Sulfur and gasoline

A U.S. Environmental Protection Agency review of emissions standards for model year 2004 autos has the oil and auto industries at odds over sulfur levels in gasoline. The 1990 Clean Air Act Amendments require EPA to consider stricter, Tier II, tailpipe emission standards. EPA plans to issue a draft report early in March and decide in 1999 if more stringent standards are needed. The American Automobile Manufacturers Association favors reducing sulfur to California's standards of 30 ppm

Feb. 2, 1998

3 min read

Patrick Crow
Washington, D.C.
[email protected]

A U.S. Environmental Protection Agency review of emissions standards for model year 2004 autos has the oil and auto industries at odds over sulfur levels in gasoline.

The 1990 Clean Air Act Amendments require EPA to consider stricter, Tier II, tailpipe emission standards. EPA plans to issue a draft report early in March and decide in 1999 if more stringent standards are needed.

The American Automobile Manufacturers Association favors reducing sulfur to California's standards of 30 ppm average, 80 ppm maximum.

Elsewhere in the U.S., sulfur levels in gasoline are 300-350 ppm.

AAMA said, "New emission control technologies are more sensitive to sulfur than previous technologies and require higher catalyst efficiency levels for all operating conditions."

It said studies have shown the benefits of low-emission vehicle hardware diminish as fuel sulfur increases above 40 ppm.

It said sulfur levels should be low enough "to ensure that existing and new technology vehicles meet the stringent emission and performance standards for which they were designed."

Tosco's proposal

Last month, Tosco Corp., the nation's largest independent refiner and marketer of petroleum products, recommended that EPA require refiners to slash the sulfur content of gasoline to 80 ppm.

It said, "There seems to be broad consensus that reducing sulfur levels in gasoline on a national basis will result in much lower emissions."

Tosco Chairman and CEO Thomas O'Malley said, "Gasoline is the best practical motor fuel for the American public today, and gasoline can be the environmental fuel of the future.

"We think that our industry has not moved far enough or fast enough on this issue. Gasoline must be constantly improved on both an environmental and performance basis, and our recommended change is a clear move in that direction.''

Tosco said 80 ppm is the highest level that would not affect gasoline emissions.

The American Petroleum Institute responded that Tosco's proposal was premature.

Caution urged

API said it and the National Petroleum Refiners Association want to cooperate with EPA.

API said, "We recognize that reducing the sulfur content of conventional gasoline is part of the national commitment to improve air quality and that, for certain areas of the country that need nitrogen oxide reductions to meet air quality standards, even lower sulfur levels may be effective."

It said EPA should determine how much emissions need to be reduced, the most cost-effective mix of changes to the vehicle-fuel system, what is practical, and what air quality improvements would result.

API said any sulfur cuts should not result in serious operational or distributional problems for industry or substantial costs.

It said research shows reducing sulfur can cut tailpipe emissions, but the magnitude varies significantly from vehicle to vehicle.

API said the trick is to find "the right balance between fuel sulfur levels and improved vehicle emissions controls" to meet clean air goals at the lowest possible cost to the consumer.