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Diesel

Diesel

:This article is about the fuel. For other uses see diesel (disambiguation) Diesel or Diesel fuel is a specific fractional distillate of fuel oil (mostly petroleum) that is used as fuel in a diesel engine invented by German engineer Rudolf Diesel. The term typically refers to fuel that has been processed from petroleum, but increasingly, alternatives such as biodiesel or biomass to liquid (BTL) or gas to liquid (GTL) diesel that are not derived from petroleum are being developed.

Petroleum diesel

gas to liquid Diesel is produced from petroleum, and is sometimes called petrodiesel (or, less seriously, dinodiesel) when there is a need 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. Petro Diesel is considered to be a fuel oil and is about 18% heavier than gasoline. Diesel typically weighs about 7.1 pounds (lb) per US gallon (gal.) (850 grams per liter (g/l)), whereas gasoline weighs about 6.0 lb per US gal. (720 g/l), or about 15% less. When burnt diesel typically releases about 147,000 British thermal units (BTU) per US gal. (40.9 megajoules (MJ) per liter), whereas gasoline releases 125,000 BTUs per US gal. (34.8 MJ/l), also about 15% less. Diesel is generally simpler to refine than gasoline and often costs less (although price fluctuations often mean that the inverse is true; for example, the cost of diesel traditionally rises during colder months as demand for heating oil, which is refined much the same way, rises). Diesel fuel, however, often contains higher quantities of sulfur. In Europe, emission standards and preferential taxation have both forced oil refineries to dramatically reduce the level of sulfur in diesel fuels. In contrast, the United States has long had "dirtier" diesel, although more stringent emission standards have been adopted with the transition to ultra-low sulfur diesel (ULSD) occurring in 2006 (see also diesel exhaust). US diesel fuel typically also has a lower cetane number (a measure of ignition quality) than European diesel, resulting in worse cold weather performance and some increase in emissions. High levels of sulfur in diesel are harmful for the environment. It prevents the use of catalytic diesel particulate filters to control diesel particulate emissions, as well as more advanced technologies, such as nitrogen oxide (NOx) adsorbers (still under development), to reduce emissions. However, lowering sulfur also reduces the lubricity of the fuel, meaning that additives must be put into the fuel to help lubricate engines. Biodiesel is an effective lubricity additive. 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.

Chemical composition

Petroleum derived diesel is composed of about 75% saturated hydrocarbons (primarily paraffins including n, iso, and cycloparaffins), and 25% aromatic hydrocarbons (including naphthalenes and alkylbenzenes).

Synthetic diesel

Wood, straw, corn, garbage, and sewage-sludge may be dried and gasified. After purification the so called Fischer Tropsch process is used to produce synthetic diesel. Other attempts use enzymatic processes and are also economic in case of high oil prices. Synthetic diesel may also be produced out of natural gas in the GTL process. Such synthetic diesel has 30% less particulate emissions than conventional diesel (US- California) .

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. There have been reports that a diesel-biodiesel mix results in lower emissions than either can achieve alone. A small percentage of biodiesel can be used as an additive in low-sulfur formulations of diesel to increase the lubricating ability that is lost when the sulfur is removed. Chemically, biodiesel consists of alkyl (usually methyl) esters instead of the alkanes and aromatic hydrocarbons of petroleum derived diesel. However, biodiesel has combustion properties very similar to regular diesel, including combustion energy and cetane ratings.

Uses

Diesel fuel is very similar to heating oil which 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. Similarly, "untaxed" diesel is available in the United States, which is available for use primarily in agricultural applications such as for tractor fuel. This untaxed diesel is also dyed red for identification purposes, and should a person be found to be using this untaxed diesel fuel for a typically taxed purpose (such as "over-the-road", or driving use), the user can be fined $10,000 USD on the spot. Also, in the United Kingdom and Ireland it is known as red diesel, and is also used by agricultural vehicles. The term DERV (short for "diesel engined road vehicle") is also used in the UK as a synonym for diesel fuel. Diesel is used in diesel engines, 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. Diesel engines are used in cars, trucks, motorcycles, boats and locomotives. 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, Virginia (near Washington, D.C.). In 1931, Walter Lees and Fredrick Brossy set the nonstop flight record flying a Bellanca powered by a Packard Diesel for 84h 32m. The very 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. The following year Dave Evans drove his Cummins Diesel Special to a nonstop finish in the Indianapolis 500, the first time a car had completed the race without a pit stop. That car and a later Cummins Diesel Special are on display at the Indianapolis Motor Speedway Hall of Fame Museum. Westport claims to have invented a process called Westport-Cycle with comparable efficiency using natural gas and petrodiesel.

Notes

# Agency for Toxic Substances and Disease Registry (ATSDR). 1995. [http://www.atsdr.cdc.gov/toxprofiles/tp75-c3.pdf Toxicological profile for fuel oils]. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service # # # #

External links

- [http://www.straightdope.com/mailbag/mdieselvsgas.html Can I use diesel fuel instead of regular gas?] (from The Straight Dope)
- [http://www.dieselnet.com/standards/fuels/us.html DieselNet.com: US Diesel Fuel]
- [http://www.greencarcongress.com/2005/07/opel_offers_par.html Opel announces particulate filter] Category:Petroleum products category:engine technology Category:Solvents Category:German loanwords ko:경유 ja:軽油

Diesel (disambiguation)

Diesel has several possible meanings:
- Diesel, the fuel-type
- Diesel engine
- Diesel cycle
- Diesel multiple unit
- Diesel exhaust
- Devious Diesel, a character in Thomas the Tank Engine and Friends
- Diesel (clothing company)
- Diesel (band), Dutch band that sang the 1981 hit Sausalito Summernights ;People:
- Rudolf Diesel, German engineer who invented the diesel engine
- Vin Diesel, American actor
- Johnny Diesel, Australian rock singer
- Professional wrestlers Kevin Nash, and later Glen Jacobs ;Diesel oil
- Diesel, the fuel-type
- Lubrication oil for use in diesel engines

Fractional distillation

Fractional distillation is the separation of a mixture of compounds by their boiling point, by heating to high enough temperatures. boiling point

Fractional Distillation in a Laboratory

Apparatus

- round bottom flask
- conical flask
- fractionating column
- liebig condenser
- graham condenser
- alhin condenser
- thermometer
- anti-bumping granules
- rubber bungs (unless quickfit apparatus is used)

Method

As an example, consider the distillation of a mixture of water and ethanol. Ethanol boils at 78.5°C whilst water boils at 100°C. So by gently heating the mixture, the most volatile component will boil off first. Some mixtures form azeotropes, where the mixture boils at a lower temperature than either component. In this example, a mixture of 95% ethanol and 5% water boils at 78.2°C, being more volatile than pure ethanol, so the ethanol cannot be completely purified by distillation. The apparatus is assembled as in the diagram. The mixture is put into the round bottomed flask along with a few anti bumping granules, and the fractionating column is fitted into the top. As the mixture boils, vapor rises up the column. The vapor condenses on the glass platforms, known as trays, inside the column, and runs back down into the liquid below, refluxing distillate. The column is heated from the bottom. The hottest tray is at the bottom the coolest is at the top. At steady state conditions the vapor and liquid on each tray is at equilibrium. Only the most volatile of the vapors stays in gaseous form all the way to the top. The vapor at the top of the column, then passes into the condenser, which cools it down until it liquefies. The separation is more pure with the addition of more trays (to a practical limitation of heat, flow, etc.) The condensate that was initially very close to the azeotrope composition becomes gradually richer in water. The process continues until all the ethanol boils out of the mixture. This point can be recognized by the sharp rise in temperature shown on the thermometer. The Liebig condenser is characterized by a straight tube within a water jacket construction, it is the simplest form of condenser. The Graham condenser is a spiral tube within a water jacket, and the Alhin condensor is a series of large and small constrictions on the inside tube, each increasing the surface area that the vapor constituents may condense upon. Being more complex shapes to manufacture they are more expensive to purchase, hence condensors are usually sold by the mm: 100, 200, and 400 mm are common lengths and are connected to the other vessels with ground glass fittings.

