Aviation fuels are specialized petroleum-based fuels used to power aircraft. They have stricter requirements compared to fuels used for things like heating and road transport.
Aviation fuels can be petroleum-based or a combination of petroleum and synthetic fuel blends. They also contain additives that help improve or maintain important properties for fuel performance and handling.
Aviation fuels can be categorized into two types: kerosene-based fuels like JP-8 and Jet A-1, used in gas turbine-powered aircraft, and leaded gasoline used in piston-engined aircraft. Some aircraft with diesel engines may also use kerosene-based jet fuel. In 2012, the U.S. Air Force certified all their aircraft to run on a blend of 50% kerosene and 50% synthetic fuel derived from coal or natural gas. This allowed them to stabilize fuel costs.
When choosing fuel for aircraft, specific energy (energy per unit mass) is a key factor. Hydrocarbon fuels have a much higher energy storage capacity than batteries, which is why electric aircraft using batteries as the main energy source are not yet viable for most small personal aircraft. However, in 2018, the first battery electric vehicle (BEV) aircraft was officially certified.
Types of Aviation fuels
1.Jet fuel is a transparent to light yellow fuel used in aviation. It is available in two main types: Jet A-1, which is unleaded kerosene, and Jet B, which is a blend of kerosene and naphtha. Jet fuel can be used in engines that use compression ignition, like diesel engines, or turbine engines. Jet-A is specifically used in modern commercial airliners and is a highly refined form of kerosene. It burns at temperatures equal to or greater than 49 °C (120 °F).
Jet-A is the fuel used to power modern commercial airliners. It is a blend of highly refined kerosene that burns at temperatures of 49 °C (120 °F) or higher. Compared to gasoline, kerosene-based fuel has a higher flash point, meaning it requires more heat to ignite. Jet-A is considered a high-quality fuel. If it doesn’t meet the strict standards for use in aircraft, it can still be sold to ground-based users, such as railroads, who have less stringent requirements.
2. Avgas, short for aviation gasoline, is specifically designed for use in small aircraft, light helicopters, and older piston-engined aircraft. It is different from the regular gasoline used in cars, which is called mogas or autogas in the aviation context. Avgas comes in various grades, but generally has a higher octane rating compared to regular gasoline.
3.Biofuels serve as alternatives to traditional fossil-based aviation fuels. They are produced through biomass to liquid methods, such as sustainable aviation fuel, as well as certain vegetable oils. One key advantage of fuels like sustainable aviation fuel is that they require minimal or no modifications to the aircraft itself, as long as they meet specific requirements for lubricity, density, and compatibility with elastomer seals in existing aircraft fuel systems.
Production
Aviation fuel can be categorized into two types. : One for turbine engines and the other for spark-ignition piston engines.
There are specific international standards for each type.
Jet fuel, used in propeller and jet aircraft as well as helicopters, is designed for gas turbine engines. It has low viscosity at low temperatures, limited density and calorific value ranges, burns cleanly, and remains chemically stable even at high temperatures.
Aviation gasoline, commonly known as “avgas” or 100-LL (low-lead), is a specially refined type of gasoline for aircraft.
It is carefully formulated to ensure purity, prevent spark plug fouling, and provide excellent anti-knock properties. Avgas is designed to meet specific performance requirements for both take-off power settings, which require a richer fuel mixture, and cruise settings, where leaner mixtures are used to reduce fuel consumption.
It’s worth mentioning that aviation fuel cannot be used as compressed natural gas (CNG) fuel.The net energy content of aviation fuels varies depending on their composition. Here are some typical values:- BP Avgas 80: 44.65 MJ/kg, with a density of 690 kg/m3 at 15 °C (equivalent to 30.81 MJ per liter).- Kerosene type BP Jet A-1: 43.15 MJ/kg, with a density of 804 kg/m3 at 15 °C (equivalent to 34.69 MJ per liter).- Kerosene type BP Jet TS-1 (for lower temperatures): 43.2 MJ/kg, with a density of 787 kg/m3 at 15 °C (equivalent to 34.00 MJ per liter).
