5-hydroxymethylfurfural and Dehydration

5-Hydroxymethylfurfural (HMF) is identified as an important bio-based platform chemical to bridge petroleum-based and biomass-based resources. It can be obtained through dehydration of various carbohydrates as well as converted to value-added fuels and chemicals. As designer solvents, ionic liquids (ILs) and deep eutectic solvents (DESs) have been widely used in catalytic transformation of biomass derivatives to various chemicals. This Review summarizes recent progress in experimental and theoretical studies on dehydration of carbohydrates such as fructose, glucose, sucrose, cellobiose, chitosan, cellulose, inulin, and even raw biomass to generate HMF using ILs and DESs as catalysts/cocatalysts and/or solvents/cosolvents. It also gives an overview of IL and DES-involved catalytic transformation of HMF to downstream products via oxidation, reduction, esterification, decarboxylation, and so forth. Challenges and prospects of ILs and DESs are also proposed for further production of HMF and HMF derivatives from biomass in green and sustainable processes.

Topics: Biomass; Cellulose; Deep Eutectic Solvents; Dehydration; Furaldehyde; Humans; Ionic Liquids; Solvents

Topics: Biomass; Carbohydrates; Dehydration; Furaldehyde; Ionic Liquids

Biomass-derived 5-hydroxymethylfurfural (HMF) holds potential for applications in green materials, but its conventional synthesis is hindered by undesired side reactions. This study presents a catalytic system that effectively suppresses the formation of byproducts, thus enhancing HMF yield. The system demonstrated synergistic effects between Lewis acid NaY zeolite and formic acid sacrificial agent for the production of HMF from glucose. The results indicate that formic acid reacts with reactive intermediates from glucose decomposition, preventing their interactions with other sugar-derived species in the dehydration path to HMF. Such effect originates from the neutral formic acid species rather than the dissociated acidic proton normally observed in Brønsted acid-catalyzed reactions. The NaY/formic acid catalysts in isopropanol/water achieved a 57% HMF yield, a significant improvement over 31% and 27% yields with NaY or formic acid alone, respectively. Moreover, performance of the spent catalysts was easily restored to the original state via a simple NaCl wash.

Topics: Catalysis; Dehydration; Furaldehyde; Glucose; Humans; Lewis Acids; Zeolites

5-Hydroxymethylfurfural (5-HMF) is a high value-added platform compound which can be obtained by dehydration of hexose under acidic conditions.. In this paper, a novel impregnation strategy for the molecular sieves (ZSM-5) as carrier and phosphotungstic acid (TPA) as active ingredient is proposed, the influence of the fructose dehydration process were studied and eco-friendliness, low-cost 5-hydroxymethylfurfural (5-HMF) was successfully obtained.. The structure surface area, pore size, acidity and microstructure of solid acid catalysts were investigated by XRD, BET, NH3-TPD and SEM. The influences of reaction temperature, reaction time, catalyst dosage on the yield of 5-hydroxymethylfurfural (5-HFM) were investigated.. The results showed that TPA/ZSM-5 (mass ratio 20:10) has good dispersion and catalytic activity, fructose dosage 5 g, reaction temperature 140 °C, reaction time 2 h, catalyst dosage 0.5 g, and the yield of 5-hydroxymethylfurfural was 80.75% and after five times use the yield of 5-HMF remained above 75%.. The novel solid acid TPA/ZSM-5 catalyst exhibited good catalytic activity and stability for the fructose dehydration to produce 5-HMF.

Topics: Catalysis; Dehydration; Fructose; Furaldehyde; Humans

Topics: Alkanesulfonates; Carbon; Catalysis; Chitosan; Dehydration; Fructose; Furaldehyde; Solvents; Sulfanilic Acids; Temperature; Water

A series of defect pyrochlores of the composition (H3O)1+pSb1+pTe1-pO6 have been prepared by ion exchange from K-containing pyrochlores K1+pSb1+pTe1-pO6 in sulfuric acid at 280 °C for 24 h. The structural characterization of the hydronium-containing pyrochlores, including the location of the H3O+ units within the three-dimensional framework, was possible from neutron powder diffraction data in undeuterated samples. The crystal structure for all the compounds is defined in the Fd3[combining macron]m space group, and consists of a covalent framework of SbVO6 and TeVIO6 octahedra distributed at random and connected by their vertices with (Sb,Te)-O1-(Sb,Te) angles close to 136°, conforming to large cages where the hydronium species are located off-center. The absence of K+ ions in the ion-exchanged pyrochlores was confirmed by inductively coupled plasma optical emission spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The shape and size of the hydronium units evolve along with the series, becoming more compact as the framework covalence and Lewis-basicity decrease upon Sb enrichment of the structure (for greater p values). The amount and lability of the H3O+ species also increase throughout the series, as wanted: a straightforward correlation of the catalytic activity in the fructose dehydration reaction to 5-hydroxymethylfurfural has been observed, reaching conversion rates up to 88.5% of concentrated fructose solution for the p = 0.25 catalyst. Moreover, a pseudo-first-order kinetic mechanism was simulated, and the kinetic constants obtained from diluted and concentrated enhanced reaction systems were determined and compared.