Industrial uses of Fractional Distillation

Main article: Oil refinery Distillation is the most common form of separation technology in the chemical industry. In most chemical processes, the distillation is continuous steady state. New feed is always being added to the distillation column and products are always being removed. Unless the process is disturbed due to changes in feed, heat, ambient temperature, or condensing, the amount of feed being added and the amount of product being removed are normally equal. This is known as continuous steady state fractional distillation. The most important industrial application of continuous steady state fractional distillation is the distillation of crude oil. The process is similar in principle to the laboratory method described above except for scale, continuous feed and operation, and the fact that crude oil has many different compounds mixed together. The fractionating column has outlets at regular intervals up the column which allow the different fractions to run out at different temperatures, with the highly volatile gases coming out the topmost outlet graduating to the less volatile road tar (bitumen) coming out at the bottom. Fractional distillation process is also used in air separation, producing liquid oxygen, liquid nitrogen, and high purity argon. Distillation of chlorosilanes also enable the production of high-purity silicon for use as a semiconductor. In industrial uses, sometimes a packing material is used in the column instead of trays. The packing material is normally small equally shaped pieces that are poured into the column. Liquid and vapor pass between the pieces of packing in the column. The vapor pressure keeps the liquid suspended in the packing material as the vapors bubble through the liquid. Unlike conventional tray distillation in which every tray represents a separate point of vapor liquid equilibrium, the vapor liquid equilibrium curve in a packed column is continuous. However, when modeling packed columns it is useful to compute a number of "theoretical trays" to denote the separation efficiency of the packed column with respect to more traditional trays. Differently shaped packings have different of surface area and void space between packings. Both of these factors affect packing performance.

Fuel oil

Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking, fuel oil is any liquid petroleum product that is burned in a furnace for the generation of heat or used in an engine for the generation of power, except oils having a flash point of approximately 100 °F (about 40 °C) and oils burned in cotton or wool-wick burners. In this sense, diesel is a type of fuel oil. Fuel oil is made of long hydrocarbon chains, particularly alkanes, cycloalkanes and aromatics. Factually and in a stricter sense, the term fuel oil is used to indicate the heaviest commercial fuel that can be obtained from crude oil, heavier than gasoline and naphtha.

Six Classes

Fuel oil is classified into six classes, according to its boiling temperature, composition and purpose. The boiling point, ranging from 370 to 600 °C, and carbon chain length, 20 to 70 atoms, of the fuel increases with number. Viscosity also increases with fuel oil number and the heaviest oil has to be heated to get it to flow. Price usually decreases as the fuel number increases. No. 1 fuel oil, No. 2 fuel oil and No. 3 fuel oil are referred to as distillate fuel oils, diesel fuel oils, light fuel oils, gasoil or just distillate. For example, No. 2 fuel oil, No. 2 distillate and No. 2 diesel fuel oil are the same thing. Distillate fuel oils are distilled from crude oil. Gas oil refers to the process of distillation. The oil is heated, becomes a gas and then condenses. It differentiates distillates from residual oil. No. 1 is similar to kerosene and is the fraction that boils off right after gasoline. No. 2 is the diesel that trucks and some cars run on, leading to the name "road diesel". It is the same thing as heating oil. No. 3 is rarely used. No. 5 fuel oil and No. 6 fuel oil are called residual fuel oils or heavy fuel oils. However, since No. 6 is far more common than No. 5, the terms heavy fuel oil and residual fuel oil are sometimes used as synonyms for No. 6. They are what remains of the crude oil after gasoline and the distillate fuel oils are extracted through distillation, but No. 5 contains a little distillate fuel oil and even No. 6 may contain a small amount to get it to meet specifications. No. 4 fuel oil is usually a blend of distillate and residual fuel oils, such as No. 2 and 6, however, sometimes it is just a heavy distillate. No. 4 may be called classified as diesel, distillate or residual fuel oil. Residual fuel oils are sometimes called "light" when they have been mixed with distillate fuel oil. Bunker fuel is technically any type of fuel oil used aboard ships. It gets its name from the containers on ships and in ports that it is stored in, called bunkers. Bunker A is No. 2 fuel oil, bunker B is No. 4 or No. 5 and bunker C is No. 6. Since No. 6 is the most common, "bunker fuel" is often used as a synonym for No. 6. No. 5 fuel oil is also called navy special fuel oil, or just navy special.

Uses

Diesel has many uses. It heats homes and businesses and fuels trucks, ships and some cars. A small amount of electricity is produced by diesel, but it is dirtier and more expensive than natural gas. It is often used as a backup fuel for peaking power plants in case the supply of natural gas is interrupted or as the main fuel for small electrical generators. Residual fuel oil is less useful because it is so viscous that it has to be heated, which requires a special heating system, before use and it contains relatively high amounts of pollutants, particularly sulfur, which forms sulfur dioxide upon combustion. However, its undesirable properties make it very cheap. In fact, it is the cheapest liquid fuel available. Since it requires heating before use, residual fuel oil cannot be used in road vehicles, boats or small ships, as the heating equipment takes up valuable space and makes the vehicle heavier. Heating the oil is also a delicate procedure, which is inappropriate to do on small, fast moving vehicles. However, power plants and large ships are able to use residual fuel oil. Residual fuel oil was used more frequently in the past. It powered boilers, railroad locomotives and steamships. Locomotives now use diesel, steamships are no longer in use, and most boilers now use heating oil or natural gas. However, some industrial boilers still use it and so do a few old buildings, mostly in New York City. Residual fuel's use in electricity generation has also decreased. In 1973, residual fuel oil produced 16.8% of the electricity in the United States. By 1983, it had fallen to 6.2%, and as of 2005, electricity production from all forms of petroleum, including diesel and residual fuel, is only 3% of total production. The decline is the result of price competition with natural gas and environmental restrictions on emissions. For power plants, the costs of heating the oil, extra pollution control and additional maintenance required after burning it often outweigh the low cost of the fuel. Burning fuel oil, particularly residual fuel oil, also produces much darker smoke than natural gas, which affects the perception of the plant by the community.

Maritime

In the maritime field another type of classification is used for fuel oils:
- MGO (Marine gasoil) - roughly equivalent to No. 2 fuel oil, made from distillate only
- MDO (Marine diesel oil) - A blend of gasoil and heavy fuel oil
- IFO (Intermediate fuel oil) A blend of gasoil and heavy fuel oil, with less gasoil than marine diesel oil
- MFO (Medium fuel oil) - A blend of gasoil and heavy fuel oil, with less gasoil than intermediate fuel oil
- HFO (Heavy fuel oil) - Pure or nearly pure residual oil, roughly equivalent to No. 6 fuel oil

Transportation

Fuel oil is transported using fuel oil barges and pipelines. The major physical supply chains of Europe are centered around the Rhine, Germany.

Sources

- [http://www.nature.nps.gov/hazardssafety/toxic/fueloil.pdf National Park Service - Fuel Oil]
- [http://science.howstuffworks.com/oil-refining2.htm How Stuff Works - Oil Refining]
- [http://www.pseg.com/customer/business/industrial/convert/cost.jsp The True Cost of #6 Oil]
- [http://energyconcepts.tripod.com/energyconcepts/heavy_oil.htm Burning #6 Fuel Oil] Category:Petroleum products Category:Oils

Petroleum

]] Petroleum (from Latin petra – rock and oleum – oil), crude oil, sometimes colloquially called black gold, is a thick, dark brown or greenish liquid. A widely believed myth is that the oil itself is flammable; however, it is actually the gas that evaporates from the oil that is flammable. Petroleum exists in the upper strata of some areas of the Earth's crust. Another name is naphtha, from Persian naft or nafátá (to flow). It consists of a complex mixture of various hydrocarbons, largely of the alkane series, but may vary much in appearance, composition, and purity. Petroleum is used mostly, by volume, for producing fuel oil, which is an important "primary energy" source ([http://www.iea.org/bookshop/add.aspx?id=144 IEA Key World Energy Statistics]). Petroleum is also the raw material for many chemical products, including solvents, fertilizers, pesticides, and plastics.

Origin

Biogenic theory

Most geologists view crude oil, like coal and natural gas, as the product of compression and heating of ancient vegetation over geological time scales. According to this theory, it is formed from the decayed remains of prehistoric marine animals and terrestrial plants. Over many centuries this organic matter, mixed with mud, is buried under thick sedimentary layers of material. The resulting high levels of heat and pressure cause the remains to metamorphose, first into a waxy material known as kerogen, and then into liquid and gaseous hydrocarbons in a process known as catagenesis. These then migrate through adjacent rock layers until they become trapped underground in porous rocks called reservoirs, forming an oil field, from which the liquid can be extracted by drilling and pumping. 150 °C is generally considered the "oil window". Though this corresponds to different depths for different locations around the world, a 'typical' depth for an oil window might be 4 - 5 km. Three conditions must be present for oil reservoirs to form: a rich source rock, a migration conduit, and a trap (seal) that forms the reservoir. The reactions that produce oil and natural gas are often modeled as first order breakdown reactions, where kerogen breaks down to oil and natural gas by a large set of parallel reactions, and oil eventually breaks down to natural gas by another set of reactions.

