Why Do Diesel Vehicles Need to Add Urea and What Role Does It Play?

[RonanMarie]

Vehicles use urea to reduce harmful nitrogen oxides in the exhaust into nitrogen and water. Related introduction: 1. Development process: With the increasing requirements of national environmental regulations, the exhaust directly emitted by engines can no longer meet the regulatory standards, leading to the development of exhaust aftertreatment devices. The main harmful substances in diesel vehicle exhaust are nitrogen oxides and particulates. Technical measures can be taken inside the engine to reduce particulate emissions, leaving nitrogen oxides as the primary component in the exhaust. 2. Related principle: Urea is injected into the exhaust aftertreatment device, where it decomposes into ammonia at high temperatures. Under the action of a catalyst, the ammonia reacts with nitrogen oxides to produce harmless nitrogen and water. This device is called the SCR (Selective Catalytic Reduction) aftertreatment system.