Method for producing high-purity terephthalic acid

Disclosed herein is a method for producing high-purity terephthalic acid, including steps of dissolving crude terephthalic acid crystal in water and performing catalytic hydrogenation treatment, depressurizing and cooling a reaction liquid after the catalytic hydrogenation treatment in stages with two or more stages of crystallization vessels, to crystallize terephthalic acid to obtain a terephthalic acid slurry, introducing the terephthalic acid slurry into an upper portion of a mother liquor replacement tower, bringing the terephthalic acid crystal into contact with an upward flow of replacement water introduced from a tower lower compartment of the mother liquor replacement tower while making the terephthalic acid crystal settled down in the tower, withdrawing the terephthalic acid crystal as slurry with the replacement water from the tower lower compartment, subjecting the slurry withdrawn from the tower lower compartment to solid-liquid separation into water and the terephthalic acid crystal, and drying the separated terephthalic acid crystal.