FAQs
What is Diesel Exhaust Fluid (DEF)/ Adblue® ?
What is Diesel Exhaust Fluid (DEF)/ Adblue® ?
What is Diesel Exhaust Fluid (DEF)/ Adblue® ?
· Diesel Exhaust Fluid (DEF) / Adblue® is a precise mixture of urea and de-ionized water that is used in the SCR process. DEF is 32.5% urea and 67.5% de-ionized water, this mixture must be very precise when blended, and will cause problems if either of the parts is improperly added to the solution.
Who needs DEF ?
What is Diesel Exhaust Fluid (DEF)/ Adblue® ?
What is Diesel Exhaust Fluid (DEF)/ Adblue® ?
· Currently, DEF/ Adblue® is required by the majority of heavy duty diesel vehicles (trucks, buses and coaches) purchased after October 2006.
What are the quality certificates?
What is Diesel Exhaust Fluid (DEF)/ Adblue® ?
What are the quality certificates?
· Yes. The American Petroleum Institute (API) is a voluntary certification that was launched in March of 2009. This institute certifies the DEF/ Adblue® and monitors the market to ensure that the ISO 22241 specifications are DEF/ Adblue® are being met.
Does DEF freeze?
What is SCR technology for trucks, buses and off road heavy duty vehicles?
What are the quality certificates?
· DEF/ Adblue® will begin to crystallize and freeze at 12 degrees Fahrenheit (-11 degrees Celsius). Both the urea and the de-ionized water will begin to freeze and thaw out at the same temperatures. When DEF/ Adblue® freezes it expands roughly 7% its normal volume, but the DEF packages made for DEF are designed to handle this expansion. As the DEF thaws it will not become diluted or over concentrated.
How to store DEF?
What is SCR technology for trucks, buses and off road heavy duty vehicles?
What is SCR technology for trucks, buses and off road heavy duty vehicles?
· DEF/ Adblue® should ideally be stored in an area that is cool, dry, out of direct sunlight, and well-ventilated. The best temperature for DEF to be stored in would not exceed 77 degrees F (25 degrees C). Temperature over 90 degrees F will degrade the product and it will NOT return to proper behavior after cooling.
What is SCR technology for trucks, buses and off road heavy duty vehicles?
What is SCR technology for trucks, buses and off road heavy duty vehicles?
What is SCR technology for trucks, buses and off road heavy duty vehicles?
SCR stands for an after-treatment technology called Selective Catalytic Reduction. This technology requires the use of a reagent called AUS 32 (also known as DEF in North America or ARLA 32 in Brazil) to reduce the NOx. Almost all major heavy-duty vehicles manufacturers have decided to use this technology to meet the new emission legislation on NOx emissions. Competitive technologies offer a less beneficial fuel efficiency and higher CO2 emissions. So, SCR is the most cost-effective solution to meet NOx emission standards.
How Does DEF/AdBlue® Diesel Exhaust Fluid Work in SCR System?
How Does DEF/AdBlue® Diesel Exhaust Fluid Work in SCR System?
How Does DEF/AdBlue® Diesel Exhaust Fluid Work in SCR System?
AdBlue® Diesel Exhaust Fluid is injected into the exhaust stream, where it's water evaporates. The separation of Urea and Water due to heat, is called thermolysis.
The chemical reaction is:(NH2)2CO + Heat → NH3 + HNCONH3 is Ammonia and the substance that reacts in the SCR system but not Urea. HNCO is called isocyanic acid and cannot be used in this form in the SCR system.
Isocyanic acid is converted further with the help of the water that got evaporated from before. The process is called Hydrolysis:HNCO + H2O → NH3 + CO2
As you can see there is more Ammonia created for use, the process releases some CO2. By using Ammonia, the SCR system can target and reduce NOx.