| CPC C07D 307/68 (2013.01) [C08G 63/672 (2013.01); C07B 2200/13 (2013.01)] | 10 Claims |

|
1. A process for producing a carboxylic acid composition comprising 2,5-furandicarboxylic acid, the process comprising the steps:
a) providing or producing a crude carboxylic acid composition comprising 2,5-furandicarboxylic acid and 5-formyl-2-furancarboxylic acid;
b) purifying the crude carboxylic acid composition to produce a purified carboxylic acid composition comprising 2,5-furandicarboxylic acid, wherein the purifying comprises at least one step selected from the group consisting of:
hydrogenating at least a portion of the 5-formyl-2-furancarboxylic acid;
oxidizing at least a portion of the 5-formyl-2-furancarboxylic acid;
recrystallization of at least a portion of the 2,5-furandicarboxylic acid; and
hydrolyzing of dialkyl ester of 2,5-furandicarboxylic acid;
c) providing or producing a treatment solvent composition comprising more than 95% by weight of water, with respect to the weight of the treatment solvent composition;
d) providing or producing a thermal treatment composition comprising the purified carboxylic acid composition and the treatment solvent composition;
e) subjecting the thermal treatment composition to an elevated temperature in the range of 140 to 200° C. for a time in the range of 5 to 240 min, wherein the percentage of dissolved 2,5-furandicarboxylic acid, relative to the total amount of 2,5-furandicarboxylic acid, is in the range of 10 to 80% to obtain a treated composition; and
f) cooling the treated composition to a temperature in the range of 20 to 80° C. and separating at least a portion of the 2,5-furandicarboxylic acid from the treated composition to obtain a carboxylic acid composition and a treatment mother liquor comprising water.
|