Diesel fuel
The most common type of diesel fuel is a specific fractional distillate of petroleum fuel oil, but alternatives that are not derived from petroleum, such as biodiesel, biomass to liquid (BTL) or gas to liquid (GTL) diesel are increasingly being developed and adopted.
As of 2016, almost all of the petroleum-based diesel fuel available in the United Kingdom, mainland Europe, and North America is of a ULSD type.
The official term for white diesel is DERV, standing for diesel-engine road vehicle.
Instead, he claimed that the operating principle of his rational heat motor would work with any kind of fuel in any state of matter.
[17] Only in December 1899, did Diesel test a coal-dust prototype, which used external mixture formation and liquid fuel pilot injection.
[18] This engine proved to be functional, but suffered from piston ring failure after a few minutes due to coal dust deposition.
[20] The introduction of motor-vehicle diesel engines, such as the Mercedes-Benz OM 138, in the 1930s meant that higher-quality fuels with proper ignition characteristics were needed.
Other sources include biomass, animal fat, biogas, natural gas, and coal liquefaction.
One major source of additional diesel fuel is obtained by cracking heavier fractions, using visbreaking and coking.
This technology converts less useful fractions but the product contains olefins (alkenes) which require hydrogenation to give the saturated hydrocarbons as desired.
[25] Synthetic diesel produced in this way generally is mainly paraffins with low sulfur and aromatics content.
[24] Biodiesel is obtained from vegetable oil or animal fats (biolipids) which are mainly fatty acid methyl esters (FAME), and transesterified with methanol.
In order to ensure consistent quality, diesel fuel is standardised; the first standards were introduced after World War II.
[32] A higher cetane number indicates that the fuel ignites more readily when sprayed into hot compressed air.
About 86.1% of diesel fuel mass is carbon, and when burned, it offers a net heating value of 43.1 MJ/kg as opposed to 43.2 MJ/kg for gasoline.
Diesel fuel, or marked gas oil is dyed green in the Republic of Ireland and Norway.
[40] Other states, such as North Carolina, tax biodiesel (in any blended configuration) the same as petrodiesel, although they have introduced new incentives to producers and users of all biofuels.
The introduction of petrol direct injection in the 1930s outweighed these advantages, and aircraft diesel engines quickly fell out of use.
On US farms during this era, the name "distillate" often referred to any of the aforementioned light fuel oils.
[49] Such use has been proposed as a means of separating the fission product palladium from PUREX raffinate which comes from used nuclear fuel.
[51] The advantage of using diesel is its low cost and its ability to drill a wide variety of difficult strata, including shale, salt and gypsum formations.
[32] Conventional diesel flash points vary between 52 and 96 °C, which makes it safer than petrol and unsuitable for spark-ignition engines.
[58] Unlike petrol, the flash point of a diesel fuel has no relation to its performance in an engine nor to its auto ignition qualities.
Putting everything together the mass of carbon dioxide that is produced by burning 1 liter of diesel fuel can be calculated as:
European emission standards and preferential taxation have forced oil refineries to dramatically reduce the level of sulfur in diesel fuels.
The limit was lowered with the introduction of Euro 4 by 2006 to 50 ppm (ULSD, Ultra Low Sulfur Diesel).
The standard for diesel fuel in force in Europe as of 2009 is the Euro 5, with a maximum content of 10 ppm.
[60] In the United States, more stringent emission standards have been adopted with the transition to ULSD starting in 2006, and becoming mandatory on June 1, 2010 (see also diesel exhaust).
[64] After the light fractions have evaporated, a greasy slick is left on the road which reduces tire grip and traction, and can cause vehicles to skid.
The loss of traction is similar to that encountered on black ice, resulting in especially dangerous situations for two-wheeled vehicles, such as motorcycles and bicycles, in roundabouts.
