Production of 2,5-Furandicarboxylic Acid from Lignocellulosic-Biomass-Derived Glucaric Acid in an Ionic Liquid Combined Acid Catalyst Solvent System

In this study, a system for producing 2,5-furandicarboxylic
acid
(FDCA) from glucaric acid was developed. To enhance the conversion
efficiency and recyclability of the catalyst, an ionic liquid combined
acid catalyst (ILCA) system was developed. Thermogravimetric analysis
of the hydrobromic-acid-based ILCA demonstrated that its thermal stability
was enhanced due to interactions between the ionic liquid and acid
catalyst, as evidenced by an increased decomposition temperature.
Through reaction condition screening, the maximum FDCA production
was accomplished at a reaction temperature of 160 °C, reaction
time of 60 min, and glucaric acid concentration of 5 wt % in hydrobromic
acid as an acid catalyst (70.6% FDCA yield). Among the acid catalysts,
hydrobromic acid showed the highest FDCA yield due to the formation
of the brominated substituted intermediate. The performance of ILCA
was maintained after the fourth use, and the catalytic activity was
regenerated by additional ion-exchange resin treatment. The produced
FDCA was separated during ILCA recycling and purified by an activated
carbon treatment. The conversion of glucaric acid derived from enzymatic
hydrolysates into FDCA achieved a yield of 70%, comparable to that
obtained from pure glucaric acid. The newly developed process is feasible
for the effective utilization of feedstocks generated on the biosugar
platform.