Methyl tert - butyl ether - wikipedia Methyl tert - butyl ether Methyl tert - butyl ether Names IUPAC name 2 - Methoxy - 2 - methylpropane Other names Methyl tertiary - butyl ether ; Methyl tert - butyl ether ; Methyl t - butyl ether ; MTBE ; tert - Butyl methyl ether ; tBME ; tert - BuOMe Identifiers CAS Number 1634 - 04 - 4 3D model ( JSmol ) Interactive image ChEBI CHEBI : 27642 ChemSpider 14672 ECHA InfoCard 100.015. 140 KEGG C11344 PubChem CID 15413 InChI InChI = 1S / C5H12O / c1 - 5 ( 2, 3 ) 6 - 4 / h1 - 4H3 Key : BZLVMXJERCGZMT - UHFFFAOYSA - N InChI = 1 / C5H12O / c1 - 5 ( 2, 3 ) 6 - 4 / h1 - 4H3 Key : BZLVMXJERCGZMT - UHFFFAOYAA SMILES O ( C ( C ) ( C ) C ) C Properties Chemical formula Molar mass 88.15 g mol Density 0.7404 g / cm3 Melting point − 109 ° C ( − 164 ° F ; 164 K ) Boiling point 55.2 ° C ( 131.4 ° F ; 328.3 K ) Solubility in water 42 g / L ( 20 ° C ) Viscosity 0.36 cP at 25 ° C Hazards NFPA 704 Flash point − 33.0 ° C ( − 27.4 ° F ; 240.2 K ) Except where otherwise noted, data are given for materials in their standard state ( at 25 ° C ( 77 ° F ), 100 kPa ). Y verify ( what is ? ) Infobox references Methyl tert - butyl ether ( also known as MTBE and tert - butyl methyl ether ) is an organic compound with a structural formula ( CH ) COCH. MTBE is a volatile, flammable, and colorless liquid that is sparingly soluble in water. It has a minty odor vaguely reminiscent of diethyl ether, leading to unpleasant taste and odor in water. MTBE is a gasoline additive, used as an oxygenate to raise the octane number. Its use is controversial because of its contamination of groundwater and legislation favoring ethanol. However, worldwide production of MTBE has been constant owing to growth in Asian markets. Contents 1 Production and properties 2 Uses 2.1 As anti-knocking agent 2.2 Alternatives to MTBE as an anti-knock agent 2.3 As a solvent 3 Persistence and pervasiveness in the environment 4 Regulation and litigation in the U.S. 4.1 Restrictions on MTBE manufacturing and usage 4.2 Cleanup costs and litigation 4.3 Drinking water regulations 5 See also 6 References 7 External links Production and properties 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 m ) per day in 1999 ) during its use as a fuel additive. Uses MTBE is 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. As anti-knocking agent In the US it has been used in gasoline at low levels since 1979, replacing tetraethyl lead as an antiknock ( octane rating ) additive to prevent engine knocking. Oxygenates also help gasoline burn more completely, reducing tailpipe emissions and dilute or displace gasoline components such as aromatics ( e.g., benzene ). Before the introduction of other oxygenates and octane enhancers, refiners chose MTBE for its blending characteristics and low cost. Alternatives to MTBE as an antiknock agent Other oxygenates are available as additives for gasoline including ethanol and other ethers such as ETBE. Ethanol has been advertised as a safe alternative by agricultural and other interest groups in the US and Europe. In 2003, California was the first US state to start replacing MTBE with ethanol. An alternative to ethanol is 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. 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. As a solvent MTBE is extensively used in industry as a safer alternative to diethyl ether ( which is commonly used in academic research ) as the tert - butyl group prevents MTBE from forming potentially explosive peroxides. It is also used as a solvent in academic research, although it is less commonly used than diethyl ether. 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. MTBE forms azeotropes with water ( 52.6 ° C ; 96.5 % MTBE ) and methanol ( 51.3 ° C ; 68.6 % MTBE ). In a procedure called contact dissolution therapy, MTBE is injected directly into the gallbladder to dissolve gallstones. Persistence and pervasiveness in the environment MTBE gives water an unpleasant taste at very low concentrations. 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. 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, 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. According to the IARC, a cancer research agency of the World Health Organization, MTBE is not classified as a human carcinogen. MTBE can be tasted in water at concentrations of 5 -- 15 μg / l. 