Production and separation of 2,5-furandicarboxylic acid in gamma-valerolactone solvent system using glucaric acid as raw material derived from oxidation of enzymatic hydrolysate of Miscanthus sacchariflorus

In this study, alternative pathway using glucaric acid as precursor of 2,5-furandicarboxylic acid (FDCA) was proposed. The acid catalyzed cyclization and sequential dehydration of glucaric acid to FDCA was performed in gamma-valerolactone. The glucaric acid conversion to FDCA was promoted at reaction temperature over 140 C, while FDCA production from glucaric acid was achieved within 1 h. 50.25% of FDCA was produced from glucaric acid at 200(degrees) C of reaction temperature, 1 h of reaction time, 1.66% (w/v) of glucaric acid concentration (5% of sulfuric acid concentration). The acid catalyst catalyzed cyclization of glucaric acid and dehydration of intermediates, and gamma-valerolactone stabilized intermediates and FDCA from undesirable degradation. FDCA was further produced from EH-glucaric acid produced from enzymatic hydrolysate of Miscanthus, impurities in EH-glucaric acid decreased FDCA yield. Separation and purification of produced FDCA was achieved by simple precipitation followed by activated carbon treatment. Activated carbon treatment improved purity of FDCA up to 98%.