Why Do Heavy Trucks Add Urea Solution?

[Joyce]

Heavy trucks use urea primarily to reduce harmful nitrogen oxides in the exhaust into nitrogen and water. Below are the specific details about vehicle urea usage: 1. Principle: The main harmful substances in exhaust are nitrogen oxides and particulate matter. While particulate emissions can be reduced inside the engine through technical means, leaving mainly nitrogen oxides in the exhaust, urea is injected into the exhaust after-treatment device. Under high temperatures, urea decomposes into ammonia, which reacts with nitrogen oxides in the presence of a catalyst to produce harmless nitrogen and water. This device is called the SCR (Selective Catalytic Reduction) after-treatment system. 2. Urea Consumption: Vehicles have a dedicated urea tank, and urea is consumed as long as the vehicle is running. Therefore, it needs to be replenished regularly. Generally, about 4 liters of urea are consumed per 100 liters of diesel. The exact amount depends on factors such as engine displacement, model, manufacturer, etc. Different road conditions and load weights can also affect urea consumption.