Abstract A simple and effective water extraction method is presented for the purification 5‐hydroxylmethylfurfural (HMF) obtained from a biomass dehydration system. Up to 99 % of the HMF can be recovered and the HMF in aqueous solution is directly converted to 2,5‐furandicarboxylic acid (FDCA) as the sole product. This purification technique allows an integrated process to produce FDCA from fructose via HMF prepared in an isopropanol monophasic system, with an overall FDCA yield of 83 % obtained. From Jerusalem raw artichoke biomass to FDCA via HMF prepared in a water/MIBK (methyl isobutyl ketone) biphasic system, an overall FDCA yield of 55 % is obtained.