A kind of method for preparing dibasic acid dimethyl ester

A technology of dibasic acid dimethyl ester and dibasic acid, which is applied in the field of mixed ester preparation, can solve the problems of fixed bed inability to run for a long period and high energy consumption, achieve high catalytic activity and regeneration reuse rate, low energy consumption, The effect of avoiding cumbersome steps

Active Publication Date: 2016-05-18
CHINA PETROLEUM & CHEM CORP
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] 3. Due to the need for pre-esterification and the use of a large amount of superheated methanol steam, the energy consumption is very high
[0009] The catalyst used in the Chinese patent application document CN101891610A is ferric chloride or sodium bisulfate, both of which have strong hygroscopicity and are easy to absorb water and deliquesce, so the fixed bed cannot run for a long period of time

Method used

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  • A kind of method for preparing dibasic acid dimethyl ester

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Embodiment 1

[0057] The process flow of the present invention is described according to the accompanying drawings. The content of each substance in the mixed dibasic acid used is: 35.7wt% adipic acid, 45.4wt% glutaric acid, 18.3wt% succinic acid, containing 0.03wt% malonic acid. Directly use industrial grade methanol for esterification. The alcohol-carboxyl ratio (the molar ratio of methanol to carboxyl groups) of the feed in Example 1 is 3.5:1. Both tank 1 and tank 2 were kept at 50°C. Esterification feed preheater 3 heats stream 22 to 60°C. The esterification reactor 4 was previously heated with a 60°C methanol stream and maintained at 60°C with a water bath jacket. The flow rate of the material in the esterification reactor is about 1.0BV / h. The material 22 enters 4 and reacts under the action of the catalyst, and the inside of the esterification reactor 4 is kept at 60°C. Column 5 maintains rectification at atmospheric pressure, the temperature at the top of the column is about 85...

Embodiment 2

[0059] In Example 2, purified adipic acid with a purity of 99.8-100.2 wt% and industrial grade methanol were used for esterification. The alcohol-carboxyl ratio (the molar ratio of methanol to carboxyl groups) of the feed in Example 1 is about 5:1. Both tank 1 and tank 2 were maintained at 60°C. Esterification feed preheater 3 heats stream 22 to 80°C. The esterification reactor 4 was previously heated with a methanol stream at 80°C and maintained at 80°C with a water bath jacket. The material 22 enters 4 and reacts under the action of the catalyst, and the inside of the esterification reactor 4 is kept at 80°C. The material flow rate in the esterification reactor is about 1.0BV / h. Column 5 maintains rectification at atmospheric pressure, the temperature at the top of the column is about 85°C, and the reflux ratio is 0.8. Column 9 adopts atmospheric distillation, the temperature at the top of the column is about 125°C, and the reflux ratio is 0.8. The top pressure (absolut...

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Abstract

The invention discloses a preparation method for diacid dimethyl ester. The method comprises the following steps: adding diacid, recycled diacid monomethyl ester and methanol into a mixing tank and carrying out heating, dissolving and uniform mixing so as to obtain a feeding mixture; preheating the feeding mixture with a preheater, allowing the preheated feeding mixture to enter an esterification reactor from the bottom of the reactor and enabling the feeding mixture to undergo an esterification reaction under catalysis of a catalyst so as to prepare a reaction mixture; and discharging the prepared reaction mixture from the top of the reactor and allowing the reaction mixture to successively pass through a methanol rectifying tower, a water rectifying tower and a diacid dimethyl ester rectifying tower so as to respectively separate methanol, water and diacid dimethyl ester. The method has the advantages of mild reaction conditions, high yield, a high utilization rate of raw materials and low energy consumption.

Description

technical field [0001] The invention relates to a method for preparing dimethyl dibasic acid, which belongs to the field of preparation of mixed esters. Background technique [0002] Dimethyl dibasic acid is an excellent plasticizer and an important high-boiling point solvent. This kind of substance is easy to biodegrade and has good environmental protection. [0003] Existing technologies for producing dimethyl dibasic acid generally use inorganic acids as catalysts. Inorganic acids severely corrode equipment and have poor environmental protection. Some existing processes adopt batch reaction, and its operation is complicated, which is not conducive to large-scale production. These problems need to be solved urgently. [0004] At present, the novel method for producing dibasic acid dimethyl ester is as described in Chinese patent application document CN101891610A and Chinese patent CN200710064315.2. The disclosed process is: after pre-esterifying the mixed dibasic acid an...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C67/08C07C69/42C07C69/44C07C69/40
CPCC07C67/08C07C67/54C07C69/42C07C69/44C07C69/40
Inventor 邱枫鲁华
Owner CHINA PETROLEUM & CHEM CORP
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