The clean air benefits from new technology clean diesel engines and the importance of efforts to accelerate the modernizing or upgrading of existing vehicles and equipment will be important in meeting any future clean air standards, officials from the U.S. Environmental Protection Agency were told.
Allen Schaeffer, the Executive Director of the Diesel Technology Forum, made comments during the first of three national hearings being conducted by EPA regarding proposed updates to the national air quality standards for ground-level ozone (smog). EPA has proposed to strengthen the standards to a level within a range of 65 to 70 parts per billion to further reduce national air quality issues, while also taking comments on a level as low as 60 ppb.
While not commenting on the EPA’s proposed changes, Schaeffer mentioned how the cooperative working relationship between EPA, national environmental and health organizations and manufacturers had resulted in improvements to diesel efficiency and reduced emissions.
“Diesel engines are a declining contributor to the national inventory of nitrogen oxides, a key ozone precursor,” Schaeffer told the EPA panel. “The increasing utilization of new technology clean diesel engines will play the most important role in assuring continued progress toward both clean air and climate objectives.
“And according to the Advanced Collaborative Emissions Study (ACES) research co-sponsored by EPA and released this week by the Health Effects Institute, new technology diesel engines near-zero emissions performance was confirmed, as was the finding of no significant health effects in laboratory animals over lifetime exposure.
“The diesel industry is building on these clean air accomplishments and now increasingly focused on producing near zero emissions technology that also is more efficient and has lower greenhouse gas emissions as well.”
New Clean Diesel Technology Is Contributing To Clean Air Progress
Schaeffer said the NOx emissions reductions from diesel accrue from over a decade of collaboration between the leaders in clean diesel technology and the EPA in establishing a regulatory pathway that brought about the introduction of these clean diesel engines in on- and off-road applications.
“Since 2000, diesel engine manufacturers have been working to meet the challenge of virtually eliminating emissions from diesel engines,” Schaeffer said. “Today, manufacturers have met that challenge. First along the pathway were strict NOx emissions standards promulgated for the heavy-duty on-road fleet beginning in model year 2007 and further tightened for model year 2010.”
According to research commissioned by the Diesel Technology Forum, Schaeffer said, the growing share of these clean diesel heavy-duty vehicles contribute NOx emissions reduction. Today nationwide, more than one-third of all commercial heavy duty trucks are 2007 and newer and about 16 percent are 2011 and newer technology.
“As of 2013, we estimate that these clean diesel heavy-duty vehicles have reduced NOx by one million tons nationwide,” Schaeffer said. “In some regions and localities, the NOx emission reduction from clean diesel trucks has been even more substantial.
“To achieve these very low levels of nitrogen oxide emissions, engine manufacturers and emissions control technology manufacturers have invested billions of dollars to reduce the formation of nitrogen oxide emissions through controlling of the combustion process itself as well as the use of emissions control technology such as selective catalytic reduction systems (SCR).”
EPA Must Ensure a Viable Future for the National Clean Diesel Campaign
Schaeffer told the EPA panel there have been a number of approaches to reducing nitrogen oxide emissions from existing engines and equipment.
“For example, as of 2010, the ports of L.A. and Long Beach require all of the roughly 16,000 trucks transiting through America’s largest port complex every day must be deployed with an engine that meets the U.S. EPA model year 2007 emissions standard,” Schaeffer said. “The ports estimate that 90 percent of port trucks are powered with a diesel engine.
“Since that requirement, both ports estimate that NOx emissions attributable to port trucks have fallen substantially – by 92 percent since 2005. As a share of all NOx emission in the region, NOx emissions from port trucks has fallen from a peak of about 42 percent in 2006 to about 17 percent in 2012 when the emissions inventory was completed. These are significant real world emission reductions that will benefit communities surrounding the port.
“Nationwide, as more of the truck fleet is turned over to new and newer vehicles deployed with a clean diesel engine, we can expect significant improvement in air quality attributable to the heavy-duty diesel powered fleet, similar to that experienced in southern California,” Schaeffer said.
Construction, Agricultural & Other Off-Road Diesel Technology Are Also Reducing Emissions & Increasing Efficiency
Schaeffer explained that 2014 was a “milestone year” for clean diesel in other applications – namely Tier 4 final requirements for off-road diesel technology.
“Similar NOx emissions standards promulgated for the heavy-duty vehicles are now required of new engines found in most off-road applications including construction, agricultural and other applications,” Schaeffer said. “Construction equipment at work on a road or other public works project deployed with a Tier 4 final engine may contribute to NOx emissions reduction for a region or locality. Additionally, NOx reduction benefits from the use of agricultural equipment deployed with a Tier 4 final engine may accrue to rural regional and localities.
Older Diesels Can Also Be Modernized & Upgraded For Lower Emissions
“Finally there is the Diesel Emissions Reduction Act which since its inception in 2005 has played a key role in catalyzing the move to new and cleaner diesel engines and equipment and the modernizing and upgrading of existing engines and equipment,” Schaeffer said. “According to the most recent EPA Report to Congress, emissions of nitrogen oxide emissions have been slashed by over 203,000 tons thanks to funding provided by the DERA program between 2008 and 2010.”