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Synthetic oil



  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 (or 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. When synthetic oil is made as a substitute for lubricant refined from petroleum, it is generally to provide superior mechanical and chemical properties than those found in traditional mineral oils.

Additional recommended knowledge

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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.

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 early 1970s, synthetic oils 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 API-approved formula for automobile engines when the French Oil company MOTUL introduced a commercial ester-based synthetic oil in 1971[1]. Other early synthetic motor oils included All-Proof, a 10W50 polyolester-based motor oil introduced in 1970; Amsoil, introduced in 1972[2] (with a diester-based 10W40 formula developed by Hatco); and Mobil 1, introduced in North America in 1974[3] (with a PAO-based 5W-20 formula).

Synthetic Base Stocks

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

  • Polyalphaolefin (PAO) = API (American Petroleum Institute) Group IV base oil
  • Synthetic esters, etc = API Group V base oils (non-PAO synthetics, including diesters, polyolesters, alklylated napthlenes, alkyklated benzenes, etc.)
  • Hydrocracked/Hydroisomerized = API Group III base oils. Chevron, Mobil, 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. The best of these perform much like polyalphaolefin. Group III base stocks are considered synthetic motor oil in North America.[4][5]

Required applications

Many vehicle manufacturers specify synthetic motor oils.

  • VW 502.00/505.00/503.01 (includes both diesel and petrol or gasoline engines) [6]
  • MB 229.5 ( (4G63 engine)
  • Honda HTO-06
  • Porsche Approval list 2002
  • Some Briggs & Stratton small engines.
  • Dodge Viper V10
  • Ridley Motorcycle Company
  • Mercury Grand Marquis (2003 & newer) 5W-20
  • Shelby Dodge Automobiles
  • Chevrolet Trailblazer SS (2006-2008)
  • Cars equipped with Chrysler Hemi engines (2002 & newer)

Various motor oils made from Group III, Group IV, and/or Group V base oils are on the market that meet one or more of these

  • Chevrolet Corvette (1997 & newer)

Advantages

The technical advantages of synthetic motor oils include:

  • Measurably better low and high temperature viscosity performance[citation needed]
  • Better chemical & shear stability
  • Decreased evaporative loss[citation needed]
  • Resistance to oxidation, thermal breakdown and oil sludge problems
  • Extended drain intervals with the environmental benefit of less waste oil created.[citation needed]

Disadvantages

The disadvantages of synthetic motor oils include:

  • Initial costs are usually three 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. As many vehicles now use synthetic oils as factory fill, this is less of an issue than it once was.
  • 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 oil[1]. 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." [2] 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.[3]

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 oil. MOTUL introduced the first semi-synthetic motor oil in 1966.[7]

See also

Energy Portal

Notes

  1. ^ Consumer Reports Oil Testing Results. Retrieved on 2007-10-15.
  2. ^ (July 1996) "The surprising truth about motor oils". Consumer Reports: 10-13. Retrieved on 2007-01-29.
  3. ^ Statistical problems of Consumer Reports auto ratings (English). Retrieved on 2007-04-08.
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Synthetic_oil". A list of authors is available in Wikipedia.
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