Process for recovering catalyst components from a mother liquor of liquid phase oxidation

摘要

A process for recovering components of a catalyst from a mother liquor of liquid phase oxidation in production of aromatic carboxylic acids by liquid phase oxidation of aromatic hydrocarbons having substituents with a gas containing oxygen in a presence of a catalyst comprising cobalt, manganese and bromine in acetic acid or acetic acid containing water as a solvent, which process comprises adding a compound generating an ion of an alkali metal to the mother liquor of liquid phase oxidation obtained after separating crystals of the aromatic carboxylic acid from a reaction fluid of the liquid phase oxidation, bringing the mother liquor containing the compound into contact with an ion exchange resin so that the components of the catalyst are adsorbed to the ion exchange resin and recovering the components of the catalyst comprising cobalt, manganese and bromine ion by passing an elution liquid through the ion exchange resin. By adding the compound generating an ion of an alkali metal to the mother liquor supplied to an ion exchange resin column, contamination of the recovered components of the catalyst with eluted metal ions such as iron can be suppressed and an increase in the concentration of the eluted metal ions in the mother liquor of the oxidation can be prevented. Therefore, the amount of the recycled mother liquor can be increased and the recovery of the catalyst components can also be increased.