Dehydration Of Fructose Research Articles

Triazolium‐based Ionic Liquids Supported on Alumina as Catalysts to Produce 5‐HMF from Fructose

AbstractThe dehydration of fructose to selectively produce 5‐HMF was catalytically developed in a new type of ionic liquids based on triazoles supported on alumina (Al2O3). The synthesis of triazoles by 1,3‐dipolar cycloaddition allows for creating a tailor‐made triazole, that was eventually used to design catalysts based on triazolium‐based ionic liquids. In this work, four catalysts based on triazolium‐ionic liquids supported on Al2O3 were synthesized to produce 5‐HMF from fructose in DMSO as the reaction solvent. According to their molecular structure, the catalysts were tagged as TR1/Al2O3, TR1‐HSO4/Al2O3, TR2/Al2O3, and TR2‐HSO4/Al2O3.

Solvent-mediated Zr-based coordination polymer with tunable acid properties for the dehydration of fructose and catalytic transfer hydrogenation of 5-hydroxymethylfurfural

In this work, a porous Zirconium based coordination polymer (Zr-ATMP) was facilely synthesized at room temperature with amino tris(methylene phosphonic acid) (ATMP) as ligand, and the surface acidic sites could be adjusted in different solvents. Specifically, the coordination polymer with equivalent content of Bronsted and Lewis acid sites was synthesized in aqueous system, showing high-efficiency catalytic activity for fructose dehydration to 5-hydroxymethylfurfural (HMF). In comparison, the coordination polymer containing an abundance of Lewis acid sites was synthesized in DMF solvent, which efficiently catalyzed the transfer hydrogenation of HMF. Compared to the catalysts preparation in organic solvents, the coordinatively unsaturated Zr4+ could be hydrated in water during catalyst preparation, resulting in the generation of additional Bronsted acid sites at the cost of Lewis acid sites. This contribution proposed a facile approach to prepare Zr-based coordination polymer with tunable acid properties for biomass valorization.

Synthesis of Boron-Doped Phenolic Porous Carbon As Efficient Catalyst for the Dehydration of Fructose into 5-Hydroxymethylfurfural

Porous carbon materials are widely used in adsorption, supercapacitors, catalytic reactions, electrochemistry, and so on. However, the need to develop porous carbon materials with easy template removal and controllable pore size is urgent. This study provides an efficient strategy for the preparation of boron-doped phenolic porous carbon through in situ pyrolysis to form a template. Phenylboronic acid is used to cross-link novolac resin. The optimization of the pyrolysis conditions reveals that boron oxide (B2O3) is formed at 400 °C. The porous carbon material with a high specific surface area is obtained utilizing the hydrolysis characteristics of B2O3. After loading titanate, 5-hydroxymethylfurfural with a high yield (92%) is achieved at 20 °C in ethanol. The catalytic activity showed no significant decrease after utilization six times. The method is simple and easy to implement, providing an efficient catalyst for the conversion of biomass materials into biofuels.

Direct conversion of fructose to levulinic acid in water medium catalyzed by a reusable perfluorosulfonic acid Aquivion® resin

In this work, we reported an environmental-benign and cost-effective route for the direct conversion of fructose to levulinic acid. A commercial perfluorosulfonic acid resin in a pellet form, that is, Aquivion® P98, was shown as a water-tolerant and reusable solid acid catalyst. The influence of catalyst dosage, reaction temperature and reaction time on the dehydration of fructose was systematically investigated. It was disclosed that fructose was initially dehydrated to 5-hydroxymethylfurfural as the intermediate and it was subsequently hydrolyzed to produce levulinic acid and formic acid over the Brønsted acidic sites provided by Aquivion® P98. Under the optimum reaction conditions, 96% yield to levulinic acid at 100% conversion of fructose was obtained in water at 120 °C after 12 h. Productivity of levulinic acid reached 3.2 mol mol−1H+, an outstanding value reported in literature to date. The Aquivion® P98 catalyst can be regenerated through a simple ion-exchange method, and a stable yield of levulinic acid was maintained after six consecutive reuses. The controlled experiments proved that the acidic products, i.e., formic acid and levulinic acid, allowed working as homogeneous catalysts to accelerate the dehydration of fructose and the subsequent hydrolysis of 5-hydroxymethylfurfural.

