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Synthetic oil is oil consisting of chemical compounds which were not originally present in crude oil (petroleum), but were artificially made (synthesized) from other compounds. Synthetic oil could be made to be a substitute for petroleum, or specially made to be a substitute for a lubricant oil, such as conventional (mineral) motor oil refined from petroleum. When a synthetic oil or synthetic fuel is made as a substitute for petroleum, it is generally produced because of a shortage of petroleum or because petroleum is too expensive^{citation needed}. When synthetic oil is used as a substitute for lubricant refined from petroleum, it generally provides superior mechanical and chemical properties than those found in traditional mineral oils.

Synthetic oil as a substitute for petroleum-based oil

One form of synthetic oil is that manufactured using the Fischer-Tropsch process which converts carbon dioxide, carbon monoxide, and methane into liquid hydrocarbons of various forms. This process was developed and used extensively in World War II by Germany, which had limited access to crude oil supplies. Germany's yearly synthetic oil production reached millions of tons in 1944. It is today used in South Africa to produce most of that country's diesel. Dr. Hermann Zorn of I.G. Farben Industrie in Germany actually began to search for lubricants with the properties of natural oils but without the tendencies to gel or gum when used in an engine environment. His work led to the preparation of over 3500 esters in the late 1930s and early 1940s including diesters and polyol esters and banana oil.

Another form of synthetic oil is that produced at Syncrude sands plant in Alberta, Canada. This huge facility removes highly viscous bitumen from oil sands mined nearby, and uses a variety of processes of hydrogenation to turn it into high-quality synthetic crude oil. The Syncrude plant supplies about 14% of Canada's petroleum output. A similar plant is the smaller nearby facility owned by Suncor. See synthetic fuel.

Synthetic engine oil

In the mid 1960s Chevron U.S.A was the first to market and produce a complete range of 100% synthetic Polyalphaolefins based lubricants, which began to be marketed as a substitute for mineral oils for engine lubrication. Although in use in the aerospace industry for some years prior, synthetic oil first became commercially available in an American Petroleum Institute (API)-approved formula for automobile engines when standards were formalized for synthetic based lubricants.

Other early synthetic motor oils marketed included "The Original Syn!" by SynLube in 1969, NEO Oil Company (formally EON) in 1970, which were dibasic acide esters, or diesters, and polyol esters based synthetic lubricants. In 1971 All-Proof now called Red Line; followed fourth by Amsoil who packaged and resold a diester-based 10W40 grade from Hatco¹ in 1972, and then Mobil 1, introduced in North America in 1974 (with a PAO-based 5W20 grade).

Synthetic Base Stocks

Synthetic motor oils have been made from the following classes of lubricants:

• Polyalphaolefin (PAO) = American Petroleum Institute (API) Group IV base oil
• Synthetic esters, etc = API Group V base oils (non-PAO synthetics, including diesters, polyolesters, alklylated napthlenes, alkyklated benzenes, polyglycols etc.)

Other Base Stocks Helps Semi-Synthetic Lubricants²

Group II and Group III type base stocks help to formulate more economic type semi-synthetic lubricants. Group I, II, II+ and III type mineral base oil stocks are widely used in combination with additive packages, performance packages, ester and/or Group IV polyalphaolefins in order to formulate semi-synthetic based lubricants. Group III base oils are sometimes considered as synthetic but they are still classifed as highest top level mineral base stocks. A Synthetic or Synthesized material is one that is produced by combining or building individual units into a unified entry. Synthetic base stocks as described above, unlike mineral base oils, which are complex mixture of naturally occuring hydrocarbons, synthetic base fluids are man-made and tailored to have a controlled molecular structure with predictable properties.[Ref: Lubrication Fundemantals, J. George Wills, Mobil Oil Corporation]

• Hydrocracked/Hydroisomerized = API Group III base oils. Chevron, Shell, and other petrochemical companies developed processes involving catalytic conversion of feed stocks under pressure in the presence of hydrogen into high quality mineral lubricating oil. In 2005 production of GTL (Gas-to-liquid) Group III base stocks began. Even they are considered as synthetic product they are still mineral base stocks and counted as the mineral part of all semi-synthetic lubricants. Group III base stocks [with certain amount of mixture of PAOs and esters and Group V] are considered synthetic motor oil ONLY in the United States.^{citation needed}. Group III based lubricants are not allowed to be marketed as "synthetic" in any market outside of the USA.

Advantages

The technical advantages of synthetic motor oils include:^{citation needed}

• Measurably better low and high temperature viscosity performance
• Better chemical & shear stability
• Decreased evaporative loss
• Resistance to oxidation, thermal breakdown and oil sludge problems
• Extended drain intervals with the environmental benefit of less oil waste.
• Improved fuel economy in certain engine configurations.
• Better lubrication on cold starts

Disadvantages

The disadvantages of synthetic motor oils include:

• Initial costs are usually two to four times greater than petroleum-based oils, though at one time, man-made oils cost ten times more than petroleum^{citation needed}. Initial costs are often mitigated by extended change intervals, which individuals may confirm through used oil analysis (UOA).
• The lower friction may make them unsuitable for break-in (i.e. the initial run-in period of the vehicle) where friction is desirable to cause wear. Improved engine part machining has made break-in less critical than it once was though. Many modern cars now come with synthetic oil as a factory fill.
• Potential decomposition problems in certain chemical environments (industrial use dominantly)
• Potential stress cracking of plastic components like POM (polyoxymethylene) in the presence of PAOs (polyalphaolefins).
• Potential on some older pushrod race engines with roller lifters for the roller itself not to spin with camshaft movement, but rather slide while the roller itself remains either stationary or at a lower circumferential speed than that of the camshaft lobe^{citation needed}
• In July 1996, Consumer Reports published the results of a two year motor oil test involving a fleet of 75 New York taxi cabs and found no noticeable advantage of synthetic oil over regular oil³. In their article, they noted that "Big-city cabs don't see many cold start-ups or long periods of high speed driving in extreme heat. But our test results relate to the most common type of severe service - stop-and-go city driving." According to their study, synthetic oil is "worth considering for extreme driving conditions: high ambient temperatures and high engine load, or very cold temperatures." ⁴ This research was criticized by some because most engine damage appears to be caused by cold starts, and their research method may not have included enough cold starts to be representative of personal vehicle use.⁵

Especially synthetic base stocks help to improve ashless engine oil formulations both for passenger vehicles(PVL, CVL) and heavy commercials engine oils (HCVL, HHDO) and especially for new generation combined cycle type power generator gas engines.

Synthetic base stocks, inside the engine oil formulations, decrease the emissions, increase the catalytic converter life with their low ash & zero sulphur properties and especially their low evaporation rates (Noack volatility values)

Semi-synthetic oil

Semi-synthetic oils (also called 'synthetic blends') are blends of mineral oil with no more than 30% synthetic oil. Designed to have many of the benefits of synthetic oil without matching the cost of pure synthetic oil. Motul introduced the first semi-synthetic motor oil in 1966.⁶.

Lubricants which have synthetic base stocks even lower 30%, high performance additive packs consisting of esters can also be considered as synthetic lubricants. Ratio of the synthetic base stock is generally used to define commodity codes among the customs declarations of tax purposes.

See also

Energy portal

• Abiogenic petroleum origin
• Fischer-Tropsch process
• Renewable Energy
• Royal Purple
• Synthetic fuel

Notes

External links

• About Synthetic Lubricants
• Development of the modern Fischer-Tropsch process (1958–1999)
• Scientists find bugs that eat waste and excrete petrol - Times Online