C&EN: TODAY'S HEADLINES - RETHINKING ETHANOL

CHERYL HOGUE

The Environmental Protection Agency must reconsider its decision forcing California to blend ethanol into gasoline once the state bans the additive methyl tert-butyl ether (MTBE), a federal court ruled earlier this month.

The 9th U.S. Circuit Court of Appeals said EPA erred by failing to weigh how its decision would affect particulate matter pollution. In its analysis, the agency considered only the effect on ground-level ozone. The court said EPA must revisit its decision and consider impacts on both pollutants.

California is poised to ban MTBE, effective Jan. 1, 2004, to protect drinking water supplies. The smelly chemical is moving into aquifers from leaking underground gasoline storage tanks and fuel spills.

Refiners use MTBE widely to boost the oxygen content of gasoline to make the fuel burn cleaner. The Clean Air Act requires that gasoline sold in polluted urban areas contain 2% oxygen by weight. About 70% of the gasoline sold in California must meet this oxygen standard.

But California does not want to have to use ethanol, also employed as an oxygenate in gasoline, as a replacement for MTBE in urban-area gas pumps. The state asked EPA to waive the Clean Air Act’s 2% oxygen requirement, saying refiners now can make cleaner burning gasoline without adding an oxygenate such as ethanol.

EPA turned down the request in 2001, a move praised by midwestern corn growers delighted by the prospect of supplying corn-derived ethanol to California’s huge gasoline market (C&EN, June 18, 2001, page 10). In response, California challenged the decision in court. EPA has not yet decided whether to appeal the court’s ruling.