High-Yield Synthesis of 5-Hydroxymethylfurfural from Untreated Wheat Straw Catalyzed by FePO4 and Organic Acid in a Biphasic System

It is of great significance to develop an affordableand environmentallyfriendly method for producing 5-hydroxymethylfurfural (HMF) and furfuralfrom inexpensive and abundant agricultural waste. Herein, FePO4 combined with organic acids such as mandelic acid were usedas catalysts in a one-pot catalytic conversion of untreated wheatstraw into HMF and furfural in a two-phase system of THF/H2O saturated by NaCl. H+, Fe(OH)(2+), and Fe(OH)(2) (+) originated from partially dissolved FePO4 in hot water together with organic acids provided Bronstedand Lewis acid sites for the cascade conversion of wheat straw. Whereasorganic acid could regulate the concentrations of Lewis and Bronstedacid sites to promote the dehydration process of fructose and hinderthe production of by-products and humins, boosting the yield of HMFand furfural. The response surface methodology (RSM) was used to optimizethe reaction conditions. The highest yield of HMF was 62.9% at 200 & DEG;C and 120 min, which is higher than the reported yield of HMFusing lignocellulose as raw material in the current literature. Furfuralhas also achieved a higher yield (93.9%) at 180 & DEG;C and 90 min.This study demonstrates the rationality of the deployment of lignocelluloseto produce furan compounds by organic acids and FePO4, providing thepossibility for efficient production of HMF and furfural from recalcitrantagricultural waste.

Automated summary

In this study, FePO4 combined with organic acids were used as catalysts to convert untreated wheat straw into 5-hydroxymethylfurfural (HMF) and furfural. The use of organic acids regulated the acidity and promoted the dehydration process, resulting in higher yields of HMF and furfural. This method offers an affordable and environmentally friendly approach to produce these valuable compounds from agricultural waste.