Diesel engines are pillars of the world's heavy industrial economy. But they are also big-time polluters. So depending where you sit, the proposed requirement to cut the sulfur in diesel fuel by up to 97% is either a lemon or lemonade. For commuters stuck behind a bus or a tractor-trailer rig, cleaner diesel exhaust will be sweet relief. But for someone hauling a truckload of widgets from Tucson to Tucumcari, N.M., the projected costs of the latest clean-air thrusts by the Environmental Protection Agency leave a very sour taste indeed.
This summer, the EPA laid down the law: All new, heavy-duty diesels sold after 2006 must conform to its new clean-engine standards. In addition, the agency said it may slap a limit of 15 parts per million (ppm) on sulfur in diesel fuel--a dramatic reduction from the current cap of 500 ppm.
For the trucking industry and diesel-engine makers, complying with the new mandate will be expensive. Engine manufacturers are already spending hundreds of millions designing more efficient diesels, despite howls from at least one engine maker that the technology remains unproved. As for fleet owners and independent truckers, they can look forward to paying an extra $6,000 apiece for the new, cleaner engines, plus as much as 52 cents more per gallon for new, low-sulfur fuel. These will be hefty surcharges for the notoriously low-margin trucking business. For some weaker members of the industry, the effects could be devastating, says Diego Saltes, an economist at the American Trucking Assn. (ATA).
Of all the measures under consideration, the heaviest burden would come from an EPA decision to clamp a 15-ppm lid on sulfur. To slim down to that level, petroleum refiners say they would have to revamp their plants to the tune of $8 billion. Moreover, U.S. production of diesel fuel could drop as much as 30% for at least a couple of years while refineries are being upgraded. That could lead to a fuel shortage, which would mean "idle trucks, undelivered shipments, unusable equipment, and loss of livelihood," said ATA Vice-President Beth Law at a recent EPA hearing.
The EPA is taking such reactions in stride. It's just the usual last-minute posturing, says Robert Perciasepe, the EPA's assistant administrator for air and aviation. "With every instance of rule-making we undertake," he says, "people harden their positions."
LUNG DAMAGE. Industry has had plenty of time to refine its arguments. The sulfur proposal has been in the works for years. The EPA adopted its first emissions standards for heavy-duty diesels in 1985. Back then, diesel fuel contained 3,000 ppm of sulfur. The EPA demanded a reduction of 83%, to 500 ppm. Sulfur is noxious stuff, and most of it gets coughed out through the tailpipe. These emissions not only contribute to acid rain but also can cause breathing problems or even lung damage in people who are exposed to too much.
While it is true that diesels produce less carbon dioxide than other engines, that doesn't offset their liabilities. In addition to sulfur, diesel engines release more nitrogen oxides, or NOx, than gasoline burners. NOx compounds react with hydrocarbon emissions to foster low-level ozone, or smog, plus poisonous particulate matter. The dark exhaust spewing from a diesel is the visible part of this problem, but there are invisible particles as well.
COST FACTOR. In 1990, tougher standards became all but inescapable when Congress amended the Clean Air Act and called for further limits on diesel emissions. The EPA decided that a "systems approach" was needed. Neither cleaner fuel nor cleaner engines would be sufficient--only both together could pull it off. The main reason: Just as lead in gasoline damages catalytic converters on cars, sulfur would poison the new catalytic cleaning process then being developed for diesel exhaust systems.
Five years ago, the EPA won what it called a "historic statement of principles" from makers of heavy-duty diesel engines. They agreed to start developing cleaner engines. But the new engines would deliver on the EPA's goals only if they burned low-sulfur fuel.
Since then, the only real issue has been how low the new cap would be. Refiners suggest a 90% cut in sulfur, to 50 ppm. That would involve retooling costs of about $4 billion. But dropping to 15 ppm, they say, would require much higher refining temperatures, and that would mean substantial rebuilding at refineries--doubling their costs. "The emissions standards were picked by the EPA out of the air," asserts James E. Williams, products coordinator at the American Petroleum Institute. "There is a lot of uncertainty about whether or not the technology the EPA is relying on will work."
A common complaint is that 50 ppm is nearly as good for the environment as 15 ppm. "The agency has a well-established reputation of going after the vanishingly small," says Tom Van Arsdall, vice-president of the National Council of Farmer Cooperatives, which includes a small group of refiners who supply diesel fuel to farmers. He's not too upset, though, because farm vehicles would be exempt from the EPA's new mandates, at least for now--as would construction vehicles, boats, and trains. But that irritates truckers all the more. "The EPA has singled out the diesel-fueled truck," says ATA's Law. "This not only raises obvious issues of fairness, but it promises to create an inconsistent, balkanized regulatory scheme."
Surprisingly, engine makers and auto companies think the EPA should push for even lower levels of sulfur. They'd like a 5-ppm cap. Carmakers figure fuel-efficient diesels would mean they could sell more sport-utility vehicles and pickup trucks and still meet the EPA's mileage requirements. The engine companies worry that even 15 ppm will strain the new catalytic cleaners. "We are committing every effort to put these expensive catalysts on trucks," says Glenn F. Keller, an executive at the Engine Manufacturers Assn. "The kitchen sink is going to be thrown at these engines to get them to these levels. But we're going to need these fuels."
The EPA is now evaluating claims and counterclaims from the recent round of hearings. "We are very sensitive to businesses, including the truckers," says EPA's Perciasepe. "The diesel engine is the workhorse of the American economy, but it needs to be cleaner." The agency plans to announce its final decision before yearend. Wanna bet on how many parties it will satisfy?