METHOD FOR PRODUCING HIGH PURITY TEREPHTHALIC ACID

摘要

A method for producing high purity terephthalic acid, characterized in that it comprises conducting pressure-release and cooling in a crystallizing step in a crystallizing vessel (14) to generate steam (H), subjecting the steam to the heat exchange with a crude terephthalic acid slurry (C) to thereby use the steam (H) as a part of the heat source for heating the crude terephthalic acid slurry (C), and condensing the steam generated in the crystallization step by the above heat exchange into a condensate (I) to use the condensate (I) as a part of an aqueous medium (B). The method allows the effective use of an aqueous medium and the steam generated in a crystallization step in combination with the production of the high purity terephthalic acid having a concentration of p-toluic acid limited to a specific range, and also allows the effective use of a condensate from the steam.