Selective Catalytic Reduction

How SCR Works
Selective Catalytic Reduction uses basic chemistry to reduce NOx emissions through a process that is simple, extremely efficient, very reliable and safe. The major components of the process are hot exhaust, Diesel Exhaust Fluid and a catalytic converter.

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Vaporized DEF and hot exhaust gases enter a catalytic converter located in the exhaust system after the diesel particulate filter. The catalytic converter contains a catalyst, which is a substance that causes or accelerates a chemical reaction, without being affected itself. [Catalysts are common in everyday life; for example, gasoline powered vehicles have used catalytic converters to control emissions for several decades.]

DEF is a solution of purified water and urea, an organic nitrogen compound that turns to ammonia when heated. When this urea and water solution is injected into the hot exhaust stream and comes in contact with the SCR catalyst, the ammonia created from urea reacts with NOx to form nitrogen and water vapor -- two clean and harmless components of the air we breathe.

The following major truck stops have already committed to having DEF available for SCR trucks starting in 2010:

Pilot is First to Proved DEF "At the Pump" for SCR

TA and Petro reaffirm DEF Distribution Plans to Support 2010 SCR Engines

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Click here for interviews with top industry professionals exploring the impact of SCR technology on their companies, the freight industry, the infrastructure and the general public.

Did you know?  According to an online study conducted in November 2008, 53% of truck buyers will likely consider the purchase of SCR technology to meet the 2010 EPA standards compared to only 29% that will likely consider increased EGR.  See the full release: New Study Benchmarks Truck Industry Preference for EPA 2010 Emissions Technologies