ABSTRACT
Etherification processes are relatively new additions to refinery configuration. The first methyl tertiary-butyl ether (MTBE) units were built in the 1970s, when phase-out of lead-containing octane enhancers started. The big expansion of etherification units took place in the late 1980s and early 1990s, when the U.S. Clean Air Act Amedment (CAAA) was passed. U.S. legislation mandated use of oxygentaes in reformulated fuel gasoline (RFG) in areas where specified air quality targets were not met. As a result, several new MTBE and tertiary-amyl methyl ether (TAME) plants were built and MTBE became a worldwide-traded chemical. Ethanol is another oxygenate which can be used in RFG, but due to higher production costs than ethanol, ethers are preferred almost everywhere.
