Fuels, oils and lubricants
diesel fuel, heating oil, gasoline, gas stations and fuel transport
Diesel fuel
Diesel fuel is a mixture of liquid hydrocarbons. It is produced through distillation and refining from crude oil, usually at temperatures between 150-370 °C. Diesel fuel quality is signified by acetane number that expresses its diesel characteristic.
Diesel fuel is required for the use of diesel engines.
Cetane number
A cetane number is a value marked by the abbreviation CČ or CN that indicates the quality of the diesel fuel in terms of its diesel characteristic. It indicates the amount of n-hexadecane (cetane) in volume percentages in a mixture with aromatic hydrocarbon 1-methylnaftalene that has the same diesel characteristic as a compared sample of the actual fuel (diesel fuel). A cetane number of zero then corresponds to diesel fuel with the same characteristics as pure methylnaphthalene; a cetane number 100 corresponds to pure cetane (hexadecane). The cetane number is then comparable with octane number in auto gasoline for spark ignition engines.
The higher the cetane number for diesel engines, the better the quality. Engines with direct injection in this case start better, demonstrate better performance, are quieter and smoother, and their exhaust gases contain less unwanted combustion by-products. As a result of better performance, fuel consumption decreases. This then leads to less of a burden on the environment.
Because cetane number fuel values have significant influence on environmental pollution, minimal values are prescribed by law regulations on a European Union level, as well as in national legislative regulations of the separate EU member states, including the Czech Republic. At present (at the beginning of 2006), current legislation allows the usage of diesel fuel in EU territory with a minimum cetane number value of 51.0, even if quite a few older vehicles with diesel engines work dependably using fuel of CN = 40.
Material here is based on information provided by Wikipedia