Isuzu Commercial Truck of America announced Monday, Dec. 29, that it intends to use selective catalytic reduction (SCR) to achieve the 2010 standards for emissions of nitrogen oxides (NOx) by diesel engines. The new technology will be used in Isuzu engines sold in its trucks in the United States under the Isuzu, Chevrolet and GMC trademarks.
SCR is an aftertreatment technology that involves injecting a water-based solution containing urea into the hot exhaust stream of an engine. This diesel exhaust fluid (DEF), working with a catalyst in the exhaust aftertreatment system, breaks down the NOx into harmless nitrogen and water vapor, the company says.
DEF, which contains an organic nitrogen compound used as a fertilizer in agriculture, is classified as a nonhazardous substance by the U.S. Environmental Protection Agency. Isuzu intends to continue to use both a diesel particulate filter (DPF) and exhaust gas recirculation (EGR), which it introduced in its trucks in 2007.
“Isuzu has been developing aftertreatment technology in Japan for many years,” says Shaun Skinner, executive vice president and general manager. “We’ve studied different systems, and found SCR to be highly reliable under even the most extreme applications and conditions.”