Process and equipment for preparing adipic acid by catalyzing air and oxidizing cyclohexane

A technology of air oxidation and cyclohexane, applied in the preparation of organic compounds, catalytic reaction, preparation of carboxylate, etc., to achieve the effect of improving the conversion rate of cyclohexane and the yield of adipic acid

Inactive Publication Date: 2009-01-07
HUNAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the above-mentioned technologies using metalloporphyrins to catalyze the oxidation of cyclohexane all use air as an oxidant instead of nitric acid that corrodes equipment and causes environmental pollution problems, but the oxidation products are all intermediate products cyclohexanol and cyclohexanone and the target product adipic acid mixed product of

Method used

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  • Process and equipment for preparing adipic acid by catalyzing air and oxidizing cyclohexane
  • Process and equipment for preparing adipic acid by catalyzing air and oxidizing cyclohexane
  • Process and equipment for preparing adipic acid by catalyzing air and oxidizing cyclohexane

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] The reaction equipment consists of 6 standard reaction kettles with stirring and air distributor and 1 standard flash tank with condensing device connected in series.

[0020] The production process is as follows: at 150°C, the metalloporphyrin dissolved in 3PPM structural formula (I) is introduced, wherein R 1 =R 2 =R 3 =H, M=Co cyclohexane, pass 8atm of air through the gas distributor into the bottom of the first stirred reactor, and mix the reaction solution overflowed from the upper part of the first stirred reactor with air and then pass it into the At the bottom of the second stirred reactor, the reaction solution overflowed from the upper part of the second stirred reactor is mixed with air and then passed into the third stirred reactor, and then passed through the fourth, fifth and sixth stirred Reactor. Control the cyclohexane flow rate to make the residence time 50 minutes, and control the air flow rate to make the tail oxygen content not exceed 5%. The re...

Embodiment 2

[0022] The special equipment consists of 5 standard bubble column reactors with air distributor and 1 standard flash tank with condensing device connected in series. The production process is as follows: at 140° C., feed the metalloporphyrin that is dissolved with 10PPM structural formula (I), R1=CH3, R2=R3=H, the cyclohexane of M=Fe, and 12atm oxygen-containing 17% oxygen-deficient The air passes through the gas distributor and passes into the bottom of the first bubble column reactor, and the reaction liquid overflowed from the upper part of the first bubble column reactor is mixed with oxygen-deficient air containing 17% oxygen and then passed into the second bubble column reactor. The reaction liquid overflowed from the upper part of the second reactor is mixed with air and then passed through the third, fourth and fifth standard bubble column reactors in sequence. The cyclohexane flow rate is controlled so that the residence time is 80 minutes, and the air flow rate is co...

Embodiment 3

[0024] The reaction equipment consists of 2 standard reactors with stirring and air distributors, 3 bubble column reactors with air distributors and 1 flash tank in series. The production process is as follows: at 160 ° C, the metalloporphyrin dissolved in 40PPM structural formula (II) is introduced, R 1 =OCH 3 , R 2 =R 3 =H, M=Mn cyclohexane, 5atm oxygen-containing 23% oxygen-enriched air is passed through the gas distributor to the bottom of the first stirred reactor, and the reaction overflows from the upper part of the first stirred reactor The liquid is mixed with oxygen-enriched air containing 23% oxygen and passed into the bottom of the second stirred reactor, and the reaction liquid overflowed from the upper part of the second stirred reactor is mixed with air, and then passed through the first and the second in turn and a third bubbling reactor. The cyclohexane flow rate is controlled so that the residence time is 120 minutes, and the air flow rate is controlled s...

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Abstract

The invention discloses a process and a plant for preparing adipic acid by catalytically aerobically oxidizing cyclohexane. The process comprises the following steps: dissolving 1 to 50 PPM of a catalyst including single metalloporphyrin or mu-oxo bimetallic porphyrin or a mixture of single metalloporphyrin, mu-oxo bimetallic porphyrin and transition metal salt or oxide in cyclohexane; introducing 5 to 12 atm of air or oxygen-rich or oxygen-poor air into a multi-stage oxidation reactor with a gas distributor; controlling the reaction temperature at 140 to 160 DEG C; oxidizing cyclohexane for 45 to 120 min; feeding the mixture of the oxidation reaction into a flash separator to carry out flash evaporation at the temperature of 78 to 155 DEG C and under the pressure of 0.1 to 1.0 atm, so that the low-boiling-point products such as cyclohexane, cyclohexanol and cyclohexanone change to gas and are separated from adipic acid with the content above 80%; continuously circularly oxidizing the low-boiling-point products to separate and purify the high-boiling-point oxidation product; and purifying and separating by the existing technique to obtain fine adipic acid product. The process can directly prepare adipic acid by aerobically oxidizing cyclohexane, wherein the conversion rate of cyclohexane is up to 95%, and the yield of adipic acid is up to 70%.

Description

technical field [0001] The invention relates to a process and special equipment for preparing adipic acid by catalytic air oxidation of cyclohexane. technical background [0002] Chinese patent CN101186570 discloses a two-step method for synthesizing adipic acid from cyclohexane as a raw material. Firstly, the cyclohexane oxidation mixture is obtained under the catalysis of metalloporphyrin, and then the cyclohexane oxidation mixture is oxidized by nitric acid to obtain adipic acid. The scheme disclosed in this patent directly uses cyclohexane instead of high-cost cyclohexanone as a raw material, but still needs to use nitric acid as an oxidant, but nitric acid will corrode equipment and have environmental pollution problems; A method for synthesizing adipic acid in one step by iron porphyrin catalyzed oxygen oxidation of cyclohexane, the method reacts for 8 hours at a concentration of 100-1000ppm iron porphyrin chloride and 25 atmospheric pressure, and the mass yield of ad...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C55/14C07C51/215B01J31/02
CPCB01J2531/025B01J31/1815B01J2531/62B01J2531/72B01J2231/70B01J2531/842C07C51/313B01J2531/84
Inventor 郭灿城徐庆利罗伟平刘强
Owner HUNAN UNIV
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