Hexylene Glycol (HG) is an important raw material for the production of chemicals, which is widely used in the fields of solvents, plasticizers, moisturizers, preservatives and so on. In this paper, the manufacturing method of Hexylene Glycol will be introduced in detail, including raw material preparation, reaction process, post-treatment and precautions.
I. Raw material preparation
1. Ethylene oxide: Ethylene oxide is the main raw material for the production of hexylene glycol, which is highly active and can have ring-opening addition reaction with water, alcohol and other compounds.
2. 1,6-Hexanediol: 1,6-hexanediol is the initiator of hexanediol production, used to promote the ring-opening polymerization reaction of ethylene oxide.
2. Reaction process
Hexanediol is manufactured mainly through the ring-opening addition reaction between ethylene oxide and water in the presence of an acidic catalyst. The specific steps are as follows:
1. 1,6-hexanediol is added to the reactor, followed by the addition of an appropriate amount of acidic catalyst, such as sulfuric acid or phosphoric acid.
2. Slowly add ethylene oxide dropwise under stirring conditions, controlling the reaction temperature within an appropriate range.
3. Continue to stir and keep warm, so that the ethylene oxide is fully reacted to produce hexylene glycol.
III. Post-treatment
After the reaction, post-treatment is required to obtain a pure hexylene glycol product. The specific steps are as follows:
1. Neutralize the acidic catalyst in the reactor with alkaline absorbent to make it inactive.
2. The reaction solution is distilled to separate the unreacted feedstock and by-products.
3. By distillation, the product of hexanediol with higher purity is obtained.
4. Precautions
1. The temperature of the reaction should be strictly controlled during operation to avoid the generation of by-products due to high temperature.
2. The dosage of acid catalyst should be appropriate, too much will lead to equipment corrosion, too little may affect the reaction rate.
3. In the post-treatment process, make sure the neutralization is complete to avoid the acid catalyst affecting the quality of the product.
In conclusion, the manufacturing process of hexanediol requires strict control of the reaction conditions to ensure product quality. Through the manufacturing method introduced in this paper, high purity hexanediol can be produced, providing high quality raw materials for chemical production.
