Highest HMF Yield Research Articles

Conversion of biomass-derived carbohydrates into 5-hydroxymethylfurfural catalyzed by sulfonic acid-functionalized carbon material with high strong-acid density in γ-valerolactone

A carbonaceous solid acid catalyst with high strong-acid density was synthesized by facile functionalization of a biomass-derived mesoporous carbon with benzenesulfonic acid. The catalyst was characterized by using Fourier transform infrared spectroscopy, elemental analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, and N2 adsorption–desorption. The carbonaceous solid catalyst containing Bronsted acid sites was used for the production of 5-hydroxymethylfurfural (HMF) from hexoses such as fructose, glucose, and cellulose in γ-valerolactone (GVL)-H2O mixture. By reaction at 130 °C for 20 min using fructose as a feedstock, an HMF yield 78.1% was achieved. The catalytic performance of the catalyst in conversion of fructose into HMF hardly changed over seven cycles, demonstrating that the catalyst had excellent recyclability. The yields of HMF derived from glucose and cellulose reached 33.2 and 22.5%, respectively, whereas those of total furans were 42.1 and 33.7%, respectively. The proposed reaction system was promising in transforming biomass-based carbohydrates into fine chemicals, given the use of green functionalization methods, the utilization of sustainable biomass-derived carbon precursor and solvents, catalyst with high acid density, and the availability of high HMF yield.

Starbon/High-Amylose Corn Starch-Supported N-Heterocyclic Carbene-Iron(III) Catalyst for Conversion of Fructose into 5-Hydroxymethylfurfural.

Iron-N-heterocyclic carbene complexes (Fe-NHCs) have come to prominence because of their applicability in diverse catalytic reactions, ranging from C-C cross-coupling and C-X bond formation to substitution, reduction, polymerization, and dehydration reactions. The detailed synthesis, characterization, and application of novel heterogeneous Fe-NHC catalysts immobilized on mesoporous expanded high-amylose corn starch (HACS) and Starbon 350 (S350) for facile fructose conversion into 5-hydroxymethylfurfural (HMF) is reported. Both catalyst types showed good performance for the dehydration of fructose to HMF when the reaction was tested at 100 °C with varying time (10 min, 20 min, 0.5 h, 1 h, 3 h and 6 h). For Fe-NHC/S350, the highest HMF yield was 81.7 % (t=0.5 h), with a TOF of 169 h-1 , fructose conversion of 95 %, and HMF selectivity of 85.7 %, whereas for Fe-NHC/expanded HACS, the highest yield was 86 % (t=0.5 h), with a TOF of 206 h-1 , fructose conversion of 87 %, and HMF selectivity of 99 %. Iron loadings of 0.26 and 0.30 mmol g-1 were achieved for Fe-NHC/expanded starch and Fe-NHC/S350, respectively.

Catalytic conversion of glucose to 5-hydroxymethylfurfural using zirconium-containing metal-organic frameworks using microwave heating.

5-Hydroxymethylfurfural (5-HMF) can be prepared by the catalytic dehydration of glucose or fructose using a range of homogeneous or heterogeneous catalysts. For our research, a selection of closely related Metal–Organic Frameworks (MOFs) were used as catalysts in the conversion of glucose to 5-HMF due to their chemical and thermal stability as well as the Lewis acidity of zirconium. Our initial study focused on the use of UiO-66–X (X = H, NH2 and SO3H), optimization of the dehydration reaction conditions, and correlation of the catalytic activity with the MOF's properties, in particular, their surface area. The highest yield of 5-HMF (28%) could be obtained using UiO-66 under optimal reaction conditions in dimethylsulfoxide and this could be increased to 37% in the presence of water. In catalyst recycling tests, we found the efficiency of UiO-66 was maintained across five runs (23%, 19%, 21%, 20%, 22.5%). The post-catalysis MOF, UiO-66–humin, was characterized using a range of techniques including PXRD, FT-IR, 13C Solid State NMR and N2 gas adsorption. We continued to optimize the reaction using MOF 808 as the catalyst. Notably, MOF 808 afforded higher yields of 5-HMF under the same conditions compared with the three UiO-66–X compounds. We propose that this might be attributed to the larger pores of MOF 808 or the more accessible zirconium centres.

