Patent ID: 8809556

Claim:
A process to produce a carboxylic acid composition, said process comprising: (a) oxidizing in an primary oxidation zone an oxidizable compound in a oxidizable raw material stream in the presence of a solvent stream comprising acetic acid, an oxidizing gas stream comprising oxygen, and a catalyst system comprising cobalt, manganese and bromine, wherein said an oxidizable raw material stream comprises at least one compound selected from the group consisting of 5-(hydroxymethyl)furfural (5-HMF), 5-HMF esters (5-R(CO)OCH2-furfural where R=alkyl, cycloalkyl and aryl), 5-HMF ethers (5-R′OCH2-furfural, where R′=alkyl, cycloalkyl and aryl), 5-alkyl furfurals (5-R″-furfural, where R″=alkyl, cycloalkyl and aryl), mixed feedstocks of 5-HMF and 5-HMF esters, mixed feedstocks of 5-HMF and 5-HMF ethers, and mixed feedstocks of 5-HMF and 5-alkyl furfurals to produce a carboxylic acid composition comprising furan-2,5-dicarboxylic acid (FDCA); (b) routing said carboxylic acid composition to a liquid displacement zone to produce a displaced mother liquid stream and a low impurity slurry stream; (c) routing said low impurity slurry stream to a secondary oxidation zone to form a purified slurry stream; wherein said purified slurry stream comprises FDCA; wherein said FFCA in said slurry is less than 1000 ppm; and wherein said the oxidizing temperature in said secondary oxidation zone is higher than the oxidizing temperature in the primary oxidation zone.