Diesel is a fuel that is used in diesel engines. It is an essential part of the four stroke cycle that
provides the engine with power. Atomised diesel fuel is ignited by compression in the cycle. It is one
of three main fuel types - the others being gasoline and kerosene - that are used to power a number of
machines from automobiles to factory machinery and even aircraft. The majority of these fuels derive from
crude oil. Diesel is generally used for engines that require more push over a longer period of time.
Ultra-low Sulphur Diesel & Alternatives
Diesel is available in a variety of forms. The most common is that which is derived from petroleum. This
is used almost exclusively across America and Europe and is referred to as ULSD (Ultra-low Sulphur Diesel).
This is because of its much lower sulphur contents, when compared to other diesel types. Biodiesel, BTL
(biomass to liquid) and GTL (gas to liquid) are three other variants. These alternatives are becoming
popular and being adapted amidst concern for the environment.
Biodiesel
Biodiesel is made from vegetable oil or animal fat and is, as such, much more environmentally friendly
than regular petrol-diesel. It burns a lot cleaner and so leaves fewer hydrocarbons. It's also bio-degradable,
free of aromatics, produces less carbon dioxide and is non-toxic. It is currently being integrated into the
modern automobile world but is being used in conjunction with petrol-diesel at the moment. This is due to the
diesel engines of today struggling to keep up with this new branch of diesel. It certainly looks to be the
prominent diesel fuel of the future though.
Composition
Approximately 18% heavier than gasoline, diesel is made up of a composition of hydrocarbons that is much higher
than other fuels. The hydrocarbons can have anything from about 10 to 25 carbon atoms attached (C10-C25).
Gasoline is rarely more than C10, and kerosene not usually more than C15. The number of carbon atoms determines
how heavy the fuel is. How heavy a fuel is can have an effect on its performance during extreme weather, so it
is important that it is distilled correctly during production. Diesel fuel is lighter than petroleum-based oils.