Manufacturing method of urobase
In the field of raw materials for chemical production, urobase is an important organic compound, which is widely used in pesticides, pharmaceuticals, dyestuffs and other industries. In this article, we will introduce the manufacturing method of urobase, including raw material preparation, reaction process, post-treatment and so on.
I. Raw material preparation
The main raw materials for manufacturing urobase are urea and formaldehyde. Urea is a common nitrogen fertilizer, which can be produced by synthesizing ammonia and carbon dioxide reaction. Formaldehyde is a colorless, irritating odor gas that can be obtained by oxidizing methanol.
II. Reaction process
1. Reaction between urea and formaldehyde
Mix urea and formaldehyde according to a certain molar ratio, add an appropriate amount of catalyst, such as hydrochloric acid or sulfuric acid, and control a certain temperature and pH, so as to make urea and formaldehyde undergo a condensation reaction to produce hydroxymethylurea.
2. Dehydration of hydroxymethylurea
Hydroxymethylurea undergoes a dehydration reaction at a certain temperature to produce urea base. This process needs to control the appropriate temperature and time to ensure the yield and purity of urea base.
Third, post-treatment
After the end of the reaction, the reaction solution needs to be post-treated to obtain a higher purity urobase product. The post-treatment process includes:
1. Neutralization: add alkaline absorbent to the reaction solution to make it react with the residual acidic catalyst and adjust the pH to neutral.
2. Decolorization: Add appropriate amount of activated carbon to adsorb the pigment and impurities in the reaction solution and improve the purity of urine base.
3. Filtration: Remove solid impurities such as unreacted raw materials and by-products from the reaction solution by filtration.
4. Crystallization: The filtered solution is cooled and crystallized to obtain crystals of urea base.
5. Drying: the crystals of urushiol are dried to remove water and other volatile substances from them.
Through the above steps, the product of urobase with high purity can be manufactured.
4. Precautions
1. Control the reaction temperature and pH: During the reaction between urea and formaldehyde, it is necessary to control the appropriate temperature and pH to ensure the smooth progress of the reaction and the yield of urobase.
2. Preventing the occurrence of side reactions: In the process of making urea base, some side reactions may occur and some impurities may be generated. Therefore, it is necessary to choose suitable catalyst and reaction conditions to minimize the occurrence of side reactions.
3. Pay attention to safety: Formaldehyde is a toxic and harmful gas, which is harmful to human health. In the process of manufacturing the urine base, it is necessary to pay attention to safety measures to avoid formaldehyde leakage and contact.
In short, the manufacturing method of urine base includes raw material preparation, reaction process and post-treatment. In the manufacturing process, attention needs to be paid to issues such as controlling the reaction conditions, preventing the occurrence of side reactions and paying attention to safety measures to ensure the yield and purity of the urine base.