Abiogenic Theory

The idea of abiogenic petroleum origin was championed in the Western world by Thomas Gold based on thoughts from Russia, mainly on studies of Nikolai Kudryavtsev. The idea proposes that large amounts of carbon exist naturally in the planet, some in the form of hydrocarbons. Hydrocarbons are less dense than aqueous pore fluids, and migrate upward through deep fracture networks. Thermophilic, rock-dwelling microbial life-forms are in part responsible for the biomarkers found in petroleum. However, their role in the formation, alteration, or contamination of the various hydrocarbon deposits is not yet understood. Thermodynamic calculations and experimental studies confirm that n-alkanes (common petroleum components) do not spontaneously evolve from methane at pressures typically found in sedimentary basins, and so the theory of an abiogenic origin of hydrocarbons suggests deep generation (below 200 km) (see results [http://www.gasresources.net/]). As with any petroleum, the idea goes, these hydrocarbons would migrate upwards with methane, sometimes bearing helium and nitrogen and frequently heavy metals such as Nickel, Vanadium, Arsenic, Lead, Cadmium, Copper, Zinc, Mercury and others. Diamondoids are common in oil and gas and its nature probably is related to natural diamonds that come from earth's mantle. The proponents of abiogenic petroleum claim that reserves are never exhausted because they are filled from below. This idea has not been supported by any critically reviewed research. It has been widely discredited by scientists and geologists alike. Also, even if oil fields can be replenished from abiotic deposits that exist deeper within the earth, it would be very near impossible that they could be replenished at current rates of depletion, future rates aside. It would certainly take many thousands if not millions of years for oil fields to regain original levels.

Composition

In refining, the component chemicals of petroleum are separated by fractional distillation, which is a separation based on relative boiling points (or equivalently relative volatility). The different products (in order of boiling points) include light gases (e.g. methane, ethane, propane), gasoline, jet fuel, kerosene, diesel, gasoil, paraffin wax, and asphalt. Subtler techniques, such as gas chromatography, HPLC, and GC-MS, can separate some fractions of petroleum into individual compounds; these are analytical chemistry methods used mainly in quality control in refineries. Strictly speaking, petroleum consists of hydrocarbons (compounds of hydrogen and carbon) and non-hydrocarbon fractions, which might also include nitrogen, sulfur, oxygen, or traces of metals such as vanadium or nickel, such elements often constituting less than 1% of the whole. The four lightest alkanes — CH₄ (methane), C₂H₆ (ethane), C₃H₈ (propane) and C₄H₁₀ (butane) — are all gases, boiling at -161.6 °C, -88.6 °C, -42 °C, and -0.5 °C, respectively (-258.9°, -127.5°, -43.6°, and +31.1° F). Crude oil is non-polar. The chains in the C_5-7 range are all light, easily vaporized, clear naphthas. They are used as solvents, dry cleaning fluids, and other quick-drying products. The chains from C₆H₁₄ through C₁₂H₂₆ are blended together and used for gasoline. Kerosene is made up of chains in the C₁₀ to C₁₅ range, followed by diesel fuel/heating oil (C₁₀ to C₂₀) and heavier fuel oils as the ones used in ship engines. These petroleum compounds are all liquid at room temperature. Lubricating oils and semi-solid greases (including Vaseline®) range from C₁₆ up to C₂₀. Chains above C₂₀ form solids, starting with paraffin wax, then tar and asphaltic bitumen. Boiling ranges of petroleum atmospheric pressure distillation fractions in degrees Celsius:
- petrol ether: 40 - 70 °C (used as solvent)
- light petrol: 60 - 100 °C (gasoline)
- heavy petrol: 100 - 150 °C (automobile fuel)
- light kerosene: 120 - 150 °C (household solvent and fuel)
- kerosene: 150 - 300 °C (jet fuel)
- gasoil: 250 - 350 °C (diesel fuel/heating oil)
- lubrication oil: > 300 °C (engine oil)
- remaining fractions: tar, asphalt, residual fuel

Extraction

Generally the first stage in the extraction of crude oil is to drill a well into the underground reservoir. Historically, in the USA some oil fields existed where the oil rose naturally to the surface, but most of these fields have long since been depleted, except for certain remote locations in Alaska. Often many wells (called multilateral wells) will be drilled into the same reservoir, to ensure that the extraction rate will be economically viable. Also, some wells (secondary wells) may be used to pump water, steam, acids or various gas mixtures into the reservoir to raise or maintain the reservoir pressure, and so maintain an economic extraction rate. If the underground pressure in the oil reservoir is sufficient, then the oil will be forced to the surface under this pressure. Gaseous fuels or natural gas are usually present, which also supplies needed underground pressure. In this situation it is sufficient to place a complex arrangement of valves (the Christmas tree) on the well head to connect the well to a pipeline network for storage and processing. This is called primary oil recovery. Usually, only about 20% of the oil in a reservoir can be extracted this way. Over the lifetime of the well the pressure will fall, and at some point there will be insufficient underground pressure to force the oil to the surface. If economical, and it often is, the remaining oil in the well is extracted using secondary oil recovery methods (see: energy balance and net energy gain). Secondary oil recovery uses various techniques to aid in recovering oil from depleted or low-pressure reservoirs. Sometimes pumps, such as beam pumps and electrical submersible pumps (ESPs), are used to bring the oil to the surface. Other secondary recovery techniques increase the reservoir's pressure by water injection, natural gas reinjection and gas lift, which injects air, carbon dioxide or some other gas into the reservoir. Together, primary and secondary recovery allow 25% to 35% of the reservoir's oil to be recovered. Tertiary oil recovery reduces the oil's viscosity to increase oil production. Tertiary recovery is started when secondary oil recovery techniques are no longer enough to sustain production, but only when the oil can still be extracted profitably. This depends on the cost of the extraction method and the current price of crude oil. When prices are high, previously unprofitable wells are brought back into production and when they are low, production is curtailed. Thermally-enhanced oil recovery methods (TEOR) are tertiary recovery techniques that heat the oil and make it easier to extract. Steam injection is the most common form of TEOR, and is often done with a cogeneration plant. In this type of cogeneration plant, a gas turbine is used to generate electricity and the waste heat is used to produce steam, which is then injected into the reservoir. This form of recovery is used extensively to increase oil production in the San Joaquin Valley, which has very heavy oil, yet accounts for 10% of the United States' oil production. In-situ burning is another form of TEOR, but instead of steam, some of the oil is burned to heat the surrounding oil. Occasionally, detergents are also used to decrease oil viscosity. Tertiary recovery allows another 5% to 15% of the reservoir's oil to be recovered.

Alternate means of producing oil

As oil prices continue to escalate, other alternatives to producing oil have been gaining importance. The most viable of these is the coal to oil process, known as the Fischer-Tropsch process, that aims to convert coal into crude oil. It was a concept pioneered in Nazi Germany when imports of petroleum were restricted due to war and Germany found a method to extract oil from coal. It was known as Ersatz ("substitute" in German), and accounted for nearly half the total oil used in WWII by Germany. However, the process was used only as a last resort as naturally occurring oil was much cheaper. As crude oil prices increase, the cost of coal to oil conversion becomes comparatively cheaper. The method involves converting high ash coal into synthetic oil in a multistage process. Ideally, a ton of coal produces nearly 200 liters of crude, with by-products ranging from tar to rare chemicals. Currently, two companies have commercialised their Fischer-Tropsch technology. [http://www.shell.com.my/smds Shell] in Bintulu, Malaysia, uses natural gas as a feedstock, and produces primarily low-sulfur diesel fuels. [http://www.sasol.com Sasol] in South Africa uses coal as a feedstock, and produces a variety of synthetic petroleum products. The process is today used in South Africa to produce most of the country's diesel fuel from coal by the company Sasol. The process was used in South Africa to meet its energy needs during its isolation under Apartheid. This process has received renewed attention in the quest to produce low sulfur diesel fuel in order to minimize the environmental impact from the use of diesel engines.

