Rudolf Diesel's invention of the compression-ignition engine in 1892 revolutionized the way we use fuel. Since then, diesel engines have been used in a variety of applications, from passenger cars to military vehicles and maritime vessels. But what materials are used to construct modern-day diesel engines?The most common type of diesel fuel is a fractionated distillate specific to petroleum fuel oil. However, more and more alternatives that are not derived from petroleum are being developed and adopted, such as biodiesel, biomass-to-liquid (BTL) diesel, or diesel to liquid (GTL).
Before diesel fuel was standardized, most diesel engines used to run on cheap fuel oils. In India, taxes on diesel fuel are lower than on gasoline, since most of the transportation of cereals and other essential products across the country is carried out with diesel. In maritime vessels, where diesel propulsion had gained ground in the late 1970s due to the increase in fuel costs caused by the energy crisis of the 1970s, cheap heavy fuel oils are still used instead of conventional diesel fuel for motor vehicles. Despite being specifically designed for diesel engines, diesel fuel can also be used as fuel for several non-diesel engines, for example the Akroyd engine, the Stirling engine or the boilers of steam engines. During its first tests with diesel engines, Diesel also used illuminating gas as fuel and managed to build functional designs, with and without pilot injection. Since diesel fuel is not suitable for Otto engines, passenger cars, which usually use Otto or Otto derivatives, usually run on gasoline instead of diesel fuel.
Since World War II, several military vehicles have been manufactured with diesel engines, capable of running on diesel fuel. This category of diesel fuels involves the conversion of triglycerides from vegetable oil and animal fats into alkanes through refining and hydrogenation, such as Neste Renewable Diesel or H-Bio. There is little need to use diesel fuel in aircraft, and diesel fuel is not used commercially as an aviation fuel. Modern-day diesel engines are constructed using a variety of materials. The most common materials used include petroleum-based fuels such as fractionated distillates and heavy fuel oils; alternative fuels such as biodiesel, biomass-to-liquid (BTL) diesel, or diesel to liquid (GTL); illuminating gas; and triglycerides from vegetable oil and animal fats.