US 12,281,090 B2
Process for producing 2,5-furandicarboxylic acid from ethers of 5-hydroxymethylfurfural
Hendrikus Jacob Baars, Amsterdam (NL); Jan Hendrik Blank, Amsterdam (NL); Jeffrey John Kolstad, Amsterdam (NL); and Ana Sofia Vagueiro De Sousa Dias, Amsterdam (NL)
Assigned to Furanix Technologies B.V., Amsterdam (NL)
Appl. No. 17/778,921
Filed by Furanix Technologies B.V., Amsterdam (NL)
PCT Filed Dec. 18, 2020, PCT No. PCT/EP2020/087052
§ 371(c)(1), (2) Date May 23, 2022,
PCT Pub. No. WO2021/123189, PCT Pub. Date Jun. 24, 2021.
Claims priority of application No. 19218642 (EP), filed on Dec. 20, 2019.
Prior Publication US 2022/0411393 A1, Dec. 29, 2022
Int. Cl. C07D 307/68 (2006.01)
CPC C07D 307/68 (2013.01) 21 Claims
 
1. A process for producing a carboxylic acid composition comprising 2,5-furandicarboxylic acid, comprising the steps:
a) oxidizing an oxidizable compound comprising 5-alkoxymethylfurfural in an oxidation reactor in the presence of a saturated organic acid solvent having from 2 to 6 carbon atoms and a catalyst system comprising cobalt, manganese and bromine using an oxidizing gas at a temperature in the range of 160 to 210° C. to obtain a crude carboxylic acid composition comprising mono alkyl ester of 2,5-furandicarboxylic acid and solid 2,5-furandicarboxylic acid,
b) isolating at least a portion of the solid 2,5-furandicarboxylic acid from the crude carboxylic acid composition in a solid-liquid separation zone to generate a solid cake and a mother liquor,
c) determining the amount of manganese and/or cobalt in the cake, and
d) increasing the amount of one or more controlling acids in the oxidation reactor, if the determined amount of manganese and/or cobalt in the cake exceeds a predefined threshold value,
wherein the one or more controlling acids are selected from the group consisting of hydrobromic acid and mono—or dicarboxylic acids having from 2 to 5 carbon atoms and a pKa of less than 3.2, and
wherein the mother liquor comprises mono alkyl ester of 2,5-furandicarboxylic acid in the range of 0.5 to 7% by weight with respect to the weight of the mother liquor.