Hexafluoroisopropanol as a Low‐Boiling Extraction Solvent for 5‐Hydroxymethylfurfural Production

AbstractIn this study, we show that the fluorous alcohol hexafluoroisopropanol (HFIP) can act as a superior solvent for the in situ extraction of 5‐hydroxymethylfurfural (HMF) from an aqueous reaction system. HFIP has a far higher partition coefficient for HMF than common extraction solvents such as methyl isobutyl ketone (MIBK) and n‐butanol and has a significantly lower boiling point of 58–59 °C. In a system containing fructose, HCl as the catalyst, and HFIP as the extraction solvent, a high HMF yield of 89 % is achieved, which is far better than the HMF yields in common MIBK/butanol extraction systems. HFIP extracts HMF from the reaction phase without extraction of the fructose educt. In addition, the aqueous catalyst phase can be reused.

Catalytic conversion of glucose to 5-hydroxymethyfural over Fe/β zeolites with extra-framework isolated Fe species in a biphasic reaction system

A series of Fe/β zeolite catalysts with various Fe/Al ratios were prepared by liquid ion-exchanged method and were characterized by N2 adsorption, XRD, UV–Vis DRS, EPR, NH3-TPD, and FTIR of pyridine adsorption techniques. The catalysts were used to catalyze the transformation of glucose into 5-hydorxymethyfural (HMF) in a biphasic reaction system under mild reaction conditions. The Fe/β catalysts with Lewis acidic Fe sites is able to effectively improve the HMF yield compared to H-β zeolite under identical reaction conditions, which is ascribed to the enhanced isomerization activity of glucose-to-fructose by Lewis acidic Fe species. Moreover, the Fe/Al ratio had a remarkable impact on the conversion of glucose and the yield of HMF, indicating that the synergetic effect of Lewis and Brønsted acid sites is critical to achieving high HMF yield. Under optimal reaction conditions, Fe/β-0.06 catalyst afforded 61% HMF yield at glucose conversion of 95% after the reaction of 90 min at 120 °C, which is one of the most effective catalysts for the conversion of glucose into HMF in a biphasic medium up to now. Furthermore, extra-framework isolated Fe species bound to the framework Al sites, are most likely the active sites for the isomerization of glucose-to-fructose in the conversion of glucose. The catalysts were very stable and could be reused at least five runs without significant loss in the catalytic activity.

Tin phosphate as a heterogeneous catalyst for efficient dehydration of glucose into 5-hydroxymethylfurfural in ionic liquid

5-Hydroxymethylfurfural (HMF) is a key versatile building block in the valorization of lignocellulosic biomass. A series of metal oxides and metal phosphates was investigated as heterogeneous catalyst to convert glucose into HMF in the ionic liquid 1-ethyl-3-methylimidazolium bromide (EMIMBr). The heterogeneous conversion of a high-concentration glucose (up to 20wt%) into HMF in ionic liquid has been achieved for the first time. Tin phosphate in the medium could afford a high HMF yield (58.3%) comparable to the best results obtained with the most effective homogeneous catalysts. To elucidate the reaction mechanism, SnO2, sSnPO and SnPO were characterized by N2 adsorption-desorption, XRD, TEM, XPS, UV–vis, FIIR, Py-IR and CD3CN-IR. It was found that tetra-coordinated Sn4+ sites from tin phosphate are responsible for the isomerization of glucose into fructose, while the conversion of fructose into HMF is mainly catalyzed by the ionic liquid EMIMBr. The excellent catalytic performance was attributed to the synergistic effect between SnPO and EMIMBr.

“One-pot” conversions of carbohydrates to 5-hydroxymethylfurfural using Sn-ceramic powder and hydrochloric acid

5-Hydroxymethylfurfural (HMF), converted from sustainable biomass resources, is a versatile intermediate in chemical industry. A kind of ceramic powder containing Sn4+ ions (Sn-CP) with good hardness was synthesized by a rapid method for the isomerization of glucose. HCl was introduced for catalysing the fructose-to-HMF reaction and promoting the isomerization reaction. Production of HMF from glucose catalysed by Sn-CP/HCl demonstrated high HMF yield (63.9%) and effective catalyst recyclability (HMF yield >53.7%). Moreover, when fructose and poly-saccharides (sucrose, inulin, starch and maltose) as feedstocks, HMF yields of more than 55% were obtained. Hence integration of catalytic reaction and conversion of carbohydrates to HMF provided a green process over inexpensive catalyst.

