Production method of dimethyl sebacate

A technology of dimethyl sebacate and a production method, which is applied in the separation/purification of carboxylate, the preparation of carboxylate, chemical instruments and methods, etc., can solve the problems of being difficult to be distilled off, reducing methanol concentration, and consuming heat energy. , to achieve the effect of improving product purity, reducing product acid value and improving utilization rate

Active Publication Date: 2021-09-28
ZHEJIANG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The use of solid acid catalysts solves the problem of sulfuric acid as a catalyst, but since the reaction is carried out in a tank-type stirred reactor, the first-stage esterification temperature is between the boiling points of methanol and water, so that part of the added methanol is vaporized, which not only consumes heat energy Moreover, the concentration of methanol in the reaction system is reduced, and the water generated by esterification is not easy to evaporate, so the esterification rate is slow, the esterification time is long, and the esterification rate is low due to the limitation of reversible reactions.
The second-stage esterification temperature is higher than the boiling point of water, which is beneficial to the removal of water, but it will cause a large amount of methanol to distill out, and the amount of methanol remaining in the reaction system is very small, which is not conducive to the second-stage esterification reaction. There is still a high acid value, which needs to be refined by rectification, which further increases energy consumption and equipment investment

Method used

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  • Production method of dimethyl sebacate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] 1) First, put the solid sebacic acid into the melting kettle 1, and heat it by passing heating steam into the jacket of the melting kettle, and heat it to 140°C to completely melt the solid sebacic acid; the melting time is 60 minutes, and the product is measured The acid value is 554.5mgKOH / g;

[0025] 2) The melted sebacic acid is pumped from the lower part of the melting tank 1 into the primary esterification tank 3 through the sebacic acid feed pump 2, and a strong acidic ion exchange resin is added. 12.5wt%, using the methanol feed pump 10 to add the liquid methanol flow into the primary esterification tank 3, so that the primary esterification reaction of sebacic acid and methanol occurs, and the flow rate of methanol is 0.007 mL / (g sebacic acid min ), reacted at 140°C for 120min, the acid value of the primary esterified product was measured to be 15.2gmgKOH / g, and the esterification rate was 97.3%;

[0026] 3) Use the first infusion pump 4 to pump the primary es...

Embodiment 2

[0030] 1) First, put the solid sebacic acid into the melting kettle 1, and heat it by passing heating steam into the jacket of the melting kettle, and heat it to 130°C to completely melt the solid sebacic acid; the melting time is 70 minutes, and the product is measured The acid value is 554.5mgKOH / g;

[0031] 2) The melted sebacic acid is pumped from the lower part of the melting kettle 1 into the primary esterification kettle 3 through the sebacic acid feed pump 2, and sulfonated carbon is added. The amount of sulfonated carbon is 3wt% of the raw material mass. The methanol feed pump 10 feeds the liquid methanol flow into the primary esterification tank 3 to cause the primary esterification reaction between sebacic acid and methanol. The methanol flow rate is 0.02 mL / (g sebacic acid min), at 150°C After reacting for 60 minutes, the acid value of the primary esterified product was measured to be 18.1 mgKOH / g, and the esterification rate was 96.7%;

[0032] 3) Use the first i...

Embodiment 3

[0036] 1) First put the solid sebacic acid into the melting kettle 1, and heat it by passing heating steam into the jacket of the melting kettle, and heat it to 150°C to completely melt the solid sebacic acid; the melting time is 50 minutes, and the product The acid value is 554.5mgKOH / g;

[0037] 2) The melted sebacic acid is pumped from the lower part of the melting kettle 1 into the primary esterification kettle 3 through the sebacic acid feed pump 2, and a strong acidic ion exchange resin is added. 6.25wt%, using the methanol feed pump 10 to add the liquid methanol flow to the primary esterification tank 3, so that the primary esterification reaction of sebacic acid and methanol occurs, and the flow rate of methanol is 0.015 mL / (g sebacic acid min ), reacted at 130°C for 100min, the acid value of the primary esterified product was measured to be 17.4gmgKOH / g, and the esterification rate was 96.8%;

[0038] 3) Use the first infusion pump 4 to pump the primary esterified pr...

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Abstract

The invention discloses a production method of dimethyl sebacate. The production method adopts a solid acid catalyst to catalyze esterification of sebacic acid and methanol to produce dimethyl sebacate. The method comprises the following specific operation processes: melting of sebacic acid, reaction in a primary esterification kettle, and fixed-bed final reaction. The process of the reaction in the primary esterification kettle adopts a methanol fed-batch coupled vaporization dehydration method, the reaction is carried out at a temperature slightly higher than the melting point of sebacic acid, and 95% or more of sebacic acid is converted into methyl sebacate; and the fixed-bed final reaction is carried out at a temperature lower than the boiling point of methanol, a small amount of residual carboxylic acid in a primary reaction product is subjected to a refined reaction, so an esterification rate is increased, the acid value of a product is reduced, and the purity of the product is improved. The method has the advantages of short reaction time, high esterification rate, high product purity, easy separation of the catalyst, long service life, less methanol consumption and low energy consumption.

Description

technical field [0001] The invention belongs to the acid-catalyzed esterification method of fatty acid, in particular to a production method of dimethyl sebacate. Background technique [0002] As a widely used organic chemical product, dimethyl sebacate is often used in the preparation of surfactants, leather additives, textile auxiliaries, etc. At present, the main method for preparing dimethyl sebacate is to esterify sebacic acid and methanol under acid catalysis. The acid catalysts used mainly include homogeneous catalysts such as sulfuric acid and p-toluenesulfonic acid and solid acid catalysts. CN1070395A discloses a kind of concentrated sulfuric acid as the production method of catalyst. Put sebacic acid and methanol into the stirring tank in a certain proportion, add a certain amount of concentrated sulfuric acid, when the sebacic acid is completely dissolved, the temperature drops to the solution to form an interface, and the water phase is separated; continue to a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/08C07C67/48C07C69/50
CPCC07C67/08C07C67/48
Inventor 计建炳李梦静陆向红
Owner ZHEJIANG UNIV OF TECH
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