Aerobic oxidation of a biomass-derived substrate [5-(hydroxymethyl)furfural; HMF] in methanol and ethylene glycol produces monomers MFDC — the methyl ester of furan-2,5-dicarboxylic acid (FDCA) — and HEFDC — the ethylene glycol ester of FDCA. These monomers are recognized as crucial for the manufacture of polyethylene furanoate (PEF) — a promising 100% renewables-based polymer that can replace polyethylene terephthalate (PET). However, MFDC production has so far been exclusively studied for dilute HMF solutions, and more desirable routes for the production of HEFDC is currently impractical because a high-yield of the monomer cannot be produced efficiently.
Now, the two monomers can be produced by a one-step, energy-efficient process developed by the research teams of Kiyotaka Naakajima at Hokkaido University (Hokkaido, Japan; www.global.hokudai.ac.jp) and Emiel Hensen of Eindhoven University of Technology (the Netherlands). The researchers previously developed a stable compound called HMF-acetal, and have now shown that 80–95% of HMF-acetal in a concentrated (10–20 wt.%) solution can be efficiently converted to MFDC and HEFDC with a gold nanoparticle catalyst. The researchers note that this method has fewer reaction steps and requires less energy than conventional processes.
This study was conducted jointly with Mitsubishi Chemical Corp. (Tokyo) and findings were published in the journal ACS Catalysis.
Credit – Tetsuo Satoh, Chemical Engineering Online