Methyl tert-butyl ether
Methyl tert-butyl ether (also known as MTBE, tert-butyl methyl ether, tertiary butyl methyl ether and tBME) is an organic compound with molecular formula (CH3)3COCH3. 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 in the US and declining in use in part because of its occurrence in groundwater 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.
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 m3) per day in 1999) during its use as a fuel additive.
