Dioctyl ester is a widely used raw material for the production of chemicals, mainly used in the production of plastics, rubber, fibers and other polymer materials. Its manufacturing methods mainly include esterification method and ester exchange method. This article will introduce these two manufacturing methods in detail.
I. Esterification method
Esterification method is the main method of producing dioctyl ester, the principle is to let octanoic acid and ethanol carry out esterification reaction under the action of acid catalyst to produce dioctyl ester and water. The specific steps are as follows:
1. Add octanoic acid and ethanol to the reaction kettle according to a certain molar ratio, and at the same time add a certain amount of acid catalyst.
2. Heat the reactor to raise the reaction temperature to a certain value and maintain a certain reaction time.
3. At the end of the reaction, the reaction solution was cooled and separated to obtain the crude dioctyl ester product.
4. The crude product is refined to obtain a higher purity dioctyl ester product.
The advantages of the esterification method are that the process is mature and simple to operate, but the production process generates a large amount of wastewater, which needs to be treated. In addition, the use of acidic catalysts will have a certain corrosive effect on the equipment.
II. Ester exchange method
Ester exchange method is another method to produce dioctyl ester, the principle is to let triglyceride and methanol under the action of alkaline catalyst to carry out ester exchange reaction to produce glycerol and methyl ester, and methyl ester then carries out esterification reaction with octanoic acid to produce dioctyl ester. The specific steps are as follows:
1. Add triglyceride and methanol to the reactor according to a certain molar ratio, and add a certain amount of alkaline catalyst at the same time.
2. Heating the reaction kettle to raise the reaction temperature to a certain value, and maintaining a certain reaction time.
3. At the end of the reaction, the reaction solution is cooled and separated to obtain a mixture of glycerol and methyl ester.
4. Methyl ester and octanoic acid are added to the reaction kettle in a certain molar ratio, and a certain amount of acid catalyst is added.
5. The reactor is heated to raise the reaction temperature to a certain value and maintained for a certain reaction time.
6. At the end of the reaction, the reaction solution was cooled and separated to obtain the crude dioctyl ester product.
7. The crude product is refined to obtain a higher purity dioctyl ester product.
The advantage of the ester exchange method is that it can reduce the generation of wastewater, and it can also utilize waste triglycerides as raw materials, which is economical. However, the operation of this method is complex and requires control of multiple reaction steps.
Regardless of which method is used, the production process needs to be strictly controlled to ensure the quality and purity of the product. At the same time, the waste generated in the production process also needs to be reasonably treated to avoid pollution of the environment.
In conclusion, the manufacturing methods of dioctyl ester mainly include esterification and transesterification, and different methods have different advantages and disadvantages and scope of application. In the actual production, it is necessary to choose the appropriate method according to the specific situation, and strictly control and manage the production process to ensure the quality of the product and environmental protection.
