Base oil
Base oils (also known as base oils ) are used to make petroleum products including lubricating greases , engine oils, and cooling lubricants . The products differ among other things in the viscosity at different temperatures.
Base oil is made from refining crude oil by separating light and heavy hydrocarbons from one another by distillation . The former are processed into gasoline and other fuels, while bitumen and base oils belong to the heavier fraction.
There are many deposits of crude oils worldwide from which base oils are made. The most common is a type of paraffinic crude, although there are also naphthenic crude oils, the products of which have better solubility and very good properties at low temperatures. By using the hydrogenation process , sulfur and aromatics are removed and, with hydrogen under high pressure, result in very pure base oils, which are suitable for particularly high quality requirements.
Additives are chemical substances and are added to the base oil in order to meet the quality requirements for the end products, for example with regard to inhibitors against rust and corrosion , detergents , dispersants and surfactants for cleaning and protecting metallic surfaces. Some engine oils contain more than twenty percent additives.
Official classifications
In 1993 the American Petroleum Institute (API) categorized base oils into five main groups. This breakdown is based on the refining method and the properties of the base oil, including viscosity and saturation level and sulfur content.
Group I.
The least refined type made by Solvent Refining dates back to the 1930s. This base oil usually consists of conventional petroleum . An improvement in the refining process in the 1960s called hydrotreatment made this base oil more stable, less reactive and longer lasting than the earlier base oils.
The API defines group I as “basic substances that contain less than 90 percent saturated compounds and / or more than 0.03 percent sulfur and have a viscosity index of at least 80 and a maximum of 120”.
Group II
From 1971 onwards, petroleum became a better base oil, some of which can be produced by hydrocracking . All impurities are removed from the oil, resulting in a clearer color.
The API defines group II as “basic substance with at least 90 percent saturated compounds and a maximum of 0.03 percent sulfur and a viscosity index of at least 80 and less than 120”.
Group III
The highest grade of petroleum base oils dates from 1993 , which are made entirely through hydrocracking , hydroisomerization and hydrodesulfurization , which make these oils chemically purer .
The API defines group III as “basic substance with at least 90 percent saturated compounds and a maximum of 0.03 percent sulfur and a viscosity index of at least 120”.
This group can be described as technologically synthetic oils or by hydrocracked synthetic oils . However, some mineral oil companies call their products “synthetic oil” under this group.
Group IV
From 1974, consists of synthetic oils made from polyalphaolefins (PAO) . Group IV base oils have a viscosity index in the range of 125-200.
Poly-Alpha-Olefins (PAO) oils are much more stable in extreme temperatures, making them suitable for use in very cold weather (such as in the Northwest of the US and Northern Europe ) as well as very hot weather (such as in the Middle East ).
Group v
Dating from the 1940s, each type of base oil can be mentioned differently than in the groups previously defined.
These include, among other things, naphthenic oils and esters .
Unofficial classifications
Unofficial base oil classifications are not recognized by the American Petroleum Institute (API), but they are widely used to market motor oils and automatic transmission oils .
Group II +
Dating from the 1990s, a refined note of Group III petroleum base oil made by hydrodesulfurization . Group II + base oils have a high viscosity index at the upper end of API group II. The viscosity index is at least 110–115.
Group III +
Originally from 2015 to produce gas to liquid (GTL) process. Group III + base oils have a very high Viscosity Index (VHVI) at the upper end of the API Group III range. The viscosity index is at least 130-140.
Group VI
Consists of synthetic oils made from internal polyolefins (PIO).
Polyinternolefin (PIO) oils are similar to polyalphaolefins (PAO) , but they use different chemicals in the synthesis process to obtain an even higher viscosity index (VI).
Web links
Individual evidence
- ↑ SPBI: Archived copy ( memento of the original from August 20, 2012 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ 2004/284 / EC: Commission decision of September 29, 1999 declaring a concentration to be compatible with the common market and the EEA Agreement (Case No. IV / M.1383 - Exxon / Mobil)
- ↑ QRP OIL: http://www.qrpoil.com/site/?baseoilsn500
- ↑ http://www.api.org/~/media/files/certification/engine-oil-diesel/publications/anne-rev-03-25-15.pdf
- ↑ https://www.bobistheoilguy.com A Review of Mineral and Synthetic Base Oils
- ↑ Archived copy . Archived from the original on July 2, 2016. Retrieved May 31, 2016.
- ↑ API 1509, Appendix EQRP OIL: http://www.qrpoil.com/site/?baseoilsn500
- ↑ https://patents.google.com/patent/US20140113847 High viscosity index lubricating oil base stock and viscosity modifier combinations, and lubricating oils derived therefrom
