Nippon Steel Chemical Co., Ltd.

Haruki Kawano

Kazuyoshi Horibe

Masakazu Takeuchi

Hiroyuki Kuwahara

Nobumasa Noma

Yuji Arifuku

This invention relates to a process for purifying benzoic acid continuously to a purity of 99.9% or more by introducing crystals of crude benzoic acid with a bulk density of 0.2 g/cm,or more and an average particle diameter of 0.3 mm or more into a continuous crystallization apparatus equipped with a stirrer and a heating device from the upper portion of the apparatus, effecting counter-current contact of the falling crystals of crude benzoic acid with the melt generated by heating with the heating device, withdrawing the purified benzoic acid as melt from the lower portion of the apparatus, and withdrawing the mother liquor from the upper portion of the apparatus. The process makes it possible to prepare high-purity benzoic acid continuously in a relatively simple apparatus at high efficiency.

Growing community of inventors

Tokai, Japan

Haruki Kawano