Facile synthesis of hierarchical porous catalysts for enhanced conversion of fructose to 5-hydroxymethylfurfural

Facile synthesis of solid acid carbonaceous catalysts with hierarchical pore structure has been reported. As carbonaceous catalyst precursor, MOF-derived carbon (MDC) was prepared by a simple heat-treatment of highly crystalline metal-organic framework-5 (MOF-5) without any complicated process and environmental burden. Subsequently, −SO3H groups with high catalytic activity were successfully grafted onto the carbonaceous support by the sulfonation process. The obtained catalysts, MDC-SO3H have been systematically studied as acidic heterogeneous catalyst in dehydration of fructose into 5-hydroxymethylfurfural (5-HMF) with isopropanol-mediated DMSO solvent. The experiment results proved that the efficient 5-HMF yield was gained in mixed solvent which a large amount of DMSO was substituted by isopropanol. The highest yield of 5-HMF (89.57%) was obtained at 120°C for 2 h with the use of 90 vol. % isopropanol as the cosolvent in our experiment. What's more, the catalyst showed excellent recyclability after 5 times catalyze reaction without significant loss of catalytic activity.

Highly efficient preparation of 5-hydroxymethylfurfural from sucrose using ionic liquids and heteropolyacid catalysts in dimethyl sulfoxide–water mixed solvent

Several types of ILs and solid acids were used as catalysts in one-pot conversion of sucrose to 5-hydroxymethylfurfural (abbreviated as 5-HMF) in a dimethyl sulfoxide (DMSO)/water mixed solvent under hydrothermal conditions. A remarkable 5-HMF yield of 91.8% was achieved catalyzed by the cesium salt of dodecatungstophosphoric acid (Cs2.3H0.7PW12O40) within 3h at 180°C. The ionic liquid N-methylimidazolium hydrogen sulfate ([Hmim][HSO4]) gave the 5-HMF in 82.0% yield from sucrose. To the best of our knowledge, it was almost the highest yield of HMF from sucrose by now. Various reaction parameters including reaction temperature and time and catalyst dosage were optimized. A possible mechanism for this catalytic process was proposed. Furthermore, fructose and glucose were also investigated, good yields of 5-HMF was obtained respectively. This increases the possibility of large-scale production of 5-HMF from carbohydrates.

One-pot production of 5-hydroxymethylfurfural from cellulose using solid acid catalysts

5-Hydroxymethylfurfural (HMF) is one of the most important intermediate platforms for production of both chemicals and liquid fuel derived from biomass. The one-pot production of HMF from cellulose was conducted in a batch reactor in the presence of various solid acid catalysts. The prepared catalysts were characterized by means of Brunauer–Emmett–Teller measurement and pyridine adsorption FT-IR to investigate their pore structure and acidic properties. The presence of gaseous hydrogen enhanced the formation of HMF by suppressing the formation of byproducts. Increasing the acid amount of the catalyst caused an increase in the conversion and selectivity for organic acid and a decrease in the HMF selectivity. A Brønsted-type catalyst (Al-SBA-15) favored the formation of HMF. The reaction conditions of 220°C, 5min, and a hydrogen pressure of 1MPa resulted in the highest yield of HMF, and selectivity of 26.9% was achieved when the Al-SBA-15 catalyst was used. Moreover, under the same conditions, cellulose extracted from eucalyptus, a practical biomass, was converted to HMF in a one-pot synthesis with a yield of 13.0C-mol.%.

Efficient conversion of carbohydrates into 5-hydroxylmethylfurfan and 5-ethoxymethylfurfural over sufonic acid-functionalized mesoporous carbon catalyst

Catalytic conversion of carbohydrates into valuable chemical and liquid fuels has received considerable attention in recent years. In this study, sulfonic acid-functionalized ordered mesoporous carbon (OMC-SO3H) was prepared and well characterized by physical techniques such as TEM, nitrogen physisorption measurements and XRD. The as-prepared OMC-SO3H was then used for the acid-catalyzed conversion of fructose based carbohydrates into 5-hydroxylmethylfurfan (HMF) or 5-ethoxymethylfurfural (EMF). Due to the high surface area and high acidity, the OMC-SO3H catalyst showed a comparable catalytic performance as the homogeneous catalysts. The dehydration of fructose over the OMC-SO3H catalyst produced a high HMF yield of 89.4% in DMSO at 120°C within 30min. The one-pot transformation of fructose carbohydrates were also smoothly performed, affording EMF yields of 55.7%, 53.6% and 26.8% from fructose, iuline and sucrose after 24h at 140°C, respectively. Furthermore, the OMC-SO3H catalyst can be reused and no apparent loss of the activity was observed.