History

The first oil wells were drilled in China in the 4th century or earlier. They had depth of up to 800 feet and were drilled using bits attached to bamboo poles. The oil was burned to evaporate brine and produce salt. By the 10th century, extensive bamboo pipelines connected oil wells with salt springs. Ancient Persian tablets indicate the medicinal and lighting uses of petroleum in the upper echelons of their society. In the 8th century, the streets of the newly-constructed Baghdad were paved with tar, derived from easily-accessible petroleum from natural fields in the region. In the 9th century, oil fields were exploited in Baku, Azerbaijan, to produce naphtha. These fields were described by the geographer Masudi in the 10th century, and by Marco Polo in the 13th century, who described the output of those wells as hundreds of shiploads. (See also: Timeline of Islamic science and technology.) The modern history of oil began in 1853, with the discovery of the process of oil distillation. Crude oil was distilled into kerosene by Ignacy Lukasiewicz, a Polish scientist. The first "rock oil" ("petr-oleum") mine was created in Bobrka, near Krosno in southern Poland in the following year and the first refinery (actually a distillery) was built in Ulaszowice, also by Lukasiewicz. These discoveries rapidly spread around the world, and Meerzoeff built the first Russian refinery in the mature oil fields at Baku in 1861. 1861 by Russian engineer F.N. Semyenov, on the Aspheron Peninsula north-east of Baku.38]] The first commercial oil well drilled in North America was in Oil Springs, Ontario, Canada in 1858, dug by James Miller Williams. The American petroleum industry began with Edwin Drake's discovery of oil in 1859, near Titusville, Pennsylvania. The industry grew slowly in the 1800s, driven by the demand for kerosene and oil lamps. It became a major national concern in the early part of the 20th century; the introduction of the internal combustion engine provided a demand that has largely sustained the industry to this day. Early "local" finds like those in Pennsylvania and Ontario were quickly exhausted, leading to "oil booms" in Texas, Oklahoma, and California. By 1910, significant oil fields had been discovered in Canada (specifically, in the province of Alberta), the Dutch East Indies (1885, in Sumatra), Persia (1901, in Masjed Soleiman), Peru, Venezuela, and Mexico, and were being developed at an industrial level. Even until the mid-(1950s), coal was still the world's foremost fuel, but oil quickly took over. Following the 1973 energy crisis and the 1979 energy crisis there was significant media coverage of oil supply levels. This brought to light the concern that oil is a limited resource that will eventually run out, at least as an economically viable energy source. At the time, the most common and popular predictions were always quite dire, and when they did not come true, many dismissed all such discussion. The future of petroleum as a fuel remains somewhat controversial. USA Today news (2004) reports that there are 40 years of petroleum left in the ground. Some would argue that because the total amount of petroleum is finite, the dire predictions of the 1970s have merely been postponed. Others argue that technology will continue to allow for the production of cheap hydrocarbons and that the earth has vast sources of unconventional petroleum reserves in the form of tar sands, bitumen fields and oil shale that will allow for petroleum use to continue for an extremely long period in the future. Today, about 90% of vehicular fuel needs are met by oil. Petroleum also makes up 40% of total energy consumption in the United States, but is responsible for only 2% of electricity generation. Petroleum's worth as a portable, dense energy source powering the vast majority of vehicles and as the base of many industrial chemicals makes it one of the world's most important commodities. Access to it was a major factor in several military conflicts, including World War II and the Persian Gulf War. About 80% of the world's readily accessible reserves are located in the Middle East, with 62.5% coming from the Arab 5: Saudi Arabia (12.5%), UAE, Iraq, Qatar and Kuwait. The USA has less than 3%.

Environmental effects

The presence of oil has significant social and environmental impacts, from accidents and routine activities such as seismic exploration, drilling, and generation of polluting wastes. Oil extraction is costly and sometimes environmentally damaging, although Dr. John Hunt from Woods Hole pointed out in a 1981 paper that over 70% of the reserves in the world are associated with visible macroseepages, and many oil fields are found due to natural leaks. Offshore exploration and extraction of oil disturbs the surrounding marine environment. Extraction may involve dredging, which stirs up the seabed, killing the sea plants that marine creatures need to survive. Crude oil and refined fuel spills from tanker ship accidents have damaged fragile ecosystems in Alaska, the Galapagos Islands, Spain, and many other places. Burning oil releases carbon dioxide into the atmosphere, which contributes to global warming. Per energy unit, oil produces less CO2 than coal, but more than natural gas. However, oil's unique role as a transportation fuel makes reducing its CO₂ emissions a particularly thorny problem; amelioration strategies such as carbon sequestering are generally geared for large power plants, not individual tailpipes. Renewable energy source alternatives do exist, although the degree to which they can replace petroleum and the possible environmental damage they may cause are uncertain and controversial. Sun, wind, geothermal, and other renewable electricity sources cannot directly replace high energy density liquid petroleum for transportation use; instead automobiles and other equipment must be altered to allow using electricity (in batteries) or hydrogen (via fuel cells or internal combustion) which can be produced from renewable sources. Other options include using biomass-origin liquid fuels (ethanol, biodiesel). Any combination of solutions to replace petroleum as a liquid transportation fuel will be a very large undertaking.

Future of oil

Main article: Hubbert Peak The Hubbert peak theory, also known as peak oil, is a theory concerning the long-term rate of production of conventional oil and other fossil fuels. It assumes that oil reserves are not replenishable (i.e. that abiogenic replenishment is negligible), and predicts that future world oil production must inevitably reach a peak and then decline as these reserves are exhausted. Controversy surrounds the theory, as predictions for when the global peak will actually take place are highly dependent on the past production and discovery data used in the calculation. The issue can be considered from the point of view of individual regions or of the world as a whole. Originally M. King Hubbert noticed that the discoveries in the United States had peaked in the early 1930s, and concluded that production would then peak in the early 1970s. His prediction turned out to be correct, and after the US peaked in 1971 - and thus lost its excess production capacity - OPEC was finally able to manipulate oil prices, which led to the oil crisis in 1973. Since then, most other countries have also peaked: Britain's North Sea, for example in late 1990s. China has confirmed that two of its largest producing regions are in decline, and Mexico's national oil company, Pemex, has announced that Cantarell Field, one of the world's largest offshore fields, is expected to peak in 2006, and then decline 14% per annum. For various reasons (perhaps most importantly the lack of transparency in accounting of global oil reserves), it is difficult to predict the oil peak in any given region. Based on available production data, proponents have previously (and incorrectly) predicted the peak for the world to be in years 1989, 1995, or 1995-2000. However these predictions date from before the recession of the early 1980s, and the consequent reduction in global consumption, the effect of which was to delay the date of any peak by several years. A new prediction by Goldman Sachs picks 2007 for oil and some time later for natural gas. Just as the 1971 U.S. peak in oil production was only clearly recognized after the fact, a peak in world production will be difficult to discern until production clearly drops off. One signal is that 2005 saw a dramatic fall in announced new oil projects coming to production from 2008 onwards. Since it takes on average four to six years for a new project to start producing oil, in order to avoid the peak, these new projects would have to not only make up for the depletion of current fields, but increase total production annually to meet increasing demand.

Classification

The oil industry classifies "crude" by the location of its origin (e.g., "West Texas Intermediate, WTI" or "Brent") and often by its relative weight (API gravity) or viscosity ("light", "intermediate" or "heavy"); refiners may also refer to it as "sweet", which means it contains relatively little sulfur, or as "sour", which means it contains substantial amounts of sulfur and requires more refining in order to meet current product specifications. The world reference barrels are:
- Brent Blend, comprising 15 oils from fields in the Brent and Ninian systems in the East Shetland Basin of the North Sea. The oil is landed at Sullom Voe terminal in the Shetlands. Oil production from Europe, Africa and Middle Eastern oil flowing West tends to be priced off the price of this oil, which forms a benchmark. See also Brent crude.
- West Texas Intermediate (WTI) for North American oil.
- Dubai used as benchmark for the Asia-Pacific region for Middle East Oil
- Tapis (from Malaysia, used as a reference for light Far East oil)
- Minas (from Indonesia, used as a reference for heavy Far East oil)
- The OPEC Basket consisting of
- Arab Light Saudi Arabia
- Bonny Light Nigeria
- Fateh Dubai
- Isthmus Mexico (non-OPEC)
- Minas Indonesia
- Saharan Blend Algeria
- Tia Juana Light Venezuela OPEC attempts to keep the price of the Opec Basket between upper and lower limits, by increasing and decreasing production. This makes the measure important for market analysts. The OPEC Basket, including a mix of light and heavy crudes, is heavier than both Brent and WTI. See also [http://tonto.eia.doe.gov/ask/crude_types1.html]

