Process for synthesizing symmetric oxalate through ester exchange path

A technology of transesterification and oxalate, which is applied in the preparation of organic compounds, chemical industry, and preparation of carboxylic acid esters, etc.

Inactive Publication Date: 2018-12-25
SHENYANG INSTITUTE OF CHEMICAL TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0019] There are a large number of domestic reports on the transesterification reaction, such as the transesterification of propylene carbonate and methanol to prepare dimethyl carbonate, the transesterification of dimethyl carbonate and ethanol to prepare ethyl methyl carbonate, etc. Most of them use homogeneous soluble basic catalysts, but There are very few reports on the synthesis of oxalate by transesterification of dimethyl oxalate and various alcohols (ethanol, propanol, butanol, etc.)

Method used

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  • Process for synthesizing symmetric oxalate through ester exchange path
  • Process for synthesizing symmetric oxalate through ester exchange path
  • Process for synthesizing symmetric oxalate through ester exchange path

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0061] Using ethanol and dimethyl oxalate as raw materials, the ratio of diethyl oxalate and methanol produced by the reaction is 1:2, and the distilled ethanol is recycled.

[0062] The catalyst is an alkaline composite material 15%CaO-5%Cr 2 o 3 -3%La 2 o 3 / Zn-meso-Y, the amount used is 3% of the total mass of raw materials, and the ratio of the cross-sectional area of ​​the initial distillation section to the side line section is 1:1.

[0063] The operating conditions are as follows:

[0064] The first reactive distillation column T1: column diameter 1000mm; column height 19000mm; the number of plates in the public rectification section, initial distillation section, side line section, and public stripping section are 10, 20, 30, 15 respectively; the pressure in the column is 1 MPa; tower top temperature 60°C; tower bottom temperature of common stripping section 160°C; tower bottom temperature of side line section 180°C.

[0065] The second reactive distillation colum...

Embodiment 2

[0072] Under the operating conditions of Example 1, when the total raw material mass flow rate is 3000kg / h, the reflux ratio of the T3 vacuum distillation column is changed, and the mass fraction changes of the liquid phase components are shown in Table 2.

[0073] Table 2 The influence of different reflux ratios on the mass fraction of each liquid phase component in T3 vacuum distillation column

[0074]

[0075] As can be seen from Table 2, with the increase of reflux ratio, the mass fraction of ethanol remains basically unchanged after decreasing, and the mass fraction of diethyl oxalate remains basically unchanged after increasing. When the reflux ratio is greater than 3, each liquid The mass fraction of phase composition is almost unchanged. The reason is that after the reflux ratio reaches a certain value, the composition of the reflux of the kettle liquid has reached equilibrium. However, an excessively large reflux ratio will also reduce the processing capacity of ...

Embodiment 3

[0077] Under the operating conditions of Example 2, when the total raw material mass flow rate is 3000kg / h, the pressure of the T3 vacuum distillation column is changed, and the mass fraction changes of each liquid phase are shown in Table 3.

[0078] Table 3 The influence of different pressures on the mass fraction change of each liquid phase component in T3 vacuum distillation column

[0079]

[0080] As can be seen from Table 3, with the increase of the reaction pressure, the ethanol in each liquid phase composition remains basically unchanged after decreasing, and the mass fraction of diethyl oxalate remains basically unchanged after increasing, because the ethanol at a lower pressure The boiling point difference with diethyl oxalate increases, and ethanol and diethyl oxalate are more easily separated. However, when the pressure is higher than 3 MPa, the components remain basically unchanged. Since high pressure requires high equipment, it will greatly increase the inpu...

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Abstract

The invention relates to a process for synthesizing symmetric oxalate, in particular to a process for synthesizing symmetric oxalate through an ester exchange path. A process route for synthesizing oxalate through ester exchange of dimethyl oxalate and various alcohols (high-carbon alcohol like alcohol, propanol and butanol) is created. Rectifying simple separation technology is realized in a fixed bed catalytic rectifying tower and a reaction kettle by using a multifunctional composite alkaline material to directly catalyze dimethyl oxalate and various alcohols. Taking preparing of diethyl pure oxalate as an example, a product-diethyl oxalate and methanol or alcohol are not be azeotropic, methanol is separated out through simple distillation to continuously push reaction to go forwards, ahigh-purity diethyl oxalate alcohol solution is obtained in tower kettle liquid finally, and high-purity diethyl oxalate is crystallized out after alcohol is separated out through decompression rectifying.

Description

technical field [0001] The invention relates to a process for synthesizing symmetrical oxalic acid esters, in particular to a process for synthesizing symmetric oxalic acid esters through transesterification. Background technique [0002] As an important organic chemical raw material, oxalate is widely used in the field of fine chemicals such as the preparation of various dyes, medicines, solvents, extractants and various intermediates. Among them, diethyl oxalate is the most widely used. Diethyl oxalate (Diethyl oxalate, which can be abbreviated as DEO), also known as diethyl oxalate, is a colorless oily liquid at room temperature with an aromatic smell. It is miscible with common solvents such as ethanol and ether, and is easily hydrolyzed when it meets water. [0003] Diethyl oxalate is an important organic chemical raw material, which can be used as an important chemical intermediate to produce ethylene glycol and other substances, and can react with many heterocyclic c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/03C07C67/54C07C69/36
CPCC07C67/03C07C67/54C07C69/36Y02P20/10Y02P20/584
Inventor 石磊邓文杰范琳琳訾文慧崔明晶陈天浩
Owner SHENYANG INSTITUTE OF CHEMICAL TECHNOLOGY
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