Industrial production of ethylene glycol

Ethylene glycol is a slightly oily, viscous, odorless liquid. It is very soluble in alcohols, water, acetone and turpentine. Ethylene glycol is the basis for automotive and household antifreezes, as it lowers the freezing threshold of water and aqueous solutions. An interesting fact is that even a frozen liquid does not harden, turning into ice, but simply becomes loose. In addition, aqueous solutions of ethylene glycol do not expand and therefore do not damage the tubes and radiator in the car.

This substance is very hygroscopic, that is, it absorbs water from the environment (air, various gases) well. Industrial production of ethylene glycol is established at many chemical enterprises. It should be remembered that this substance is poisonous, although it has a sweetish flavor. Therefore, when dealing with it, you need to take precautions. The vapors of this substance have not too much toxicity and can pose a health hazard only if they are inhaled long. Ethylene glycol is a fuel compound. High concentrations of its vapors in the air are explosive, however, in mixture with water, ethylene glycol loses these properties.

Application

Ethylene glycol is used in various fields of activity and industries: automotive, chemical, aviation, textile, electrical, oil and gas. One of the most important applications of this substance is the production of coolants and antifreezes. Due to the high demand for industrial production of ethylene glycol has acquired enormous proportions. This product can be used as a solvent for paint and varnish products.

Methods for the production of ethylene glycol

Techniques for obtaining this substance are many, but not all of them are suitable for industrial production . One of the most popular methods is the production of ethylene glycol from ethylene by oxidation of the latter with oxygen in the presence of a silver catalyst, followed by subsequent hydration. However, another technique is still in demand. Preparation of ethylene glycol by hydrolysis of ethylene chlorohydrin. In both cases, the hydration reaction of ethylene oxide is carried out in the presence of catalysts and at an elevated temperature. In the literature there is also a method in which the production of ethylene glycol is carried out by the interaction of water, formaldehyde and carbon monoxide. The glycolic acid obtained in the first step is subjected to esterification and ether is obtained. It is then hydrogenated to ethylene glycol. This technique is used in the USA.

The product obtained is thoroughly purified, because even a small content of foreign impurities adversely affects its properties. For example, in the presence of substances such as polyglycols and diethylene glycol in ethylene glycol, its thermal stability is significantly reduced. Therefore, in a high-quality product, the percentage of third-party connections should be minimal. This is especially true for chlorine-containing substances and aldehydes. The mass fraction of the basic compound must be at least 99.5%.