Efficient dehydration of fructose into 5-HMF using a weakly-acidic catalyst prepared from a lignin-derived mesoporous carbon

A lignin-derived mesoporous carbon solid acid catalyst (LDMCC) was prepared using alkali lignin as a carbon source and KCl as a salt template to generate a carbon support that was carboxylated with acrylic acid. The prepared LDMCCs were characterized by various spectroscopies (FTIR, XPS, XRD, Raman), porosity determinations (BET), microscopies (SEM, TEM), thermogravimetric analysis, and acid-base titration. The LDMCC produced at the highest carbonization temperature (900 °C) possesses a rich porous structure, high specific surface area (1197.1 m2·g−1), large pore volume (0.63 cm3·g−1), and abundant –COOH groups (2.4 mmol·g−1). This weakly acidic catalyst exhibits excellent synergistic catalytic performance with DMSO in the catalytic dehydration of fructose to prepare 5-hydroxymethylfurfural (5-HMF); the yield of 5-HMF was 96.0% using dimethyl sulfoxide as the solvent, reaction conditions of 180 °C for 2.0 h, and a catalyst loading of 0.1 mg·mg−1. In addition, the prepared LDMCC exhibits excellent reusability over five cycles of use without significant loss in its catalytic activity. This study provides a novel green route for the preparation of a weakly acidic catalyst which may be useful for a variety of biomass conversion processes.

Production of crude 5-hydroxymethylfurfural from glucose by dual catalysts with functional promoters in low-boiling hybrid solvent

5-Hydroxymethylfurfural (5-HMF) is a value-added versatile platform chemical from renewable biomass resources. In addition to improving the efficiency of catalysts for glucose conversion in reaction media, the product separation and purification represent another significant barrier in large scale production of 5-HMF. In this work, 5-HMF production from carbohydrates using a combination of Lewis and Brønsted acid catalysts was investigated in a low boiling point solvent consisting of ethylene glycol dimethyl ether (GDE) and water, allowing for feasible recycling of catalysts and product separation. High yield (70%) of 5-HMF from glucose is achieved in the presence of reaction additives, isopropanol (IPA) and NaCl, that help to stabilize 5-HMF and promote fructose dehydration, respectively. The results are validated in larger scale (glucose 140 g, reaction volume 2.2 L). To recover product free of the catalysts, the low-boiling polar solvents are evaporated and the crude product containing 80% 5-HMF is recovered by dissolution in a small amount of ethyl acetate (EA) followed by evaporation of EA. This 5-HMF production system offers the advantage of high 5-HMF yield from glucose and the feasibility of product separation.

Effect of membrane purification and concentration of sucrose in sugar beet molasses for the production of 5-hydroxymethylfurfural

Production of 5-hydroxymethylfurfural from sugar beet molasses as feed-stock should in theory be a straight-forward process: first, hydrolysis of sucrose, followed by dehydration of fructose, but is in reality challenging. The enzyme-catalysed sucrose hydrolysis is inhibited by impurities and the dehydration of fructose has low conversions. In this study, pretreatment of crude molasses through purification using membrane filtration was investigated. The pretreatment process was evaluated with respect to the sucrose hydrolysis reaction rates and for the downstream 5-hydroxymethylfurfural production. Results from the ultra-/nanofiltration experiments showed good filtration fluxes (11–34 L/m2 h bar), high flux recovery after being heavily fouled (>80%) and ability to purify sucrose. The sucrose hydrolysis results showed an improved reaction rate for nanofiltered molasses (concentrate), while the ultrafiltration permeate showed no major difference from the crude molasses, indicating that the inhibitory compounds are of low molecular weight. Furthermore, the ultrafiltered molasses showed highly efficient fructose conversion (near 100%) and 5-hydroxymethylfurfural selectivity of 57% in the biphasic acid-catalysed dehydration, in contrast to only 49% fructose conversion in the crude molasses.