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. Regulation and litigation in the US The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject. You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate. ( April 2018 ) Main article : MTBE controversy Restrictions on MTBE manufacturing and usage In 2000, EPA drafted plans to phase out the use of MTBE nationwide over four years. Some states enacted MTBE prohibitions without waiting for federal restrictions. California banned MTBE as a gasoline additive in 2002. The State of New York banned the use of MTBE as a `` fuel additive '', effective in 2004. MTBE use is still legal in the state for other industrial uses. The Energy Policy Act of 2005, as approved by 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. This bill did include a provision that gives MTBE makers, including some major oil companies, $2 billion in transition assistance while MTBE was phased out over the next nine years. Due to opposition in the Senate, the conference report dropped all MTBE provisions. The final bill was signed into law by President George W. Bush. The lack of MTBE liability protection is resulting in a switchover to the use of ethanol as a gasoline additive. Cleanup Costs and litigation MTBE removal from groundwater and soil contamination in the U.S. was estimated to cost from $1 billion to $30 billion, 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 the city of Santa Monica, California was estimated to exceed $200 million. In another case, New York City estimated a $250 million cost for cleanup of a single wellfield in the borough of Queens in 2009. In 2013 a jury awarded the State of New Hampshire $236 million in damages in order to treat groundwater contaminated by MTBE. As of 2016, hundreds of lawsuits are still pending regarding MTBE contamination of public and private drinking water supplies. Drinking water Regulations EPA first listed MTBE in 1998 as a candidate for development of a national Maximum Contaminant Level ( MCL ) standard in drinking water. As of 2018 the Agency has has not announced whether it will develop an MCL. EPA uses toxicity data in developing MCLs for public water systems. California established a state - level MCL for MTBE in 2000. See also Cyclopentyl methyl ether ( CPME ) Ethyl tert - butyl ether ( ETBE ) tert - Amyl methyl ether ( TAME ) Tetraethyl lead ( TEL ) References ^ Jump up to : Record of Methyl tert - butyl ether in the GESTIS Substance Database of the Institute for Occupational Safety and Health Jump up ^ 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 Jump up ^ http://www.nesteengineering.com/default.asp?path=111,360,362,477 Archived January 6, 2006, at the Wayback Machine. Jump up ^ http://www.halliburton.com/kbr/hydroChem/petroChem/nexoctane.jsp Jump up ^ 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. doi : 10.1194 / jlr. D700041 - JLR200. PMC 2311442. Jump up ^ Vopička, Ondřej ; Pilnáček, Kryštof ; Číhal, Petr ; Friess, Karel ( 2016 - 03 - 01 ). `` Sorption of methanol, dimethyl carbonate, methyl acetate, and acetone vapors in CTA and PTMSP : General findings from the GAB Analysis ''. Journal of Polymer Science Part B : Polymer Physics. 54 ( 5 ) : 561 -- 569. doi : 10.1002 / polb. 23945. ISSN 1099 - 0488. Jump up ^ Vopička, Ondřej ; Radotínský, Daniel ; Friess, Karel ( 2016 - 02 - 01 ). `` Sorption of vapour mixtures of methanol and dimethyl carbonate in PTMSP : Cooperative and competitive sorption in one system ''. European Polymer Journal. 75 : 243 -- 250. doi : 10.1016 / j. eurpolymj. 2015.12. 015. Jump up ^ `` Interaction between bromine and tert - butyl methyl ether ''. Retrieved 13 May 2010. Jump up ^ Zeon Corporation Archived 2011 - 07 - 22 at the Wayback Machine. Jump up ^ CRC Handbook of Chemistry and Physics, 90th edition Jump up ^ Schoenfield LJ, Marks JW ( 1993 ). `` Oral and contact dissolution of gallstones ''. Am. J. Surg. 165 ( 4 ) : 427 -- 30. PMID 8480875. Jump up ^ `` Health Guide : Gallstones ''. New York Times. Jump up ^ San Francisco Bay Area Regional Water Quality Control Board Integrated Basin Management Plan ( 2004 ) Archived 2008 - 02 - 29 at the Wayback Machine. Jump up ^ link text Archived 2011 - 07 - 28 at the Wayback Machine. Jump up ^ Fischer A, Oehm C, Selle M, Werner P ( 2005 ). `` Biotic and abiotic transformations of methyl tertiary butyl ether ( MTBE ) ''. Environ Sci Pollut Res Int. 12 ( 6 ) : 381 -- 6. doi : 10.1065 / espr2005. 