Catalytic Synthesis of Oxalic Acid Combined Process of Batch Reaction and Continuous Reaction Rectification

A technology of reactive distillation and combined process, applied in the chemical industry, sustainable manufacturing/processing, separation/purification of carboxylic acid compounds, etc., can solve the problems of complicated purification and separation of subsequent products, long reaction time, low conversion rate, etc. , to achieve the effect of saving energy consumption and investment, reducing energy consumption, and reducing the ratio of water to ester

Active Publication Date: 2016-09-07
FUZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, there is little research on the process of hydrolyzing dimethyl oxalate. The main reaction device is a hydrolysis reactor or a batch reactor. Disadvantages such as complicated purification and separation and high energy consumption

Method used

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  • Catalytic Synthesis of Oxalic Acid Combined Process of Batch Reaction and Continuous Reaction Rectification

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Water and dimethyl oxalate are mixed at a molar ratio of 5:1, enter the batch reactor, and carry out preliminary reaction at 65℃. After 3 hours of reaction, feed to the next-wall rectification tower. The reaction liquid in the batch reactor is fed from the upper inlet Continuously enter the reaction zone (zone b) of the next-wall tower RD, and the corresponding ratio (total water-to-ester ratio of the entire process is 10:1) of room temperature water enters the tower from the lower feed port of the reaction zone (zone b), and the top of the tower will react The methanol produced in the reactor is continuously discharged, part of the water is continuously produced in the lower part of the rectification zone (zone d) on the right side of the next wall tower, and oxalic acid, excess water and a very small amount of methanol are continuously produced in the tower bottom. The specific parameters are as follows:

[0030] (1) The volume of the batch reactor is 10m 3 The reaction t...

Embodiment 2

[0037] Water and dimethyl oxalate are mixed with a molar ratio of 4:1, enter the intermittent reactor, and carry out preliminary reaction at 60℃. After about 4 hours, feed to the next rectification tower. The reaction liquid in the intermittent reactor is fed from the upper inlet Continuously enter the reaction zone (zone b) of the next-wall tower RD, and the corresponding ratio (total water to ester ratio of the whole process is 10:1) of room temperature water enters the tower from the lower feed port of the reaction zone (zone b), and the top of the tower will react The methanol produced in the reactor is continuously discharged, part of the water is continuously produced in the lower part of the rectification zone (zone d) on the right side of the next wall tower, and oxalic acid, excess water and a very small amount of methanol are continuously produced in the tower bottom. The specific parameters are as follows:

[0038] (1) The volume of the batch reactor is 10m 3 The reacti...

Embodiment 3

[0045] Water and dimethyl oxalate are mixed at a molar ratio of 5:1, enter the batch reactor, and carry out preliminary reaction at 65℃. After 3 hours of reaction, feed to the next-wall rectification tower. The reaction liquid in the batch reactor is fed from the upper inlet Continuously enter the reaction zone (zone b) of the next-wall tower RD, and the corresponding ratio (total water to ester ratio of the whole process is 11:1) of room temperature water enters the tower from the lower feed port of the reaction zone (zone b), and the top of the tower will react The methanol produced in the reactor is continuously discharged, part of the water is continuously produced in the lower part of the rectification zone (zone d) on the right side of the next wall tower, and oxalic acid, excess water and a very small amount of methanol are continuously produced in the tower bottom. The specific parameters are as follows:

[0046] (1) The volume of the batch reactor is 10m 3 The reaction te...

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Abstract

The invention discloses an intermittent reaction-continuous reaction rectification combined process for catalytic synthesis of oxalic acid. The process particularly comprises the following steps: (1) continuously feeding materials into a reactive dividing-wall rectification tower in a double batch reactor switching mode; (2) enabling dimethyl oxalate and water to enter a batch reactor to react primarily, wherein the equilibrium conversion rate reaches 50%-60%; and (3) continuously feeding reaction solution into a left-side reaction section ( zone b) of the reactive dividing-wall rectification tower from an upper feeding opening, continuously feeding normal-temperature water into the reactive dividing-wall rectification tower from a lower feeding opening of the zone b, and continuously discharging methyl alcohol produced in the reaction process from the tower top, wherein due to the discharging of methyl alcohol, the reaction proceeds to production of oxalic acid until dimethyl oxalate is completely hydrolyzed and the conversion rate can reach 99.5% or above. By virtue of the reactive dividing-wall rectification tower, the synthesis reaction and product separation and purification are implemented in the same tower, the existing process flow is simplified, and energy consumption and investment can be lowered. The intermittent reaction-continuous reaction rectification combined process for catalytic synthesis of oxalic acid has the characteristics of no addition of extra additives, high reaction speed, high conversion rate, low water-ester ratio, simple product separation operation, low energy consumption and the like.

Description

Technical field [0001] The invention belongs to the technical field of preparation of oxalic acid, and specifically relates to a combined process of catalyzed synthesis of oxalic acid by batch reaction and continuous reactive distillation. Background technique [0002] Oxalic acid is an important organic chemical raw material. It is widely used in medicine, textile, organic synthesis, rare earth element refining and leather industries. It can also be used to synthesize dye intermediates, and purify metal equipment, prepare catalysts, and synthesize oxalic acid derivatives. Synthetic chemical intermediates and certain necessary reagents. [0003] At present, the main methods for producing oxalic acid in China are sodium formate method and nitric acid oxidation method. These two methods not only have high production costs but also seriously pollute the environment. Although most companies have made corresponding improvements to these two methods, the overall level is still not high....

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C55/06C07C51/09C07C51/44
CPCC07C51/09C07C51/44C07C55/06Y02P20/10
Inventor 邱挺周丽华黄智贤李玲王红星杨臣叶长燊
Owner FUZHOU UNIV
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