Method for purifying diacid dimethyl esters by plate distillation separation

Abstract

The invention discloses a method for purifying diacid dimethyl esters by plate distillation separation. The distillation separation is successively finished in three series-wound distillation towers. The bottom of a second distillation tower is vertically provided with a separator plate, which divides the bottom cavity into a first tower chamber and a second tower chamber. A material inlet of the second distillation tower is positioned below the top of the separator plate. The method provided by the invention comprises the following steps of: mixing a raw material with diacid dimethyl esters, allowing the mixture to enter into the first distillation tower, separating a light component out from the top of first distillation tower, allowing the material at the tower bottom to enter into the second distillation tower, separating 1,4-succinic acid dimethyl ester out from the top of the distillation tower, separating 1,5-dimethyl glutarate out from the bottom of the second tower chamber of the second distillation tower, allowing the material at the tower bottom of the first tower chamber of the second distillation tower to enter into the third distillation tower, separating 1,6-adipic acid dimethyl ester out from the top of the third distillation tower, and discharging a heavier component in the raw material from the tower bottom. Starting with the first distillation tower, the temperature of the distillation towers successively rises and the pressure successively reduces.

Description

technical field [0001] The invention relates to the technical field of separation and purification of organic mixtures, in particular to a method for preparing 1,4-dimethyl succinate, 1,5-dimethyl glutarate and 1,6- Dimethyl adipate method. Background technique [0002] Dimethyl 1,4-succinate, dimethyl 1,5-glutarate and dimethyl 1,6-hexanedioate are all important chemical raw materials. [0003] Dimethyl 1,4-succinate is mainly used in food spices, in the preparation of fruit and fruit wine flavors and in the pharmaceutical industry, and in the synthesis of light stabilizers, high-grade paints, fungicides, and pharmaceutical intermediates, etc.; 1 , Dimethyl 5-glutaric acid is mainly used in organic synthesis; dimethyl 1,6-adipate can be used as a raw material for synthetic intermediates, medicines, and spices, as a plasticizer and high-boiling solvent, or as nylon acid The main component of dimethyl ester can also be used as a raw material for hydrogenation to produce 1,6...

AI Technical Summary

Problems solved by technology

[0004] Dibasic acid dimethyl ester is a mixture obtained by esterification of mixed diacid, a by-product of adipic acid production, and methanol. In addition to the three esters, there are a certain amount of light components and heavy components in the mixture. To obtain a higher purity For three esters, it is necessary to separate the various components. The traditional distillation separation device and distillation method can separate five mixtures and obtain three pure products. At least four distillation towers are required, one tower separates and removes light components, and the tower The bottom material enters the second tower, the top of the second tower is separated and purified to obtain dimethyl succinate, the bottom material of the second tower enters the third tower, the top of the third tower is separated and purified to obtain dimethyl glutarate, and the bottom material of the third tower enters the fourth tower, the top of the four towers is separated and purified to obtain dimethyl adipate, and the bottom of the four towers is heavy components. Therefore, the traditional production process has complex production processes, large equipment investment, and high production costs.

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