SCR Technology
SCR Technology  |  How it Reduces Emissions  |  Advantages

What Is Selective Catalytic Reduction (SCR) Technology

EPA 2010 is the final phase of the Environmental Protection Agency's plan to assure that medium and heavy-duty trucks run cleaner by the year 2010. In fact, EPA 2010 standards require that NOx levels from new trucks be reduced to almost zero.

The preferred technology to meet EPA 2010 is Selective Catalytic Reduction (SCR) – an emissions-reduction technology using Diesel Exhaust Fluid (DEF) to deliver near-zero emissions of nitrogen oxides (NOx) that contributes to acid rain, smog and greenhouse gas levels.

SCR reduces NOx emissions to extremely minute levels, while at the same time delivering improved fuel economy and reliability. SCR technology does not change the design or operation of the basic engine. Rather, SCR is a simple after treatment system that converts NOx in the exhaust stream into harmless gases. Modern diesels already use exhaust after treatment systems, called diesel particulate filters, to control emissions of another pollutant, soot (also known as particulate matter or PM).

SCR works by injecting BlueDEF diesel exhaust fluid into the exhaust stream only as required. BlueDEF works with the heat of the exhaust and a catalyst to convert NOx into nitrogen and water vapor - two harmless and natural components of the air we breathe.

 

What impact will SCR technology have on engine maintenance?

  • With SCR technology, maintenance intervals will remain the same as 2007, with one additional service point: the DEF filter.
  • The DEF filter will need to be changed every 200,000 to 300,000 miles, and can be easily changed in minutes
  • With SCR technology, engine components may last longer due to less heat being generated and fewer contaminants.

 

What are the advantages of SCR technology?

  • By treating the exhaust gases outside of the engine and using less EGR, SCR technology can provide up to 5% better fuel economy.
  • SCR technology offers better engine reliability, reducing downtime
  • SCR causes no additional wear on the engine

The trucking industry believes SCR is the best EPA 2010 solution based on environmental advantages and payback to fleet owners. OEMs prefer SCR because it's proven – it's been around for years, with hundreds of thousands of SCR equipped commercial vehicles in operation in Europe since 2006.

Best of all, SCR is better for the planet.