Facile Production of 2,5-Furandicarboxylic Acid via Oxidation of Industrially Sourced Crude 5-Hydroxymethylfurfural.

The oxidation of 5-hydroxymethylfurfural (HMF) produces value-added chemicals such as 2,5-diformylfuran (DFF) and 2,5-furandicarboxylic acid (FDCA). In this work, FDCA production was achieved by oxidation of crude HMF solution containing around 45 % HMF and unwanted byproducts such as 5,5'-[oxy-bis(methylene)]bis-2-furfural (HMF dimer) and polymers. At optimized reaction conditions similar to the Mid-Century process, homogeneous oxidation of the crude HMF (up to 20 wt% in the feed) by Co/Mn/Br catalyst in acetic acid solution produced FDCA at >95 % yield. The solid FDCA product contained <4000 ppm 5-formyl-2-furancarboxylic acid (FFCA). Such high yields were observed because the impurities in crude HMF were also converted to FDCA, as confirmed by the facile oxidation of HMF dimer to FDCA under reaction conditions. The successful demonstration of crude HMF as feed, obviating the need for HMF purification, suggests potential for cost-effectively producing FDCA in existing terephthalic plants.

Insight into the dehydration of high-concentration fructose to 5-hydroxymethylfurfural in oxygen-containing polar aprotic solvents

A high 5-HMF yield of 85.4% was achieved in polar aprotic oxygen-containing solvent with strong electrophilic maleic acid by quenching DHH.

Dehydration of fructose to 5-hydroxymethylfurfural over a mesoporous sulfonated high-crosslinked polymer in different solvents

SHCP was active and stable for dehydration of fructose to 5-HMF in DIO/H2O as H2O depressed oligomerization of 5-HMF.

Efficient Continuous Dehydration of Fructose to 5-Hydroxymethylfurfural in Ternary Solvent System

Efficient Continuous Dehydration of Fructose to 5-Hydroxymethylfurfural in Ternary Solvent System

One-Pot Production of 2,5-Furandimethanol from Fructose Co-catalyzed with Formic Acid and Heterogeneous Co Catalysts

2,5-Furandimethanol (FDM) is currently produced via a two-step process involving fructose dehydration over inorganic acids (H2SO4 and HCl) and the subsequent hydrogenation of 5-hydroxymethylfurfural (HMF) with H2. Because of the separation difficulty and unstable feature of HMF, the direct transformation of hexose to FDM is still challenging yet crucial. In this work, we first reported that formic acid served as both a renewable Bronsted acid and a hydrogen donor for one-pot dehydration–hydrogenation of fructose over a heterogeneous Co catalyst. Under optimal conditions of 170 °C for 3 h, 60.2% FDM yield was achieved with full conversion of fructose. Kinetic studies showed that the apparent activation energy (Ea) of the one-pot dehydration–hydrogenation of fructose was 80.5 kJ/mol and indicated that the rate-determining step of the whole process is fructose dehydration. The Co–NC catalyst was reusable and was also capable of gram-scale one-pot dehydration–hydrogenation of fructose.

Efficient synthesis of 2,5-furandicarboxylic acid from biomass-derived 5-hydroxymethylfurfural in 1,4-dioxane/H2O mixture

The catalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), a renewably sourced substitution for petroleum-derived terephthalic acid, at a high concentration is highly demanding but challenging. Herein, the efficient conversion of HMF (10–25 wt%) in 1,4-dioxane/H2O was achieved, and a desirable FDCA yield of 98% was obtained from HMF (10 wt%) over commercial Ru/C (2 Equiv. NaHCO3, 4 MPa O2, 3 h, and 140 ℃). In addition, a two-step cascade reaction was developed for FDCA production, in which FDCA was employed as the acid catalyst to promote the dehydration of fructose (10 wt%) to HMF, followed by oxidation in 1,4-dioxane/H2O to FDCA over Ru/C. As compared to pure water or 1,4-dioxane, the better stability of HMF in 1,4-dioxane/H2O with a weak alkaline environment and the enhancement of superoxide radicals (·O2-) in 1,4-dioxane/H2O could ensure high FDCA yield at high HMF concentration.