08.277. PMID 16305145. Jump up ^ http://www.epa.gov/mtbe/faq.htm#concerns Jump up ^ `` California Reformulated Gasoline Phase 3 ''. Sacramento, CA : California Air Resources Board. 2015 - 07 - 24. Jump up ^ `` Spill Response & Remediation FAQ ''. Chemical and Pollution Control. Albany, NY : New York State Department of Environmental Conservation. Retrieved 2018 - 04 - 06. Jump up ^ State of New York. New York Consolidated Laws, Agriculture and Markets Law. `` AGM § 192 - g. Methyl tertiary butyl ether ; prohibited. '' Jump up ^ http://www.cnn.com/2005/POLITICS/04/21/energy.bill.mtbe.ap/ Archived 2005 - 04 - 22 at the Wayback Machine. Jump up ^ http://www.msnbc.msn.com/id/7574562/+MTBE&hl=en Archived 2010 - 09 - 07 at the Wayback Machine. Jump up ^ 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 ). Jump up ^ United States. Energy Policy Act of 2005. Pub. L. 109 -- 58. Approved 2005 - 08 - 08. Jump up ^ `` MTBE Cleanup Estimates ''. SIGMA Weekly Report. Fairfax, VA : Society of Independent Gasoline Marketers of America ( SIGMA ). 2005 - 05 - 23. Archived from the original on 2009 - 10 - 09. Jump up ^ `` Long Island Utility Fighting to Defeat MTBE Safe Harbor ''. The MTBE e-Resource. New York, NY : Napoli Bern, LLP. 2004 - 03 - 16. Archived from the original on 2007 - 10 - 20. Jump up ^ `` Oil Companies Pay Santa Monica MTBE Cleanup Costs ''. Environment News Service. Ecology Prime Media, Inc. 2005 - 02 - 17. Jump up ^ Navarro, Mireya ( 2009 - 10 - 20 ). `` City Awarded $105 Million in Exxon Mobil Lawsuit ''. The New York Times. Retrieved 2010 - 05 - 12. Jump up ^ Earle, Sarah ( 2013 - 04 - 09 ). `` Exxon Mobil is Found Negligent in New Hampshire MTBE Use ''. Bloomberg. Jump up ^ EPA ( 1998 - 03 - 02 ). `` Announcement of the Drinking Water Contaminant Candidate List. '' Federal Register, 63 FR 10274 Jump up ^ `` Drinking Water Regulations Under Development or Review ''. EPA. 2017 - 01 - 27. Retrieved 2018 - 04 - 06. Jump up ^ `` How EPA Regulates Drinking Water Contaminants ''. EPA. 2017 - 05 - 03. Jump up ^ `` MTBE : Regulations and Drinking Water Monitoring Results ''. Sacramento, CA : California State Water Resources Control Board. 2014 - 08 - 04. External links 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 Motor fuels Fuel types Gasoline / petrol Diesel Biodiesel Lead Replacement Petrol Kerosene Compressed natural gas Hydrogen Ethanol Butanol fuel Racing fuel ( Tetraethyllead ) Fuel additives Butyl rubber Butylated hydroxytoluene 1, 2 - Dibromoethane 1, 2 - Dichloroethane Dimethyl methylphosphonate 2, 4 - Dimethyl - 6 - tert - butylphenol Dinonylnaphthylsulfonic acid 2, 6 - Di - tert - butylphenol Ecalene Ethylenediamine Metal deactivator Methyl tert - butyl ether Nitromethane Tetraethyllead Tetranitromethane Fluids Motor oil Antifreeze Automatic transmission fluid Brake fluid Gear oil Windshield washer fluid Retail Fuel card Full service MTBE controversy Pay at the pump Retrieved from `` https://en.wikipedia.org/w/index.php?title=Methyl_tert-butyl_ether&oldid=841522219 '' Categories : Hazardous air pollutants Dialkyl ethers Ether solvents Pollutants Soil contamination Oxygenates Tert - butyl compounds Hidden categories : Webarchive template wayback links All articles with dead external links Articles with dead external links from September 2014 Articles without UNII source ECHA InfoCard ID from Wikidata Articles containing unverified chemical infoboxes Chembox image size set Articles with limited geographic scope from April 2018 Pages in non-existent country centric categories All articles with unsourced statements Articles with unsourced statements from April 2018 Talk Contents About Wikipedia Afrikaans تۆرکجه Dansk Deutsch Eesti Español فارسی Français हिन्दी Italiano Nederlands 日本 語 Norsk Polski Português Русский Српски / srpski Srpskohrvatski / српскохрватски Suomi Svenska Українська 中文 14 more Edit links This page was last edited on 16 May 2018, at 10 : 42. 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Question: why is mtbe used as a gasoline additive
Answer: to prevent engine knocking