Patent ID: 6972342
Filing Date: 2005-12-06
Classification: C07C

Abstract:
1. An improved process for producing a purified aromatic carboxylic acid which comprises: (i) producing a crude aromatic carboxylic acid by liquid phase oxidation of a precursor of said aromatic carboxylic acid in an aliphatic carboxylic acid solvent; (ii) recovering the crude aromatic carboxylic acid oxidation product, and dissolving said oxidation product in water; (iii) purifying the dissolved oxidation product, and recovering the purified product from the aqueous solution in the form of crystals; (iv) drying the purified crystals at an elevated temperature in the range of from about 100° C. up to about 180° C.; and (v) transferring the dried crystals to a silo for storage, the improvement comprising cooling the purified acid crystals in a fluidized state with a cooling means to a temperature below about 100° C. prior to, while or after transferring said purified crystals to said silo; wherein the cooling means comprises at least one heat exchanger deployed within a holding vessel, and wherein the at least one heat exchanger is selected from the group consisting of: a tube-type heat exchanger and a plate-type heat exchanger.