The raw materials for making urea are carbon dioxide and ammonia.

Urea is an inorganic fertilizer whose main component is ammonium bicarbonate, which can also be understood as potassium bicarbonate. The main function of urea is to improve soil fertility, promote crop growth and development, and improve the quality of agricultural products. The raw materials for making urea are carbon dioxide and ammonia. Production process: Use carbon dioxide and ammonia to synthesize ammonium carbamate and excess ammonia under high temperature and high pressure, then reduce the pressure and lower the temperature, evaporate the urea liquid after separating ammonia and ammonium carbamate to above 99.5, and then granulate in a granulation tower to obtain Urea finished product.

Urea is used in a wide range of applications, and almost all crops cannot grow without urea. As a neutral fertilizer, urea is suitable for a variety of soils and plants. It is easy to preserve, convenient to use, and has little damage to the soil. It is a chemical nitrogen fertilizer that is used in large quantities and is also the nitrogen fertilizer with the highest nitrogen content. Industrially, ammonia and carbon dioxide are used to synthesize urea under certain conditions.

Types of urea

1. Ordinary urea

The nitrogen content in urea is relatively high. Qualified products require a nitrogen content of 46.0, and first-class products require a nitrogen content of 46.2 , the high-quality product is 46.4, which can be used as base fertilizer and top dressing.

2. Polypeptide urea

The nitrogen content of polypeptide urea is the same as that of ordinary urea, still 46-46.4, but the fertilizer effect is longer than that of ordinary urea, and it can be used as base fertilizer, top dressing and production Slow-release fertilizer is used, but when used as top dressing, it is best to mention it earlier than the date of normal top dressing.

3. Slow-release urea

Slow-release urea adds a certain proportion of urease inhibitor in the production process of ordinary urea to reduce the loss of nitrogen, thereby improving fertilizer efficiency and extending fertilizer efficiency. .

4. Coated (controlled release) urea

Coated urea is a semi-permeable or impermeable substance coated on the surface of urea to allow nutrients to pass through the micropores of the coating. The gaps are slowly released, and the controlled release of nitrogen nutrients is slowly released, improving fertilizer utilization.

5. Urea-formaldehyde urea

Urea-formaldehyde urea is a product produced by the reaction of urea and formaldehyde at high temperature. However, this product is not a single substance. It mainly contains 1 methylene 2 It is composed of two colloids: urea and 2-methylene-3-urea.

Reference for the above content: Baidu Encyclopedia-Urea