Green Technology - SCR - How It Works

SCR is Selective Catalytic Reduction. This technology reduces tailpipe nitrogen oxide emissions, NOx, by treating the exhaust stream with a spray of diesel exhaust fluid (DEF). DEF, along with the exhaust heat and a catalyst, converts NOx into nitrogen and water vapor, which are clean, harmless and present in the air we breathe every day.

Thomas Built's complete line of diesel buses will be equipped with SCR technology to meet EPA 2010 emissions standards. Thomas Built's mission is to provide reliable, durable, safe and innovative buses to our customers. And SCR technology, with its near-zero emissions, was the environmental choice to meet these new standards.

SCR technology uses the existing engine architecture, diesel oxidation catalyst and diesel particulate filter, plus SCR hardware. This technology allows the engine to function at optimal combustion temperatures, which increases fuel efficiency and reliability. Take a look at the diagram below to see how SCR works.