Sulfated zirconia catalysts supported on mesoporous Mg-SBA-15 with different morphologies for highly efficient conversion of fructose to 5-hydroxymethylfurfural

In this work, the novel acid-base bi-functional mesoporous SBA-15 catalysts with four kinds of morphologies were synthesized by Mg incorporated and sulfated zirconia (SZ) grafted. The introduction of Mg to mesoporous SBA-15 materials significantly improves the strength of the base. And the supported SZ group exhibit effective Brønsted/Lewis acid strength. The physical and chemical properties of the prepared materials were systematically analyzed by the characterization tests of SEM, TEM, XRD, N 2 adsorption-desorption of, FT-IR, TGA, XPS, NH 3 /CO 2 -TPD and in-suit PY-IR. The obtained catalysts of SZ@Mg-SBA-15 could be applied to the fructose conversion into 5-hydroxymethylfurfural (5-HMF) with the co-solvent system of iPrOH/DMSO ( v / v = 9:1). 5-HMF was achieved under the optimal reaction condition with the highest yield of 98.6%. The result shows that the reaction of fructose dehydration into 5-HMF could be caused by the combination of Brønsted acid site and basic site. This work developed reaction system could avoid the large use of environmentally dangerous solvents, and provides a new economical and feasible method for the large-scale conversion of fructose biomass. • Mesoporous SZ@Mg-SBA-15 catalysts were successfully synthesized. • The acid-base bifunctional sites showed synergistic effects in catalytic activity. • The highest 5-HMF yields of 98.6% can be obtained from fructose. • The developed iPrOH/DMSO co-solvent has a minimal environmental impact. • The prepared catalyst can be reused without significant loss of activity.

Reaction Mechanism of the Microwave-Assisted Synthesis of 5-Hydroxymethylfurfural from Sucrose in Sugar Beet Molasses

5-hydroxymethylfurfural (HMF) stands out among the chemical products derived from biomass as a building block in the chemical industry. The conventional production of HMF is usually carried out from fructose, glucose, or other monosaccharides as feedstock, but sugar beet molasses, a by-product of the sugar industry containing sucrose (45–55%), is promising. This exploratory study used three aqueous stock solutions and one biphasic system as the sources of sucrose. The dehydration of sucrose to 5-hydroxymethylfurfural was assisted by microwave heating and subcritical water conditions. The maximum yield of HMF was 27.8 mol % for the aqueous solution of synthetic sucrose at 80 min of treatment. Although HMF yield was 7.1 mol % in the aqueous sugar beet molasses solution, it increased 2-fold after clarification (15.1 mol %) and 1.6-fold in the biphasic system (11.4 mol %). These are favorable outcomes since this is an exploratory investigation. The pseudo-first-order model fitted experimental data from the conversion of the sucrose from the stock solutions, and kinetic parameters were estimated and compared. The estimated reaction rate constant showed that inversion of sucrose is faster than fructose dehydration to HMF, but the latter reaction was the rate-determining step only for the biphasic system. The maximum partition coefficient value was four between 40 min and 60 min of reaction, calculated at room temperature. These predictions help investigators to estimate conversions and selectivity when pilot plants need to be simulated.

Hafnium-tin composite oxides as effective synergistic catalysts for the conversion of glucose into 5-hydroxymethylfurfural

