Manufacturing method of DMF (N,N-dimethylformamide)
DMF is a commonly used raw material for the production of chemicals, which is widely used in the fields of pharmaceuticals, pesticides, synthetic fibers, plastics, solvents and so on. The following are the manufacturing methods of DMF:
I. Formic acid method
Formic acid method is the main method to produce DMF at home and abroad, and its process route is that formic acid reacts with dimethylamine to produce dimethylformamide. The specific steps are as follows:
1. Formic acid and dimethylamine are added into the reactor according to a certain proportion, and the reaction temperature is controlled to be between 60-80℃, and dimethylformamide and water are generated.
2. The reaction solution is distilled, and the unreacted formic acid and dimethylamine are separated to obtain crude DMF.
3. The crude DMF is refined to remove water and other impurities to obtain a pure DMF product.
The advantages of the formic acid method are that the process is mature, the operation is simple, and the cost is low, but the disadvantages are that the water generated by the reaction needs to be treated, and the equipment is easy to be corroded.
Two, methanol method
Methanol method is another method to produce DMF, its process route for methanol and dimethylamine in the catalyst under the action of the reaction to generate dimethylformamide and hydrogen. The specific steps are as follows:
1. Methanol and dimethylamine are added to the reactor in a certain proportion, a catalyst is added, and the reaction temperature is controlled to be between 200-300°C. The reaction generates dimethylformamide and hydrogen.
2. The reaction product was cooled and separated to obtain crude DMF and hydrogen.
3. The crude DMF is refined and impurities are removed to obtain a pure DMF product.
The advantage of the methanol method is that the reaction conditions are relatively mild, and the hydrogen generated by the reaction can be utilized as an energy source, but the disadvantage is that it requires the use of a catalyst and a large investment in equipment.
Third, acetic acid method
Acetic acid method is a more traditional method of producing DMF, its process route for acetic acid and dimethylamine reaction to generate dimethylformamide and ethylamine. Specific steps are as follows:
1. Acetic acid and dimethylamine are added to the reactor according to a certain ratio, and the reaction temperature is controlled between 100-150 ℃ to produce dimethylformamide and ethylamine.
2. The reaction solution is distilled, and the unreacted acetic acid and dimethylamine are separated to obtain crude DMF.
3. The crude DMF is refined to remove ethylamine and other impurities to obtain a pure DMF product.
The disadvantages of the acetic acid method are that the reaction produces ethylamine which needs to be treated, and the yield is low, so it is less used nowadays.
In short, all the above three methods can be used to produce DMF, the advantages and disadvantages of different methods are different, you can choose the suitable production method according to the actual situation.
