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IMPERIAL OIL

Looking Ahead

by Rolf Lockwood
Untitled Document


Pollution and politics go together like pork and beans, especially in Washington, DC. Controversy has surrounded the U.S. Environmental Protection Agency since its birth in 1970 and its first victory, which was to ban lead in gasoline and require catalytic converters in cars. It's been winning on the diesel front too, but the tough emissions standards it has ordered for 2007 are still the source of much second-guessing. And then there's 2010.

The coming EPA standards - mirrored here in Canada - really are tough. In 2007, half of all on-highway diesels sold will be allowed to emit no more than 0.20 g/hp-hr (grams per horsepower-hour) of nitrogen oxide (NOx), which is a whopping 90% drop from 2002/04 levels. By 2010, 100% of on-highway engines must be at the 0.20 mark. On top of those reductions, '07 particulate emissions can't exceed 0.01 g/hp-hr, also a stunning 90% drop, a standard that will remain in place for 2010. The challenge is enormous.

And what will you see in January, 2007?

All engines except the Mercedes diesels found in some Freightliner, Sterling, and Western Star trucks will follow the basic technology paths that met the 2004 standards. Cummins, Detroit Diesel, Mack and Volvo will continue with cooled-exhaust-gas recirculation (EGR), while Caterpillar will continue using its ACERT technology. All will add a diesel particulate filter, including Cat, which is already using an oxidation catalyst behind its engines. Mercedes engines will use both EGR and a particulate filter. None of them will use selective catalytic reduction (SCR) technology (see sidebar).

All of these 2007 engines will be running on ultra-low-sulphur diesel fuel (ULSD), which the EPA has mandated for mid-2006. It's a radical reduction of the sulphur content in fuel from 500 to just 15 parts per million. Because it will require different and additional refining methods, transportation means, and storage facilities, it will cost more, though how much more remains to be seen. U.S. estimates suggest up to five cents per gallon. Older diesels will run fine on the new fuel.

And yet again, '07 diesels will require another new lube-oil spec just as present models did.

That much we know, more or less, but the fighting really doesn't seem to be over. Even the General Accounting Office, the non-partisan investigative arm of the U.S. Congress, called for an independent examination of the '07 rules in a report issued in mid-March (see www.gao.gov).

"We think there are sufficient technological challenges to justify a second independent review," said John Stephenson of the GAO in a presentation to delegates at the annual meeting of the Technology & Maintenance Council in Fort Lauderdale, Fla., on March 16. Taking part in a full day of panel sessions, called the Diesel Engines Emissions Summit II (another was held last fall), he said several technological issues were missed in a previous review. Among them, he said, is the distribution of ULSD fuel.

He wants incentives for truck buyers, in hopes of preventing the massive pre-buy of trucks with old-style engines that occurred in advance of October, 2002 when the '04 standards went into effect. The American Trucking Associations is also looking for tax credits to encourage truck buyers to accept '07 engines.

At the lively first session of the TMC summit, populist Republican Congressman Mac Collins from Georgia was hard on the EPA and its ham-fisted handling of the 2002/04 emissions rules. A truck fleet owner himself, he said he doesn't buy the EPA's stated commitment to make all this work.

He said the consumer's pocketbook must be considered in the course of protecting the environment. He added that we don't know enough about the economic impact of the pull-forward of 2004 rules to October, 2002, and he guessed that it was much more than anyone imagines.

"The truth of the matter is that I don't trust the EPA, and I caution you to be careful," he told the 1100 Summit delegates in closing. "We should never have a government that we can't trust."

The New Engines
Some time next year engines meeting the 2007 emissions standards will be on the road in real-world tests, operated by fleets in revenue service. All diesel makers say they'll meet this goal, and oil refiners say they can supply enough ULSD fuel to facilitate the testing. They'll establish "corridors" in the U.S., routes along which the fuel will be available in advance of 2006. It's not clear if similar corridors will be set up in Canada.

The test engines will be pre-production models, giving the industry a chance to work out the inevitable bugs over the course of 18 months or so. That will be a welcome change from October of 2002, when engine makers and fleets alike complained of too little development and testing time.

Here's what you can expect:

Caterpillar's ACERT solution, which presently employs a mix of injection, combustion, and electronic tools along with exhaust aftertreatment, will continue on that path. Cat's John Campbell told Summit delegates that the 2007 ACERT engine will employ a "next generation" fuel system, advanced combustion technology, better thermal management, and a particulate filter. Cat's aiming at a 150,000-mile interval for filter maintenance. There may also be a secondary filter required, he said.

Selective catalytic reduction (SCR) was once thought to be part of the 2007 emissions solution in North America, but its chief proponents, Detroit Diesel and Volvo, recently announced they'll go with EGR after all. SCR is the choice for Europe's next round of emissions rules ('Euro 4') coming in October, 2005. They're roughly equivalent to the 2007 North American standards.

SCR is a well developed technology that reduces NOx while returning better fuel consumption than EGR. It uses ammonia produced on board the vehicle from a non-toxic liquid urea solution in a separate tank. The urea solution is added to a catalytic converter to make the required ammonia. Urea is a colorless, odorless liquid widely used in many industries.

The downside of SCR is that it demands a supply network for the urea, with special pumps for filling urea tanks at truckstops and fleet yards. That didn't endear it to the EPA, which has also expressed concern about enforcement issues - how could it ensure that urea tanks were always filled?

But don't count SCR out for 2010. Most engine makers have extensive experience with it, and Cummins says it's already using it in some off-highway applications. Detroit Diesel calls it "a viable alternative for 2010." Cat's investigating it but it's at "the bottom of our list," according to on-highway engine chief John Campbell.

