Synthesis of 2,5-Furandicarboxylic Acid from Natural Raw Materials

2,5-Furandicarboxylic acid (FDCA) and polyethylene furanoate are now considered as an alternative to terephthalic acid and polyethylene terephthalate (PET), which are produced from fossil sources. FDCA can be obtained by dehydration of polysaccharides and biomass feedstock to 5-hydroxymethylfurfural (5-HMF) with its following catalytic oxidation. A procedure for obtain 2,5-furandicarboxylic acid with using jerusalem artichoke rhizomes as raw materials for the 5-HMF preparation without prior isolation of inulin has been shown. In first step jerusalem artichoke rhizomes dehydration in a two-phase system of «aqueous solution of Na2SO4 · 10 H2O – methyl isobutyl ketone» 40% 5-HMF yield has been achieved. In second step 5-HMF was oxidized by KMnO4 in alkaline medium to FDCA with 100% yield according to HPLC and 89% yield (99% purity) after isolation. The optima time of intervals and amount of oxidizer - potassium permanganate and importance of maintaining the exact pH= 10.5 ± 0.5 of the reaction mixture have been shown. A perspective of using this approach to create the FDCA synthesis technology by oxidizing the product from 5-HMF raw material with 60% main product content, avoiding expensive and long-term 5-HMF purification steps have been proved.