| 摘要 |
PURPOSE:To obtain high-purity naphthoquinone, by washing a formed gas of gaseous phase catalytic oxidation reaction of naphthalene and collecting it to give an aqueous slurry containing naphthoquinone and phthalic acid, separating both by the use of difference of water solubility. CONSTITUTION:A reaction mixture gas containing naphthoquinone and phthalic anhydride obtained by catalytic gaseous phase oxidation of naphthalene is brought into contact with an aqueous medium containing maleic acid, 10- 10,000ppm iron ion and 10-10,000ppm copper ion to give a slurry containing naphthoquinone and phthalic acid, from which wet cake containing the two compounds is filtered, washed fully with water. A sufficient amount of water is added to it, phthalic acid is dissolved in water at 60-85 deg.C under heating, and naphthoquinone is filtered and separated. EFFECT:Polymerization of naphoquinone will not take place. Only water is used as a collecting solvent so there is no danger. Filtrate prepared by separation of phthalic acid from a phthalic acid solution can be recycled for water washing and collection and an amount of waste water is reduced.
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