Automotive oil recycling involves the

recycling Recycling is the process of converting waste materials into new materials and objects. The recovery of energy from waste materials is often included in this concept. The recyclability of a material depends on its ability to reacquire the p ...

of used

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...

s and the creation of new products from the recycled oils, and includes the recycling of motor oil and

hydraulic oil A hydraulic fluid or hydraulic liquid is the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water. Examples of equipment that might use hydraulic fluids are excavators and backhoes, ...

. Oil recycling also benefits the environment: increased opportunities for consumers to recycle oil lessens the likelihood of used oil being dumped on lands and in waterways. For example, one

gallon The gallon is a unit of volume in imperial units and United States customary units. Three different versions are in current use: *the imperial gallon (imp gal), defined as , which is or was used in the United Kingdom, Ireland, Canada, Austr ...

of motor oil dumped into waterways has the potential to pollute one million gallons of water.

Motor oil

Recycled motor oil can be combusted as fuel, usually in plant boilers, space heaters, or industrial heating applications such as blast furnaces and cement kilns. When used motor oil is burned as fuel it must be burned at high temperatures to avoid gaseous pollution. Alternatively, waste motor oil can be distilled into

diesel fuel Diesel fuel , also called diesel oil, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a result of compression of the inlet air and ...

or marine fuel in a process similar to oil re-refining, but without the final hydrotreating process. The lubrication properties of motor oil persist, even in used oil, and it can be recycled indefinitely.

Used motor oil re-refining

Used oil re-refining is the process of restoring used oil to new oil by removing chemical impurities, heavy metals and dirt. Used industrial and automotive oil is recycled at re-refineries. The used oil is first tested to determine suitability for re-refining, after which it is dehydrated and the water distillate is treated before being released into the environment. Dehydrating also removes the residual light fuel that can be used to power the refinery, and additionally captures

ethylene glycol Ethylene glycol (IUPAC name: ethane-1,2-diol) is an organic compound (a vicinal diol) with the formula . It is mainly used for two purposes, as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odo ...

for re-use in recycled antifreeze. Next, industrial fuel is separated out of the used oil then

vacuum distillation Vacuum distillation is distillation performed under reduced pressure, which allows the purification of compounds not readily distilled at ambient pressures or simply to save time or energy. This technique separates compounds based on differences i ...

removes the lube cut (that is, the fraction suitable for reuse as lubricating oil) leaving a heavy oil that contains the used oil's additives and other by-products such as asphalt extender. The lube cut next undergoes hydro treating, or

catalytic hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic ...

to remove residual polymers and other chemical compounds, and saturate carbon chains with hydrogen for greater stability. Final oil separation, or fractionating, separates the oil into three different oil grades: Light viscosity lubricants suitable for general lubricant applications, low viscosity lubricants for automotive and industrial applications, and high viscosity lubricants for heavy-duty applications. The oil that is produced in this step is referred to as re-refined base oil (RRBL). The final step is blending additives into these three grades of oil products to produce final products with the right detergent and anti-friction qualities. Then each product is tested again for quality and purity before being released for sale to the public.

REOB

The sludge ("residue") associated with engine oil recycling, which collects at the bottom of re-refining vacuum distillation towers, is known by various names, including "re-refined engine oil bottoms" (abbreviated "REOB" or "REOBs").Arnold, Terence S. (senior research chemist, Pavement Materials Team, Office of Infrastructure Research and Development,

Federal Highway Administration The Federal Highway Administration (FHWA) is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two programs, the Federal-aid Highway Program ...

; Federal lab manager for the chemistry lab,

Turner-Fairbank Highway Research Center Turner-Fairbank Highway Research Center is a U.S. Department of Transportation facility located in McLean, Virginia. The center carries out research studies and was renamed after Francis Turner in 1983. It had been known as the Fairbank Highway Re ...

; fellow of the

Royal Society of Chemistry The Royal Society of Chemistry (RSC) is a learned society (professional association) in the United Kingdom with the goal of "advancing the chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Royal Instit ...

in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

)
"What's in Your Asphalt?,"
September 2017 (last modified October 25, 2017), ''Public Roads,'' FHWA-HRT-17-006.htm," Office of Research, Development, and Technology, Office of Corporate Research, Technology, and Innovation Management,

U.S. Department of Transportation The United States Department of Transportation (USDOT or DOT) is one of the executive departments of the U.S. federal government. It is headed by the secretary of transportation, who reports directly to the President of the United States and ...

A report from the U.S.

(FHWA) states that: :The oil in a car engine... contains a variety of additives to enhance the vehicle’s performance. These include polymers, viscosity modifiers, heat stabilizers, additional lubricants, and wear additives. The REOB contains all the additives that were in the waste oil as well as the wear metals from the engine (mainly

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

and

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

). These additives include zinc dialkyldithiophosphate, which contains

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

, sulfur, and

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

; calcium phenate, which contains

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...

; and molybdenum disulfide, which contains molybdenum and sulfur. Some producers of

asphalt Asphalt, also known as bitumen (, ), is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term ...

for paving have—openly or secretly—incorporated REOBs into their asphalt, creating some controversy and concern in the traffic engineering community, with some experts suggesting it reduces the durability of the resulting pavement.

References

External links

Recycleoil.org

American Petroleum Institute The American Petroleum Institute (API) is the largest U.S. trade association for the oil and natural gas industry. It claims to represent nearly 600 corporations involved in production, refinement, distribution, and many other aspects of the ...

Energy Efficiency and Recycling
at the American Petroleum Institute {{Recycling, state=expanded Motor oils Vehicle recycling Recycling by product Water pollution

Motor oil

Used motor oil re-refining

REOB

See also

References

External links