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Method for preparing dimethyl maleate

A technology of dimethyl maleate and maleic anhydride, which is applied in the field of preparing dimethyl maleate, can solve the problem of dimethyl maleate selectivity and yield reduction, material Difficult to separate and refine, difficult to remove water, etc., to achieve high selectivity and yield, reasonable process, and reduce production costs

Active Publication Date: 2010-09-08
河北彩客新材料科技股份有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0013] In the prior art, the main problem in the synthesis of dimethyl maleate from maleic anhydride or maleic acid and methanol is that in the second step, the diesterification reaction between monomethyl maleate and methanol generates In the process of dimethyl maleate, because the reaction of monomethyl maleate and methanol is an equilibrium reversible reaction, and the by-product water in the reaction process, the prior art adopts methanol evaporation to take out water to achieve the effect of water removal. The purpose is very difficult, it is difficult to effectively remove the water of by-product in the reaction, so the reaction of monomethyl maleate is difficult to carry out thoroughly, the reaction conversion rate is low, the process reaction rate is slow, and the diesterification reaction product maleic acid di The selectivity and yield of methyl esters are reduced, and dimethyl maleate forms an azeotrope with water, which leads to difficulties in the separation and purification of materials after the diesterification reaction, and the product has low purity and poor quality

Method used

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  • Method for preparing dimethyl maleate
  • Method for preparing dimethyl maleate
  • Method for preparing dimethyl maleate

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Experimental program
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Effect test

Embodiment 1

[0050] Main process equipment The chemical reactor for monomethyl ester reaction, diesterification reaction and re-esterification reaction is a tank-type stirred chemical reactor, the solid-liquid separation device is a sedimentation type solid-liquid separation device, and the oil-water separation device is a sedimentation oil-water separator.

[0051] As shown in the figure, a method for preparing dimethyl maleate is to prepare dimethyl maleate with maleic anhydride and methanol as raw materials, and the method steps are as follows:

[0052] (1) Dehydration and impurity removal: methanol is added to the dehydration and impurity removal equipment, and alkaline earth metal oxides are added to mix evenly for dehydration and impurity removal operations. The alkaline earth metal oxides are calcium oxide, and the amount of calcium oxide is 1% of the methanol mass;

[0053] (2) Solid-liquid separation: The material obtained in the previous step is subjected to solid-liquid separati...

Embodiment 2

[0068] Main process equipment The chemical reactor for monomethyl ester reaction, diesterification reaction and re-esterification reaction is a tubular chemical reactor, the solid-liquid separation device is a filter type solid-liquid separation device, and the oil-water separation device is a centrifugal type Water separator.

[0069] As shown in the figure, a method for preparing dimethyl maleate is to prepare dimethyl maleate with maleic anhydride and methanol as raw materials, and the method steps are as follows:

[0070] (1) Dehydration and impurity removal: methanol is added to the dehydration and impurity removal equipment, and alkaline earth metal oxides are added to mix evenly for dehydration and impurity removal operations. The alkaline earth metal oxides are magnesium oxide, and the amount of magnesium oxide is 3% of the methanol mass;

[0071] (2) Solid-liquid separation: The material obtained in the previous step is subjected to solid-liquid separation in a filter...

Embodiment 3

[0086] Main process equipment The chemical reactor for monomethyl esterification reaction, diesterification reaction and re-esterification reaction is a static mixer, the solid-liquid separation device is a centrifugal solid-liquid separation device, and the oil-water separation device is a high-efficiency oil-water Splitter.

[0087] As shown in the figure, a method for preparing dimethyl maleate is to prepare dimethyl maleate with maleic anhydride and methanol as raw materials, and the method steps are as follows:

[0088] (1) Dehydration and impurity removal: Add methanol to the dehydration and impurity removal equipment, add alkaline earth metal oxides and mix evenly to perform dehydration and impurity removal operations. The alkaline earth metal oxides are barium oxide, and the amount of barium oxide is 4% of the methanol mass;

[0089] (2) Solid-liquid separation: The material obtained in the previous step is subjected to solid-liquid separation in a centrifugal solid-liqu...

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Abstract

The invention relates to a method for preparing dimethyl maleate, which comprises the following steps of : (1) dehydration and impurity removal: methanol is mixed with alkaline-earth metal oxide to be dehydrated and removed impurity; (2) separation of solid and liquid; (3) monoesterification reaction: maleic anhydride is added in liquid-phase material which is obtained in the previous step; (4) vacuum distillation; (5) two-esterification reaction: acid catalyst and methanol are added in the material after the vacuum distillation in the previous step; (6) evaporation; (7) mixing of oil and water; (8) separation of oil and water; (9) re-esterification reaction; (10) evaporation; (11) mixing of oil and water; (12) separation of oil and water; (13) impurity removal and dehydration; (14) separation of solid and liquid: liquid-phase material enters the next step; (15) rectification separation: the product dimethyl maleate is obtained. The method is simple and has reasonable process, low preparation cost, high product purity and good product quality.

Description

technical field [0001] The invention relates to a method for preparing dimethyl maleate, in particular to a method for preparing dimethyl maleate by using maleic anhydride and methanol as raw materials, and belongs to the field of fine chemicals. Background technique [0002] Dimethyl Maleate (DMM), also known as dimethyl maleate (Maleic Acid Ester), CAS number 624-48-6, molecular formula C 6 h 8 o 4 , the molecular weight is 144.13, it is a colorless irritating liquid, the refractive index (n25D) is 1.4405, and the relative density of the phase material (d 4 25 ) 1.462, with a melting point of -19.0°C, a boiling point of 200.4°C, and a flash point (open cup) of 112°C. It is soluble in ether and miscible with various organic solvents. It is mainly used as a raw material for solvent and fine organic chemical synthesis, and can be used for the production of paints, coatings, pesticides, anti-rust additives, etc. It is an important organic chemical raw material. [0003] ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C69/60C07C67/54C07C67/08
Inventor 许文林姚干兵王雅琼张淮浩张小兴施国茂
Owner 河北彩客新材料科技股份有限公司
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