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AssigneeAmoco Corporation
InventorsJon J. Harper, George E. Kuhlmann, Keith D. Larson, Rosemary F. McMahon, Paul A. Sanchez
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Provided is a continuous process for producing 2,6-naphthalenedicarboxylic acid by the liquid phase oxidation of 2,6-dimethylnaphthalene comprising continuously adding to a reaction zone the oxidation reaction components comprising 2,6-dimethylnaphthalene, a source of molecular oxygen, a solvent comprising an aliphatic monocarboxylic acid, and a catalyst comprising cobalt, manganese and bromine components, wherein the atom ratio of manganese to cobalt is about 5:1 to about 0.3:1, the total of cobalt and manganese is at least about 0.40 weight percent based on the weight of solvent, and maintaining the contents of the reaction zone at a temperature of about 370.degree. F. to about 420.degree. F. and at a pressure sufficient to maintain at least a portion of the monocarboxylic acid in the liquid phase thereby oxidizing the 2,6-dimethylnaphthalene to 2,6-naphthalenedicarboxylic acid. By operating according to the process of this invention, 2,6-naphthalenedicarboxylic acid can be continuously produced in high yield and with low levels of impurities.
A process for producing 2,6-naphthalenedicarboxylic acid by the liquid phase oxidation of 2,6-dimethylnaphthalene, comprising:
A process for recycling 2,6-dimethylnaphthalene oxidation reaction mother liquor comprising cobalt and manganese catalyst components, water, and trimellitic acid to an oxidation reaction mixture comprising cobalt, manganese and bromine catalyst components and used for the liquid phase oxidation of 2,6-dimethylnaphthalene to 2,6-naphthalenedicarboxylic acid, comprising:
A process for recovering cobalt and manganese oxidation catalyst metals from oxidation reaction mother liquor formed during the oxidation of 2,6-dimethylnaphthalene to 2,6-naphthalenedicarboxylic acid, comprising contacting the oxidation mother liquor with about 3.0 to about 0.6 gram moles of a source of oxalic acid per gram atom of the total of cobalt and manganese contained in the mother liquor, precipitating an insoluble complex formed by the reaction of the oxalic acid with the cobalt and manganese oxidation catalyst metals, and recovering the insoluble complex.
A process of recycling 2,6-dimethylnaphthalene oxidation reaction mother liquor comprising cobalt and manganese catalyst components, water and an aliphatic monocarboxylic acid solvent to an oxidation reaction mixture comprising 2,6-dimethylnaphthalene, aliphatic monocarboxylic acid solvent and a catalyst mixture comprising cobalt, manganese and bromine components, which process comprises adding the oxidation reaction mother liquor to the oxidation reaction mixture while removing from the oxidation reaction mixture a vaporous mixture comprising water and monocarboxylic acid solvent, and returning to the reaction mixture aliphatic monocarboxylic acid solvent containing less water than that removed as a vapor.
Dependencies are inferred from the claim text.