SCR Wars

It's not something you see every day. There, at one table, were the CEOs of most of the heavy-duty truck and diesel engine manufacturers doing business in North America, and they were all presenting a united message: you have nothing to fear from Selective Catalytic Reduction (SCR) and Diesel Emissions Fluid (DEF) in 2010.

The event was the "SCR CEO Summit," held on March 19th at the Mid-America Trucking Show in Louisville, KY, and the CEOs in question spoke to a full house about their common choice to use SCR technology to meet the 2010 EPA diesel engine emissions standards. They were in fighting mood, ready to counter what they see as misinformation being spread by Navistar/International, the only engine OEM to choose Advanced EGR over SCR.

Here are excerpts from the CEOs' comments:

President & CEO, Daimler Trucks North America

"Did you ever imagine a day when an environmental mandate would deliver technology that is as good for business as it is for the air we breathe?

"Early measures to clean up the pollution from gas engines led to widespread adoption of fuel injection, variable valve timing and electronically-controlled ignition. In turn, these led to tremendous enhancements in driveability, performance, and fuel consumption.

"And the drive to reduce the emission of oxides of nitrogen from diesel engines has had a similar effect. But one of the key differences for commercial diesel engines has been that some of the purifying technologies have had a detrimental impact on engine performance, durability, and fuel economy. With SCR, that negative trend is stopped.

"In fact, it is reversed. And that's good news for all involved...

"Selective Catalytic Reduction helps us meet the 2010 standard... but it brings other benefits, too. By substituting a small amount of a substance that is made from natural gas widely available here at home for a larger quantity of diesel fuel, it helps reduce our dependence on imported oil.

"It improves the economics of a trucker's business, by reducing diesel fuel consumption. And the virtual elimination of NOx will lower the nation's health care bill, as well as reduce suffering and premature deaths.

"SCR is NOT a new development. It's been used for decades to clean emissions at electrical generating stations. It's been deployed in huge numbers in Europe and Japan, both for commercial vehicles and passenger cars. We are simply bringing this proven and cost-effective clean air technology to Canadian and American truck operators. And there is no doubt that SCR will be adopted in other nations, like Mexico, whose air quality standards lag the 'triad' countries by a step or two.

"The four of us produce the ONLY engines in volume production today that will still be available after the new standard comes into effect. So, when we say our engines will burn up to five percent less diesel fuel after the first of the year, we speak with authority born of experience.

"It might shock you to learn that we DID explore other ways to comply with the 0.2 g/bhp-hr standard, as far back as ten years ago. And we decided to go with SCR because it was the better answer for our customers, not because it was somehow an advantage for us... The other technologies burned too much fuel, weighed too much, needed oversized cooling systems that affected packaging in the worst way, and were a mess to install.

"Some of our European competitors in fact introduced engines without SCR when the EURO IV standard went into effect in 2006, but their customers quickly rebelled, and they followed up with the right answer, introducing SCR as quickly as they could.

"...for the immediate, and the foreseeable future, nothing beats diesel engines with SCR for the commercial vehicle customer. The only technology proven to be as good for business as it is for the environment, SCR may be the "silver bullet" we've all been waiting for..."

President & CEO, Volvo Trucks North America

"It strikes me as I sit here that even though we represent a very significant percentage of the world's heavy-duty engine and truck production, we must not be very good leaders. And the thousands of engineers working for us around the globe must not be very bright. Because we've selected SCR for EPA 2010.

"And, according to the sole adopter of massive EGR, we've all made the wrong choice. This will certainly come as a surprise to the many customers around the world who are already using SCR. They are running hundreds of thousand of SCR-equipped trucks--and they are running very successfully. Fuel economy is what customers demand, and fuel economy is what SCR delivers.

"Customers have a choice next year, and the EPA has clearly indicated that it won't be a choice between buying EPA '07 and EPA '10 products. It will be a choice between proven global experience and expertise, and the claims of a regional manufacturer--a manufacturer that's making its first entry into the heavy-duty engine business.

"There are currently no production trucks--anywhere in the world--that deliver 0.5 grams of NOx with EGR only. Never mind the 0.2 gram standard that we're achieving with SCR--a standard that the competition is going to have to meet once its bank of credits is exhausted."

President & CEO, Mack Trucks

"My message is very simple.

"We use EGR today. We know it puts additional stress on the engine. We know it generates a lot of heat, even at today's levels. We know it presents challenges when it comes to engine performance and fuel economy.

"We're managing all of this extremely well today. But we've reached the limits of what can be accomplished with EGR.

"More is definitely not better. We were ok in 2002 when the NOx standard was 2.5 grams and we could use low rates of EGR to meet it. When the standard was cut in half for 2007, down to 1.2 grams, it took a tremendous amount of engineering know-how to still use EGR for NOx because we had to go to higher rates.

"For 2010, the NOx standard drops to .2 grams, so small it's difficult to even measure. And it's just not possible to meet this .2 gram NOx level with EGR alone. Even the rate of EGR required to get NOx to .5 grams, the allowable limit using credits, takes the diesel engine into unknown territory with stress and heat.

"And there's no way around fuel economy and performance penalties. This isn't marketing--it's science, pure and simple.

"The bottom line? All of us up here today know EGR, we're experts in EGR, and that's why we're using SCR.

