Apparatus and method for recovering acetic acid and catalyst in process for preparation of 2,6-naphthalenedicarboxylic acid

An apparatus for recovering acetic acid together with catalyst from a mother liquor discharged from a process for preparation of 2,6naphthalenedicarboxylic a acid, containing acetic acid, catalyst and o the apparatus compnsing:

• a mother liquor receptacle having said mother liquor therein and including an inlet for receiving the mother liquor or sodium hydroxide, an outlet for acetic acid, and an outlet for catalyst and organic materials;
• a heating means for heating the mother liquor receptacle;
• an acetic acid outlet mounted on an upper part of the mother liquor receptacle for discharging acetic acid to be vaporized after the received mother liquor is heated by the heating means:
• a sodium hydroxide inlet to precipitate catalyst and organic materials from the residue remaining after the discharge of acetic acid;
• an outlet for catalyst and organic materials mounted on a lower part of the mother liquor receptacle for discharging the precipitated catalyst and organic materials;
• a downstream membrane filter connected to and mounted on a lower part of the outlet for catalyst and organic materials for separating the catalyst from the organic materials;
• and
• an agitator for agitating the inside of the mother liquor receptacle.