Search

CN-122010715-A - Adipic acid preparation method and system

CN122010715ACN 122010715 ACN122010715 ACN 122010715ACN-122010715-A

Abstract

The invention provides a preparation method and a preparation system of adipic acid. The method comprises the steps of (1) enabling cyclohexane to be in contact with hydrogen peroxide solution to obtain a material a, (2) settling the material a to obtain supernatant, and (3) enabling the supernatant to be subjected to oxidation reaction with O 2 -containing gas to obtain a adipic acid-containing product material b. The method is simple, efficient, green and environment-friendly, and the obtained adipic acid provides excellent raw materials for polyester production.

Inventors

  • CHEN YANXIN
  • GAO XIAOCHEN
  • ZHANG HONGYU
  • Chu Qinzhong
  • YAO QUANMING
  • LI JIAN

Assignees

  • 中国石油化工股份有限公司
  • 中石化（上海）石油化工研究院有限公司

Dates

Publication Date
20260512
Application Date
20241111

Claims (10)

  1. 1. A method of producing adipic acid comprising: (1) Cyclohexane is contacted with hydrogen peroxide solution to obtain a material a; (2) Settling the material a to obtain a supernatant; (3) And (3) carrying out an oxidation reaction on the supernatant and O 2 -containing gas to obtain adipic acid-containing product material b.
  2. 2. The method according to claim 1, wherein, The mass concentration of H 2 O 2 in the hydrogen peroxide solution is 25-45%, and/or The mass ratio of the hydrogen peroxide solution to the cyclohexane is (1:2) - (2:1).
  3. 3. The process according to claim 1 or 2, wherein, The temperature of the contact is 10-80 ℃, preferably 30-50 ℃, and/or The contact time is 10-120min, preferably 15-60min, and/or The sedimentation temperature is 15-25 ℃.
  4. 4. A process according to any one of claim 1 to 3, wherein, The oxidation reaction is carried out in the presence of a catalyst and a solvent; preferably, the solvent is selected from acetic acid.
  5. 5. The method according to claim 4, wherein, The catalyst is selected from metal salt catalysts; preferably, the metal element in the metal salt catalyst is selected from one or more of copper, manganese or cobalt; Preferably, the metal salt is acetate of a metal element; preferably, the catalyst is a mixture of copper acetate, manganese acetate and cobalt acetate; Preferably, the mass ratio of the copper element, the manganese element and the cobalt element in the catalyst is (5-10): (1-5): 1.
  6. 6. The method of any one of claims 1-5, wherein the oxidation reaction comprises the steps of: s1, mixing a catalyst and a solvent to obtain a catalyst solution; S2, carrying out oxidation reaction on the catalyst solution, the supernatant and the gas containing O 2 ; Preferably, the mass ratio of the catalyst solution to the supernatant is (1.5-8): 1, and/or The mass concentration of the catalyst in the catalyst solution is 0.05-5%.
  7. 7. The method according to any one of claim 1 to 6, wherein, The mass ratio of the O 2 -containing gas to the supernatant is (5-15): 1, and/or The volume content of O 2 in the gas containing O 2 is 10-25%.
  8. 8. The process according to claim 1 to 7, wherein the oxidation reaction is carried out at a temperature of 85 to 110℃and/or The pressure of the oxidation reaction is 1.5-5MPa, and/or The oxidation reaction time is 0.5-2h.
  9. 9. A system for preparing adipic acid for use in a process for preparing adipic acid in any of claims 1-8, the system comprising: a cyclohexane feed tank; a hydrogen peroxide solution tank; The mixing contactor is connected with the cyclohexane raw material tank and the hydrogen peroxide solution tank so as to enable cyclohexane to be in contact with the hydrogen peroxide solution to obtain a material a; a settler connected with the mixing contactor to settle the material a to obtain supernatant; and a reactor connected with the settler, so that the supernatant liquid and the gas containing O 2 are subjected to oxidation reaction to obtain a product material b containing adipic acid.
  10. 10. The system of claim 9, further comprising a catalyst tank coupled to the reactor such that the oxidation reaction is performed in the presence of a catalyst solution; preferably, the system further comprises a discharge tank connected to the reactor for receiving the material b.

