METHOD FOR PURIFYING AND REMOVING COLOUR OF 2,5-FURANDICARBOXYLIC ACID (FDCA)

The invention is based on the finding that when conducting crystallization of FDCA at high temperatures, the formation of significant amounts of colored byproduct can be reduced or even avoided when the FDCA mixture is kept at temperatures above 100° C. for less than 15 minutes. This is achieved by conducting the crystallization process in a continuous reactor. Accordingly, the method comprises the steps of feeding a mixture comprising undissolved FDCA and a solvent to a reactor; and dissolving FDCA by superheating the mixture in the reactor to a temperature of at least 130° C.; and crystallizing FDCA by cooling the mixture in the reactor, wherein the reactor is a continuous reactor and the residence time in the reactor zone wherein the FDCA mixture has a temperature above 100° C. is less than 15 minutes.