Topics: Antimony; Catalysis; Dehydration; Fructose; Furaldehyde; Hot Temperature; Isomerism; Molecular Conformation; Niobium; Onium Compounds; Oxides; Powder Diffraction; Tellurium; Time Factors; X-Ray Diffraction

A mixture of hexafluoroisopropanol (HFIP) and water was used as a new and unknown monophasic reaction solvent for fructose dehydration in order to produce HMF. HFIP is a low-boiling fluorous alcohol (b.p. 58 °C). Hence, HFIP can be recovered cost efficiently by distillation. Different ion-exchange resins were screened for the HFIP/water system in batch experiments. The best results were obtained for acidic macroporous ion-exchange resins, and high HMF yields up to 70% were achieved. The effects of various reaction conditions like initial fructose concentration, catalyst concentration, water content in HFIP, temperature and influence of the catalyst particle size were evaluated. Up to 76% HMF yield was attained at optimized reaction conditions for high initial fructose concentration of 0.5 M (90 g/L). The ion-exchange resin can simply be recovered by filtration and reused several times. This reaction system with HFIP/water as solvent and the ion-exchange resin Lewatit K2420 as catalyst shows excellent performance for HMF synthesis.

Topics: Catalysis; Dehydration; Fructose; Furaldehyde; Ion Exchange Resins; Kinetics; Molecular Structure; Particle Size; Propanols; Solvents; Temperature

Production of 5-hydroxymethylfurfural (HMF) from glucose was studied in ionic liquids in the presence of hydroxyapatite supported chromium chloride (Cr-HAP) using oil-bath heating and microwave irradiation (MI). Compared with oil-bath heating, the MI way obviously increased HMF yield and reduced the reaction time from days to several minutes. A maximum HMF yield of 40% was obtained from the dehydration of glucose under MI in 2.5 min. This method is potential as an energy-efficient and cost-effective approach for the conversion of biomass into platform chemicals.

Topics: Biomass; Biotechnology; Catalysis; Chlorides; Chromatography, High Pressure Liquid; Chromium Compounds; Cost-Benefit Analysis; Dehydration; Durapatite; Furaldehyde; Glucose; Microwaves; Oils; Time Factors

Kinetics of hydrothermal reaction of D-glucose was investigated at 0.02 M over a temperature range of 120-160 °C by applying in situ (13)C NMR spectroscopy. D-Glucose was found to be reversibly transformed first into D-fructose (intermediate) and successively into 5-hydroxymethylfurfural (5-HMF) through dehydration. The carbon mass balance has been kept within the detection limit, and no other reaction pathways are present. The hydrothermal reaction of d-glucose is thus understood as that of D-fructose in the sense that the D-glucose reaction proceeds only through D-fructose. All the isomers of D-glucose and D-fructose were detected by the in situ (13)C NMR in D(2)O: they are the open chains and the pyranoses and furanoses of α- and β-types. The β-forms are the most stable due to the hydration. For both D-glucose and D-fructose, the isomers are in a rapid equilibrium for each monosaccharide, and they are treated collectively in the kinetic analysis of the slower hydrothermal reactions. The reactions are of the first order with respect to the concentrations of D-glucose and D-fructose, and D-glucose converts to 5-HMF on the order of hours. The kinetic parameters were determined by the in situ method.

Topics: Biofuels; Carbohydrate Conformation; Catalysis; Dehydration; Fructose; Furaldehyde; Glucose; Green Chemistry Technology; Isomerism; Kinetics; Magnetic Resonance Spectroscopy; Temperature; Thermodynamics

The renewable furan-based platform chemical, 5-hydroxymethylfurfural (HMF), has been efficiently synthesized from d-fructose and sucrose in the presence of a catalytic amount of protic ionic liquids. The 1-methylimidazolium-based and N-methylmorpholinium-based ionic liquids are employed. As a result, 74.8% and 47.5% yields of HMF are obtained from d-fructose and sucrose, respectively, at 90 degrees C for 2h under nitrogen atmosphere when N-methylmorpholinium methyl sulfonate ([NMM](+)[CH(3)SO(3)](-)) is used as the catalyst in an N,N-dimethylformamide-lithium bromide (DMF-LiBr) system. The acidities of ionic liquids are determined by the Hammett method, and the correlation between acidity and catalytic activity is discussed. Moreover, the effects of reaction temperature and time are investigated, and a plausible reaction mechanism for the dehydration of d-fructose is proposed.

Topics: Catalysis; Dehydration; Fructose; Furaldehyde; Ionic Liquids; Molecular Structure; Protons; Sucrose; Temperature