Description

Adipic acid preparation method and system Technical Field The invention relates to the technical field of chemical industry, in particular to a preparation method and a preparation system of adipic acid. Background Adipic acid and its derivatives are extremely important commercial aliphatic dibasic organic acids, can be polycondensed to synthesize high molecular compounds, and have important roles in chemical production, organic synthesis industry, medicine, lubricant manufacturing and other aspects. In particular, adipic acid can be used for synthesizing nylon 66 and producing polyurethane, can also be used as food acidulant for keeping food fresh and stable, and can also be used for producing perfume and dye. In the traditional industrial adipic acid production, benzene is used as a raw material to prepare cyclohexene, cyclohexane, phenol and the like, and the cyclohexene, cyclohexane, phenol and the like are further oxidized to obtain KA oil and adipic acid. The production method of adipic acid is mainly divided into a cyclohexane oxidation method, a cyclohexene oxidation method and a phenol method according to raw materials. Cyclohexane molecules are used as a rigid ring, the difficulty of oxidative ring opening is extremely high, particularly, air with poor oxidizing property is used as an oxidant, the reaction initiation is difficult, once the reaction is started, the free radical reaction chain is difficult to control, various byproduct impurities are easy to generate, and the selectivity of the adipic acid as a target product is difficult to improve. If hydrogen peroxide is directly used as an oxidant, although the reaction efficiency can be improved, the hydrogen peroxide is easy to decompose at high temperature, the utilization rate is lower, cyclohexane is easy to explode, the generation cost is increased, and the safety of the system is greatly reduced. Therefore, the conversion efficiency of cyclohexane direct feeding in the prior art is not high, higher reaction temperature and longer reaction time are generally required, the adipic acid yield is improved through a large amount of cyclohexane circulation, the impurity byproducts generated by the reaction are difficult to separate, the separation energy consumption is high, and the atomic economy is poor. Disclosure of Invention The invention aims to overcome the defects in the prior art and provides a preparation method and a system of adipic acid. The method is simple, efficient, green and environment-friendly, and the obtained adipic acid provides excellent raw materials for polyester production. In a first aspect, the present invention provides a process for the preparation of adipic acid comprising: (1) Cyclohexane is contacted with hydrogen peroxide solution to obtain a material a; (2) Settling the material a to obtain a supernatant; (3) And (3) carrying out an oxidation reaction on the supernatant and O 2 -containing gas to obtain adipic acid-containing product material b. The inventor of the application surprisingly found that by pre-activating cyclohexane by hydrogen peroxide solution and then carrying out oxidation reaction on the pre-activated cyclohexane and O 2 -containing gas, the reaction rate is greatly accelerated, meanwhile, the impurity content in the product material is greatly reduced, and the yield and selectivity of adipic acid are improved. In some embodiments, the hydrogen peroxide solution has a mass concentration of H 2O2 of 25-45%, such as 25%, 28%, 31%, 34%, 37%, 40%, 43%, or any value therebetween. In some embodiments, the hydrogen peroxide solution to cyclohexane mass ratio is (1:2) - (2:1), e.g., 1:2, 0.8:1, 1:1, 1.5:1, 2:1. In some embodiments, the temperature of the contacting is 10-80 ℃, e.g., 15 ℃,25 ℃, 35 ℃, 45 ℃,55 ℃, 65 ℃, 75 ℃, or any value therebetween. In some embodiments, the temperature of the contacting is from 30 ℃ to 50 ℃. In some embodiments, the contacting is for a time of 10 to 120 minutes, for example, 20 minutes, 40 minutes, 60 minutes, 80 minutes, 100 minutes, 120 minutes, or any value therebetween. In some embodiments, the contacting is for a period of 15 to 60 minutes. In some embodiments, the temperature of the sedimentation is 15-25 ℃, e.g., 17 ℃, 19 ℃, 21 ℃, 23 ℃, 25 ℃, or any value therebetween. In some embodiments, the oxidation reaction is performed in the presence of a catalyst and a solvent. In some embodiments, the solvent is selected from acetic acid. In some embodiments, the catalyst is selected from metal salt catalysts. In some embodiments, the metal element in the metal salt catalyst is selected from one or more of copper, manganese, or chromium. In some embodiments, the metal salt is an acetate of a metal element. In some embodiments, the catalyst is a mixture of copper acetate, manganese acetate, and cobalt acetate. In some embodiments, the mass ratio of copper element, manganese element, cobalt element in the catalyst is (5-10): (1-5): 1, for example, 5:1-5:1, 6:1-5:1, 7:1-