This article is about the fuel. For other uses see diesel (disambiguation).

Diesel is a product used as a fuel in a diesel engine invented by Rudolf Diesel, and perfected by Charles F. Kettering.

Petrodiesel

One can obtain diesel from petroleum, which is called petrodiesel to distinguish it from diesel obtained from other sources. As a hydrocarbon mixture, it is obtained in the fractional distillation of crude oil between 250 °C and 350 °C at atmospheric pressure. Diesel is generally simpler to refine than gasoline and often costs less (though price fluctuations often mean that the inverse is true). However, diesel fuel often contains higher quantities of mineral compounds and sulfur. Emission standards in Europe have forced oil refineries to dramatically reduce the level of these impurities, resulting in a much cleaner-burning fuel that produces less soot. The United States has worked to reduce the emissions from gasoline-powered vehicles in the last few decades, but diesel engines have not been regulated as heavily. Diesel fuel in the U.S. is generally much less pure than European diesel, though the transition to ultra-low sulfur diesel (ULSD) will begin in 2006.

Reducing the level of sulfur in diesel is better for the environment, and it allows the use of more advanced catalytic converters to reduce emissions of oxides of nitrogen (NOx). However, this also reduces the lubricity of the fuel, meaning that additives must be put into the fuel to help lubricate engines.

Diesel contains approximately 18% more energy per unit of volume than gasoline, which along with the greater efficiency of diesel engines contributes to fuel economy (distance traveled per volume of fuel consumed).

In the Maritime field various grades of Diesel fuel are used from Gas Oil to Heavy Fuel Oil:

• Gas Oil - slightly less refined than Diesel for road usage.
• MDO (Marine Diesel Oil) - Thin Diesel, less refined than Gas Oil.
• IFO (Intermediate Fuel Oil)
• MFO (Medium Fuel Oil) - A mixture of HFO and MDO
• HFO (Heavy Fuel Oil) - Thick, viscous dark brown gunk. Requires heating to flow.

Biodiesel

Main article: Biodiesel

Biodiesel can be obtained from vegetable oil and animal fats (bio-lipids, using transesterification). Biodiesel is a non-fossil fuel alternative to petrodiesel. It can also be mixed with petrodiesel in any amount in modern engines, though it is a strong solvent and can cause problems in some cases. A small percentage of biodiesel can be used as an additive in low-sulfur formulations of diesel to increase lubricating ability.

Uses

Diesel is identical to heating oil, used in central heating. In both Europe and the United States taxes on diesel fuel are higher than on heating oil, and in those areas, heating oil is marked with dye and trace chemicals to prevent and detect tax fraud.

Diesel is used in diesel engines (cars, boats, motorbikes...), a type of internal combustion engine. Rudolf Diesel originally designed the diesel engine to use coal dust as a fuel, but oil proved more effective.

Packard diesel motors were used in aircraft as early as 1927, and Charles Lindbergh flew a Stinson SM1B with a Packard Diesel in 1928. A Packard diesel motor designed by L.M. Woolson was fitted to a Stinson X7654, and in 1929 it was flown 1000 km non-stop from Detroit to Langley, VA. In 1931, Walter Lees and Fredrick Brossy set the nonstop flight record flying a Bellanca powered by a Packard Diesel for 84h 32m.

The first diesel-engine automobile trip was completed on January 6, 1930. The trip was from Indianapolis to New York City - a distance of nearly 800 miles (1300 km). This feat helped to prove the usefulness of the internal combustion engine.

See also

• Liquid fuels

External links

• Can I use diesel fuel instead of regular gas? (http://www.straightdope.com/mailbag/mdieselvsgas.html) (from The Straight Dope)