Patent ID: 10843995

Abstract:
A process for manufacturing a carboxylic acid is provided, in one aspect, the process comprises oxidizing a feedstock comprising a substituted aromatic hydrocarbon to form a liquid-phase aromatic carboxylic acid; crystallizing at least a portion of the liquid-phase aromatic carboxylic acid in the presence of oxygen and an oxidation catalyst in a first crystallizer to form solid aromatic carboxylic acid, under reaction conditions suitable to oxidize unreacted feedstock to form additional aromatic carboxylic acid; and crystallizing at least a portion of the first crystallization effluent in the presence of oxygen and an oxidation catalyst in a second crystallizer to form additional solid aromatic carboxylic acid, under reaction conditions suitable to oxidize unreacted feedstock to form additional aromatic carboxylic acid, wherein the oxygen is present in a gaseous phase inside the second crystallizer in an amount of no more than 11% by volume on a dry basis.