INTRODUCTION

During the early 1990s, the oxygenate portion of the gasoline pool was the fastest-growing gasoline component, and the majority of this growth was in methyl tertiary butyl ether (MTBE). The major reasons for this growth were generally considered to be environmental concerns and octane upgrades. Countries such as the United States, Korea, and Taiwan mandated the use of oxygenates in gasoline to promote cleaner-burning fuels. Lead phasedown programs, the introduction of midgrade and higher-octane premium gasolines, and newer, more sophisticated car engines all contributed to a steadily increasing demand for higher-quality gasoline and thus a continuing need to increase the octane of the refinery gasoline pool.

In the late 1990s regulators in the United States passed legislation requiring the phaseout of MTBE from many markets in the early 2000s, due to numerous instances of groundwater contamination with MTBE. The major cause of the contamination is leaking underground storage tanks and pipelines and limited biodegradability. Some people have a very low taste threshold of ~ 10 ppb MTBE in H ₂O. Very few new ether units for fuels applications have been constructed since the U.S. action. By 2002 many U.S. producers stopped MTBE production and were considering alternative technology to consume isobutene by reusing MTBE plant equipment (see UOP InAlk process).

An important source...