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| Urea DEF (Diesel Exhaust Fluid) – FACT vs FICTION |
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As of 2010, all new diesel-powered trucks will have to meet tougher federal emission standards that will reduce allowable nitrogen oxide levels (NOx). 2007 regulations also mandated the use of diesel particulate filters (DPF) and ultra low sulfur fuel to cut soot emissions. New Kenworth trucks will use urea SCR (selective catalytic reduction) where a urea based solution (32.5% urea and 67.5% de-ionized water) held in a separate tank is injected into the exhaust gasses turning the urea into ammonia that combined with a special catalytic converter breaks the NOx into harmless nitrogen gas and water vapor. Here we try to separate some UREA DEF FACT from FICTION… Q. Urea DEF is cold and heat tolerant? A. FICTION… the Urea solution is composed of 67.5% de-ionized water and will start to freeze and crystallize at 11 degrees Fahrenheit. In these climates heater lines must be used. There is a concern about trucks going short distances and/or idling in colder temperatures as well as the supply lines running from the reservoir. However, freezing does not affect its functionality once it is re-thawed. Urea DEF can also loose its potency if stored for prolonged periods over 86 degrees Fahrenheit. Q. Urea DEF is readily available today? A. FICTION… to date there seems to be very few outlets handling the product, although we are told that Urea DEF will be conveniently available at the diesel pump as well as packaged for emergency supply and top-off by 2010 at most truck stops. Q. I can substitute homemade Urea DEF if need be? A. FICTION… Sensors can detect the composition of the Urea DEF. Product impurities can detrimentally affect or plug injectors and filters rendering the SCR ineffective and may also void warranty. Q. Does Urea SCR really work? A. FACT… the use of SCR together with EGR and DPF is the only current feasible technology to meet 2010 EPA and EURO 6 emission standards without significant losses in efficiency. Q. All new Kenworth trucks in 2010 will have Urea SCR? A. FICTION… Camex has ordered in excess of 100 “Pre-Urea” CAT and Cummins equipped Kenworth T800’s and C500’S. These units will start arriving April 1, 2010 and are available for customer specific rig-up. Q. Urea DEF has a long shelf life? A. FACT… Stored at temperatures between 11 and 86 degrees Fahrenheit it will last about 1 year. In colder regions it is recommended to store the solution in a storage unit and in hotter areas in a shaded area (at higher temperatures, the solution starts to convert to ammonia and losses its effectiveness). It is recommended not to use Urea DEF that is over a year old. Q. I can go a long time/way without refilling? A. FACT… depending on the size of reservoir tank a typical fleet tractor will likely fill every 10 days – approximately one gallon of DEF per 300 miles. There is still a lack of study on off-road vehicles and required refills versus running hours and mileage. Q. My Diesel truck can still function if I run out of Urea DEF? A. FICTION… the SCR monitoring system will warn drivers of low levels of Urea DEF and then automatically cut the engine’s speed performance. After the tank goes dry and the operator fails to fill up with the proper solution of Urea DEF, the next time the engine is shut off the truck will be immobilized. Q. SCR with Urea DEF equipped trucks are available with higher horsepower engines? A. FICTION… to date, new trucks with Urea SCR systems are only available with 485 HP or less engines. Now’s the time to order your Camex 2010/2011 “Pre-Urea” Kenworth T800 or Kenworth C500 while they are still here and in stock Important: We tried to glean as much relevant information as possible from various Internet sites on Urea SCR technology. The information was often open to interpretation and left many questions unanswered. We recommend that you do as much research as possible to fully understand the implications of Urea SCR. We found these links on Urea SCR technology helpful: www.brenntagdef.com www.factsaboutscr.com www.kenworth.com/brochures/PACCARSCR.pdf |