Vehicles with SCR technology have a separate tank filled with AdBlue. This is then injected into the exhaust pipe, in front of the SCR catalyst, downstream of the engine.
Heated in the exhaust, it decomposes into ammonia and CO₂. When the NOx from the engine exhaust reacts inside the catalyst with the ammonia, the harmful NOx molecules in the exhaust are converted to harmless nitrogen and water, which are released from the tail pipe as steam.
On May 11st, 2018