DIESEL EXHAUST AFTER-TREATMENTConverting Challenges Into
Growth Opportunities SAN ANTONIO, TX (March 5, 2006) - In an interview with Frost & Sullivan, Tenneco Chief Engineer Adam Kotrba discussed the opportunity for diesel after-treatment technologies in the coming years, and how Tenneco plans to convert the challenges of the U.S. Environmental Protection Agency's (EPA) 2007 and 2010 regulations into growth opportunities for the company. Kotrba said, "Definitely, we have a global plan to leverage our resources effectively and synergize between our businesses, while meeting the unique preferences of OEMs. But be it North America or Europe, Asia or Australia we are well equipped and have unique marketing plans and strategies for catering to these local markets." Three key points to effective conversion, he emphasized, are maintaining a global awareness of emerging technologies in after-treatment; a continuing dialogue with automakers to ensure an alignment between OEM needs and new technology available; and focusing on optimal design processes. He added that this is where Tenneco's advanced engineering group comes in. The group works upfront in meeting the advanced technologies and product demands for the future. "For instance, we have been working for the past five years in North America in developing the technologies like DOCs [diesel oxidation catalysts] and DPFs [diesel particulate filters] and other systems that are required to meet the 2007 EPA regulations. We are currently actively working with the OEMs as well as consortiums and government affiliates to prepare for 2010. So we work with the OEMs upfront before the products are needed, and we let them know what technologies are available." As an example, Kotrba said that the company uses knowledge gained about diesel aftertreament technologies in Europe that can be exported to the United States or other markets. But more than just migrate the knowledge, he said, Tenneco would also merge the special needs here in the United States in the development of relevant market products. He cited three technologies used in Europe as examples: Selective Catalytic Reduction (SCR), Lean NOxTraps (LNT) and Exhaust Gas Recirculation (EGR). SCR-based exhaust after-treatment provides sufficient reduction in nitrogen oxide (NOx) emissions and also achieves a further 30 percent reduction in particulate emissions. LNTs are a type of emission control device for diesel and gasoline direct injection engines that work like a trap to capture NOx emissions and convert them into harmless nitrogen gas. The trap periodically is "emptied," and the stored NOx converted to nitrogen, all while the engine is running to keep the system well within emissions standards. EGR uses exhaust gas entering the intake manifold to cool the combustion chamber and thereby reduce the production of NOx . SCR technology has been very successful in Europe in meeting emission regulations. It also offers low up-front and lifecycle costs to the truck owners. Kotrba said that for the light and heavy vehicle segments, as well as the truck and engine manufacturing side, the merits of the SCR technology would be helpful, especially for more stringent EPA 2010 standards. As we move closer to 2010, Kotrba felt EGRs would begin to fade in use. In contrast, he shared that there are some concerns regarding LNTs meeting the regulator's longevity requirements of 435,000 miles, and that rather than heavy trucks, LNTs would be more useful in light-duty vehicles applications. "I think most industry experts feel that the technology for LNTs will eventually be optimized to meet that sort of mileage requirements, but not for 2010," he explained. "We really think that LNTs without a doubt will be used in that period for certain applications, but then more so for light vehicles than heavy-duty trucks. EGR and SCR are much better suited to heavier trucks." Negotiating the threat of rising prices of precious metals used in after-treatment systems will need attention from suppliers, Kotrba said. At Tenneco, it is driving the company towards higher levels of optimal design and efficiencies of the after-treatment systems. "From an engineering standpoint, there is a lot we can do to improve the designs to minimize the dependence on precious metals, like having uniform flow distribution or moving the catalyst as close to the engine as possible, which also poses some challenges in coming up with packaging," Kotrba shared. Staying focused on optimizing design, he said, can insulate a firm from price fluctuations. Design changes coming in 2007 included construction in which the diesel oxidation catalysts and diesel particulate filters were in one shell, depending upon the OEM and their needs. These technologies would have to be combined with some form of selective catalytic reduction and lean NOx traps to meet NOx gas emission reductions by 2010. Continued improvement of combustion and engine technologies to reduce emissions will be something engine makers pursue. But Kotrba said the emission levels set by EPA for 2010 will make it difficult for engine makers to meet the tailpipe emission levels without some form of after-treatment. "As time progresses there will be improvements to the engine, but I don't think after-treatment technologies will become redundant," he said. "Gasoline combustion engine technology has reached a point where there not a lot more that can be done, other than lean burn or alternative fuels, but advanced engine technologies also need advanced after-treatment systems." Kotrba also said that there were a number of refinements to DPFs that will emerge. For example, active regenerative filters enhance the value proposition of DPFs. "I don't think there isn't any system that's not considered as an active DPF system. So without a doubt those are coming forward in 2007 and even further improvements are expected in these systems in 2010." He said using ceramics for particulate filtration would be introduced in 2007, but noted that there are differences in the type of ceramic, each with their own attributes. He also felt that other materials such as metal filters and fibers would be used as well. Finally, another area of improvement would be the use of plasma fuel reformers to eliminate the need of reforming the catalyst.
(Source: Frost &
Sullivan) 
