Birch, Stewart, Kolasch & Birch, LLP
Method of refining benzoic acid
 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.sup.3 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. 
Nippon Steel Chemical Co., Ltd.
C B
C07C B01D
inventional inventional
Hiroyuki Masakazu Yuji Kazuyoshi Nobumasa Haruki
Kuwahara Takeuchi Arifuku Horibe Noma Kawano