At Cummins, said Dr. Steve Charlton, '07 engines will look exactly like their '02 brethren, though they'll need an 'active' particulate filter.

A 'passive' filter takes advantage of normal exhaust heat to 'regenerate' itself periodically, meaning it oxidizes or burns accumulated soot and cleans itself with the help of a catalyst. An 'active' filter creates additional heat when needed by electric means or by an injection of fuel, managed by engine software. Passive filters are generally ineffective at low loads and low ambient temperatures.

PM filter technology has been under development at Cummins since the 1980s. The company is working with lube-oil additive suppliers to come up with low-ash compounds with the target of maintenance-free filters by the time we get to 2007.

Charlton said a particulate filter will not be irreparably harmed if fed high-sulphur fuel. It will get dirty faster, and the truck will probably not meet emissions standards for a time, but the filter will eventually clean itself out.

Cummins is now working on packaging and integration issues with truck makers. It has prototype engines running in trucks today and will have 20-30 development engines in customers hands by mid-2005.

Detroit Diesel's Tim Tindall said the company is still running parallel development programs with both EGR and SCR technologies, having chosen the former for North America, the latter for Europe. Developments of the '02 Series 60 technology now in use include changes to the fuel system and to the troublesome EGR valve, advanced electronics, additional sensors, and a closed crankcase ventilation system as well as an active particulate filter.

The filter's design is not finalized, Tindall said. Engineers are still working on its regeneration method and its physical shape. He added that heat rejection remains an issue, saying an '07 engine may run a little hotter and could conceivably require a larger radiator.

A new 14.8-litre engine being developed by DDC and parent company DaimlerChrysler, scheduled for release in 2007, will also employ EGR and diesel particulate filters for North American applications.

At Mack and Volvo a common base engine (a variation on the present Volvo 12-litre model, though a larger block may be coming) will find its way into both chassis brands, marking the end of the Mack E7, and will feature cooled EGR with active particulate filtration.

Volvo's Tony Greszler told the packed TMC auditorium that the company's target is to offer a filter that needs no service until 300,000 miles, double what most others were estimating. That service cost should be about $150, he said. He anticipates no reduction in other service intervals, and said they might even be extended. The company plans to have about 30 engines in field testing by next spring.

Four men in charge of trucks at four of the biggest U.S. fleets expressed universal displeasure with '02 diesels in a panel session during the Engine Emissions Summit at TMC. Fuel-economy losses reported were as high as 15%, as low as 3%.

Dennis Beal controls 9130 tractors doing LTL work at FedEx Freight. He told delegates that his 758 '02 engines have run a combined 29 million miles, the highest single mileage figure being 175,000.

"We've had no horror stories," he said, "but we've had a lot of pain and the costs have been horrendous... We still believe there's a big improvement that can be made."

He's been surprised by the relationship between horsepower and fuel efficiency. "Everything I thought I knew about horsepower, I've had to throw out the window," he said. At FedEx, the higher the horsepower rating of an '02 engine, the better the fuel economy has been.

Beal added that there have been relatively minor reliability issues, and on the positive side, routine oil and coolant analyses have shown no problems. He's been able to maintain his 36,000-mile service intervals.

Steve Duley, vice president of purchasing at Schneider National, said oil-drain intervals have gone unchanged on his fleet's 1000 '02 engines (a mix of Caterpillar, Cummins, and Detroit) as well. He also said that there have been significant improvements in the engines he's buying now compared to the first batch of '02 motors, proving that the regulatory pull-ahead from January 2004 to October of 2002 was very costly.

Fuel-economy losses at Schneider have been in the 3-5% range, though parts costs have doubled, and overall the incremental price of these engines works out to 2-3 cents per mile.

Marty Fletcher, director of technology at U.S. Xpress, has some 1200 '02 motors, also a mix of Caterpillar, Cummins and Detroit. They have collectively suffered a fuel-economy degradation of 9-12% based on engine ECM data.

Jim Salas, manager of application engineering at Ryder Transportation Services, the final speaker on this panel, said he's charted a four-cent-per-mile operating cost increase. Among his main concerns is the growing lack of choice in engine/chassis combinations, given various alliances and the onset of vertical integration at some truck OEMs.

Having also developed SCR engines for Europe (until recently it was thought Volvo would use them here too), Volvo says that technology remains promising for future applications in North America.

Clearly, the key to the success - and much of the extra cost - of all 2007 engines will be the particulate filters they employ. Steve Duley, vice president of purchasing at Schneider National, says he's concerned about the cost of these particulate filters, saying they look simple but aren't likely to be as simple to own.

They will add some weight, about 140-170 lb for heavy-duty engines, says Pedro Ferro, vice president and general manager of ArvinMeritor's Commercial Vehicle Exhaust division.

His company, better known for axles and brakes and such, is in fact a leader in the exhaust filtration field, including SCR, and its Thermal Regenerator is an active particulate filter that boasts 99% filtration efficiency without using expensive precious metals on the filter media. The system identifies when regeneration is required, then injects a small amount of fuel into the exhaust stream to reach soot-burning temperature in seconds. The regeneration takes about 10 minutes and would typically be required every 100 hours, consuming a half-litre of diesel fuel.

Ferro looks ahead to 2010 and, as most engine makers are speculating, sees the need for additional hardware to control NOx in the exhaust stream, not in the cylinder. SCR can achieve that, but EGR probably can't do it on its own.

But the more immediate questions concern 2007 and especially the likelihood of another round of pre-buying. There's no doubt that these engines will be more expensive, though cost estimates are impossible to come by. Same with fuel economy: it's up in the air, though it probably won't change too much. And as for how an '07 diesel will fell under your right foot, nobody knows that either.

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