Method for extracting and rectifying separation of dimethyl carbonate and methanol mixture

A technology of dimethyl carbonate and separation method, which is applied in the field of continuous extraction, rectification and separation of dimethyl carbonate and methanol, and can solve the problems that the extractant cannot be operated continuously

Active Publication Date: 2021-11-30
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problem that the ionic liquid existing in the azeotrope separation of dimethyl carbonate and methanol cannot operate continuously as an extractant, the present invention provides a continuous extraction and rectification separation method, which has good separation effect and stable continuous operation of the device advantage

Method used

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  • Method for extracting and rectifying separation of dimethyl carbonate and methanol mixture
  • Method for extracting and rectifying separation of dimethyl carbonate and methanol mixture

Examples

Experimental program
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Effect test

Embodiment 1

[0025] Such as figure 2 The extractive distillation process shown. The extractive distillation column has 33 theoretical plates (the number of plates is counted from top to bottom), and the mixed extractant contains 30wt% triethylene glycol dimethyl ether and 70wt% 1-hexyl-3-methylimidazole tetrafluoroboric acid salt([hmim][BF 4 ]) add from the 3rd tray, total flow is 7.5kg / h, the mixture of raw material dimethyl carbonate and methyl alcohol adds from the 29th tray, dimethyl carbonate content is 30wt%, methanol content is 70wt%, The total flow rate is 1kg / h, and the molar solvent ratio of the extractant to the raw material is 1.3 at this moment. The extractive distillation column operates under normal pressure, the top of the tower is fully condensed, the reflux ratio is 1.2, and the output at the top of the tower is 0.7kg / h, and 99.81wt% of methanol and 0.19wt% of dimethyl carbonate can be obtained. The temperature at the top of the distillation column is 64°C, and the te...

Embodiment 2

[0027] Such as figure 2 The extractive distillation process shown. The extractive distillation column has 38 theoretical plates (the number of plates is counted from top to bottom), and the mixed extractant contains 20wt% triethylene glycol dimethyl ether and 80wt% 1-hexyl-3-methylimidazole tetrafluoroboric acid salt([hmim][BF 4 ]) add from the 4th tray, flow rate is 7kg / h, the mixture of raw material dimethyl carbonate and methyl alcohol adds from the 34th tray, dimethyl carbonate content is 30wt%, methanol content is 70wt%, total flow is 1kg / h, and the molar solvent ratio of extractant to raw material is 1 at this time. The extractive distillation tower is operated under normal pressure, the top of the tower is fully condensed, the reflux ratio is 1.3, the output of the tower top is 0.7kg / h, and 99.9wt% of methanol and 0.12wt% of dimethyl carbonate can be obtained. The temperature at the top of the distillation column is 64°C, and the temperature at the bottom of the tow...

Embodiment 3

[0029] Such as figure 2 The extractive distillation process shown. The extractive distillation column has 42 theoretical plates (the number of plates is counted from top to bottom), and the mixed extractant contains 50wt% triethylene glycol dimethyl ether and 50wt% 1-butyl-3-methylimidazolium tetrafluoroboron Salt ([bmim][BF 4 ]) add from the 4th tray, total flow is 7.5kg / h, the mixture of raw material dimethyl carbonate and methyl alcohol adds from the 37th tray, dimethyl carbonate content is 30wt%, methanol content is 70wt%, The total flow rate is 1kg / h, and the ratio of extractant to raw material molar solvent is 1.42. The extractive distillation tower is operated under normal pressure, the top of the tower is fully condensed, the reflux ratio is 1.2, the output at the top of the tower is 0.7kg / h, and 99.8wt% of methanol and 0.2wt% of dimethyl carbonate can be obtained. The temperature at the top of the distillation tower is 64°C, and the temperature at the bottom of th...

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Abstract

The invention relates to a method for separating dimethyl carbonate and methanol, which mainly solves the problem of unstable device operation during continuous production when ionic liquid is used as an extraction agent. The separation method is extractive distillation, and the extractive distillation adopts a mixed extractant, wherein one of the mixed extractant is an ionic liquid whose anion is tetrafluoroborate, and the second of the mixed extractant is diethylene glycol dimethyl ether, One of triethylene glycol dimethyl ether or tetraethylene glycol dimethyl ether. The separation method can realize continuous separation of dimethyl carbonate and methanol, has stable product quality and device operation, and can be used in industrial production processes.

Description

technical field [0001] The present invention relates to a kind of separation method of dimethyl carbonate and methanol, specifically, relate to a kind of continuous extraction rectification separation method of dimethyl carbonate and methanol. Background technique [0002] Dimethyl carbonate (DMC) is an environmentally friendly chemical intermediate widely used in reactions such as methylation, carbonylation, carbonylmethylation and methoxylation, and is known as the "new cornerstone" of organic synthesis today . In industry, transesterification is usually used to produce dimethyl carbonate. During the production process, dimethyl carbonate and methanol form an azeotrope, which is difficult to separate by ordinary distillation methods. [0003] In recent years, technologies such as extractive distillation, pressurized distillation, azeotropic distillation and membrane separation have been used to produce high-purity dimethyl carbonate. Compared with the latter three proces...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C27/32C07C29/84C07C31/04C07C68/08C07C69/96
CPCC07C29/84C07C68/08C07C31/04C07C69/96
Inventor 李骏何文军戈军伟费泰康
Owner CHINA PETROLEUM & CHEM CORP
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