What raw materials are used to make automotive urea solution?
3 Answers
Automotive urea solution is generally synthesized from NOX with 32.5% ultra-pure urea and pure water. The following is relevant information about automotive urea: 1. Introduction: Automotive urea is a urea aqueous solution with a concentration of 32.5% and a solvent of ultra-pure water. The production raw materials are specialized automotive urea materials and ultra-pure water, with the key point being the purity of the raw materials. From a production process perspective, although the purity requirements for automotive urea raw materials are higher than those for general industrial use, current domestic processes can already meet practical application needs. The production process of automotive urea is not sufficient to create high entry barriers. 2. Principle: At temperatures between 70-75°C, urea undergoes hydrolysis in an aqueous solution. At temperatures below 30°C, urea recrystallizes from the aqueous solution. Each hydrolysis and crystallization cycle significantly improves its purity. Generally, using industrial-grade urea for one hydrolysis and crystallization cycle can meet the standard requirements for automotive urea, with a production ratio of 1.5:1.
The urea solution used in vehicles is essentially a specialized aqueous solution, primarily composed of high-purity urea and deionized water. High-purity urea serves as the core component, typically obtained through industrial synthesis, with raw materials including ammonia and carbon dioxide, processed similarly to fertilizer production. It is then dissolved in deionized water, which is specially treated to remove all minerals, preventing impurities from clogging the injectors or damaging the SCR system. I frequently add it when driving a diesel vehicle to help reduce harmful nitrogen oxides in the exhaust. If regular water or contaminated solutions are used, the vehicle may trigger fault codes or experience reduced power. Therefore, choosing urea solution from reputable brands is crucial, and it's important to regularly check the tank level to avoid compromising emission performance.
The composition of urea solution is actually quite simple, mainly consisting of urea crystals mixed with purified water. The urea is synthesized in factories from ammonia and carbon dioxide under high temperatures to ensure ultra-pure quality; the water must be deionized and free from hard water substances like calcium and magnesium to prevent clogging the pipes. When servicing vehicles, I always remind owners not to use tap water as a substitute, because SCR systems are very sensitive, and substandard urea can easily cause nozzle crystallization or damage the catalyst. This liquid typically has a ratio of 32.5% urea to 67.5% water, effectively converting pollutants when used, but it must be stored in a cool place as high temperatures can cause it to degrade.
