Manufacturing method of glyoxal
Glyoxal is an important organic compound, widely used in chemical, pharmaceutical, pesticide and other fields. In the field of raw materials for chemical production, there are mainly the following manufacturing methods of glyoxal:
1. Oxidation method
Oxidation method is one of the main methods to produce glyoxal, and its principle is to oxidize raw materials such as ethylene glycol or ethylenediamine to generate glyoxal and water. Commonly used oxidizing agents are hydrogen peroxide, nitric acid, potassium permanganate and so on. Among them, the oxidation method with hydrogen peroxide as the oxidizing agent is more commonly used because hydrogen peroxide has a high oxidizing capacity and the water generated by the reaction is pollution-free. The production process of
oxidation method generally includes the steps of raw material proportioning, oxidation reaction, separation and purification. Among them, raw material proportioning is one of the key factors affecting the yield of glyoxal, which needs to be optimized according to the nature of different raw materials and reaction conditions. At the same time, the control of oxidation reaction temperature and time also need to be adjusted according to the specific situation to ensure the reaction and the quality of the product.
2. Condensation
Condensation is the condensation reaction of acetaldehyde with formaldehyde under acidic conditions to produce glyoxal and water. Commonly used acidic catalysts include sulfuric acid and hydrochloric acid. The reaction conditions of the condensation method are relatively mild, but it is necessary to control the reaction temperature and pH value to avoid the generation of by-products and the decomposition of products. The production process of
condensation method generally includes the steps of raw material proportioning, condensation reaction, neutralization and separation and purification. Among them, the control of raw material proportioning and reaction conditions are the key factors affecting the yield and purity of glyoxal, which need to be optimized according to experimental data.
3. Acetylene method
Acetylene method is an addition reaction between acetylene and formaldehyde under alkaline conditions to produce acetaldehyde and hydrogen. Commonly used alkaline catalysts are sodium hydroxide and potassium hydroxide. The reaction conditions of the acetylene method are more demanding, requiring high temperature and high pressure conditions, but the generated glyoxal is of higher purity. The production process of
acetylene method generally includes the steps of mixing acetylene and formaldehyde, addition reaction, separation and purification. Among them, the control of reaction conditions and the selection of catalysts are the key factors affecting the yield and purity of glyoxal, which need to be verified and optimized by strict experiments.
In general, the manufacturing methods of glyoxal need to be selected and optimized according to specific raw materials and reaction conditions. Different manufacturing methods have different advantages and disadvantages and scope of application, and need to be considered and selected according to the actual situation. At the same time, the process parameters need to be strictly controlled in the production process to ensure the quality and yield of the product.