Conversion of carbohydrates into 5‐hydroxymethylfurfural in a green reaction system of CO2‐water‐isopropanol

In this work, a green reaction system of CO2‐water‐isopropanol was developed for 5‐hydroxymethylfurfural (HMF) production. The conversion of fructose in a CO2‐water system was first investigated, and the results showed this system could promote the formation of HMF compared to a pure water system. Then, isopropanol was introduced into the CO2‐water system and the HMF formation became better because the solvent effect of isopropanol increased the tautomeric composition of fructofuranose, which was easy to form HMF. The existence of isopropanol was found to greatly suppress secondary reactions where HMF was converted to levulinic acid and insoluble humin. Meanwhile, the effects of reaction parameters on the conversion of fructose to HMF in the CO2‐water‐isopropanol system were analyzed, and a high HMF yield of 67.14% was obtained. Finally, to further illustrate the merits of CO2‐water‐isopropanol system, productions of HMF from other carbohydrates were tested and satisfactory yields were achieved. © 2016 American Institute of Chemical Engineers AIChE J, 63: 257–265, 2017

Conversion of glucose into 5-hydroxymethylfurfural in different solvents and catalysts: Reaction kinetics and mechanism

Synthesis of 5-hydroxymethylfurfural (HMF) from glucose was done in H2O, dimethylsulfoxide (DMSO) and 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) catalyzed by metal (III) chloride (FeCl3·6H2O, CrCl3·6H2O and AlCl3). The effects of solvent/catalyst system and temperature/time on the performance of the reaction are studied. HMF yield in the different solvents follows a decreasing order as DMSO>[Bmim]Cl>H2O. The highest HMF yield is achieved by CrCl3·6H2O, followed by AlCl3 and then FeCl3·6H2O. An optimal temperature/time is found at 393K or 403K and a time between 30min and 480min. Under the optimal reaction conditions, HMF yields of 54.43% and 52.86% are obtained in DMSO with CrCl3·6H2O at 403K and 480min and AlCl3 at 393K and 240min, respectively. The mechanism of the halide chlorides catalyzed glucose conversion reaction is proposed. The kinetic model is established to describe the HMF formation and the experimental data conform to the model.

Saccharification of lignocellulosic biomasses via ionic liquid pretreatment

The current work focuses on the pretreatment efficiency of ILs combined with heat for woody biomass consisting of spruce, birch and pine as well as winter wheat straw. The latter was investigated as a comparison and with the aim to enhance its digestibility during enzymatic hydrolysis whereby the influence of IL-treatment to cellulose resistance for hydrolysis was investigated. Considering the wood species, the most common and industrially important wood species in Northern Europe were chosen in the present work and the goal was to obtain fermentable sugars and their degradation product, i.e. 5-hydroxymethylfurfural (5-HMF), which is known valuable platform chemical. Further, the differences in the yields of IL-obtainable carbohydrates between these species were studied. The highest sugar yields were obtained to glucose in the case of spruce and arabinose in the case of pine sapwood, 12.07 and 7.72mmol/L, respectively. The highest 5-HMF yield was obtained for spruce heartwood (9.18mmol/L) with longer treatment time, such as 100h. However, regarding woody biomass, the present work was focused more on the study and analysis of the IL-containing liquid part, wood hydrolysate, after IL-treatment aiming to answer the analysis challenges related to this fraction.

Conversion of Eucalyptus Cellulose into 5-Hydroxymethylfurfural Using Lewis Acid Catalyst in Biphasic Solvent System

Conversion of eucalyptus cellulose into 5-hydroxymethylfurfural (5-HMF) by using Lewis acid catalyst in biphasic system was investigated in this study. The results show that the tetrahydrofuran/water biphasic system was more conducive to convert the eucalyptus cellulose into 5-HMF comparing to the single aqueous system. InCl3, a water-compatible Lewis acid, has the best catalytic effect. The highest yield of 5-HMF from eucalyptus cellulose is up to 45.05 mol%, which is a slight higher than that from microcrystalline cellulose. It can be ascribed to the lower crystallinity of isolated eucalyptus cellulose. The optimum conditions for catalytic conversion of eucalyptus cellulose into 5-HMF are at 200 °C for 2 h with 10 % InCl3 dosage. Additionally, the effect of recycling the whole biphasic system which contains InCl3, NaCl, H2O and THF indicated that the 5-HMF yield was gradually decreased as the cycle times increased, the possible reason could be due to the loss of partial InCl3 catalyst during the separation and distillation process.

Catalytic Conversion of Biomass-derived Carbohydrates into 5-Hydroxymethylfurfural using a Strong Solid Acid Catalyst in Aqueous γ-Valerolactone

Selective conversion of biomass-derived carbohydrates into 5-hydroxy-methylfurfural (HMF) is of great significance for biomass conversion. In this study, a novel solid Bronsted acid was prepared simply by the copolymerization of paraformaldehyde and p-toluenesulfonic acid and then used to catalyze the conversion of various carbohydrates into HMF in γ-valerolactone-water (GVL/H2O) reaction medium for the first time. The catalyst exhibited strong acidity, good water resistance, and high thermal stability. The present work focuses on the effects of various reaction parameters, including reaction temperature, time, water concentration, solvent, fructose level, and catalyst loading, on fructose dehydration. The catalyst exhibited excellent catalytic performance for HMF production from fructose in GVL and furnished a high HMF yield of 78.1% at 130 °C in 30 min. The recycling experiments suggested that the solid acid catalyst could be recycled at least seven times without a noticeable decrease in the catalytic activity. In addition, an attempt to study the one-step conversion of sucrose, glucose, and cellulose into HMF and furfural was performed using the same catalytic system.

