MTBE/Oxygenates/Clean Fuels

Oxygenates are gasoline blending compounds used extensively in worldwide gasoline. These compounds contain oxygen in their structure, and are generally described as “ethers” or “alcohols”. The two most common oxygenates are Methyl Tertiary Butyl Ether (MTBE) and ethyl alcohol (EtOH). Oxygenates reduce the carbon monoxide in gasoline engine exhausts and are generally helpful in reducing other volatile organic compounds which contribute to urban smog.

In the United States, Federal Law requires “Reformulated Gasoline”(RFG) used in the smoggiest areas to contain two percent oxygen by weight. This corresponds to 11% MTBE by volume, or 5.7% EtOH by volume. Since RFG makes up about a third of US gasoline, the quantities involved are substantial. In 2001, about 300,000 barrels of MTBE were used in the USA, and another 120,000 barrels of EtOH was also blended. MTBE is used in other parts of the world to help in reducing smog, and helping to eliminate the formerly wide use of lead in gasoline formulations.

MTBE is slightly soluble in water, and has been found in ground-water formations in the vicinity of leaking underground storage tanks. Its use is under severe attack in the USA., with active political maneuvering to replace it with ethanol. This is not easily carried out.

Dewitt & Company has been following the development of fuel oxygenates for more than 15 years, and has studied the dynamics of the US gasoline markets extensively.