Method for preparing electronic dimethyl carbonate by coupling rectification with crystallization

A technology of dimethyl carbonate and electronic grade, which is applied in the preparation of electronic grade dimethyl carbonate by coupling of rectification and crystallization, and the preparation field of dimethyl carbonate, can solve the problems of unstable product quality, low product purity, residual impurities and the like. , to achieve the effect of simple structure, high purity and low cost

Inactive Publication Date: 2017-12-22
TIANJIN UNIVERSITY OF SCIENCE AND TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] At present, the purification or refining of dimethyl carbonate is mainly through adsorption and distillation or rectification, or a combination of adsorption and rectification. However, there are still certain problems in the purification method

Method used

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  • Method for preparing electronic dimethyl carbonate by coupling rectification with crystallization

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Embodiment 1

[0063] This embodiment provides a method for preparing electronic-grade dimethyl carbonate by coupling rectification and crystallization, and its technological process is as follows figure 1 shown.

[0064] figure 1 Including pre-reactor 100, reactive distillation column 200, dimethyl carbonate crude product storage tank 300, ethylene glycol storage tank 400, feed liquid delivery pump 301, falling film crystallizer 500, crystallization mother liquid storage tank 600, mother liquid delivery Pump 601 and product tank 700. Wherein, the top of the reactive distillation column 200 is provided with a condenser 201, the bottom of the column is provided with a reboiler 202, the prereactor 100 is connected with the feed port of the reactive distillation column 200, and the outlet of the reactive distillation column 200 is Link to each other with dimethyl carbonate crude product storage tank 300, dimethyl carbonate crude product storage tank 300 links to each other with the top feed i...

Embodiment 2

[0073] The method for preparing electronic-grade dimethyl carbonate provided by the coupling of rectification and crystallization provided in this embodiment specifically includes the following steps:

[0074] (1) Reactive distillation: take methanol and ethylene carbonate as raw materials, and its ethylene carbonate and methyl alcohol are 1: 8 according to molar ratio, send into the pre-reactor 100 that catalyst sodium methylate is housed and carry out pre-reaction, pre-reaction obtains The mixture of the mixture is sent into the reactive distillation tower 200 again, and the reactive distillation tower 200 is a pressurized rectification tower, and the operating pressure of the pressurized rectification tower is 10Mpa~12Mpa, and the operating temperature is 160 ℃~190 ℃, and the reflux ratio is 25, The number of theoretical boards is 50.

[0075] The ethylene glycol solution is obtained at the bottom of the reactive distillation tower 200; the crude product of dimethyl carbona...

Embodiment 3

[0081] The method for preparing electronic-grade dimethyl carbonate provided by the coupling of rectification and crystallization provided in this embodiment specifically includes the following steps:

[0082] (1) Reactive distillation: take methanol and ethylene carbonate as raw materials, and its ethylene carbonate and methyl alcohol are 1: 10 according to molar ratio, send into the pre-reactor 100 that catalyst sodium methylate is housed and carry out pre-reaction, pre-reaction obtains The mixture of the mixture is sent into the reactive distillation tower 200 again, and the reactive distillation tower 200 is a pressurized rectification tower, and the operating pressure of the pressurized rectification tower is 8Mpa~12Mpa, and operating temperature is 150 ℃~200 ℃, and the reflux ratio is 15, The number of theoretical boards is 30.

[0083] The ethylene glycol solution is obtained at the bottom of the reactive distillation tower 200; the crude product of dimethyl carbonate w...

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Abstract

The invention belongs to the technical field of chemical production and relates to a method for preparing electronic dimethyl carbonate by coupling rectification with crystallization. The method for preparing electronic dimethyl carbonate by coupling rectification with crystallization provided by the invention comprises the following steps: reactive distillation, namely taking methyl alcohol and ethylene carbonate as raw materials, performing transesterification in a reactive distillation column under the existence of catalyst, acquiring an ethylene glycol solution at the bottom of the reactive distillation column and acquiring the dimethyl carbonate in mass fraction of 98%-99.5% at the top of the reactive distillation column; and falling film crystallization, namely conveying the dimethyl carbonate acquired from the top of the reactive distillation column into a falling film crystallizer, crystallizing in the manner of gradually cooling, stopping till cooling to -5 DEG C to 2 DEG C and then acquiring the dimethyl carbonate in mass fraction of 99.99% in the manner of gradually warming, sweating and fully melting. The method has the advantages of simple operation, easiness in control, high purity and high yield of prepared products, stable product quality, low cost and low energy consumption.

Description

technical field [0001] The invention belongs to the technical field of chemical production and relates to the preparation of dimethyl carbonate, in particular to a method for preparing electronic-grade dimethyl carbonate by coupling rectification and crystallization. Background technique [0002] Dimethyl carbonate, molecular formula C 3 h 5 OH is a colorless and odorless liquid at room temperature, with a melting point of 4°C and a boiling point of 90.3°C. It can be miscible with organic solvents such as alcohols, esters, and ketones. In 1992, dimethyl carbonate was listed as a non-toxic chemical in Europe. It has the advantages of safe use, convenience, less pollution, and easy transportation. In particular, due to its low toxicity and low reactivity, it can be used as a fluid with low environmental impact in applications requiring the presence of a variety of solvents, for example as a replacement for fluorinated solvents used in the electronics industry. [0003] With...

Claims

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Application Information

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IPC IPC(8): C07C68/06C07C68/08C07C69/96
CPCC07C68/065C07C68/08C07C69/96Y02P20/10
Inventor 王红星窦雅利刘伯潭盖晓龙
Owner TIANJIN UNIVERSITY OF SCIENCE AND TECHNOLOGY
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