'Tell It Like It Is' Panelists See Clean-Diesel Deadline Problem

Diesel Fuel News, Nov 13, 2000 by Jack Peckham

Hart/IRI refining consultant Nick Economides said that the 15 ppm sulfur limits proposal "is a very tall order and it's difficult, although the refining technology is there." While not referring specifically to the diesel rule, Economides pointed out that "our industry suffers a loss of credibility if we say the cost is 25 cents/gallon and then it comes in at under 10 cents.

"We still don't know all the parameters. I'd want to know the off-road fuel parameters before I do on-road, and if 10% aromatics may become another limit."

U.S. DOE refining industry analyst Barry McNutt pointed out that diesel vehicle catalyst sulfur tolerance hasn't yet been definitively established, so it's premature to set ULSD sulfur cap specifications right now.

"We don't have the information now, though an average of less than 10 ppm is what's going to be required," McNutt said. "So there's no point in doing what doesn't work, and we don't know the right sulfur cap. It also will take more work to understand pipeline [sulfur] contamination, and more work to see whether an exhaust catalyst can tolerate intermittent exposure to higher-sulfur fuel, and how much it can tolerate."

A new ULSD trend seems to be emerging, however, DaimlerChrysler's Loren Beard said. "Sweden and Finland are already using 10 ppm sulfur fuel, Germany is going to 10 ppm, and others will follow," although southern European refiners are much less enthusiastic about 10 ppm than northern refiners, as one Euro refiner at the Hart conference pointed out.

"It seems there is some degree of uncertainty on cost-effectiveness for both the auto/engine industry and the oil industry," Hart/IRI's Economides said. "But there's a lot less uncertainty about whether the oil industry will hold up its end [producing ULSD] at some cost. However, [refiners fear] they may move ahead when the other side [engine/auto] doesn't keep its promise.

"They [engine/auto] seem to have a lot more work to demonstrate commercial viability. Let them demonstrate this before putting this marriage together."

Asked whether EPA may be pushing near-impossible "best available control technology" NOx/PM limits by the mid-2006 deadlines, EPA's Oge defended the plan.

"The 90% PM and 97% NOx reductions come from our air quality assessment," Oge said. "We hope the diesel will continue to be a future fuel of choice and for it to do that it has to become cleaner, because it's a significant problem," especially in many major cities. "You look at air toxics and it's the biggest contributor" in areas such as New York City, she said.

"Remember that we're talking about technology for seven years from now. We're not worried about PM traps. NOx traps are not as developed, but we believe we can get the 97% efficiency. If we had 50 ppm sulfur fuel, based on what we know today, we'd only get 30% NOx reduction rather than 97% NOx reduction.

"We push the most aggressive technology possible, taking into consideration cost and energy and supply and price spikes," she said.

But achieving that at some reasonable cost may require much more flexibility (such as a compliance phase-in) for the refining industry, McNutt said, pointing hopefully to EPA Administrator Carol Browner's earlier promise at the Hart conference to try to achieve such flexibility.