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Method for preparing acetic acid and acetic anhydride respectively or synchronously

A technology of acetic anhydride and acetic acid, which is applied in the direction of chemical instruments and methods, carbon monoxide reaction to prepare carboxylic acid, organic compound/hydride/coordination complex catalyst, etc., which can solve the problems of rising production cost, easy precipitation, poor product purity, etc. , to achieve the effects of improved stability, reduced corrosion, and reduced manufacturing costs

Active Publication Date: 2010-03-03
SHANGHAI HUAYI ENERGY CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Adopt this rhodium-based catalyst carbonylation method to prepare the mixture of acetic anhydride or acetic acid, acetic anhydride and there are following three problems: (1) can produce tar (the mixture of macromolecular organic polymer) while reacting; (2) the carbonylation The acetic acid and acetic anhydride product potassium permanganate index that method obtains is high, and the purity of product is poor; (3) the rhodium catalyst stability that this carbonylation method uses is poor, easily precipitates
However, there is no great breakthrough in the research of new catalysts for acetic anhydride
[0008] However, the world's carbonylation reactors for the production of acetic acid combined with acetic anhydride still use rhodium-based catalysts, and the production cost is still rising

Method used

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  • Method for preparing acetic acid and acetic anhydride respectively or synchronously

Examples

Experimental program
Comparison scheme
Effect test

Embodiment A

[0043] Add rhodium precursor rhodium iodide and iridium iodide in the reaction still prepared by catalyst, make the mass ratio of rhodium and iridium be (2~10):(5~20), add the N with iridium mole fraction 1:1 -Methylalanine and water; add methyl iodide and acetic acid as a solvent in accordance with the production process; then feed CO, and stir for 2 hours at a reaction temperature of 150° C. and a pressure of 3.0 MPa. After cooling, it is detected with an infrared spectrometer that rhodium in the catalyst solution is [Rh(CO) 2 I 2 ] - Exists in the form of iridium [Ir(CO) 2 I 2 ] - form exists.

Embodiment B

[0045] Add the rhodium precursor rhodium iodide into the reaction kettle prepared by the catalyst, then add the amount of methyl iodide in line with the production process, solvent acetic acid, and then pass in CO, react at a reaction temperature of 150 ° C and a pressure of 3.0 MPa for 2 hours, and prepare A coordination compound of rhodium, which is in the form of a solution.

[0046] This example is not an example of the invention because there is no amino acid or amino acid derivative stabilizer in the catalyst system.

Embodiment 1

[0048] in the process as attached figure 1 In the continuous device, the product prepared in Example A is added to the reactor together with methyl iodide, acetic acid, acetic anhydride, and lithium acetate. The addition of methyl iodide, acetic acid, and acetic anhydride depends on the needs of the reaction. Water added in preparation. The reaction temperature is 190°C, the pressure is 4.0MPa, the mass concentration of rhodium in the control reaction solution is 800ppm, the mass concentration of iridium is 1000ppm, the mass concentration of lithium is 250ppm, the molar ratio of N-methylalanine and iridium is 1.0, methyl iodide Consumption is 12% of the weight of the mixed reaction solution, methyl acetate is 15% of the weight of the mixed reaction solution, the reaction raw materials are 43% methanol and 57% methyl acetate by weight, the solvent is acetic acid, and the other raw material is carbon monoxide and hydrogen. Mixed gas, the amount of hydrogen used is 5% of the mol...

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Abstract

The invention discloses a method for preparing an acetic acid and an acetic anhydride respectively and synchronously, which is characterized in that: a methanol, a methylacetate or a mixture of the methanol and the methylacetate and a mixed gas of carbon monoxide and hydrogen are reacted at 150 to 250 DEG C and 2.0 to 6.0 MPa; and a catalyst system used in the reaction comprises a mixture of rhodium or one of rhodium compounds and iridium or one of iridium compounds, a methyl iodide, at least one selected from mixtures of an amino acid and an amino acid derivative, the amino acid or the aminoacid derivative, and an accelerant. The method for preparing the acetic acid and the acetic anhydride in the invention has the advantages of: (1) reducing the generated tar, (2) reducing substance content of the acetic anhydride product, and (3) improving the stability of the catalyst system in the invention and avoiding the precipitation phenomenon. Due to the fact that the reaction system has no water, the corrosion to devices is also reduced.

Description

technical field [0001] The invention relates to a method for preparing acetic acid, acetic anhydride or simultaneously preparing acetic acid and acetic anhydride. Background technique [0002] As an important basic organic chemical raw material, acetic acid and acetic anhydride and their downstream derivatives are widely used in medicine, synthetic fiber, light industry, textile, leather, pesticide, explosive, rubber and metal processing, food and fine organic Synthesis of chemicals. At present, the market prospect of acetic acid and acetic anhydride in the world is quite promising. [0003] The method for producing acetic acid and acetic anhydride in the prior art is to take a continuous production device, which is produced by the reaction of methanol and methyl acetate or dimethyl ether and methanol and carbon monoxide. [0004] The catalytic system for oxo-synthesizing acetic acid or acetic anhydride has gone through three stages. The first stage is cobalt iodide cataly...

Claims

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Application Information

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IPC IPC(8): C07C53/08C07C51/10B01J31/02
Inventor 王群山炜巍赖春波赵兵兵李俊岭
Owner SHANGHAI HUAYI ENERGY CHEM
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