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Method for producing adipic acid and dibasic acid by using nitric acid to oxidizing cyclohexane bionic oxidation mixture

A technology of nitric acid oxidation and cyclohexane, applied in the preparation of organic compounds, chemical instruments and methods, organic compounds/hydrides/coordination complex catalysts, etc. The problems of large circulation volume and complex process can achieve the effect of reducing the consumption of nitric acid, reducing energy consumption and manufacturing cost, and simplifying the process.

Inactive Publication Date: 2008-05-28
SHENYANG POLYTECHNIC UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Purpose of the invention: the present invention provides a method for preparing adipic acid and dibasic acid by nitric acid oxidation of a cyclohexane biomimetic oxidation mixture, and its purpose is: (1) to solve the existing problems in the process of preparing adipic acid by cyclohexane oxidation The single-pass conversion rate of cyclohexane is low, the circulation volume of cyclohexane is large, the consumption of nitric acid is high, the process is complicated, and the waste water discharge is reduced; (2) The biomimetic catalytic air oxidation cyclohexane technology is successfully applied to the production of adipic acid in the process

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] In a high-pressure reactor, add catalyst tetrakis-(3,4-dimethylphenyl) porphyrin cobalt as 4ppm cyclohexane solution, and oxidize with air for 120min at 150°C and 1.0Mpa pressure, the air flow rate is controlled at 1.0~1.2m 3 / h. After the oxidation reaction is finished, the cyclohexane oxidation reaction solution is subjected to flash distillation to recover the cyclohexane to obtain a cyclohexane oxidation mixture mainly composed of cyclohexanol, cyclohexanone and adipic acid. The conversion rate of cyclohexane was 31%, the total selectivity of cyclohexanol, cyclohexanone and adipic acid was 91%, and the selectivity of adipic acid was 31%. This cyclohexane oxidation mixture is directly oxidized with nitric acid, and the nitric acid oxidation condition is: the concentration of oxidant nitric acid is 55%, the copper content is 0.3%, the vanadium content is 300ppm, the quality of cyclohexane oxidation mixture and nitric acid (calculated as anhydrous) The feed ratio is ...

Embodiment 2

[0027] The process of synthesizing adipic acid from cyclohexane is the same as in Example 1, except for the following differences: (1) air oxidation conditions of cyclohexane: the catalyst is cobalt tetraphenylporphyrin, the reaction temperature is 155° C., and the reaction time is 130 minutes. The conversion rate of cyclohexane was 26%, the total selectivity of cyclohexanol, cyclohexanone and adipic acid was 90.8%, and the selectivity of adipic acid was 23%. (2) Conditions for direct nitric acid oxidation of the cyclohexane oxidation mixture: the mass feed ratio of the cyclohexane oxidation mixture to nitric acid (calculated as anhydrous matter) is 1.0:2.0.

[0028] The obtained refined adipic acid product has adipic acid content of 99.51%; the obtained dibasic acid product has a dibasic acid content of 95.7%. For every 100 g of cyclohexane converted, 124 g of refined adipic acid and 26 g of dibasic acid were obtained.

Embodiment 3

[0030] The technological process of synthesizing adipic acid by cyclohexane is the same as embodiment 1, and difference is as follows: (1) cyclohexane air oxidation condition: catalyst is four-(2,4-dichlorophenyl) porphyrin cobalt, temperature of reaction 155°C, reaction time 150min. The conversion rate of cyclohexane was 18%, the total selectivity of cyclohexanol, cyclohexanone and adipic acid was 91.2%, and the selectivity of adipic acid was 19%. (2) Conditions for direct nitric acid oxidation of the cyclohexane oxidation mixture: the mass feed ratio of the cyclohexane oxidation mixture to nitric acid (calculated as anhydrous matter) is 1.0:2.3.

[0031] The obtained purified adipic acid product has adipic acid content of 99.56%; the obtained dibasic acid product has a dibasic acid content of 95.2%. For every 100 g of cyclohexane converted, 124 g of refined adipic acid and 25 g of dibasic acid were obtained.

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Abstract

The invention relates to a method for directly preparing adipic acid and diacid from cyclohexane bionic oxidation mixture by nitric acid oxidation. The invention is characterized in that in the presence of 1-10mg / L metalloporphyrin catalyst, at 140-160DEG C and 0.8-1.2MPa, cyclohexane is oxidized by air, and the cyclohexane oxidation mixture is directly prepared into adipic acid and diacid by nitric acid oxidation. Compared with prior adipic acid preparation, the invention can simultaneously improve single-pass conversion of cyclohexane and total yield of diacid respectively more than 10% and 80%. At the same level of adipic acid yield, the circulation quantity of cyclohexane is reduced more than 50%, nitric acid consumption is reduced about 10%, to reduce the load on cyclohexane distillation system, reduce energy consumption, and reduce production cost. The invention can be directly used in prior industrial unit that prepares adipic acid from cyclohexane, to reduce production cost and improve yield. The invention can simplify prior production that prepares adipic acid by cyclohexane oxidation, to eliminate washing, cyclohexyl hydrogen dioxide decomposition, and cyclohexanone-and-cyclohexanol distillation systems, and avoid tert-butyl chromic acid catalyst.

Description

1. Technical field [0001] The invention relates to a method of oxidizing cyclohexane into a mixture of cyclohexanol, cyclohexanone and adipic acid by air under the catalysis of metalloporphyrin, and then oxidizing the mixture with nitric acid to produce adipic acid and co-producing dibasic acid . 2. Background technology [0002] Adipic acid is an important chemical raw material, mainly used in the production of nylon 66, polyurethane, plasticizer, etc. At present, in the existing technology, the main method of producing adipic acid is the two-step oxidation method of cyclohexane, which adopts the French Lumberly technology. Cyclohexyl hydroperoxide is produced by catalyzing oxygen-lean oxidation, the by-products of deep oxidation are removed by washing with water, and then cyclohexyl hydroperoxide is catalytically decomposed to obtain cyclohexanol and cyclohexanone, and the refined cyclohexanol and cyclohexanone are oxidized with nitric acid to produce adipic acid. The m...

Claims

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Application Information

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IPC IPC(8): C07C55/14C07C51/21B01J31/16B01J31/28
Inventor 唐丽华张晓娟沈国良陈恩之周亚绵邵英贵徐淑媛贾长英徐铁军樊友
Owner SHENYANG POLYTECHNIC UNIV
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