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Alternative fuels and green aviation
Published in Emily S. Nelson, Dhanireddy R. Reddy, Green Aviation: Reduction of Environmental Impact Through Aircraft Technology and Alternative Fuels, 2018
The most common military fuels areJet propellant 4 (JP-4): the military equivalent of Jet B with the addition of corrosion inhibitors and anti-icing additives. It used to be the primary fuel of the U.S. Air Force, but it was phased out in the 1990s because of safety concerns. Although still in use by other air forces around the world, it is in limited production.JP-5: a high flash-point, wide-cut kerosene fuel used by the U.S. Navy, primarily for aircraft carriersJP-8: the military equivalent of Jet A-1 with the addition of corrosion inhibitor and anti-icing additives
In-Situ Venting of Jet-Fuelrcontaminated Soil
Published in Bell John W., Proceedings of the 44th Industrial Waste Conference May 9, 10, 11, 1989, 1990
Michael G. Elliott, David W. DePaoli
On January 9, 1985, in a fuel yard at Hill AFB, Utah, approximately 27,000 gallons of jet fuel (JP-4) spilled on the ground after an automatic filling system malfunctioned and underground storage tanks overfilled. JP-4 is made by blending various proportions of distillate stocks such as naphtha, gasoline and kerosene to meet military and commercial specifications. In general, it has more heavy molecular weight hydrocarbons and is less volatile than gasoline and other contaminants which have previously been investigated for remediation by in-situ soil venting.
Air Force-Related Jet Fuel Toxicology Research (1991-2010)
Published in Mark L. Witten, Errol Zeiger, Glenn D. Ritchie, Jet Fuel Toxicology, 2010
The worldwide, multipurpose use of JP-8 jet fuel provides opportunities for many varied types of exposures to the unburned fuel, such as during cold engine starts, fueling and de-fueling, engine and fuel cell maintenance, fuel transportation, and accidental spills. JP-8 was developed as a replacement fuel for JP-4 and, with safety in mind, was designed to reduce the inherent risks of fire and toxicity associated with JP-4. In contrast to the gasoline-like nature of JP-4, JP-8 is more kerosene-like. That is, relative to JP-4, JP-8 is formulated to contain more long-chain aliphatic hydrocarbons and fewer low-molecular-weight constituents that tend to raise the flash point and lower the vapor pressure of the fuel. This formulation renders JP-8 less volatile than JP-4 and thus less flammable and less likely to catch fire or explode upon collision. Moreover, most of the carcinogenic (benzene) and neurotoxic (n-hexane) constituents found in JP-4 are eliminated from JP-8 when the low-molecular-weight fractions are removed during its formulation. For example, benzene has been reduced to a level less than 100 μg/ml [3]. The replacement of JP-4 with JP-8 has succeeded in yielding fewer fuel-related fires and lower exposures to benzene and n-hexane, ostensibly saving lives and reducing the potential for adverse health effects. The same properties of JP-8 (low vapor pressure and high flash point) that are responsible for saving lives and protecting health also slow its rate of evaporation, allowing JP-8 to remain in its liquid phase much longer than JP-4. This means that if JP-8 is unintentionally released into the environment, then fuel exposure times could increase along with health risks. For example, starting cold engines with JP-8 often can produce sizable exhaust plumes of unburned aerosolized particles that could be either inhaled or deposited on surfaces (including skin and clothing) for a time long enough to be easily absorbed—a problem not previously encountered with JP-4. On cold days, this is especially troublesome for military flight-line personnel whose necessary proximity to the aircraft during engine start-up virtually ensures some skin and clothing exposure to JP-8 even when proper protective gear is donned. Other exposure scenarios, such as leaks and spills of JP-8 during transportation or engine maintenance, have also produced situations where clothing, skin, and surfaces are contaminated with fuel that evaporates slowly, enhancing exposure time and therefore the likelihood of both the inhalation and dermal absorption of JP-8 constituents.
Use of GreenZyme® for remediation of porous media polluted with jet fuel JP-5
Published in Environmental Technology, 2020
Valentinos Loukopoulos-Kousis, Constantinos V. Chrysikopoulos
Jet propellant (JP) fuels are used mainly in military and civilian aircrafts, and consist of relatively complex mixtures of hydrocarbons [33]. Hydrocarbons are composed only of the elements carbon (C) and hydrogen (H) and they are the main constituents of petroleum and natural gas. The hydrocarbons are classified based on their structure into two major groups: aliphatic and aromatic. Aliphatic hydrocarbons are classified based on the types of bonds they contain into: alkanes also called paraffins (contain only single bonds), alkenes also called olefins (contain a carbon–carbon double bond), and alkynes (contain a carbon–carbon triple bond). Aromatic hydrocarbons have unique stability, and they contain one or more planar rings of carbon atoms joined by aromatic (not single) bonds [34]. Alkanes are classified as saturated hydrocarbons (no hydrogen can be added to them), whereas alkenes, alkynes and aromatics as unsaturated hydrocarbons (hydrogen can be added to carbon atoms). The first turbine engines were fueled with plain illuminating kerosine (also spelled as kerosene, which is the general name of paraffin), which was widely available because it was used for wick lamps. Subsequently, after World Was II, the U.S. Air Force developed wide-cut jet fuels, also known as naphtha-type (JP-4) from hydrocarbon mixtures produced by distillation of crude oil. Because these fuels were found to have operational disadvantages due to their high volatility, the Air Force in the 1970s developed kerosine-type jet fuels (JP-8). The U.S. Navy used on aircraft carriers a kerosine-type jet fuel (JP-5) since the 1950s. Also, the commercial jet industry developed in the 1950s kerosine-type jet fuels (Jet A, Jet A-1) balancing performance, fuel price and availability, and (Jet B) for its enhanced cold-weather performance [33]. Several other military fuels are available, which have been developed for highly specific applications. Fuel-soluble chemicals are added to some of the kerosine-type jet fuels in very small amounts to enhance fuel performance and fuel handling. These chemicals are refered to as additives. Furthermore, it should be noted that some military fuels are very similar to their civilian counterparts, containing just different additives.