• What is SCR?
• Performance
• Environment
• Public Health Impact
• Diesel Exhaust Fluid

September 2008 – Being environmentally friendly is a serious business, and one that is proving to be strongly enforced. This week’s action by the California Air Resources Board (CARB) leaves no room for doubt that tightening emissions standards for heavy-duty diesel vehicles will allow no room for complacency or mistakes in today’s competitive trucking landscape as the industry races to develop the best “green” solutions for EPA 2010 and other standards.  But as everyone gets on the “green” bandwagon, there will be, and needs to be, vigilant scrutiny of environmental claims versus a company’s demonstrated reality.

A good example of governing agency oversight in enforcing compliance with environmental standards was evident this week, as CARB fined truck engine manufacturer Navistar, Inc. $281,500 for clean-air violations in two separate court cases.  According to CARB, Navistar failed to implement mandatory emissions controls and further neglected to properly label and document previously installed emissions systems.

“California’s motor vehicle regulations are the most progressive in the world,” said CARB Chairman Mary Nichols in a press release issued by the agency. “Our auditors make sure engine manufacturers comply with our stringent requirements in order to ensure air quality and public health goals are met.” 

As emissions requirements inevitably become more stringent and strictly enforced, another example of claims versus social responsibility and credibility in “green” emissions technology comes to mind – particularly as it relates to preparing for 2010 in the heavy duty trucking industry.

Using Emissions Credits to Meet EPA Requirements

To encourage early adoption of emissions control technologies and to offset some of the research and development strain, emissions control oversight agencies developed a family credit system whereby companies could earn credits based on sales of vehicles in their product portfolios that produce less than mandated emissions. These credits can be used to offset the company's sale of higher emissions emitting vehicles for a period of time prior to the company's development and delivery of technologies that would meet the emissions criteria.

The concept of using credits was created to encourage adoption of new emissions reduction technologies, such as Selective Catalytic Reduction (SCR). At this time, it could be argued that using those credits meets the letter of the law but not the spirit of the law.

Since SCR Technology is Proven, Why Not Use It?

It is foreseeable that when nitrogen oxide (NOx) emissions credits run out, and barring any revolutionary combustion or alternate NOx aftertreatment technology breakthroughs, SCR will remain the only long-term viable solution.

As the near unanimous choice for meeting emissions standards in the trucking industry, SCR technology works by injecting a Diesel Exhaust Fluid solution (32.5% automotive-grade urea and purified water) into the exhaust stream of a diesel engine.  The mixture enters an SCR catalyst where it is converted into pure nitrogen and water vapor, two common elements of the everyday breathable air, which are then emitted through the tailpipe.  Tests have shown that SCR offers a 3-5 percent fuel savings while reducing NOx emissions by up to 90 percent, carbon monoxide (CO) emissions by 50-90% and particulate matter (PM) emissions by 30-50 percent.

The North American SCR Stakeholder Group – an ad-hoc industry alliance made up of automotive, light duty and heavy duty OEMs, producers, distributors and governing agencies.  Visit www.factsaboutscr.com which offers additional news and information related to the use and benefits of SCR, particularly in commercial applications, for the automotive industry and the general public.

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