Highly efficient preparation of HMF from cellulose using temperature-responsive heteropolyacid catalysts in cascade reaction

A series of heteropolyacid catalysts (HOCH2CH2N(CH3)3) xH3−xPW12O40 (abbreviated as ChxH3−xPW12O40, x=1, 2 and 3) had been synthesized using choline chloride and H3PW12O40 as the raw materials, which were used as heterogeneous catalysts in one-pot conversion of cellulose to 5- hydroxymethylfurfural (abbreviated as HMF) in double solvent system containing methyl isobutyl ketone (abbreviated as MIBK) and H2O. A remarkable HMF yield of 75.0% was achieved catalyzed by ChH2PW12O40 within 8h at 140°C attributed to its higher Brønsted acidity and thermoregulate property comparable to its homogeneous form H3PW12O40. To the best of our knowledge, it was almost the highest yield of HMF from cellulose by now, while the best yield of 64.0% was reported so far over AlCl3 in biphasic system. Using our biphasic reaction protocol, even raw lignocellulosic biomass straw, gave HMF yields of 27.6%. Moreover, such heteropolyacid catalysts could be recycled under simply lowering the reaction temperature to room temperature without loss of its weight, which were reused for more than 10 times.

Catalytic Conversion of Glucose into 5-Hydroxymethyl-Furfural Over Chromium-Exchanged Bentonite in Ionic Liquid-Dimethyl Sulfoxide Mixtures

A recoverable catalyst chromium-exhanged bentonite (bentonite-Cr) was prepared and its structures were characterized by many technologies, including XRD, FT-IR, ICP-AES, XPS, SEM, TEM. The prepared catalysts were used to catalyze the conversion of glucose into 5-hydromethylfurfural (HMF) in ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]+Cl−) and dimethyl sulfoxide (DMSO) mixtures. Various reaction conditions, including catalyst loading, temperature, reaction duration and solvent, were investigated. A high HMF yield of 61.45 % was obtained at the mild reaction conditions (120 °C for 4 h). More importantly, the catalyst could be reused for several times without the loss of its significant catalytic activities. After five reaction runs, a HMF yield about 57.26 % was also obtained.

An efficient heterogeneous CrOx–Y zeolite catalyst for glucose to HMF conversion in ionic liquids

ABSTRACTIn this study, CrCI3, H–Y, Cr–Y and calcined CrOx–Y zeolites were studied in the liquid phase heterogeneous catalytic conversion of glucose to HMF in ionic liquids. Characterization of catalysts was done in XPS, XRD and NH3-TPD. Both glucose conversion and HMF yield decreased with the addition of chromium (III) chloride impregnated catalysts in comparison to the homogeneous CrCI3–[BMIM]CI system. High glucose and HMF yields were obtained with heterogeneous calcined CrOx–Y zeolite. Best HMF yield achieved was 52.8%.

Functionalized silica nanoparticles for conversion of fructose to 5-hydroxymethylfurfural

Functionalized silica nanoparticles with strong acidity and different hydrophobicity were successfully synthesized by an alkali co-condensation method. The structure of the hydrophobic solid acids were characterized, and the catalytic properties were investigated in fructose dehydration to 5-hydroxymethylfurfural (5-HMF). Experiment results indicated that catalyst hydrophobicity has a positive influence on both 5-HMF yield and selectivity. The highest yield of 5-HMF (87%) with full conversion of fructose was obtained when the most hydrophobic solid acid (SiNP-SO3H-C16) was used as the catalyst. The reason can be interpreted as the hydrophobic groups in the silica nanoparticles can effectively isolate SO3H groups with water molecules in the reaction system, and thus hinder the rehydration of 5-HMF, which is the main side-reaction in 5-HMF formation. Other important reaction parameters such as reaction medium, temperature, time and catalyst loading were also studied for fructose dehydration. Recycling and control experiments demonstrated the good reusability and stability of the functionalized silica nanoparticles. Furthermore, inulin was also used as a feedstock for 5-HMF production and gave a high 5-HMF yield of 65% in the catalysis of a moderate hydrophobic silica nanoparticle.