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Time:14months ago
Source:Transform the World with Simplicity
Glycol (pentanediol) is a common raw material for chemical production, which is widely used in plastics, fibers, coatings, medicine and other fields. Next, several manufacturing methods of the pteradiol will be described.
1. Ethylene oxidation
Ethylene oxidation is a commonly used method of manufacturing. The method uses ethylene as a raw material to produce ethylene glycol through an oxidation reaction. The specific steps are as follows:
(1) Ethylene and oxygen are mixed, and then introduced into an oxidation reactor. Under the action of a silver catalyst, an oxidation reaction is performed to generate glyoxylic acid.
(2) reacts glyoxylic acid with water to produce ethylene glycol and formic acid. Ethylene glycol and formic acid are separated by distillation
(3) to obtain pure pyrediol.
The advantages of this method are that the raw materials are readily available, the reaction conditions are mild, and the product purity is high. However, this method requires the use of an expensive silver catalyst, and the production cost is high.
2. Dimethyl carbonate method
Dimethyl carbonate method is a relatively new method of manufacturing. The method uses dimethyl carbonate and hydrogen as raw materials to produce a glycol by hydrogenation reaction. The specific steps are as follows:
(1) After mixing dimethyl carbonate and hydrogen, it is introduced into the hydrogenation reactor, and under the action of the copper-zinc catalyst, the hydrogenation reaction is carried out to generate the alcohol and methanol.
(2) separates the alcohol and methanol by distillation to obtain pure alcohol.
The advantages of this method are that the raw materials are readily available, the reaction conditions are mild, and the catalyst price is low. However, this method requires high-pressure hydrogen and requires high safety production.
3. Chloroethanol method
Chloroethanol method is a traditional manufacturing method. The method uses chloroethanol as a raw material to generate a glycol through a hydrolysis reaction. The specific steps are as follows:
(1) After mixing chloroethanol with water, it is introduced into a hydrolysis reactor, and under the action of an acidic catalyst, a hydrolysis reaction is carried out to generate trol alcohol and hydrochloric acid.
(2) removes hydrochloric acid by neutralization treatment, and then separates pteradiol and water by distillation to obtain pure pteradiol.
The advantages of this method are simple process and less equipment investment. However, this method will produce a large amount of acidic wastewater, environmental protection treatment is difficult.
To sum up, the above three methods can be used for the manufacture of P. D., but each has its own advantages and disadvantages. In actual production, the appropriate method should be selected according to the specific situation. At the same time, in order to reduce production costs and improve product quality, it is necessary to continuously optimize production processes and equipment, and strengthen production management and quality control.