Process for production of terephthalic acid

Process for production of terephthalic acid

  • CN 1,038,580 C
  • Filed: 02/03/1992
  • Issued: 06/03/1998
  • Est. Priority Date: 02/05/1991
  • Status: Active Grant
First Claim
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1. method for preparing terephthalic acid, wherein terephthalic acid is by becoming terephthalic acid to make p xylene oxidation in containing the liquid reaction medium of acetate, wherein, terephthalic acid is isolated from liquid reaction medium with the form of thick solid product, it is dissolved in makes a solution in liquid, aqueous, then by under reductive condition, this solution being purified with the method that hydrogen contacts with heterogeneous catalyst, to be reduced by at least some impurity, this solution precipitation of reduction postcooling goes out the solid purification of terephthalic acid, separate water-bearing mother liquor from throw out, it is characterized in that handling this water-bearing mother liquor and contain the low-purity throw out and second mother liquor of terephthalic acid, and use the following step with generation:

  • A) the low-purity throw out turns back to directly or indirectly p-Xylol is oxidized in the reaction medium of terephthalic acid;

    WithB) directly or after handling be used to dissolve thick solid product indirectly to said second mother liquor of small part itself;

    And/orC) carry out fractionation to said second mother liquor of small part and be used for washing the throw out that reclaims by the solution after the reduction step with the water of therefrom recycle-water and recovery.

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