AdBlue is a trade name for a diesel exhaust fluid (DEF) that is used in diesel-powered vehicles equipped with selective catalytic reduction (SCR) systems. It is a clear, non-toxic, and colorless liquid that is composed primarily of purified water and high-purity urea. AdBlue is used to reduce harmful emissions from the exhaust of diesel engines, particularly nitrogen oxides (NOx), which are a major contributor to air pollution.
Here’s how AdBlue works:
- AdBlue is stored in a separate tank in a diesel vehicle.
- During the operation of the vehicle, a small amount of AdBlue is injected into the exhaust stream before it passes through the SCR catalyst.
- In the SCR catalyst, the heat from the exhaust causes the urea in AdBlue to decompose into ammonia (NH3) and carbon dioxide (CO2).
- The ammonia then reacts with the NOx emissions in the exhaust, converting them into harmless nitrogen (N2) and water vapor (H2O).
This chemical reaction helps to significantly reduce the levels of harmful NOx emissions, making diesel engines more environmentally friendly and compliant with strict emission standards.
AdBlue is widely used in Europe and other parts of the world, and its usage is often mandated by regulations to meet emissions standards. Drivers of diesel vehicles equipped with SCR systems need to periodically refill the AdBlue tank to ensure the system operates properly and continues to reduce emissions effectively.