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Methyl tert-butyl ether

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Title: Methyl tert-butyl ether  
Author: World Heritage Encyclopedia
Language: English
Subject: MTBE controversy, Biofuel in the United States, Neste, Tetraethyllead, Petrochemical
Collection: Dialkyl Ethers, Ether Solvents, Ethers, Hazardous Air Pollutants, Oxygenates, Pollutants, Soil Contamination
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Methyl tert-butyl ether

Methyl tert-butyl ether
Skeletal formula of MTBE
Ball-and-stick model of the MTBE molecule
IUPAC name
Other names
Methyl tertiary-butyl ether; Methyl tert-butyl ether; Methyl t-butyl ether; MTBE; tert-Butyl methyl ether; tBME; tert-BuOMe
ChemSpider  Y
Jmol-3D images Image
Molar mass 88.15 g·mol−1
Density 0.7404 g/cm³
Melting point −109 °C (−164 °F; 164 K)
Boiling point 55.2 °C (131.4 °F; 328.3 K)
26 g/L (20 °C)[1]
NFPA 704
Flash point −10 °C (14 °F; 263 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 Y  (: Y/N?)

Methyl tert-butyl ether (also known as MTBE, tert-butyl methyl ether, tertiary butyl methyl ether and tBME) is an

  • MTBE in Europe
  • MTBE webpage from the EPA
  • Summary of health effects data from IACR
  • Eliminating MTBE in Gasoline in 2006 (pdf)
  • An online resource about MTBE litigation and the surrounding issues
  • MTBE: What The Oil Companies Knew And When They Knew It (from the Environmental Working Group)
  • MTBE Resource Guide
  • European Union MTBE Risk Assessment Report
  • Fuel Quality Directive Impact Assessment
  • Council Directive 85/536/EEC of 5 December 1985 on crude-oil savings through the use of substitute fuel components in petrol
  • An assessment of the impact of ethanol-blended petrol on the total NMVOC emission from road transport in selected countries

External links

  1. ^ a b Record in the GESTIS Substance Database of the IFA
  2. ^ M. Winterberg, E. Schulte-Korne, U. Peters, F. Nierlich "Methyl Tert-Butyl Ether" in Ullmann's Encyclopedia of Industrial Chemistry, 2010, Wiley-VCH, Weinheim. doi:10.1002/14356007.a16_543.pub2
  3. ^,360,362,477 Archived January 6, 2006 at the Wayback Machine
  4. ^
  5. ^ Matyash, V.; Liebisch, G.; Kurzchalia, T. V.; Shevchenko, A.; Schwudke, D. (2008). "Lipid extraction by methyl-tert-butyl ether for high-throughput lipidomics". The Journal of Lipid Research 49 (5): 1137.  
  6. ^ Zeon Corporation
  7. ^ CRC Handbook of Chemistry and Physics, 90th edition
  8. ^ "Interaction between bromine and tert-butyl methyl ether". Retrieved 13 May 2010. 
  9. ^
  10. ^ San Francisco Bay Area Regional Water Quality Control Board Integrated Basin Management Plan (2004)
  11. ^ link text
  12. ^ Fischer A, Oehm C, Selle M, Werner P.; Oehm; Selle; Werner (2005). "Biotic and abiotic transformations of methyl tertiary butyl ether (MTBE)". Environ Sci Pollut Res Int 12 (6): 381–6.  
  13. ^
  14. ^ SIGMA - Weekly Report
  15. ^ Long Island Utility Fighting to Defeat MTBE Safe Harbor - Napoli Bern - Attorneys
  16. ^ AmeriScan: February 17, 2005
  17. ^ Navarro, Mireya (2009-10-20). "City Awarded $105 Million in Exxon Mobil Lawsuit". The New York Times. Retrieved 2010-05-12. 
  18. ^ Earle, Sarah (2013-04-09). "Exxon Mobil is Found Negligent in New Hampshire MTBE Use". Bloomberg. Retrieved 2013-04-09. 
  19. ^ Website U.S. Department of Energy
  20. ^
  21. ^
  22. ^ Charles Babington, House Again Passes GOP Energy Measures, Washington Post, June 16, 2004, at A4 (House passes Energy Bill, but Senate opponents of MTBE provision in House Bill have the votes to prevent its enactment).
  23. ^
  24. ^ prices ethanol/index.htm?cnn=yes prices ethanol/index.htm?cnn=yes
  25. ^ CCL 2 List


See also

The U.S. EPA currently lists MTBE as a candidate for a maximum contaminant level (MCL) in drinking water.[25] MCLs are determined by the EPA using toxicity data.

The Energy Policy Act of 2005, passed in the U.S. House of Representatives, did not include a provision for shielding MTBE manufacturers from water contamination lawsuits. This provision was first proposed in 2003 and had been thought by some to be a priority of Tom DeLay and Rep. Joe Barton, then chairman of the Energy and Commerce Committee.[20] This bill did include a provision that gives MTBE makers, including some major oil companies, $2 billion in transition assistance as MTBE is phased out over the next nine years.[21] Due to opposition in the Senate,[22] the conference report dropped all MTBE provisions. The final bill was passed by both houses and signed into law by President Bush.[23] The lack of MTBE liability protection is resulting in a switchover to the use of ethanol as a gasoline additive. Some traders and consumer advocates are blaming this for an increase in gasoline prices.[24]

In 2000, the U.S. EPA drafted plans to phase out the use of MTBE nationwide over four years. As of fall 2006, hundreds of lawsuits are still pending regarding MTBE contamination of public and private drinking water supplies.

