[MBZ] From Greenwire -- AIR POLLUTION: EPA issues guidance for diesel engine NOx controls
This Greenwire story was sent to you by: [EMAIL PROTECTED] [1]Greenwire An EE Publishing Service Greenwire -- Friday, March 30, 2007 AIR POLLUTION: EPA issues guidance for diesel engine NOx controls Daniel Cusick, Greenwire reporter Tens of millions of tons of diesel fuel pollution, including nitrogen oxides (NOx) and particulate matter, could be reduced under new U.S. EPA guidance that allows automakers to install selective catalyst reduction (SCR) technology on diesel-powered cars and trucks, the agency said today. The [2]guidance, issued this week in a 10-page memo from Karl J. Simon, EPA's acting compliance and innovative director, to automakers, will help manufacturers comply with tough new emissions standards for NOx emitted from diesel engines. The standard, set at 0.20 grams of NOx per brake horsepower-hour, is being phased in between model years 2007 to 2010, according to EPA. NOx is a primary component of ground-level ozone, the nation's leading air pollution threat, and is also a precursor pollutant in the formation of fine particulate matter, or soot, that affects millions with asthma, bronchitis or other lung ailments. Since EPA published its diesel engine NOx standard in 2001, engine makers have experimented with a variety of technologies to control the pollutant. Selective catalytic reduction, which is already widely used to control NOx from area source emitters such as industrial plants, ultimately won favor with EPA and manufacturers because it can achieve as high as 90 percent reductions in NOx. In a release, EPA said the new guidance on emission certification procedures for on-road diesel engines using SCR technology helps pave the way for putting more innovative and fuel-efficient clean diesel cars and trucks on America's roads. While endorsing the move toward greater use of SCR on diesel engines, Simon noted that the technology is still evolving and added that EPA reserves the right to make any necessary changes to the guidance as conditions warrant. One concern about SCR's use in motor vehicle engines is that the technology requires regular replenishment of a NOx reducing agent, usually ammonia or urea, to be effective. If an engine were to run out of its reducing agent while in use, its NOx reduction capability would drop to zero, according to EPA. Because the NOx efficiency and thus the NOx emissions performance of an SCR system is so dependent upon a nitrogen-containing reducing agent, it is critical than a vehicle using SCR never operate without the reducing agent, Simon wrote in the guidance letter. Yet many manufacturers have warned that they would not be able to store sufficient volumes of ammonia or urea on a motor vehicle to allow for federally recommended maintenance intervals of between 100,000 and 150,000 miles. As such, It may be appropriate for EPA to approve an industry-wide scheduled maintenance change, as we have done previously in similar situations, the guidance states. Manufacturers will need to gain approval for their SCR strategies as part of the EPA certification process. Among the other requirements for certification are driver warning systems and inducement measures, a track record of system durability and reliability, and reducing agent quality and availability, EPA said. Diesel engine manufacturers, represented by the Diesel Technology Forum, have assured that all new engines being produced for highway use will meet EPA's air pollution standards, including for NOx and particulate matter. In January, the group announced that all new big rigs are equipped with innovative new PM-trapping filters and that NOx emissions have also been significantly cut due to improved technology. The enginemakers said model year 2007 trucks are 90 percent cleaner than the previous generation of trucks. Allen Schaeffer, director of the Diesel Technology Forum, said this morning that the new SCR guidance comes after nearly two years of conversations between EPA and enginemakers over how to make further reductions in NOx emissions. He said it sets the stage closer to a time when we'll have even cleaner diesel engines that are delivering even higher fuel efficiency. Dieter Zetsche, chairman of DaimlerChrysler and head of its Mercedes car division, also issued a statement saying his company welcomes and supports EPA's guidance on SCR technology for on-road diesel engines, adding it serves to reinforce diesel's benefit as a viable alternative to help reduce fuel consumption and ultimately, reduce oil imports. [3]Click here to read the diesel engine guidance memo. Want more stories like this every day? Sign up for a free trial and get the best environmental and energy policy coverage available. Go to [4]http://www.eenews.net/trial/
