Continuous Production of 5‐Hydroxymethylfurfural from Monosaccharide over Zirconium Phosphates

Abstract

Abstract5‐hydroxymethylfurfural (HMF), an important platform compound produced from lignocellulosic biomass, is widely applied in petrochemical industry for downstream synthesis of medical supplies or intermediate of the other important chemicals by the typical catalytic processes. A continuous production route was developed to yield HMF from monosaccharides by using zirconium phosphate (ZrP) with different Zr/P ratios as catalysts. Its physicochemical properties were then characterized by Brunauer‐Emmett‐Teller (BET), X‐ray powder diffraction (XRD), X‐ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FT‐IR), pyridine adsorbed Fourier transform infrared spectroscopy (Py‐FT‐IR), X‐ray fluorescence (XRF) and temperature programmed desorption of ammonia (NH3‐TPD) techniques. A mixed phase containing monosaccharide in aqueous and dimethyl sulfoxide (DMSO) phase was applied in the fixed bed to keep the continuous production. The optimized reaction conditions were applied to maximized HMF yield by varying the processing parameters. The highest HMF yield of 56.3% was obtained when using fructose as the feedstock under the reaction condition of 120 °C, 180 min, N2 pressure 2 MPa and DMSO: fructose solution of 9:1 over ZrP with the P/Zr with molar ratio of 2. Comparatively, the glucose conversion of 72% with the HMF yield of 32% were gained under the same conditions using glucose as the feedstock. It is deduced that the ZrP catalysts simultaneously possessing Brönsted/Lewis acid showed synergy in glucose dehydration to HMF. The ZrP catalyst showed good stability and no obvious deactivation was observed after 30 h of time‐on‐stream, due to the primary structure and acidic properties of catalyst can be kept during the reaction. Finally, it is generally efficient for some C6 sugars dehydration to HMF with the Brönsted/Lewis acid synergy of ZrP.