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xcel
08-29-2006, 06:54 PM
EPA ready to set urea guidelines. (http://www.autoweek.com/apps/pbcs.dll/article?AID=/20060829/FREE/60828027/1024/LATESTNEWS)

Richard Truett - Automotive News - August 29, 2006

http://www.cleanmpg.com/photos/data/501/2007_Mercedes_Benz_E320_CDI.jpg
MB 320 CDI Diesel w/ Urea injection - EPA rated at 27 City/37 highway

WHY UREA?
Selective catalytic reduction, which uses urea to scrub NOx from diesel exhaust, offers these advantages.
Simplicity: Automakers can meet the toughest emissions standards on the books with a system that could be used in all markets.
Cost: Depending on the vehicle, a urea system could cost about half as much as the alternative, a lean NOx trap.
Integration: The system does not affect engine performance and could be installed without extensive modifications to the vehicle or engine.
DETROIT - For the first time, the EPA is ready to hand drivers the responsibility for making sure a vehicle's emissions system works properly.

All emissions systems now are passive and require no owner maintenance. But if urea systems are used to remove NOx from diesel exhausts, the EPA says drivers will have to get involved.

Urea injection is expected to be used on diesel-powered cars and trucks starting in 2010. The EPA guidelines will be issued in the next few weeks.

The rules will address the main problem regulators have with urea: The system won't work unless an on-board urea tank is replenished. Otherwise, the car won't meet emissions standards.

The EPA is considering rules that will require the vehicle to eventually stop running if drivers don't keep the tank filled.

Karl Simon, the EPA's assistant director for the office of transportation and air quality, said the agency is focusing on an early-warning system that notifies drivers when the urea tank is low.

The agency also is considering an inducement that forces drivers to refill the urea tank - for example, preventing the engine from starting if the tank is empty or automatically locking the fuel filler door until the urea supply is replenished.

The agency says automakers will have to make it easy for drivers and technicians to identify the urea tank and refill it.

Areas of focus

Simon says the EPA also is focusing on:

Ensuring the urea system is tamperproof and can't be disabled. Since urea is injected into the vehicle's exhaust system, the engine runs normally without it.

Assuring that the system works in cold weather. Urea freezes at about 11 degrees Fahrenheit.

Widespread availability of urea. It could be sold at auto parts stores, quick lube shops, dealership service departments and gas stations.

Assurance that the urea refill interval is at least as long as the manufacturer's oil change interval so both items can serviced at the same time by the dealership.

DaimlerChrysler, Ford Motor Co., General Motors, BMW and other automakers favor urea, an ammonia-based acid, to reduce NOx, a precursor of smog. The system, also called selective catalytic reduction, is seen as the best way to enable widespread use of diesels in North America, Europe and Japan. It enables diesel engines to meet the most stringent emissions standards in all countries.

The EPA guidelines will be issued as early as October, said Margo Oge, director of the EPA's Office of Transportation and Air Quality. She was in Detroit last week to address a diesel engine and emissions conference.

The guidelines for urea injection systems are expected to be used on diesel-powered cars and trucks starting in 2010. All diesels sold in the United States after Jan. 1, 2010, must meet Tier 2 Bin 5 levels of emissions, just like gasoline engines.

Running on empty

Oge would not talk specifically about the guidelines. But she said disabling the car's engine when the urea tank is empty is a possibility. Automakers oppose preventing the engine from starting when the urea tank is empty, citing safety issues.

Oge says the EPA doesn't want to endanger drivers by having their engines turn off when the urea tank runs dry. But she said the EPA cannot allow vehicles that do not meet emission standards to be driven.

Once the guidelines are published, automakers will have a chance to petition the EPA for changes.

Cost-effectiveness is a key reason most automakers are working on urea systems. Kevin McMahon, managing partner at the Martec Group, a Detroit research and consulting firm, said it should cost automakers about $880 to equip a diesel-powered vehicle with a urea system. The alternative, McMahon, said is a NOx trap in the exhaust system that costs about $1,400.

The rules will address the main problem regulators have with urea: The system won't work unless an on-board urea tank is replenished. Otherwise, the car won't meet emissions standards.

The EPA is considering rules that will require the vehicle to eventually stop running if drivers don't keep the tank filled.

Karl Simon, the EPA's assistant director for the office of transportation and air quality, said the agency is focusing on an early-warning system that notifies drivers when the urea tank is low.

The agency also is considering an inducement that forces drivers to refill the urea tank - for example, preventing the engine from starting if the tank is empty or automatically locking the fuel filler door until the urea supply is replenished.

The agency says automakers will have to make it easy for drivers and technicians to identify the urea tank and refill it.

Tochatihu
08-30-2006, 12:56 PM
"The agency also is considering an inducement that forces drivers to refill the urea tank..."

Just wondering if folks here remember the chemistry of mammalian urine. Adult humans produce 20 grams urea/day; more on very high protein diets. Is that enough?

"...other automakers favor urea, an ammonia-based acid..."

Sorry, but this sort of thing irks me! It's not an acid.

DAS

xcel
08-30-2006, 02:15 PM
Hi Tochatihu:

___Being the scientist that you are, I can imagine stuff like this drives you nuts! I hope I am not the cause of that sometimes ;)

___The big news is that with UREA based injection into an SCR CAT, Diesels can far less expensively fall into line within the Tier II/Bin5 limits (as long as that urea tank has fluid and the pump is working). Ford has a ton of patents on the systems involved but traded some away to Toyota for the eCVT in the Escape and appear to be reluctant to use it overseas with their co-designed Peugeot small diesels where anything that runs today can meet the Emissions belching Euro III and IV specs. I just do not know if Ford is willing given the cancellation of the PZEV Diesel project which did rely on the UREA injection as a key component to bring the emissions down to the SULEV-2 limits.

Mercury MetaOne: The most important, domestically designed HEV "NEVER" produced? (http://www.cleanmpg.com/forums/showthread.php?t=1193)

___Either way, it gives the diesel makers a shot at bringing over some of their best out of Europe and go head to head with the hybrids at emissions levels that should be at least acceptable if not downright exemplary if taken to their logical conclusion. The big question is “IF” they will take the chance or not? We know Honda is going to bring over a Tier II/Bin5 diesel (probably that magnificent 2.2 iCDTi with an emission package of their own) for the Civic and Accord’s or a 3.0 L for everything larger (MDX/Pilot/Ody) by 08/09, MB will do it (they are already doing it) with the Blu-Tec 320 CDI as posted above, and who knows what BMW will do. Add the DualMode to these things and it is going to scare some people! Of course there is this little problem with paying > $50K for a car the size of an Accord with just a tad more luxury and less reliability with a new emissions system that has yet to be proven over the longer term with user intervention at the appropriate times …

___I guess why this story means so much to me (apparently not to many others ;)) is that Ford will have the opportunity to bring over their 1.6L turbo diesels with a Urea injection package and place it into a Focus or the yet to be released Ka/Fiesta B-Class sized Sub they are talking about bringing out? 50 city/highway is a gimme if done properly in that small a car and it brings them back into the game instead of looking at it from the sidelines as they are doing now …

___Good Luck

___Wayne



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