Selective Catalytic Reduction Technology
Forward-thinking in design and strategy, Pierce is ever-planning for the future, and the future is SCR – a proven emission-reducing/fuel economy increasing technology. A national research study proved that 53% of truck buyers consider SCR emission technology the ideal choice in meeting 2010 EPA Emission Standards. In fact, it's estimated that 90% of the diesel trucks produced in North America will use SCR technology to meet 2010 emission standards.** There are three main components of the SCR system: Diesel Exhaust Fluid (DEF), a solution of urea and purified water; hot exhaust; and a catalytic converter.
In heavy-duty trucks alone, SCR will reduce NOx emissions up to 90%, hydrocarbons and carbon monoxide by 50-90% and PM emissions by 30-50%.With reliable and proven capabilities, SCR technology has already traveled millions of miles in Europe with commercial vehicles powered by Detroit Diesel and Cummins engines.
the advantages of scr
In addition to safeguarding public and environmental health, Pierce is excited about the performance enhancements of SCR technology. These advantages include:
- Increased fuel economy
- Efficient power and torque production over a long life
- Enhanced durability and reliability resulting in longer service intervals
- Optimized power potential; Detroit Diesel and Cummins engines deliver more horsepower without burning a single extra drop of fuel
the reach of scr
A spectrum of companies and networks are following Pierce’s lead in integrating SCR across entire families of vehicles.
These apparatus companies/networks include:
- Daimler Trucks North America
- Volvo Truck
- Mack Truck
- Peterbilt Truck
- Kenworth Truck
- Hino Truck
- Detroit Diesel Engine Support Network
- Cummins Engine Support Network
SCR technology is even being adopted by these passenger car companies in the U.S.:
- Mercedes-Benz
- Audi
- Volkswagen
- Mini
- Hyundai
- Kia
In order to streamline the overall impact to vehicles, Pierce is developing integrated “apparatus friendly” packaging solutions.
diesel exhaust fluid
Diesel Exhaust Fluid (DEF) is a crucial component of SCR technology. It is a 32.5% strength urea-water solution that is non-toxic, non-polluting and non-flammable. With an odor similar to that of ammonia, DEF is nonetheless safe to handle and store, posing no serious risk to humans, animals, equipment or the environment with proper handling.
DEF will begin to freeze to a slushy consistency at 12° F. SCR systems are designed to heat the DEF storage tank, providing lines that reduce the melting time. If DEF freezes when the vehicle is shut down, ignition and normal operation of the vehicle will not be inhibited; the SCR heating system quickly returns the DEF to liquid form without impacting the vehicle’s operation. If the vehicle is operated in such a way that is runs out of DEF, the vehicle will not shut down. However, additional methods (yet to be determined) will be employed to encourage the operator to refill the DEF tank.
Depending on vehicle operation, DEF consumption is approximately 2%-4% of fuel consumption. The tank will be sized according to usage requirements and fuel tank size, generally allowing 2-3 fuel refills before needing to replenish the DEF tank.
def readily available
Easier on the environment, easier to find. DEF will be as easy to access as standard diesel fuel. Providers of fuel and urea are building a network of DEF filling stations: Sold in either bulk or totes at service stations, DEF will also be available at truck stops, dealerships, parts stores and other retail locations.
According to Detroitdiesel.com, there are over 1,800 committed locations to find DEF in the U.S.; and the U.S. Department of Energy has developed a website to showcase DEF availability. Certified suppliers may sell their products with the API – DEF logo.
The Alternative to scr
The alternative technology to SCR relies on an in-cylinder approach, utilizing Excessive Exhaust Gas Recirculation (EEGR) technology to reduce the NOx in the engine. EEGR relies on the engine to lower the emissions level before the exhaust exits the engine. This is made possible by keeping the cylinder temperatures cooler. Still, this technology significantly increases the amount of heat that must be pulled from the engine. This may not allow for optimal performance, which is reflected in lower hp/liter ratings and fuel economy. The alternative to SCR technology is simply the second-best option.