| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing high-purity terephthalic acid by which the frequency of catalyst exchange is reduced by suppressing the reduction of the activities of the catalyst for hydrogenation by long-term use, and the catalyst cost can be reduced. SOLUTION: The method for producing the high-purity terephthalic acid includes (I) a step for forming a crude terephthalic acid slurry by mixing the crude terephthalic acid obtained by the liquid-phase oxidation of para-xylene with water, (II) a step for forming an aqueous crude terephthalic acid solution by heating and dissolving the crude terephthalic acid slurry, (III) a step for subjecting the aqueous solution of the crude terephthalic acid to hydrogenation process, (IV) a step for crystallizing the terephthalic acid from the aqueous terephthalic acid solution after hydrogenation, and (V) a step for subjecting the obtained terephthalic acid slurry to solid-liquid separation. The method is characterized by the content of microorganisms contained in the water to be mixed with the crude terephthalic acid in the step (I) and regulated so as to be≤4,000/g based on the measurement value (1-10μm) by RION. COPYRIGHT: (C)2008,JPO&INPIT
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