Pricing

Venezuela References to the oil price are usually either references to the spot price of either WTI/Light Crude as traded on New York Mercantile Exchange (NYMEX) for delivery in Cushing, Oklahoma; or the price of Brent as traded on the International Petroleum Exchange (IPE) for delivery at Sullom Voe. The price of a barrel of oil is highly dependent on both its grade (which is determined by factors such as its specific gravity or API and its sulphur content) and location. The vast majority of oil will not be traded on an exchange but on a over-the-counter basis, typically with reference to a marker crude oil grade that is typically quoted via the pricing agency Platts. For example in Europe a particular grade of oil, say Fulmar, might be sold at a price of "Brent plus US$0.25/barrel".or as an intra-company transaction. IPE claim that 65% of traded oil is priced off their Brent benchmarks. Other important benchmarks include Dubai, Tapis, and the OPEC basket. The Energy Information Administration (EIA) uses the Imported Refiner Acquisition Cost, the weighted average cost of all oil imported into the US as their "world oil price". It is often claimed that OPEC sets the oil price and the true cost of a barrel of oil is around $2, which is equivalent to the cost of extraction of a barrel in the Middle East. These estimates of costs ignore the cost of finding and developing oil reserves. Furthermore the important cost as far as price is concerned, is not the price of the cheapest barrel but the cost of producing the marginal barrel. By limiting production OPEC has caused more expensive areas of production such as the North Sea to be developed before the Middle East has been exhausted. OPEC's power is also often overstated. Investing in spare capacity is expensive and the low oil price environment in the late 90s led to cutbacks in investment. This has meant during the oil price rally seen between 2003-2005, OPEC's spare capacity has not been sufficient to stabilise prices. Energy Information Administration Oil demand is highly dependent on global macroeconomic conditions, so this is also an important determinant of price. Some economists claim that high oil prices have a large negative impact on the global growth. This means that the relationship between the oil price and global growth is not particularly stable although a high oil price is often thought of as being a late cycle phenomenon. A recent low point was reached in January 1999, after increased oil production from Iraq coincided with the Asian financial crisis, which reduced demand. The prices then rapidly increased, more than doubling by September 2000, then fell until the end of 2001 before steadily increasing, reaching US $40 to US $50 per barrel by September 2004. [http://futures.tradingcharts.com/chart/CO/M] In October 2004, light crude futures contracts on the NYMEX for November delivery exceeded US $53 per barrel and for December delivery exceeded US $55 per barrel. Crude oil prices surged to a record high above $60 a barrel in June 2005, sustaining a rally built on strong demand for gasoline and diesel and on concerns about refiners' ability to keep up. This trend continued into early August 2005, as NYMEX crude oil futures contracts surged past the $65 mark as consumers kept up the demand for gasoline despite its high price. (see Oil price increases of 2004 and 2005).) The New York Mercantile Exchange (NYMEX) trades crude oil (including futures contracts) and provides the basis of US crude oil pricing via WTI (West Texas Intermediate). Other exchanges also trade crude oil futures, eg the International Petroleum Exchange (IPE) in London trades contracts in Brent crude. International Petroleum Exchange See also [http://www.wtrg.com/prices.htm History and Analysis of Crude Oil Prices]

Top petroleum-producing countries

Source: [http://www.eia.doe.gov/emeu/cabs/topworldtables1_2.html Energy Statistics from the U.S. Government] (Ordered by amount (barrels per day) produced in 2004):
- Saudi Arabia (OPEC)
- Russia
- United States ¹
- Iran (OPEC)
- Mexico ¹
- China ¹
- Norway ¹
- Canada ¹
- Venezuela (OPEC) ¹
- United Arab Emirates (OPEC)
- Kuwait (OPEC)
- Nigeria (OPEC)
- United Kingdom ¹
- Iraq ¹ peak production already passed in this state peak production already passed in this state (Ordered by amount exported in 2003):
- Saudi Arabia (OPEC)
- Russia
- Norway ¹
- Iran (OPEC)
- United Arab Emirates (OPEC)
- Venezuela (OPEC) ¹
- Kuwait (OPEC)
- Nigeria (OPEC)
- Mexico ¹
- Algeria (OPEC)
- Libya (OPEC) ¹ ¹ peak production already passed in this state Note that the USA consumes almost all of its own production. Total world production/consumption (as of 2005) is approximately 84 million barrels per day. See also: Organization of Petroleum Exporting Countries.

External links

- [http://www.longemergency.blogspot.com Long Emergency Blog] - A site with Peak Oil news and discussion, regarding how our world will never be the same.
- [http://www.api.org/ American Petroleum Institute] - A site run by the American Petroleum Institute, the trade association of the US oil industry.
- [http://futures.tradingcharts.com/chart/CO Crude Oil Commodity Charts] - Price charts for crude oil
- [http://www.eia.doe.gov/oil_gas/petroleum/info_glance/petroleum.html US Energy Information Administration] - Part of the informative website of the US Government's Energy Information Administration.
- [http://www.geo.uw.edu.pl/BOBRKA/DATY/daty.htm Major dates of the Polish petroleum industry]
- [http://www.gasresources.net/DisposalBioClaims.htm Dismissal of the Claims of a Biological Connection for Natural Petroleum.]
- [http://www.aapg.org/explorer/2002/11nov/abiogenic.cfm Abiogenic Gas Debate 11:2002 (EXPLORER)]
- [http://www.gasresources.net/Introduction.htm An introduction to the modern petroleum science, and to the Russian-Ukrainian theory of deep, abiotic petroleum origins.]
- [http://www.spe.org/elibinfo/eLibrary_Papers/spe/1982/82UGR/00010836/00010836.htm Unconventional Ideas About Unconventional Gas (Society of Petroleum Engineers)]
- [http://www.bp.com/genericsection.do?categoryId=92&contentId=7005893 BP Statistical Revue of World Energy ]
- [http://www.nymex.com Nymex] - oil trading center of the US
- [http://www.bloomberg.com/energy/ Bloomberg Energy Prices] - current prices on world mercantile exchanges
- [http://www.oilmarketer.co.uk/ Oil Marketer] - oil news and market information
- [http://www.economist.com/surveys/displaystory.cfm?story_id=3884623 Oil in troubled waters] - Economist article on investor approaches to oil markets, supply, and future
- [http://www.pdvsa.com] - The site for the state-owned oil company of Venezuela, much of whose profits go to helping the poor of the country as well as others.
- [http://www.venezuelanalysis.com] - A site focusing on developments in Venezuela, with a big emphasis on the oil issue.

Articles

- [http://pr.caltech.edu/periodicals/CaltechNews/articles/v38/oil.html The End of the Age of Oil] - article adapted from a talk by Caltech vice provost and professor of physics David Goodstein
- [http://www.publicintegrity.org/oil/ The Politics of Oil] - A report on the oil industry's influence of lawmakers and public policy by the Center for Public Integrity.
- [http://news.bbc.co.uk/2/hi/business/3953907.stm BBC: Stability fears rise as oil reliance grows]
- [http://www.washingtonpost.com/wp-dyn/content/article/2005/06/09/AR2005060900148_pf.html Top Saudi Says Kingdom Has Plenty of Oil] "261 billion barrels in reserve..."
- [http://business.timesonline.co.uk/article/0,,16849-1733893,00.html Lee Raymond of Exxon Mobile believes oil supplies will rise]
- [http://www.arabnews.com/?page=6§ion=0&article=44011&d=29&m=4&y=2004 Known Saudi Arabian Oil Reserves Tripled]
- [http://www2.eluniversal.com.mx/pls/impreso/noticia.html?id_nota=6110&tabla=miami Pemex's oil estimates double:] Mexican Oil company's estimate of reserves doubled.
- [http://www.gasresources.net/DisposalBioClaims.htm Dismissal of the Claims of a Biological Connection for Natural Petroleum]
- [http://www.aapg.org/explorer/2002/11nov/abiogenic.cfm Abiogenic Gas Debate 11:2002 (EXPLORER)]

Data

- [http://www.eia.doe.gov/emeu/international/petroleu.html Department of Energy EIA - World supply and consumption]
- [http://www.eia.doe.gov/oil_gas/petroleum/info_glance/prices.html US petroleum prices]

References

# [http://www.pnas.org/cgi/content/full/99/17/10976 Article link] #

Books about the petroleum industry

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Films about petroleum

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Writers covering the petroleum industry

- Colin J. Campbell
- Jay Hanson
- Kenneth S. Deffeyes
- David Goodstein
- Daniel Yergin
- Thomas Gold Category:Lubricants Category:Petroleum Category:Oils ko:석유 ja:石油

Diesel engine

The diesel engine is a type of internal combustion engine; more specifically, it is a compression ignition engine, in which the fuel is ignited by being suddenly exposed to the high temperature and pressure of a compressed gas containing oxygen (usually atmospheric air), rather than a separate source of ignition energy (such as a spark plug), as is the case in the gasoline engine. This is known as the diesel cycle, after German engineer Rudolf Diesel, who invented it in 1892 and received the patent on February 23, 1893 (1893-02-23). Diesel intended the engine to use a variety of fuels including coal dust. He demonstrated it in the 1900 Exposition Universelle (World's Fair) using peanut oil (see biodiesel).

