Divalent acid ester is an important raw material for the production of chemicals, which is widely used in plastics, fibers, coatings, pharmaceuticals and other fields. In this article, we will introduce the manufacturing methods of divalent acid esters, including esterification method, ester exchange method, reduction method and so on.
I. Esterification method
Esterification method is one of the commonly used methods to produce divalent acid esters, and its main raw materials are dibasic acid and dibasic alcohol. In the esterification reaction, dibasic acid and diol react under the action of catalyst to produce divalent acid ester and water. Commonly used catalysts include acidic catalysts such as sulfuric acid and hydrochloric acid and basic catalysts. The production process of
esterification is relatively simple and easy to operate, but there are problems such as slow reaction rate, large catalyst dosage and serious equipment corrosion. In addition, the water generated by the reaction needs to be discharged in time to avoid affecting the reaction balance and product quality.
II, ester exchange method
ester exchange method is a method of using existing ester compounds to produce divalent acid esters. In the ester exchange reaction, two molecules of the same ester compounds are exchanged under the action of an acidic or basic catalyst to produce one molecule of divalent acid ester and one molecule of alcohol.
Compared with esterification, the reaction rate of ester exchange method is faster, the amount of catalyst is less, and the equipment is less corrosive. At the same time, the ester exchange method can utilize the existing ester compounds for production, which has certain economic advantages.
Third, reduction method
Reduction method is a method to produce divalent acid esters by reducing dibasic acid esters. In the reduction reaction, the dibasic acid ester is reduced to a divalent acid ester under the action of a reducing agent, and at the same time a by-product alcohol is produced. Commonly used reducing agents include hydrogen and metal hydrides. The advantage of the
reduction method is that it can avoid the use of acidic or basic catalysts and reduce the problems of equipment corrosion and catalyst residue. However, the production cost of the reduction method is high, requiring the use of large amounts of reducing agent and high-pressure equipment.
Four, other methods
In addition to the above three methods, there are some other methods for the production of divalent acid esters, such as photogasification method, dimethyl carbonate method. These methods have their own advantages and disadvantages, and can be selected according to the specific production requirements and raw materials. In conclusion, there are various methods for the production of divalent acid esters, which can be selected according to the specific production needs and raw materials. In the actual production, it is necessary to make comprehensive consideration according to the purity of the product, yield, production cost and other factors, and choose the most suitable production method. At the same time, it is necessary to strengthen the safety management and environmental protection measures in the production process to ensure the quality of the product and the safety and environmental protection of the production.
