COMPLIANCE with the Environmental Protection Agency (EPA) 2007 emission regulations poses a significant technical challenge for heavy-duty diesel engine manufacturers, says Tony Grezler, vice-president, engineering, Volvo Powertrain Inc. Volvo Powertrain is the engine, transmission, and driveline supplier for six divisions within the Volvo Group, including Mack Trucks Inc and Volvo Trucks North America.
“The 2007 standards are very aggressive, requiring dramatic reductions in NOx and particulate matter emissions,” says Grezler. “Although the company has yet to decide on a final solution to achieve these reductions, it is currently considering several technologies.”
For particulate matter control, Volvo Powertrain views the diesel particulate filter as the best option. For NOx control, the company believes selective catalytic reduction (SCR) is a promising technical solution. SCR involves the use of a catalyst — a solution of urea and water — to reduce NOx.
Volvo Powertrain plans to use SCR for NOx control in Europe. But EPA has reservations about a urea distribution system in the United States, so the company is currently working with a variety of industry partners to develop an integrated urea distribution proposal for discussion with EPA.
Although the company emphasizes that it has not decided to use SCR in the United States, Volvo Powertrain contends that its participation in the Urea Distribution Stakeholder Group is necessary to demonstrate that SCR is a viable option for the market.
The company also believes that high-performance exhaust gas recirculation (HEGR) shows promise, and continues to evaluate it as a potential NOx control solution.
HEGR involves in-cylinder reduction of NOx, and represents an evolution of current cooled exhaust gas recirculation (CEGR) technology.
“The most important point is that regardless of which technology we ultimately use, we believe that as the world's largest producer of heavy-duty engines, with an entirely new family of group engines fully commercialized by 2007, we have the volume base and the technical expertise to deliver the best engine available for North American customers,” says Grezler. “We're confident that the 2007 engines will bring breakthrough quality and performance for both Mack and Volvo customers.”
He pointed out that Volvo Powertrain is making every effort to have production quality solutions available for customer testing as soon as possible. “We are actively involved with the American Trucking Associations' Diesel Rule Task Force to ensure that as the industry moves toward EPA'07, the needs and concerns of our customers are addressed,” he added.