How diesel engines work

When a gas is compressed, its temperature rises (see the combined gas law); a diesel engine uses this property to ignite the fuel. Air is drawn into the cylinder of a diesel engine and compressed by the rising piston at a much higher compression ratio than for a spark-ignition engine, up to 25:1. The air temperature reaches 700–900 °C, or 1300–1650 °F. At the top of the piston stroke, diesel fuel is injected into the combustion chamber at high pressure, through an atomising nozzle, mixing with the hot, high-pressure air. The resulting mixture ignites and burns very rapidly. This contained explosion causes the gas in the chamber to heat up rapidly, which increases its pressure, which in turn forces the piston downwards. The connecting rod transmits this motion to the crankshaft, which is forced to turn, delivering rotary power at the output end of the crankshaft. Scavenging (pushing the exhausted gas-charge out of the cylinder, and drawing in a fresh draught of air) of the engine is done either by ports or valves. To fully realize the capabilities of a diesel engine, use of a turbocharger to compress the intake air is necessary; use of an aftercooler/intercooler to cool the intake air after compression by the turbocharger further increases efficiency. In very cold weather, diesel fuel thickens and increases in viscosity and forms wax crystals or a gel. This can make it difficult for the fuel injector to get fuel into the cylinder in an effective manner, making cold weather starts difficult at times, though recent advances in diesel fuel technology have made these difficulties rare. A commonly applied advance is to electrically heat the fuel filter and fuel lines. Other engines utilize small electric heaters called glow plugs inside the cylinder to warm the cylinders prior to starting. A small number use resistive grid heaters in the intake manifold to warm the inlet air until the engine reaches operating temperature. Engine block heaters (electric resistive heaters in the engine block) plugged into the utility grid are often used when an engine is shut down for extended periods (more than an hour) in cold weather to reduce startup time and engine wear. A vital component of any diesel engine system is the governor, which limits the speed of the engine by controlling the rate of fuel delivery. Older governors were driven by a gear system from the engine (and thus supplied fuel only linearly with engine speed). Modern electronically-controlled engines achieve this through the electronic control module (ECM) or electronic control unit (ECU) - the engine-mounted "computer". The ECM/ECU receives an engine speed signal from a sensor and then using its algorithms and look-up calibration tables stored in the ECM/ECU, it controls the amount of fuel and its timing (the "start of injection") through electric or hydraulic actuators to maintain engine speed. Controlling the timing of the start of injection of fuel into the pistons is key to minimising their emissions and maximising the fuel economy (efficiency) or the engine. The exact timing of starting this fuel injection into the cylinder is controlled electronically in most of today's modern engines. The timing is usually measured in units of crank angles before Top Dead Center (TDC) that the piston is at. For example, if the ECM/ECU initiates fuel injection when the piston is 10 degrees before TDC, the start of injection or "timing" is said to be 10 deg BTDC. The optimal timing will depend on both the engine design as well as its speed and load. Advancing (injecting when the piston is further away from TDC) the start of injection results in higher in-cylinder pressure and higher efficiency but also results in higher Nitrous Oxide (NOx) emissions. At the other extreme, very retarded start of injection or timing causes incomplete combustion. This results in higher Particulate Matter (PM) emissions and higher smoke.

Fuel injection in diesel engines

Early diesels often employed indirect injection in order to use simple, flat-top pistons, and made the positioning of the early, bulky diesel injectors easier, but all modern diesel engines employ some form of direct injection, coupled with more complicated bowl-in-piston designs. Modern engines also use a very highly pressurised fuel supply line, which replaces the older, noisier, and mechanically more complicated combined pump and selector valve assembly (see below).

Indirect Injection

An indirect injection diesel engine delivers fuel into a chamber off the combustion chamber, called a prechamber, where combustion begins and then spreads into the main combustion chamber. The prechamber is carefully designed to ensure adequate mixing of the atomized fuel with the compression-heated air. This has the effect of slowing the rate of combustion, which tends to reduce audible noise. It also softens the shock of combustion and produces lower stresses on the engine components. The addition of a prechamber, however, increases heat loss to the cooling system and thereby lowers engine efficiency.

Direct injection

Modern diesel engines make use of one of the following direct injection methods:

Common rail direct injection

The common rail system on its prototype was already developed in late sixties with Mr. Hiber in Switzerland. After that, Ganser of the Swiss Federal Institute of Technology focusing on his research the common rail technology was advanced. In mid nineties, Dr. Shohei Itoh and Masahiko Miyaki, Japanese automotive parts manufacturer Denso Corporation, developed the Common Rail Fuel System for Heavy Duty Vehicles and finally turned into its first practical use on their ECD-U2 common Rail system, which was mounted on the HINO RAISING RANGER truck and sold for general use in 1995. Later in 1997 the German automotive parts manufacturer Robert Bosch GmbH extended its use for passenger car. Today the common rail system is responsible for a revolution in diesel engine technology. Delphi Automotive Systems of the US also make common-rail systems. Different car makers refer to their common rail engines by different names, e.g. DaimlerChrysler's CDI, Ford Motor Company's TDCi (most of these engines are manufactured by PSA), Fiat Group's (Fiat, Alfa Romeo and Lancia) JTD, Renault's DCi, GM/Opel's CDTi (most of these engines are manufactured by Fiat, other by Isuzu), PSA Peugeot Citroen's HDI, Toyota's D-4D, and so on. In older diesel engines, a distributor-type injection pump, regulated by the engine, supplies bursts of fuel to injectors which are simply nozzles through which the diesel is sprayed into the engine's combustion chamber. As the fuel is at low pressure and there cannot be precise control of fuel delivery, the spray is relatively coarse and the combustion process is relatively crude and inefficient. In common rail systems, the distributor injection pump is eliminated. Instead an extremely high pressure pump stores a reservoir of fuel at high pressure - up to 1,800 bar (180 MPa) - in a "common rail", basically a tube which in turn branches off to computer-controlled injector valves, each of which contains a precision-machined nozzle and a plunger driven by a solenoid. Driven by a computer (which also controls the amount of fuel to the pump), the valves, rather than pump timing, control the precise moment when the fuel injection into the cylinder occurs and also allow the pressure at which the fuel is injected into the cylinders to be increased. As a result, the fuel that is injected atomises easily and burns cleanly, reducing exhaust emissions and increasing efficiency. In addition, the engine's Electronic Control Unit (ECU) can inject a small amount of diesel just before the main injection event ("pilot" injection) that reduces noise and vibration, as well as optimises injection timing and quantity for variations in fuel quality, cold starting, and so on. Most European automakers have common rail diesels in their model lineups, even for commercial vehicles. Some Japanese manufacturers, such as Toyota, Nissan and recently Honda, have also developed common rail diesel engines.

Unit direct injection

This also injects fuel directly into the cylinder of the engine. However, in this system the injector and the pump are combined into one unit positioned over each cylinder. Each cylinder thus has its own pump, feeding its own injector, which prevents pressure fluctuations and allows more consistent injection to be achieved. This type of injection system, also developed by Bosch, is used by Volkswagen AG in cars, and most major diesel engine manufactures, in large commercial engines (Cat, Cummins, Detroit Diesel). With recent advancements, the pump pressure has been raised to 2,050 bar (205 MPa), allowing injection parameters similar to common rail systems.

Types of diesel engines

There are two classes of diesel engines: two-stroke and four-stroke. Most diesels generally use the four-stroke cycle, with some larger diesels operating on the two-stroke cycle. Normally, banks of cylinders are used in multiples of two, although any number of cylinders can be used as long as the load on the crankshaft is counterbalanced to prevent excessive vibration. The inline-6 is the most prolific in medium- to heavy-duty engines, though the V8 and straight-4 are also common.

