Ethanol in Motor Fuels

The article on renewable fuels makes apparent that the objective of using ethanol in U.S. automotive fuel has shifted away from smog-reducing fuel oxygenation, for which it was introduced in additive concentrations a few decades ago, toward the complete substitution of crude oil as feedstock (C&EN, Sept. 17, page 28). The article also points out some of the drawbacks of ethanol, most notably that it is hydrophilic, unlike the fuel additive ethers methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME), which ethanol has recently displaced in the U.S., ostensibly on environmental grounds.

In contrast to the U.S., in Europe ether oxygenate usage has not aroused legislative ire. Fuel ether is, after all, undoubtedly less toxic than the benzene, which evidently also seeps from leaky U.S. gasoline station tanks. Now that U.S. motives have been clarified, isn't it time that the dubious environmental objections against ether fuel oxygenates be reconsidered by the state and federal bodies that raised them?

Jonathan Targett
London