Patent ID: 7935845

Claim:
A process for manufacture of aromatic carboxylic acids comprising contacting a feed material comprising at least one substituted aromatic hydrocarbon in which substituents are oxidizable to carboxylic acid groups with gaseous oxygen in a liquid phase oxidation reaction mixture comprising monocarboxylic acid solvent and water and in the presence of a catalyst composition comprising at least one heavy metal component in a reaction zone at temperature and pressure effective to maintain a liquid phase oxidation reaction mixture and form an aromatic carboxylic acid and impurities comprising reaction by-products dissolved or suspended in the liquid phase oxidation reaction mixture and a high pressure vapor phase comprising solvent monocarboxylic acid, water and minor amounts of the substituted aromatic hydrocarbon and oxidation by-products of the substituted aromatic hydrocarbon and of the solvent monocarboxylic acid; transferring a high pressure vapor phase removed from the reaction zone to a separation zone capable of separating solvent monocarboxylic acid, water and oxidation by-products into at least one solvent monocarboxylic acid-rich first liquid phase and at least one water-rich second liquid phase and at least one solvent monocarboxylic acid-depleted second high pressure vapor phase comprising water vapor such that at least about 75 wt % of the oxidation by-products of the substituted aromatic hydrocarbon are apportioned to the first liquid phase with no more than about 25 wt % of such by-products present in a water-rich second liquid phase and oxidation by-products of the solvent monocarboxylic acid are apportioned to the second high pressure vapor phase such that no more than about 10 wt % of such by-products are present in the second liquid phase; and removing from the separation zone in separate streams a solvent monocarboxylic acid-rich first liquid phase and a water-rich second liquid phase and a second high pressure vapor phase comprising no more than about 10 wt % oxidation by-products of the substituted aromatic hydrocarbon.