5-Hydroxymethylfurfural (5-HMF), an important and value-added platform chemical, has inspired increasing attention. In this study, hafnium-tin composite oxides (Sn-HfO2) were prepared by one-pot coprecipitation process and used as effective synergistic catalysts for 5-HMF synthesis from the conversion of glucose. Pyridine-FTIR results reveal that Sn-HfO2 catalysts have strong Lewis and weak Brønsted acid sites. With 0.5Sn-HfO2 as the catalyst, the highest yield of 5-HMF obtained from glucose was 75.5% with 99.5% conversion at 170 °C for 2 h in a methyl isobutyl ketone (MIBK)/water biphasic system. Furthermore, the catalytic system also possesses excellent performance in converting other carbohydrates. The catalysis mechanism for the isomerization of glucose to fructose was explored by the density functional theory (DFT) method, indicating that Lewis acidic Hf active sites and proton mediator Sn-O species synergistically catalyzed the isomerization process, effectively lowering the reaction energy barrier. The cooperative action of terminal Hf-OH and Sn-OH also facilitated the formation of 5-HMF in fructose dehydration. 0.5Sn-HfO2 could be reused for four runs without significant loss of catalytic activity. This approach provides the feasibility of composite oxides as synergistic catalysts for carbohydrate conversion to 5-HMF.

Fabrication of Brønsted acidic ionic liquids functionalized organosilica nanospheres for microwave-assisted fructose valorization

A series of Brønsted acidic ionic liquids (BAILs) functionalized hollow organosilica nanospheres ([C3/4Im][OTs/OTf]-Si(Et)Si, C3/4 = Pr/BuSO3H) were synthesized by two steps. The process involved the preparation of hollow nanosphere supports via a toluene-swollen sol-gel co-condensation of 1,2-bis(trimethoxysilyl)ethane and 3-chloropropyltriethoxysilane in the presence of F127, and followed by a successive quaternary ammonization and protonation with imidazole, 1,3-propane/1,4-butane sultone and trifluoromethane sulfonic acid/p-toluenesulfonic acid. The adjustable acid property, hollow inner diameter (5–15 nm) and shell thickness (5–9 nm) of [C3/4Im][OTs/OTf]-Si(Et)Si are achieved by introducing different organic acids and controlling toluene concentration, respectively. The [C3/4Im][OTs/OTf]-Si(Et)Si were applied in selective conversion of fructose to 5-hydroxymethylfurfural (HMF) and 5-ethoxymethylfurfural (EMF) under microwave heating. Under the optimized conditions, the [C4Im][OTs]-Si(Et)Si3.0 nanospheres with the largest inner diameter and the smallest shell thickness exhibit the highest HMF yield (79.4%, 15 min) in fructose dehydration. And the [C3Im][OTf]-Si(Et)Si0.5 nanospheres with the highest acid strength possess the highest EMF yield (70.4%, 30 min) in fructose ethanolysis. The high Brønsted acid-site density and acid strength of [C3/4Im][OTs/OTf]-Si(Et)Si catalysts accompanied by high microwave heating energy lead to excellent dehydration/ethanolysis activity. The product selectivity strongly depended on the BAILs structures and morphological characteristics of the catalyst. More importantly, the [C3/4Im][OTs/OTf]-Si(Et)Si can be reused three times without changes in leaching of BAILs, due to strong covalent bond between BAILs and silicon/carbon framework. This work will provide a simple strategy of chemically bonded BAILs on suitable supports as efficient solid acids, and an approach of combining morphology-controlled solid acids with microwave-heating for catalytic conversion of biomass/derivatives to fuels and value-added chemicals.

Selective synthesis of 5-hydroxymethylfurfural over natural rubber–derived carbon/silica nanocomposites with acid–base bifunctionality

5-Hydroxymethylfurfural (HMF) is an important platform molecule, derived from biomass-based carbohydrates, for the production of renewable fuel additives, liquid hydrocarbon fuels, biopolymers, and specialty chemicals. In this study, a mesoporous carbon/silica (MCS) nanocomposite, as catalyst support, was prepared using a nanocomposite of natural rubber (NR) and hexagonal mesoporous silica (HMS) as a precursor. To obtain a series of acidic, basic, and bifunctional acid-base catalysts, the MCS surface was modified using post-synthesis methods in which the carbon moieties were decorated with sulfonic acid groups, whereas the silica matrix surface was grafted with 3-aminopropyl groups. The resulting materials exhibited high surface area, large pore volume, and contain some oxygen-containing functional groups. Their acid-base properties were tunable by varying the content of sulfonic acid and aminopropyl groups. The HMF was synthesized by catalytic conversion of fructose and glucose in a biphasic medium. Fructose dehydration catalyzed by sulfonated MCS catalyst (MCS-SO3H) at 150 °C for 2 h yields 56% HMF at 81% conversion. For the glucose system, the Brønsted basic sites facilitated the glucose–fructose isomerization, however, it promoted the formation of undesired humins. The acid/base ratio of bifunctional MCS catalysts (MCS-SO3H-NH2) contributes to the HMF yield and selectivity. The HMF yield of 39.4% was obtained over the MCS-SO3H-NH2 catalyst with an acid/base ratio of 0.10 at 190 °C for 1 h. In both systems, the formation of levulinic acid, a byproduct of HMF hydrolysis, was suppressed due to the hydrophobicity of the MCS catalyst. These developed catalysts are promising for the synthesis of HMF from glucose, at high substrate concentration than those reported in the literature.

