What is SCR technology for trucks, buses, off-road vehicles and cars?
"SCR" is the name of a post-combustion technology treatment for diesel vehicles, which allows them to reduce their harmful emissions of NOx (nitrogen oxides). SCR stands for Selective Catalytic Reduction. This technology requires the use of a reagent called AdBlue. Almost all of the main engine manufacturers use this technology to meet the requirements of new legislation on NOx (Nitrogen oxides) emissions.
The main components of the SCR system are the:
- SCR catalyst
- AdBlue Fluid injection unit
- AdBlue tank
- AdBlue injection control unit.
How does AdBlue work with SCR technology?
AdBlue is injected from the vehicle’s dedicated AdBlue storage tank into the exhaust pipe, which is in front of the SCR catalyst, but downstream of the engine. As it is heated in the exhaust, the AdBlue changes into ammonia (NH₃) and carbon dioxide (CO₂). When the nitrogen oxide (NOx) gases from the exhaust pipe react inside the catalyst with the ammonia, the harmful NOx molecules in the exhaust are converted into harmless nitrogen and water, which is released to the atmosphere as steam.
Do I need to maintain my vehicle’s SCR system?
The SCR system is installed in your vehicle by the manufacturer and works automatically. You do not need to maintain or modify it. AdBlue is automatically injected into the exhaust depending on your vehicle engine’s load. As for adjusting the consumption, the level of AdBlue consumption is determined by the vehicle manufacturer.
To make sure that your SCR system works correctly, please make sure that you only use high quality AdBlue, such as that sold under the brand name Air1 by Yara. This will protect the investment you have made in your vehicle as a low quality reagent would not be pure enough and could be contaminated with impurities. This could cause damage to your catalyst and lead to very high repair costs, that the vehicle manufacturer will not cover.
Yara's AdBlue is marketed under the Air1 brand. Air1’s AdBlue is produced from a high purity urea solution. Urea is produced synthetically from ammonia and CO₂ (carbon dioxide), from which Air1’s AdBlue is extracted directly as “hot melt” urea, which is a different process to fertilizer grade urea. This AdBlue process is quality assured to ensure the correct, stringent specification is attained, ensuring the quality and purity of Yara’s Air1 AdBlue. Learn more about the importance of the quality of AdBlue.