"We know there's misinformation about SCR out there, a lot of marketing over matter. Our message to customers is, 'Do your homework.' Become educated about both SCR and massive EGR so that you can make an informed decision. Explore the information on our websites, talk to us, ask questions.

"All of the talk goes away when the trucks get into the field. And based on the reaction of customers operating SCR-equipped trucks right now every day, we know this is where we will truly shine."

President of Engine Business, Cummins Inc.

"Cummins also has significant experience with both Cooled EGR and SCR. We've repeatedly said that we do not have a favorite technology. We've used Cooled EGR since 2002 to meet EPA standards for our six, eight, nine, 11 and 15 liter engines, and we've used SCR to meet EURO IV and V standards for medium-duty truck and bus throughout the continent.

"One of the advantages that Cummins has, at least in our view, is core competencies in combustion management, fuel systems, air handling and turbo machinery, filtration and aftertreatment controls. We've utilized these areas of expertise to come up with what we think is the right solution for our customers, and that's SCR.

"By thinking outside the cylinder, we've determined that the right technology to meet the near-zero 2010 emissions standards is in fact a combination of Cooled EGR and SCR.

"There are many reasons for this, but let me discuss five.
"The first is fuel-efficiency. We've clearly demonstrated through field testing and lab analysis that fuel-efficiency is greatly enhanced, both saving our customers money and emitting fewer greenhouse gasses.

"Secondly, our 2010 engines will have a much wider 'sweet spot' to hit driver capabilities. We think that this will contribute to as much as a five percent fuel economy increase.

"SCR requires no modification to cooling systems. It also provides higher power density, so we're able to provide power in a higher range at the same displacement that we enjoy today.

"And we're experiencing the ability to avoid multiple EGR coolers and valves, as well as (being able to) simplify turbo machinery.

"I do want to address one item that has come up with me, personally. There's been much discussion about some company's choice to use Cooled EGR to meet the EURO V requirements, and the perception that EURO V and EPA 2010 are close. EURO V is a long way from EPA 2010 as relates to NOx, and there's an emerging consensus that EURO VI will be met with Cooled EGR and SCR as well.

"So, we're confident in our 2010 solution, and that includes SCR. We also understand that in order to make an SCR system work we have to have DEF available... We believe that infrastructure is well underway, and will be more than capable of meeting the industry's needs."

International MaxxForce Advanced EGR

Navistar, manufacturers of MaxxForce medium- and heavy-duty diesel engines for International trucks, has also issued its own public comments on the merits of its "Advanced EGR" emissions system for 2010. The company has, in recent months, introduced its MaxxForce 13-liter engine at the World of Concrete Show in Las Vegas, its medium-duty MaxxForce DT engine at the National Truck Equipment Association Work Truck Show in Chicago, and it's top-of-the-line MaxxForce 15-liter engine at the Mid-American Trucking Show in Louisville, KY. The following is a compendium of some of the comments from Navistar from all three events:

"Our strategy of 2010 emissions compliance through the use of an EGR-only solution is on track," said Steve Guillaume, Navistar general manager, vocational trucks. "With our line-up of MaxxForce Advanced EGR engines, we're delivering a simple and straightforward solution that places the burden of emissions compliance on the manufacturer, not the consumer."

To meet the U.S. Environmental Protection Agency (EPA) 2010 emissions requirements for on-highway diesel engines, MaxxForce Advanced EGR engines will use proven technologies such as advanced fuel injection, air management, electronic controls and proprietary combustion technology.

"We've been conducting rigorous testing and analysis in our engine labs and currently have 2010 prototype engines installed in medium- and heavy-duty test trucks," said Ramin Younessi, group vice president, truck and engine product development. "These test vehicles are on the road in real-world conditions and will log millions of miles of real-world experience before the launch of these engines."

Other major truck and engine manufacturers are choosing a 2010 emissions path through Selective Catalytic Reduction (SCR), which requires the use of an additional operating fluid, called urea, as well as significant aftertreatment equipment that will add hundreds of pounds to each vehicle.

Navistar's EGR approach will not require the use of urea or the addition of heavy on-vehicle urea storage tanks, converters, heaters, and the additional electronics required by SCR systems. MaxxForce Advanced EGR engines set Navistar apart from the competition with a no-hassle, business as usual solution for the customer by delivering lower operating costs.

"Many of the OEMs adopting the SCR strategy point to the success in meeting Europe's emissions standards, which are not as stringent as the U.S.," added Younessi. "However, at least two European engine manufacturers are moving toward a non-SCR solution to meet Europe's next emissions hurdle. That should raise some doubts about the long-term viability of SCR."

For SCR systems in the U.S., the EPA will require a series of driver compliance controls, including a complex array of warning lights as well as a disabling system which will automatically power down the engine when urea levels run low.

"We strongly believe the accountability for emissions compliance should rest on the manufacturer, not on the actions of the driver, the reliability of very complex technologies or the impact of climatic conditions," added Guillaume. "The development and testing of our EGR solution for 2010 is in advanced stages and we are confident that our engines will deliver the performance, reliability and low operating costs our customers demand."

Guillaume added in his comments at the Work Truck Show that that adoption of SCR engine technologies would be hampered by what he described as an "underdeveloped urea infrastructure" and suggested that urea is "very volatile." His colleague, Jim Hebe, Navistar senior vice president, North American sales operation, softened the rhetoric a bit in his comments at a private function at the Mid-American Trucking Show, saying that urea is "possibly volatile."