What is SCR?
Selective Catalytic Reduction (SCR) is one of the most cost-effective and fuel-efficient diesel engine emissions control technologies available. For passenger cars and light duty trucks, the ability to meet strict emissions and fuel efficiency guidelines affordably without compromising driving power and performance is attractive. In the commercial trucking industry, including heavy and medium duty trucks, the ability to reduce emissions to near-zero levels while also delivering a 3-5% diesel fuel savings distinguishes SCR as one of the only emissions control technologies that is as good for business as it is for the environment.
Did you know? According to an online study conducted in May 2009, more than half (51.2%) of truck buyers are likely or very likely to consider the purchase of SCR to meet the 2010 EPA standards, compared to only 31.2% that are likely or very likely to consider increased EGR.
How Selective Catalytic Reduction Technology Works
SCR technology is designed to permit nitrogen oxide (NOx) reduction reactions to take place in an oxidizing atmosphere. It is called "selective" because it reduces levels of NOx using ammonia as a reductant within a catalyst system. The reducing agent reacts with NOx to convert the pollutants into nitrogen, water and tiny amounts of carbon dioxide (CO2) - natural elements common to the air we breathe everyday. The reductant source is usually automotive-grade urea, otherwise known as Diesel Exhaust Fluid, which can be rapidly hydrolyzed to produce the oxidizing ammonia in the exhaust stream. SCR technology alone can achieve NOx reductions in excess of 90%.