Octylene Glycol (OG) is an important raw material widely used in the production of chemicals, with excellent moisturizing properties, solubility and low toxicity, it is widely used in cosmetics, pharmaceuticals, coatings, inks and other fields. This article will introduce the manufacturing method of octanediol in detail.
I. Chloroethanol method
Chloroethanol method is one of the main methods for the production of octanediol, and the process is as follows:
1. Preparation of chloroethanol: Ethylene oxide is reacted with hydrogen chloride gas in an aqueous solution to produce chloroethanol.
2. Addition reaction of chloroethanol: Under the action of alkaline catalyst, chloroethanol and ethylene oxide undergo addition reaction to produce monochlorine substitutes of octanediol.
3. Hydrolysis reaction: the monochlorine substituent is hydrolyzed to obtain octanediol.
The method is mature and simple to operate, but the production process will produce a large amount of wastewater and exhaust gas, causing some pollution to the environment.
II. Olefin oxidation method
Olefin oxidation method is a new method developed in recent years, and its process is as follows:
1. Olefin oxidation: oxidize the olefin with oxygen to generate aldehyde or ketone.
2. Reduction of aldehyde or ketone: the aldehyde or ketone is reduced to an alcohol to obtain octanediol.
This method has the advantages of easy availability of raw materials, mild reaction conditions, high yield, and is a more promising production method.
III. Biological method
Biological method is a method of producing octanediol by microbial fermentation, and its process is as follows:
1. Cultivation of microorganisms: Inoculate microorganisms in the medium containing nutrients such as carbon, nitrogen, and inorganic salts, etc., and cultivate them.
2. Fermentation process: under suitable conditions, the microorganisms convert the carbon source into octanediol by metabolism.
3. Extraction and purification of products: Octanediol is extracted and purified from the fermentation broth by centrifugation, distillation and other processes.
Biological method has the advantages of environmental protection and energy saving, but the production process is long, and the growth and metabolic process of microorganisms need to be controlled to ensure the quality and yield of the product.
IV. Esterification
Esterification is a method of producing octanediol by esterification reaction, and the process is as follows:
1. Esterification reaction: Caprylic acid and ethylene glycol are esterified under the action of acid catalyst to produce ethylene glycol octanoate.
2. Catalytic hydrogenation: Glycol octanoate is subjected to a catalytic hydrogenation reaction to obtain octanediol.
This method has easy-to-obtain raw materials and mild reaction conditions, but the production process requires catalysts and produces a certain amount of waste water and exhaust gas.
In summary, there are various methods for the production of octanediol, and each method has its advantages and disadvantages and scope of application. In actual production, the suitable production method should be selected according to the source of raw materials, production scale, environmental protection requirements and other factors. Meanwhile, with the continuous progress of science and technology and the improvement of environmental protection awareness, the development of more environmentally friendly, efficient and economical production methods will be the future development trend.
