Abstract: Thermal treatment of purified FDCA for producing a carboxylic acid composition, the process comprising the steps of providing or producing a thermal treatment composition comprising a purified carboxylic acid composition and an organic acid containing treatment solvent composition; subjecting the thermal treatment composition to an elevated temperature, wherein the FDCA is partially dissolved, and cooling the treated composition and separating at least a portion of the FDCA from the treated composition to obtain a carboxylic acid composition.

Abstract: Thermal treatment of purified 2,5-furandicarboxylic acid (FDCA) for producing a carboxylic acid composition, the process comprising the steps of providing or producing a thermal treatment composition comprising a purified carboxylic acid composition and a water containing treatment solvent composition; subjecting the thermal treatment composition to an elevated temperature, wherein the FDCA is partially dissolved, and cooling the treated composition and separating at least a portion of the FDCA from the treated composition to obtain a carboxylic acid composition.

Abstract: A purified acid composition including 2,5-furandicarboxylic acid is prepared in a process, including oxidizing a feedstock containing 5-alkoxymethylfurfural to an oxidation product including 2,5-furandicarboxylic acid (FDCA) and 2-formyl-furan-5-carboxylic acid (FFCA), and esters of FDCA and, optionally, esters of FFCA; hydrolyzing the at least part of the oxidation product in the presence of water, thereby hydrolyzing at least esters of FDCA and, optionally, esters of FFCA to obtain an aqueous solution of an acid composition including FDCA, FFCA and ester of FDCA in an amount below the amount of ester of FDCA in the solution of the oxidation product; contacting at least part of the solution of the acid composition with hydrogen in the presence of a hydrogenation catalyst to hydrogenate FFCA to hydrogenation products, yielding a hydrogenated solution; and separating at least a portion of the FDCA from at least part of the hydrogenated solution by crystallization.

Abstract: A purified acid composition including 2,5-furandicarboxylic acid is prepared by a process including a) providing an acid composition solution of a crude acid composition in a polar solvent, the crude acid composition including 2,5-furandicarboxylic acid (FDCA) and 2-formyl-furan-5-carboxylic acid (FFCA); b) contacting the acid composition solution with hydrogen in the presence of a hydrogenation catalyst to hydrogenate FFCA to hydrogenation products, such that the hydrogenation products contain a minor amount of 2-methyl-furan-5-carboxylic acid (MFA) or no MFA, yielding a hydrogenated solution; c) separating at least a portion of the FDCA from the hydrogenated solution by crystallization.

Abstract: A purified acid composition including 2,5-furandicarboxylic acid is prepared by a process including a) providing an acid composition solution of a crude acid composition in a polar solvent, the crude acid composition including 2,5-furandicarboxylic acid (FDCA) and 2-formyl-furan-5-carboxylic acid (FFCA); b) contacting the acid composition solution with hydrogen in the presence of a hydrogenation catalyst to hydrogenate FFCA to hydrogenation products, such that the hydrogenation products contain a minor amount of 2-methyl-furan-5-carboxylic acid (MFA) or no MFA, yielding a hydrogenated solution; c) separating at least a portion of the FDCA from the hydrogenated solution by crystallization.

Abstract: A purified acid composition including 2,5-furandicarboxylic acid is prepared in a process, including oxidizing a feedstock containing 5-alkoxymethylfurfural to an oxidation product including 2,5-furandicarboxylic acid (FDCA) and 2-formyl-furan-5-carboxylic acid (FFCA), and esters of FDCA and, optionally, esters of FFCA; hydrolyzing the at least part of the oxidation product in the presence of water, thereby hydrolyzing at least esters of FDCA and, optionally, esters of FFCA to obtain an aqueous solution of an acid composition including FDCA, FFCA and ester of FDCA in an amount below the amount of ester of FDCA in the solution of the oxidation product; contacting at least part of the solution of the acid composition with hydrogen in the presence of a hydrogenation catalyst to hydrogenate FFCA to hydrogenation products, yielding a hydrogenated solution; and separating at least a portion of the FDCA from at least part of the hydrogenated solution by crystallization.