Meeting EPA's emissions standards for 2010 won't be easy, but it's not as complicated as many fleets fear — and it may even boost fuel economy.
According to Ed Saxman, product manager-drivetrain for Volvo Trucks North America, speaking at an engine makers panel at a PHH FirstFleet conference in Ft. Lauderdale, “We're going to be using the same engine designs and DPFs in use now to meet the '07 levels.”
Volvo plans to add an SCR [selective catalytic reduction] system to reduce NOx emissions. “While it's still premature to talk about costs — more sensors and hardware will be required — it isn't complicated. We're already using it on many of our engines in Europe,” he added.
Saxman said SCR works by injecting a mist of urea (34% ammonia, 66% water) into the truck's exhaust stream to convert NOx emissions to water vapor. He said the entire SCR system, including the wiring, hoses and urea container, wouldn't be much larger than current DPFs.
“We don't need a huge amount of urea,” said Tim Tindall, director of component sales for Detroit Diesel Corp. “For every 100 gallons of diesel fuel, you'll only need [about] one gallon of urea.” DDC anticipates using a four- or five-gal. urea tank, which would add about 50 or 60 lb. to the truck. He expects 2.6-liter bottles of urea to be sold in truckstops so drivers can keep the tanks topped off.
“You can tune [SCR] to handle higher emissions of NOx easily, meaning you can relax the NOx controls on the engine [and let] NOx get cleaned up in the exhaust stream,” Saxman explained. “Right now, we're looking at up to a 5% increase in fuel economy by using SCR.”
