DIESEL EXHAUST FLUID

Handling Guide Diesel Exhaust Fluid (DEF) is a colorless, non-hazardous, and non-flammable chemical. If DEF comes into contact with skin it can simply be washed off with water. It is not a dangerous substance. DEF is sensitive to chemical impurities and it is essential that it is handled carefully to prevent contamination. DEF should be treated as carefully as lube oil or diesel. If DEF is contaminated it may cause the SCR system to malfunction or fail completely. This means pumps and containers used for DEF must not be used for any other fluids and it is important to check that tanks, pumps, hoses and nozzles previously used for other products like diesel or lube oil are not used for DEF. The requirements for handling DEF are unique and specialized equip- ment must be used. DEF is corrosive to a number of materials, including carbon steel, aluminum, copper and zinc. This means that storage containers for DEF tend to be manufactured from stainless steel and heavy-duty plastics. ISO 2224 standard provides a list of recommended and not recom- mended materials, but makes it clear that neither list is exhaustive. You can contact your DEF supplier for a more comprehensive list of equipment and materials that is suitable. DEF is distributed in a variety of containers: Jugs Jugs are available in 1, 2.5 and 4 gallon volumes at retail outlets across North America. This is the most expensive supply format on a per gallon basis, but is suitable for filling pick-up trucks and other light-duty applications, and it provides a useful emergency supply for truckers. A 2.5 gallon jug of DEF weighs around 23 pounds. You can use discoverDEF.com to search for locations that stock jugs of DEF. Drums and Totes Totes are a common storage option for DEF. DEF drums (below left) and DEF totes (below right) are available in standardized sizes. A drum holds 55 gallons of DEF and totes hold either 275 or 330 gallons. Selective Catalytic Reduction (SCR) Selective Catalytic Reduction (SCR) technology uses ammonia to break down dangerous NOx emissions produced by diesel engines into ni- trogen and water. In automotive applications SCR delivers ammonia through a urea solution - Diesel Exhaust Fluid (DEF) - which is sprayed into the exhaust stream by an advanced injection system and then converted into ammonia on a special catalyst. SCR is the technology of choice for the majority of truck and engine manufacturers to meet 2010 emissions standards for heavy-duty trucks. Aside from helping the environment the biggest benefit of SCR for vehicle owners is the fuel saving which the technology provides. Because SCR deals with emissions in the exhaust pipe, engineers are able to tune the engine to provide more torque and reduce fuel consumption. For example, Detroit Diesel's BlueTec technology boasts up to 5% better fuel economy and Cummins has said its EPA 2010 technology deliv- ers a 5-7% fuel efficiency saving compared to EPA 2007. However, SCR systems require a regular top-up of DEF. The technology was first used in vehicles by Nissan Diesel in 2004. Since then Selective Catalytic Reduction (SCR) has been widely imple- mented on diesel vehicles and by the end of 2010, more than 1 million trucks and buses had been equipped with the technology in Europe alone. SCR can be implemented in many different ways on a diesel engine. One of the most common configurations includes four steps: 1. Reaction of the exhaust gas with an oxidation catalyst to remove hydrocarbons and convert some NO to NO2. 2. Conversion of urea from AdBlue/DEF to ammonia on a hydrolysis catalyst. This requires injection of the urea solution into the exhaust stream at the correct dosing rate, and in a way that results in no build-up of urea on the walls of the exhaust or on the injector itself. 3. Reaction of ammonia with NOx on an SCR catalyst to produce nitrogen and water. 4. A final oxidation catalyst is often installed after the SCR catalyst to destroy any remaining ammonia. This is sometimes called an ammonia slip catalyst.