Advantages and disadvantages versus spark-ignition engines

Diesel engines are more efficient than gasoline/petrol engines of the same power (by approx. 15%), resulting in lower fuel consumption. Naturally aspirated diesel engines are more massive than gasoline/petrol engines of the same power for two reasons; the first is that it takes a larger capacity diesel engine than a gasoline engine to produce the same power. This is essentially because the diesel cannot operate as quickly - the "rev limit" is lower - because getting the fuel-air mixture into a diesel engine is more difficult than a gasoline engine [http://www.perkins.com/perkins/cda/articleDisplay/1,4094,7___32_____7_10020408,00.html]. The second reason is that a diesel engine must be stronger to withstand the higher combustion pressures needed for ignition. Yet it is this same build quality that has allowed some enthusiasts to acquire significant power increases with turbocharged engines through fairly simple and inexpensive modifications. A gasoline engine of similar size cannot put out a comparable power increase without extensive alterations because the stock components would not be able to withstand the higher stresses placed upon them. Since a diesel engine is already built to withstand higher levels of stress, it makes an ideal candidate for performance tuning with little expense. However it should be said that any modification that raises the amount of fuel and air put through a diesel engine will increase its operating temperature which will reduce its life and service interval requirements. In addition, sending additional fuel to the cylinders will wash away lubricating oil faster. These things are issues with newer, lighter, "high performance" diesel engines which aren't "overbuilt" to the degree of older engines and are being pushed to provide greater power in smaller engines. The addition of a turbocharger or supercharger to the engine (see turbodiesel) greatly assists in increasing fuel economy and power output. Boost pressures can be higher on diesels than gasoline engines, and the higher compression ratio allows a diesel engine to be more efficient than a comparable spark ignition engine, although the calorific value of the fuel is slightly lower at 45.3 megajoules per kilogram to gasoline at 45.8 MJ/kg. The increased fuel economy of the diesel over the petrol engine means that the diesel produces less carbon dioxide (CO₂) per unit distance. The recent development of biofuel alternatives to fossil fuels has unleashed the ability to produce a net-sum of zero emissions of CO₂, as it is re-absorbed into plants and then comes full circle, being used to produce the fuel. Diesel engines can produce black soot from their exhaust. This consists of unburned carbon compounds. Modern diesel engines catch the soot in a particle filter, which when saturated is automatically regenerated by burning the particles. Other problems associated with the exhaust gases (nitrogen oxide, sulfurous fumes) can be mitigated with further investment and equipment. The lack of an electrical ignition system greatly improves the reliability. The high durability of a diesel engine is also due to its overbuilt nature (see above) as well as the diesel's combustion cycle, which creates less-violent changes in pressure when compared to a spark-ignition engine, a benefit that is magnified by the lower rotating speeds in diesels. Unfortunately, due to the greater compression force required and the increased weight of the stronger components, starting a diesel engine is a harder task. More torque is required to push the engine through compression. Either an electrical starter or an air start system is used to start the engine turning. On large engines, pre-lubrication and slow turning of an engine, as well as heating, are required to minimize the possibility of damaging the engine during initial start-up and running. Some smaller military diesels can be started with an explosive cartridge that provides the extra power required to get the machine turning. In the past, Caterpillar and John Deere used a small gasoline "pony" motor in their tractors to start the primary diesel motor. The pony motor heated the diesel to aid in ignition and utilized a small clutch and transmission to actually spin up the diesel engine. Even more unusual was an International Harvester design in which the diesel motor had its own carburetor and ignition system, and started on gasoline. Once warmed up, the operator moved two levers to switch the motor to diesel operation, and work could begin. These engines had very complex cylinder heads (with their own gasoline combustion chambers) and in general were vulnerable to expensive damage if special care was not taken (especially in letting the engine cool before turning it off).

Automobile racing

Although the weight and lower output of a diesel engine tend to keep them away from automotive racing applications, there are many diesels being raced in classes that call for them, mainly in truck racing, as well in types of racing where these drawbacks are less severe, such as land speed record racing. [http://www.cumminsracing.com/ Diesel engined dragsters] even exist, despite the diesel's drawbacks being central to performance in this sport. In 1952, [http://www.cummins.com/eu/pages/en/whoweare/cumminshistory.cfm Cummins Diesel] won the pole at the Indianapolis 500 race with a supercharged 3 liter diesel car, relying on torque and fuel efficiency to overcome weight and low peak power, and led most of the race until the badly situated air intake of the car swallowed enough debris from the track to disable the car.

Dieseling in spark-ignition engines

A gasoline (spark ignition) engine can sometimes act as a compression ignition engine under abnormal circumstances, a phenomenon typically described as "pinging" or "pinking" (during normal running) or "dieseling" (when the engine continues to run after the electrical ignition system is shut off). This is usually caused by hot carbon deposits within the combustion chamber that act as would a "glow plug" within a diesel or model aircraft engine. Excessive heat can also be caused by improper ignition timing and/or fuel/air ratio which in turn overheats the exposed portions of the spark plug within the combustion chamber.

Fuel and fluid characteristics

Diesel engines can operate on a variety of different fuels, depending on configuration, though the eponymous diesel fuel derived from crude oil is most common. Good-quality diesel fuel can be synthesised from vegetable oil and alcohol. Biodiesel is growing in popularity since it can frequently be used in unmodified engines, though production remains limited. Petroleum-derived diesel is often called "petrodiesel" if there is need to distinguish the source of the fuel. The engines can work with thicker, heavier oil, or oil with higher viscosity, as long as it is heated to ease pumping and injection. These fuels are cheaper than clean, refined diesel oil, although they are dirtier. The biofuels straight vegetable oil (SVO) and waste vegetable oil (WVO) can fall into this category. Moving beyond that, use of low-grade fuels can lead to serious maintenance problems. Most diesel engines that power ships like supertankers are built so that the engine can safely use low grade fuels. Ethanol is also used in some cases, since it has a high octane rating which means it can be highly compressed before spontaneously igniting. One way this is used is in E95 fuel which actually contains 5% gasoline along with 95% ethanol. Normal diesel fuel is more difficult to ignite than gasoline because of its higher flash point, but once burning, a diesel fire can be extremely fierce.

Diesel applications

The vast majority of modern heavy road vehicles (trucks), ships, large-scale portable power generators, most farm and mining vehicles, and many long-distance locomotives have diesel engines. However, in the U.S. they are not as popular in passenger vehicles as they are in Europe as they are perceived as being heavier, noisier, of having performance characteristics which makes them slower to accelerate, and of being more expensive than petrol vehicles. In addition, before the mandatory reduction of sulphur in on-road diesel fuel to 15 parts per million, which will start at 15 Oct 2006 (2006-10-15) in the U.S. (1 June 2006 (2006-06-01) in Canada), diesel fuel used in North America has higher sulphur content than the fuel used in Europe, effectively limiting diesel use to industrial vehicles. 2006-06-01 In Europe, where tax rates in many countries make diesel fuel much cheaper than petrol, diesel vehicles are very popular and newer designs have significantly narrowed differences between petrol and diesel vehicles in the areas mentioned. One anecdote tells of Formula One driver Jenson Button, who was arrested while driving a diesel-powered BMW coupe at 230 km/h (about 140 mph) in France, where he was too young to have a petrol-engined car hired to him. Button dryly observed in subsequent interviews that he had actually done BMW a public relations service, as nobody had believed a diesel could be driven that fast. The BMW diesel lab in Steyr, Austria is led by Ferenc Anisits and is considered to be a leader in development of automotive diesel engines. Similarly, Mercedes Benz had a successful run of diesel-powered passenger cars in the late 1970s and 1980s. After a hiatus in the 1990s with relatively few diesel cars in its lineup, Mercedes Benz has revived diesel cars in its newer ranges with an emphasis on high performance versus the older models' lack thereof. ;High-Speed :High-speed (approximately 1200 rpm and greater) engines are used to power lorries (trucks), buses, tractors, cars, yachts, compressors, pumps and small generators. ;Medium-Speed :Large electrical generators are driven by medium speed engines, (approximately 300 to 1200 rpm) optimised to run at a set speed and provide a rapid response to load changes. ;Low-Speed : The largest diesel engines are used to power ships. These monstrous engines have power outputs over 80,000 kW, turn at about 60 to 100 rpm, and are up to 15 m tall. They often run on cheap low-grade fuel, which require extra heat treatment in the ship for tanking and before injection due to their low volatility. Companies such as Burmeister & Wain and Wärtsilä (e.g., Sulzer Diesels) design such large low speed engines. They are unusually narrow and tall due to the addition of a crosshead bearing. Today (2005), the Wärtsilä-Sulzer RTA96-C turbocharged two-stroke diesel engine is the most powerful and most efficient prime-mover in the world, with cylinder bores of 960 mm (37.8 in) and stroke of 2500 mm (98.4 in), producing up to 80,080 kW (107,389 hp) in the 14-cylinder configuration. The zeppelins Graf Zeppelin II and Hindenburg were propelled by reversible diesel engines. The direction of operation was changed by shifting gears on the camshaft. From full power forward, the engines could be brought to a stop, changed over, and brought to full power in reverse in less than 60 seconds. This was done before reversible pitch propellers for aircraft had been perfected. A few airplanes have been built that use diesel engines, such as the Junkers-powered Blohm & Voss Ha 139 of the late 1930s. This is quite rare because of the high importance of power-weight ratios in aeronautical applications, and the development of kerosene-powered jet engines and the closely-related turboprop engines. However, this may change in the near future. The newer automotive diesels have power-weight ratios comparable to the ancient spark-ignition designs common in general aviation aircraft, and have better fuel efficiency. Their use of electronic ignition, fuel injection, and sophisticated engine management systems also makes them far easier to operate than mass-produced spark-ignition aircraft engines, most of which still use carburetors. Combined with Europe's very favourable tax treatment of diesel fuel compared to petrol, these factors have led to considerable interest in diesel-powered small general aviation planes, and several manufacturers have recently begun selling diesel engines for this purpose. The Diamond Twin Star is currently one of the very few general aviation aircraft manufactured with diesel engines. It can be twice as efficient as a comparable twin aircraft due to the diesel engines made by Thielert. Another major advantage for aviation users is that diesel engines can be fuelled with jet fuel, which is produced in a much greater quantity than avgas. See aircraft engine. Also, some motorcycles have been built using diesel engines.