Re: [MBZ] From Greenwire -- AIR POLLUTION: EPA issues guidance for diesel engine NOx controls
huh? i had a little difficulty with this one line: NOx is a primary component of ground-level ozone, the nation's leading air pollution threat, and is also a precursor pollutant in the formation of fine particulate matter, or soot... sounds like they're trying to say particulate matter is caused by some reaction with NOx. am i misinterpreting this, or how's that work? cheers! e [EMAIL PROTECTED] wrote: This Greenwire story was sent to you by: [EMAIL PROTECTED] [1]Greenwire An EE Publishing Service Greenwire -- Friday, March 30, 2007 AIR POLLUTION: EPA issues guidance for diesel engine NOx controls Daniel Cusick, Greenwire reporter Tens of millions of tons of diesel fuel pollution, including nitrogen oxides (NOx) and particulate matter, could be reduced under new U.S. EPA guidance that allows automakers to install selective catalyst reduction (SCR) technology on diesel-powered cars and trucks, the agency said today. The [2]guidance, issued this week in a 10-page memo from Karl J. Simon, EPA's acting compliance and innovative director, to automakers, will help manufacturers comply with tough new emissions standards for NOx emitted from diesel engines. The standard, set at 0.20 grams of NOx per brake horsepower-hour, is being phased in between model years 2007 to 2010, according to EPA. NOx is a primary component of ground-level ozone, the nation's leading air pollution threat, and is also a precursor pollutant in the formation of fine particulate matter, or soot, that affects millions with asthma, bronchitis or other lung ailments. Since EPA published its diesel engine NOx standard in 2001, engine makers have experimented with a variety of technologies to control the pollutant. Selective catalytic reduction, which is already widely used to control NOx from area source emitters such as industrial plants, ultimately won favor with EPA and manufacturers because it can achieve as high as 90 percent reductions in NOx. In a release, EPA said the new guidance on emission certification procedures for on-road diesel engines using SCR technology helps pave the way for putting more innovative and fuel-efficient clean diesel cars and trucks on America's roads. While endorsing the move toward greater use of SCR on diesel engines, Simon noted that the technology is still evolving and added that EPA reserves the right to make any necessary changes to the guidance as conditions warrant. One concern about SCR's use in motor vehicle engines is that the technology requires regular replenishment of a NOx reducing agent, usually ammonia or urea, to be effective. If an engine were to run out of its reducing agent while in use, its NOx reduction capability would drop to zero, according to EPA. Because the NOx efficiency and thus the NOx emissions performance of an SCR system is so dependent upon a nitrogen-containing reducing agent, it is critical than a vehicle using SCR never operate without the reducing agent, Simon wrote in the guidance letter. Yet many manufacturers have warned that they would not be able to store sufficient volumes of ammonia or urea on a motor vehicle to allow for federally recommended maintenance intervals of between 100,000 and 150,000 miles. As such, It may be appropriate for EPA to approve an industry-wide scheduled maintenance change, as we have done previously in similar situations, the guidance states. Manufacturers will need to gain approval for their SCR strategies as part of the EPA certification process. Among the other requirements for certification are driver warning systems and inducement measures, a track record of system durability and reliability, and reducing agent quality and availability, EPA said. Diesel engine manufacturers, represented by the Diesel Technology Forum, have assured that all new engines being produced for highway use will meet EPA's air pollution standards, including for NOx and particulate matter. In January, the group announced that all new big rigs are equipped with innovative new PM-trapping filters and that NOx emissions have also been significantly cut due to improved technology. The enginemakers said model year 2007 trucks are 90 percent cleaner than the previous generation of trucks. Allen Schaeffer, director of the Diesel Technology Forum, said this morning that the new SCR guidance comes after nearly two years of conversations between EPA and enginemakers over how to make further reductions in NOx emissions. He said it sets the stage closer to a time when we'll have even cleaner diesel engines that are delivering even higher fuel efficiency. Dieter Zetsche, chairman of DaimlerChrysler and head of its Mercedes car division, also issued a statement saying his company welcomes and supports EPA's guidance on SCR technology
