially in the liquid phase. For it to ignite in an engine, the igniters have a lot of energy and the fuel is atomized. You can drop a match in a pool of JET-A and it will snuff out the match. Of course, vapors are what one needs to be leery of. I think I have a study that was done to specify the minimum energy required for combustion of certain fuels. I'll see if I can find it.

Hi~Fred. Do you happen to know the vapor pressure curve of JetA or JP8? Or Could be be so kind to recommend me some resources where i can probably find the curve? I'm now running experiments on JP8 and very much need to know the vapor pressure of it from 80C to 150 C.
How could I contact you?
 
  • #16
Hi Maarten
I am doing calculations for occupational exposure to Jet A and Jet A1 vapor (not the liquid phase) and need a research reference listing the range of molecuar weights for these jet fuels specifically. I understand they are "similar" to JP-8, but I need a reference for them specifically. A plus would be a reference listing Jet A, Jet A1 and JP-8. Thanks for any help you can provide via your data and specs. MROIH
 
  • #17
Hi Fred (Sorry Maarten)

I am doing calculations for occupational exposure to Jet A and Jet A1 vapor (not the liquid phase) and need a research reference listing the range of molecuar weights for these jet fuels specifically. I understand they are "similar" to JP-8, but I need a reference for them specifically. A plus would be a reference listing Jet A, Jet A1 and JP-8. Thanks for any help you can provide via your data and specs. MROIH
 
  • #18
Hello MROIH,

As per the CRC 635 handbook the "JP-8, per MIL-DTL-83133 is based on the civil fuel, Jet A-1, but requires specific additive packages. F-34 (JP-8) contains a static dissipator additive, a corrosion inhibitor/lubricity improver additive and FSII additive. It may contain antioxidant and metal deactivator additives. F-35 contains a static dissipator additive, may contain antioxidant, corrosion inhibitor/lubricity improver and metal deactivator additives, but does not contain fuel system icing inhibitor additive. F-37 is F-34 with a thermal stability additive package (JP-8+100). By adopting diesel and turbine-powered ground equipment and eliminating gasoline-powered ground vehicles, the U.S. military is enabling JP-8 to become a single fuel for the battlefield. The latest variant of the JP-8 grade is JP-8+100, which is JP-8 containing a thermal stability additive." (quote p.1-16)

It does not answer to any of your questions but, I hope it could help.
 

1. What is jet fuel?

Jet fuel is a type of aviation fuel used to power jet engines. It is a complex mixture of hydrocarbons that is specifically designed to meet the high performance and safety standards required for use in aircraft.

2. What is the difference between JP-5, JP-8, and DFM?

JP-5, JP-8, and DFM are all different types of jet fuel used by different branches of the military. JP-5 is a high flash point kerosene-based fuel used by the Navy and Coast Guard, while JP-8 is a lower flash point kerosene-based fuel used by the Air Force and Army. DFM, or Diesel Fuel Marine, is a variant of JP-8 used by the Marine Corps.

3. What are the properties of jet fuel?

Jet fuel is a highly flammable liquid with a low freezing point and a high flash point. It has a high energy density, which allows it to provide a lot of power in a small amount of fuel. It also has a low viscosity, making it flow easily through fuel systems.

4. What is the chemical composition of jet fuel?

Jet fuel is primarily composed of hydrocarbons, which are molecules made up of carbon and hydrogen atoms. The exact chemical composition of jet fuel can vary depending on the source and refining process, but it typically contains a mix of alkanes, cycloalkanes, and aromatic hydrocarbons.

5. What is the toxicokinetics of jet fuel?

Toxicokinetics refers to the way a substance is absorbed, distributed, metabolized, and excreted in the body. In the case of jet fuel, it is rapidly absorbed by inhalation, ingestion, and skin contact. It is then distributed throughout the body and metabolized into various byproducts, some of which may be toxic. The remaining components are eventually eliminated through the urine and feces.

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