MTBE is banned in the US states of California and New York, starting January 1, 2004. As of September 2005, twenty-five states had signed legislation banning MTBE. (A table of state by state information, as of 2007, is available at the United States Department of Energy website.[19])

MTBE removal from groundwater and soil contamination in the U.S. is estimated to cost from $1 billion[14] to $30 billion,[15] including removing the compound from aquifers and municipal water supplies and replacing leaky underground oil tanks. In one case, the cost to oil companies to clean up the MTBE in wells belonging to Santa Monica is estimated to exceed $200 million.[16] In another case, the City of New York estimated a $250 million cost for cleanup of a single wellfield in Queens, NY.[17] More recently, a jury awarded the State of New Hampshire $236 million in damages[18] in order to treat groundwater contaminated by MTBE.

Legislation and litigation in the U.S.

As of 2007, researchers have limited data about the health effects of ingestion of MTBE. The United States Environmental Protection Agency (EPA) has concluded that available data are inadequate to quantify health risks of MTBE at low exposure levels in drinking water, but the data support the conclusion that MTBE is a potential human carcinogen at high doses.[13]

According to the carcinogen. MTBE can be tasted in water at concentrations of 5 – 15 µg/l.[12]

MTBE is biodegraded by the action of bacteria. In the proper type of bioreactor, such as a fluidized bed bioreactor, MTBE can be rapidly and economically removed from water to undetectable levels. Activated carbon produced from coconut shells and optimized for MTBE adsorption may reduce MTBE to undetectable levels,[11] although this level of reduction is likely only in the most ideal circumstances. There are currently no known published cases of any in-situ treatment method which has been capable of reducing contaminant concentrations to baseline (pre-development) conditions within the aquifer soil matrix itself.

MTBE gives water an unpleasant taste at very low concentrations, and thus can render large quantities of groundwater undrinkable. MTBE is often introduced into water-supply aquifers by leaking underground storage tanks (USTs) at gasoline stations or by gasoline containing MTBE spilled onto the ground. The higher water solubility and persistence of MTBE cause it to travel faster and farther than many other components of gasoline when released into an aquifer.[9][10]

Persistence and pervasiveness in the environment

Although an ether, MTBE is a poor Lewis base and does not support formation of Grignard reagents. It is also unstable toward strong acids. It reacts dangerously with bromine.[8]

MTBE forms azeotropes with water (52.6 °C; 96.5% MTBE)[6] and methanol (51.3 °C; 68.6% MTBE).[7]

Despite the popularity of MTBE in industrial settings, it is rarely used as a solvent in academia with some exceptions.[5]

As a solvent

Higher quality gasoline is also an alternative, so that additives such as MTBE are unnecessary. Iso-octane itself is used. MTBE plants can be retrofitted to produce iso-octane from isobutylene.[3][4]

An alternative to straight ethanol is the related ether ETBE, which is manufactured from ethanol and isobutene. Its performance as an additive is similar to MTBE, but due to the higher price of ethanol compared to methanol, it is more expensive.

Advocates of both sides of the debate in the US sometimes claim that gasoline manufacturers have been forced to add ethanol to gasoline by law. It might be more correct to say they have been induced to do so, although any oxygenate would fulfill the law.

Ethanol has been advertised as a safe alternative by the agricultural and other interest groups in the US and Europe. In 2003, California was the first US state to start replacing MTBE with ethanol. Several other states started switching soon thereafter.

Other compounds are available as additives for gasoline including ethanol and some ethers such as tert-amyl methyl ether (TAME).

Alternatives to MTBE as an anti-knock agent

In the US it has been used in gasoline at low levels since 1979 to replace tetraethyl lead and to increase its octane rating helping prevent engine knocking. Oxygenates help gasoline burn more completely, reducing tailpipe emissions from pre-1984 motor vehicles; dilutes or displaces gasoline components such as aromatics (e.g., benzene) and sulfur; and optimizes the oxidation during combustion. Most refiners chose MTBE over other oxygenates primarily for its blending characteristics and low cost.

As anti-knocking agent

MTBE is almost exclusively used as a fuel component in fuel for gasoline engines. It is one of a group of chemicals commonly known as oxygenates because they raise the oxygen content of gasoline.


MTBE is manufactured via the chemical reaction of methanol and isobutylene. Methanol is derived from natural gas, and isobutylene is derived from butane obtained from crude oil or natural gas, thus MTBE is derived from fossil fuels. In the United States, it was produced in very large quantities (more than 200,000 barrels (32,000 m3) per day in 1999) during its use as a fuel additive.

Production and properties


  • Production and properties 1
  • Uses 2
    • As anti-knocking agent 2.1
    • Alternatives to MTBE as an anti-knock agent 2.2
    • As a solvent 2.3
  • Persistence and pervasiveness in the environment 3
  • Legislation and litigation in the U.S. 4
  • See also 5
  • References 6
  • External links 7

[2] and legislation favoring ethanol. However, worldwide production of MTBE has been constant at about 18 million tons/y (2005) owing to growth in Asian markets which are less subject to ethanol subsidies.groundwater. Its use is controversial in the US and declining in use in part because of its occurrence in octane number to raise the oxygenate additive, used as an gasoline, leading to unpleasant taste and odor in water. MTBE is a diethyl ether in water. It has a minty odor vaguely reminiscent of [1]

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