Cooperative Brønsted-Lewis acid sites created by phosphotungstic acid encapsulated metal–organic frameworks for selective glucose conversion to 5-hydroxymethylfurfural

Production of 5-hydroxymethylfurfural (HMF) from biomass-derived glucose has great potential for synthesis of renewable fuels and chemicals. Selective glucose conversion to 5-hydroxymethylfurfural requires a balance between Lewis and Brønsted acids for the cascade of glucose isomerization followed by fructose dehydration. A dual Brønsted-Lewis acid, phosphotungstic acid encapsulated MIL-101(Al)–NH2 metal–organic frameworks (MOFs) was developed to catalyze the glucose dehydration reaction. The encapsulated catalysts had a high HMF selectivity of 58% at 44% glucose conversion at 120 °C in [C4C1im]Cl. Phosphotungstic acid was uniformly dispersed in the MOF pores, which provided both Brønsted and Lewis acid sites for this cascade reaction. The Brønsted acidic phosphotungstic acid-encapsulated MOF catalyst was stable and recyclable at least four times. These findings explain the effect of phosphotungstic acid location for maximizing the HMF selectivity and suggest a new approach for the design of bifunctional solid acid catalysts for selective HMF production from glucose. Moreover, the tunability of the acid properties of the encapsulated MOF catalysts provides opportunities for other biomass transformations.

Sustainable HMF synthesis from waste cooked rice water using fly-ash based Al2SiO5 supported nano-photocatalyst under halogen-ultrasound synergistic-energy: LCA and DFT based simulation

Innovative Fe3+/Fe2+/Al2SiO5/Ti4+ nano-photocatalyst (FA_NPC*) was successfully prepared employing fly ash (FA)-based unique nano-Al2SiO5 and nano-Fe3+/Fe2+ in an innovative assimilated energy-system comprising tungsten-halogen radiation and ultrasound (THUS). The energy-efficient THUS activated optimal FA_NPC* (FA_NPC*°) possessed favourably higher specific surface area (142.11 m2/g), finer nanoparticles (47.50 nm) and lower band gap energy (2.78 eV) compared (89.72 m2/g, 62.43 nm, 2.97 eV respectively) to its conventionally prepared analog (FA_NPCCO). The FA_NPC*° rendered a significantly higher HMF yield (38.37 mol%) from a kitchen waste viz., cooked rice water (CRW) under THUS at 70 °C in only 60 min compared to 21.67 mol% HMF yield provided by FA_NPCCO. The DFT based study revealed that the CRW conversion process to HMF occurred through water adsorption on FA_NPC* surface for H3O+ formation, followed by H3O+ induced CRW hydrolysis, subsequent glucose isomerization on -Ti active sites and finally fructose dehydration by H3O+. The LCA of the overall process confirmed that the FA_NPC*° catalysed CRW conversion process could appreciably alleviate harmful environmental parameters, viz. global warming, fossil depletion, human toxicity and metal depletion by 7.65%, 4.15%, 8.56% and 13.57% respectively in comparison with FA_NPCCO. Thus, the THUS stimulated system could favourably demonstrate the efficient and eco-friendly utilisations of two abundant waste resources, viz. fly ash and cooked rice water for a sustainable production of HMF.