What is the purpose of adding urea in a vehicle?

[MacGavin]

The purpose of adding urea in a vehicle: It is used for cars, trucks, buses, and heavy-duty non-road diesel engine vehicles equipped with SCR systems to purify vehicle exhaust, reduce nitrogen oxide emissions in the exhaust, optimize engine performance and fuel consumption, and reduce diesel consumption by up to 6%, significantly lowering costs. The NOx in diesel vehicle exhaust mainly consists of nitrogen monoxide (NO). If the NO concentration is too high, it can affect human pulmonary function and cause central nervous system disorders. When exhaust is discharged from the engine combustion chamber, the electric pump, following the instructions of the electronic control unit, draws an adequate amount of urea solution from the urea tank. The urea solution is mixed and atomized with compressed air and enters the injection pipeline, where it is evenly sprayed into the exhaust through the urea nozzle. At this point, the urea solution decomposes under high temperature to produce ammonia (NH3), which then undergoes a catalytic reduction reaction with NOx, ultimately producing harmless gases and water that are discharged.