Diesel fuel is a liquid specifically formulated for compression ignition engines where fuel ignites after air compression and fuel injection, as described in Wikipedia's Diesel fuel entry.
Most diesel is produced by fractional distillation of crude oil, yielding a middle distillate fraction, and refineries blend streams to meet demand, as reported by Wikipedia.
Alternatives to petroleum include biodiesel made by transesterifying vegetable oils and synthetic diesel produced from synthesis gas, and both are increasingly adopted, as noted by Wikipedia and the EIA.
Refinery yields vary, with US refineries producing about eleven to twelve gallons of diesel from a forty two gallon barrel of crude oil, as reported by the EIA.
Standards Uses And Composition
Diesel fuel quality is controlled by standards that set properties like cetane number, density, flash point, and sulfur limits, with European EN 590 and US ASTM D975 cited as examples in Wikipedia's article.
European road diesel typically has a minimum cetane number of fifty one under EN 590, and ultralow sulfur diesel has become the norm to cut harmful emissions, as reported by Wikipedia and the EIA.
Typical petroleum diesel contains mainly saturated hydrocarbons and about twenty five percent aromatics, with an average formula near C12H23, and it offers a high volumetric energy density, according to Wikipedia.
A simple carbon accounting estimate in Wikipedia calculates that burning one litre of diesel produces roughly 2.63 kilograms of carbon dioxide, based on fuel density and composition assumptions given in that article.
Diesel is widely used in heavy road vehicles, trains, buses, boats, farm and construction equipment, and in generators for remote and backup power, as reported by the EIA and Wikipedia.
Storage and handling notes in Wikipedia recommend distinctive container colors and warn of cold flow problems where diesel can gel at low temperatures, and they list additives and cold flow improvers used to manage those issues.
Wikipedia also documents that off road or untaxed fuels may be dyed and that microbial contamination can form at fuel water interfaces, potentially clogging filters and damaging injection equipment.
Both sources note that diesel exhaust, especially from older engines, can cause health damage, and that sulfur reductions in fuel have been implemented to reduce pollution, as reported by Wikipedia and the EIA.
