What is the purpose of adding urea to a car?
1 Answers
Adding urea to a car primarily serves the purpose of purifying exhaust emissions in the vehicle. The technical name for automotive urea is Diesel Exhaust Fluid (DEF), which is used in diesel engines. It reacts with nitrogen oxides (NOx) in the exhaust, reducing NOx emissions while also optimizing engine performance and fuel consumption. More detailed information is as follows: 1. Purpose of adding urea: Urea is specifically for diesel engines, as they emit harmful nitrogen oxide gases during operation. These gases are detrimental to both the atmosphere and human health, with long-term exposure leading to respiratory diseases. To mitigate these hazards, urea is employed. This involves a catalytic reaction where urea interacts with the nitrogen oxides emitted by diesel engines, triggering a chemical reaction that converts the nitrogen oxides into harmless nitrogen and water vapor, both of which are benign to the atmosphere and human health. 2. Automotive urea, technically known as Diesel Exhaust Fluid: It is an essential consumable in Selective Catalytic Reduction (SCR) technology. The SCR system includes a urea tank and an SCR catalytic converter. The SCR system operates as follows: when nitrogen oxides are detected in the exhaust pipe, the urea tank automatically sprays Diesel Exhaust Fluid. The fluid then undergoes a redox reaction with the nitrogen oxides in the SCR catalytic converter, producing non-polluting nitrogen and water vapor that are safely expelled. 3. Consequences: Failure to use Diesel Exhaust Fluid, or using fluid of insufficient purity or inferior quality, can result in automatic engine deceleration. Additionally, substandard Diesel Exhaust Fluid can contaminate the catalyst in the SCR catalytic converter, leading to severe consequences.
