Why Do Aircraft Engines Use Kerosene?
4 Answers
Aircraft engines do not use gasoline or diesel because gasoline is a volatile substance with a low flash point and rapid combustion. Below is an introduction to why aircraft engines avoid gasoline and diesel: 1. Kerosene has a higher specific gravity, allowing it to store more heat and weight, and it is not as volatile as gasoline. Since aircraft have limited fuel-carrying capacity, using kerosene is more economical and durable. Additionally, kerosene is safer than gasoline and can be better atomized in turbine engines, ensuring more stable combustion. Considering these factors, aircraft use kerosene as fuel. 2. During high-speed flight, aircraft inevitably generate heat through friction with the air, which would cause gasoline to evaporate more quickly. A mid-flight fuel shortage would have severe consequences. Diesel, on the other hand, is too viscous. While it can be used in compression-ignition engine aircraft, it is not easily atomized and sprayed in the more common turbine engines, making combustion more difficult.
Aviation engines choose kerosene as fuel primarily because of its high energy density, which allows a small amount of fuel to store enormous energy, enabling aircraft to fly farther and longer. Compared to gasoline, kerosene is less prone to freezing in low-temperature, high-altitude environments. For example, it remains stable at altitudes of 10,000 meters where temperatures drop below zero, reducing the risk of mid-flight malfunctions. As I often mention in discussions, this is particularly crucial for long-haul flights, as reducing aircraft weight saves fuel and minimizes landing frequency. Kerosene also burns more efficiently, producing less carbon buildup and extending engine lifespan. Early experiments used gasoline, but its high volatility made it prone to ground fires, whereas kerosene is much safer. Today, jet engines universally use this fuel, striking the best balance between economy and performance.
I use kerosene in aircraft engines because it is safer and more reliable than gasoline. Kerosene has lower volatility, making it less prone to combustion or explosion under high-pressure conditions, and it maintains good stability during altitude changes, reducing in-flight emergencies. I recall a report stating that an airline saw a drop in accident rates after switching to kerosene due to its higher flash point, which requires more heat to ignite. Gasoline poses risks during storage or refueling due to its tendency to vaporize, whereas kerosene avoids this issue. Additionally, its energy content is comparable to gasoline, making it suitable for propelling aircraft at high speeds. Experts prioritize this during design, especially for international flights requiring long-duration operation. Environmentally, kerosene is easier to store and transport than hydrogen fuel, and existing infrastructure supports its adoption as a global standard.
The key to aviation kerosene lies in its chemical properties. With a moderate boiling point, kerosene neither boils nor evaporates at high temperatures, nor freezes in cold conditions, maintaining stable liquid form within aircraft operational temperature ranges. This ensures smooth fuel flow for engine combustion. Post-combustion residue is minimal, reducing engine clogging and maintenance needs. Its high energy output efficiently supports jet thrust for sustained cruising. Having tested several fuels, I found kerosene optimally balances safety, cost, and performance.