Current and future developments

Already, many common rail and unit injection systems employ new injectors using stacked piezoelectric crystals in lieu of a solenoid, which gives finer control of the injection event. Variable geometry turbochargers have flexible vanes, which move and let more fuel into the engine depending on load. This technology increases both performance and fuel economy A technique called accelerometer pilot control (APC) uses a sensor called an accelerometer to provide feedback on the engine's level of noise and vibration and thus instruct the ECU to inject the minimum amount of fuel that will produce quiet combustion and still provide the required power (especially while idling.) The next generation of common rail diesels are expected to use variable injection geometry, which allows the amount of fuel injected to be varied over a wider range, and variable valve timing similar to that on gasoline engines. At least in the US, diesels will slowly face displacement by tougher emissions regulations. Other methods to achieve even more efficient combustion, such as HCCI (homogeneous charge compression ignition), are being studied.

Modern diesel facts

(Source: Robert Bosch GmbH) Fuel passes through the injector jets at speeds of nearly 1500 miles per hour (2400 km/h) – as fast as the top speed of a jet plane. Fuel is injected into the combustion chamber in less than 1.5 milliseconds (one and a half thousandths of a second) – about as long as a camera flash. The smallest quantity of fuel injected is one cubic millimetre – about the same volume as the head of a pin. The largest injection quantity at the moment for automobile diesel engines is around 70 cubic millimetres. If the camshaft of a six-cylinder engine is turning at 4500 rpm, the injection system has to control and deliver 225 injection cycles per second. On a demonstration drive, a Volkswagen 1-liter diesel-powered car used only 0.89 liters of fuel in covering 100 kilometers – making it probably the most fuel-efficient car in the world. Bosch’s high-pressure fuel injection system was one of the main factors behind the prototype’s extremely low fuel consumption. Production record-breakers in fuel economy include the Volkswagen Lupo 3L TDI and the Audi A2 3L 1.2 TDI with standard consumption figures of 3 liters of fuel per 100 kilometers. Their high-pressure diesel injection systems are also supplied by Bosch. In 2001, nearly 36% of newly registered cars in Western Europe had diesel engines. Austria leads the league table of registrations of diesel-powered cars with 66%, followed by Belgium with 63% and Luxembourg with 58%. Germany, with 34.6% in 2001, was in the middle of the league table. By way of comparison: in 1996, diesel-powered cars made up only 15% of the new car registrations in Germany. In 1998, for the very first time in the history of the legendary 24-hour race at the Nürburgring, a diesel-powered car was the overall winner – the BMW works team 320d, fitted with modern high-pressure diesel injection technology from Bosch.

External links

-
- [http://auto.howstuffworks.com/diesel.htm/ HowStuffWorks Article]
- [http://www.bath.ac.uk/~ccsshb/12cyl/ The Most Powerful Diesel Engine in the World]
- [http://www.cumminsracing.com Cummins Racing, home of the world's fastest diesel dragster...]
- [http://www.thedieselstop.com The Diesel Stop - Information on the Power Stroke Diesel]
- [http://www.northtexaspowerstrokes.com North Texas Power Stroke Association - Ford/International Power Stroke Diesel Enthusiasts]
- [http://www.rolls-royce.com/marine/product/diesel/default.jsp Rolls-Royce corporate website - diesel engines]
- [http://www.tdiclub.com TDIClub.com - TDI Enthusiasts]
- [http://www.turbodieselregister.com Turbodiesel Register - Dodge/Cummins Turbodiesel Enthusiasts]
- [http://www.volvo.com/volvopenta/global/en-gb Volvo Penta - manufacturer of marine and industrial diesel engines]
- [http://www.best-generator.com/ Best Engine - Manufacturer of Diesel Engine]
- [http://www.centurion-engines.com Centurion Engines - aeronautical applications]
- [http://www.wartsila.com/ Wärtsilä - manufacturer of diesel power plants]
- [http://www.cat.com/cda/layout?m=37532&x=7 Caterpillar - manufacturer of Caterpiller (Cat) diesel engines as well as construction equipment]
- [http://www.cummins.com Cummins - manufacturer of Cummins diesel engines]
- [http://www.detroitdiesel.com Detroit Diesel - manufacturer of diesel engines]
- [http://www.internationaldelivers.com/ -International/Navistar- manufacturer of International and Ford PowerStroke diesel engines, as well as heavy duty trucks]
- [http://www.perkins.com Perkins - manufacturer of diesel engines]
- [http://www.deutz.de Deutz - manufacturer of esoteric diesel engines]
- [http://www.deere.com John Deere - manufacturer of diesel engines and farm and construction equipment]
- [http://www.yanmar.com Yanmar - manufacturer of diesel engines, specilzing in those for marine use]
- [http://www.komatsu.com/kdl Komatsu Diesel - manufacturer of diesel engines]
- http://www.sisudiesel.com/ - Sisu Diesel
- [http://wagoneers.com/ wagoneers.com - see Mercedes Diesels and DIESELS] Category:Piston engines ko:디젤 엔진 ja:ディーゼルエンジン

Rudolf Diesel

(This article is about Rudolf Diesel, the German inventor. For other uses of the word Diesel, see Diesel (disambiguation)) Diesel (disambiguation) Rudolf Diesel (March 18, 1858 - September 30, 1913) was a German inventor, famous for the invention of the Diesel engine. He was born in Paris and died on the English Channel.

Early life

Although Diesel was born in Paris, his parents were German. His father was a leather craftsman, and his mother a governess and language tutor. Rudolf was a good student in primary school and was admitted at the age of 12 to the Ecole Primaire Superieure, then regarded as the best in Paris. On the outbreak of the Franco-Prussian War, however, he and his parents were considered enemy aliens, and were deported to neutral asylum in London. A cousin helped him to return to his father's home town, Augsburg, where he entered the Royal County Trade School. From there he won a scholarship to the Technische Hochschule of Munich, where he was an outstanding student. He became a protege of Carl von Linde, the pioneer of refrigeration. He was a devout Lutheran. After graduation, he was employed for two years as a machinist and designer in Winterthur, Switzerland. After this, he returned to Paris, where he was employed as a refrigeration engineer at Linde Refrigeration Enterprises. In Paris he became a connoisseur of the fine arts and an internationalist. He married in 1883, and had three children. He set up his first shop-laboratory in 1885 in Paris, and began full-time work on his engine. This continued when he moved to Berlin, working again for Linde Enterprises. In 1892 he was granted a German patent for the engine, and found some support for its continued development, this time in Augsburg.

The invention

Rudolf Diesel developed the idea of an engine that relied on a high compression of the fuel to ignite it, eliminating the spark plug used in the Nikolaus Otto internal combustion engine. He received a patent for the device on February 23, 1892 and a major milestone was achieved when he was able to run a single piston engine for one minute on February 17, 1894. This machine stood 10 feet tall, and acheived a compression of 80 atmospheres. He built an improved prototype in early 1897 while working at the Maschinenfabrik Augsburg (from 1906 on the MAN) plant at Augsburg. Diesel's engine had some similarities with an engine invented by Herbert Akroyd Stuart in 1890. Diesel was embroiled for some years in various patent disputes and arguments over priority, but in the end he prevailed, and his invention came to be called the diesel engine. He continued its development over the next three years, began production (the first commercial engine was at a brewer in the United States), and secured licenses from firms in several countries. He became a millionaire.

Later Life

Diesel was something of an unstable character, having several nervous breakdowns, and was somewhat paranoid at times. He defended his priority of invention tenaciously. Diesel