Mack, Volvo, commit to EGR

Mack Trucks and Volvo Trucks North America confirmed they will use technology based on exhaust gas recirculation (EGR) to meet stringent diesel engine emission regulations scheduled to take effect in 2007.

Their decision to concentrate on EGR ends speculation about the use of Selective Catalytic Reduction (SCR) here, at least in the short term. SCR is the preferred emissions reduction strategy in Europe for Volvo Trucks, the largest manufacturer of heavy-duty diesel engines in the world and the parent of Mack and Volvo Trucks NA.

Mack and Volvo both use EGR to meet current U.S. Environmental Protection Agency (EPA) standards for nitrogen oxides (NOx), which took effect in October 2002.

Mack president and CEO Paul Vikner said the decision to stay with EGR reflects Mack’s experience with similar technology in its existing ASET engine line. He also said manufacturers want to avoid the confusion and market upheavals of two years ago, when customers rushed to place orders on engines made before the October 2002 deadline.
“ASET technology continues to meet expectations in terms of fuel economy, uptime, and performance,” he said. “By building on what we’ve learned with the ASET approach, especially in optimizing engines to meet the unique demands of Mack customers, we’re confident that our ’07 engines will offer breakthrough quality and performance while meeting the new EPA emissions standards.”

Vikner said he expects to begin field trials of Mack engines designed for ’07 compliance by the middle of next year. Volvo Trucks NA president Peter Karlsten said his company has similar plans.

“It is important to realize that our customers are already familiar with EGR and have accepted it as a reliable, everyday part of their operation,” said Karlsten.
Both companies expect to use EGR and diesel particulate filters (DPF) on a new family of engines to be introduced by 2007.

EGR systems reduce emissions by returning a portion of exhaust gases back into the engine’s combustion cycle. The recirculated exhaust serves to reduce combustion temperature, which retards the formation of nitrogen oxides (NOx) in the engine’s operation. The DPF is situated in the exhaust system and works by trapping tiny particles generated by diesel combustion.

In December, Cummins and International Truck and Engine committed to using a form of EGR to meet the 2007 standards. Caterpillar said it would comply using its proprietary ACERT technology, which does not use EGR. The EGR and ACERT engines will require ultra-low sulfur diesel fuel. Detroit Diesel and Mercedes-Benz, both divisions of Freightliner, are proponents of SCR and are expected to announce their intentions for 2007 this month.

Recent EPA statements indicate doubts about SCR, which requires urea solution to operate properly. Stored in tanks on board the vehicle, urea would have to be replenished every 5,000 miles or so. EPA officials are said to be concerned about whether the distribution network for urea would exist by 2007.

Vikner said interest in SCR for Mack and Volvo would remain high, because it could help the manufacturers meet even more restrictive EPA NOx limits in 2010.