Alcoholysis Of Furfuryl Alcohol Research Articles

A novel sulfonated solid acid catalyst for efficient conversion of furfuryl alcohol to n-butyl levulinate fuel bioadditive

Furfuryl alcohol (FOL), as a cheap green biomass derivative, has high potential application value in the production of various biomass chemicals. In this work, a sulfonic acid functional porous organic polymer-coated carbon nanotubes catalyst (CNTs@PDVTA-SO3H) was successfully prepared. The structure of as-prepared catalysts was confirmed by TG/DTG, Raman spectra, TEM, FT-IR, N2 adsorption-desorption, and XPS measurements. The catalytic properties of CNTs@PDVTA-SO3H were evaluated for the synthesis of n-butyl levulinate (BL) via the alcoholysis of FOL. It was found that the 99.1 % yield of BL was achieved under optimal conditions. The apparent activation energy of FOL to 2-bufurdoxy methyl-furan (BMF) and BMF to BL was 58.08 kJ/mol and 35.38 kJ/mol, respectively. This work provides a new avenue for the preparation of alkyl levulinates using FOL as raw material.

High-yield synthesis of alkyl levulinate from furfuryl alcohol and its upgrading to 2-methyl-1,3-dioxolane over AgPW

In order to relieve greenhouse effect, it is highly urgent to convert carbon-neutral biomass to value-added chemicals and liquid fuels by designing new process. 96.5% yield of biofuel alkyl levulinate was achieved in the alcoholysis of furfuryl alcohol with ethanol over highly active Ag+ exchanged H3PW12O40 (AgPW) catalyst at low temperature. In situ XRD, 31P MAS NMR, XPS and NH3-TPD results confirm that AgPW contains large amounts of strong acid sites and stable Keggin structure, resulting in the excellent performance. Subsequently, new process was developed to synthesize biofuel 2-methyl-1,3-dioxolanes (MDL) with ∼70% yields via a tandem furfuryl alcohol alcoholysis and acetalization reaction over AgPW. Additionally, MDL can be availably obtained from furfural, xylose and hemicellulose by an integrated multi-step process.

Immobilization of HPW on UiO-66-NH2 MOF as efficient catalyst for synthesis of furfuryl ether and alkyl levulinate as biofuel

Phosphotungustic Acid (HPW) is an inorganic super acid, that is highly soluble in polar solvents limiting its applicability as acid catalysis. To overcome these limitations immobilization of HPW was carried out at room temperature by protonation of -NH2 group of UiO-66-NH2 MOF to UiO-66-NH2HPW. ATR-FTIR spectroscopy and XPS results confirmed the protonation and chemical interaction between HPW and UiO-66-NH2. STEM-EDS mapping showed homogeneous distribution of HPW on UiO-66-NH2. BET and NH3-TPD confirmed the reduction in specific surface area, total pore volume, and increase in total acidity for UiO-66-NH2HPW. Further, powder XRD, SEM, and HR-TEM prevailed that there is no change in phase and morphology after post-synthetic modification of UiO-66-NH2. The prepared catalyst is found to be effective for etherification and alcoholysis of furfuryl alcohol (FALc) to Furfuryl ether (FE) and Alkyl levulinate (AL). UiO-66-NH2HPW has shown 97 mol% FALc conversions in ethanolic media and 31 mol% Ethyl furfuryl ether (EFE) yield and 29 mol% Ethyl levulinate (EL) yield. UiO-66-NH2HPW is also found to be efficient for the multistep conversion of Furfural (FFR) to FALc, FE, and AL.

Titania Nanotubes-Bonded Sulfamic Acid as an Efficient Heterogeneous Catalyst for the Synthesis of n-Butyl Levulinate.

The titania nanotubes-bonded sulfamic acid (TNTs-NHSO3H) catalyst was designed and successfully fabricated by the post-synthesis modification method. The as-prepared catalyst was characterized by a variety of characterization techniques, including Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and thermogravimetry-differential thermal gravimetry (TG-DTG). The crystal structure of the TNTs still maintained during the modification process. Although the BET surface area was decreased, the amount of Brønsted acid sites can be efficiently fabricated on the TNTs. The catalytic activity of TNTs-NHSO3H was examined for the synthesis of n-butyl levulinate (BL) from levulinic acid (LA) and furfuryl alcohol (FA). A relatively high selectivity (99.6%) at 99.3% LA conversion was achieved for esterification of levulinic acid owing to the strong Brønsted acidity sites. And also, the TNTs-NHSO3H catalyst exhibited a higher reactivity for alcoholysis of FA and the yield of BL reached 90.4% with 100% FA conversion was obtained under the mild conditions.

Conversion of furfuryl alcohol to ethyl levulinate in the presence of mesoporous aluminosilicate catalyst

Abstract The one-pot acid-catalyzed the conversion of furfuryl alcohol (FA) to ethyl levulinate (EL) was investigated in the presence of mesoporous aluminosilicate (TUD-1) with a high surface area (up to 579 m2 g−1) and well-interconnected mesospheres synthesized via a solvothermal process and characterized using scanning electron microscope, transmission electron microscope, X-ray diffraction, 27Al-NMR, and N2 sorption isotherm. The resulting solid acid catalyst was tested for the alcoholysis of FA with ethanol, affording 87.8% EL yield under the optimal reaction conditions of 120°C and 4 h. Moreover, the catalyst showed a good reusability with less loss of activity after a simple solvent washing and calcination procedure.

Alkyl Levulinates from Furfuryl Alcohol Using CT151 Purolite as Heterogenous Catalyst: Optimization, Purification, and Recycling

Commercially available Purolite CT151 demonstrated to be an efficient acid catalyst for the synthesis of alkyl levulinates via alcoholysis of furfuryl alcohol (FA) at mild temperatures (80–120 °C) and short reaction time (5 h). Reaction conditions were first optimized for the synthesis of ethyl levulinate and then tested for the preparation of methyl-, propyl-, isopropyl-, butyl, sec-butyl- and allyl levulinate. Preliminary scale-up tests were carried out for most of the alkyl levulinates (starting from 5.0 g of FA) and the resulting products were isolated as pure by distillation in good yields (up to 63%). Furthermore, recycling experiments, conducted for the preparation of ethyl levulinate, showed that both the Purolite CT151 and the exceeding ethanol can be recovered and reused for four consecutive runs without any noticeable loss in the catalyst activity.

Selective conversion of biomass-derived furfuryl alcohol into n-butyl levulinate over sulfonic acid functionalized TiO2 nanotubes

Sulfonic acid functionalized titanate nanotubes were prepared by the sulphonation reaction of hydrothermally synthesized TiO2 nanotubes (TNTs) using chlorosulfonic acid as the sulfating agent. The as-prepared catalysts were characterized by fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD) analysis, thermogravimetry-differential thermal gravimetry (TG-DTG) and X-ray photoelectron spectroscopy (XPS) techniques. The characterization results revealed that the catalysts retained the tubular structure of the TNTs and possessed a large number of active sulfonic acid sites. The catalytic performance of the catalysts for the synthesis of n-butyl levulinate was investigated via the alcoholysis of biomass-derived furfuryl alcohol under atmospheric pressure. The effects of the reaction factors such as the catalyst dosage, reaction time, and temperature on the alcoholysis of the furfuryl alcohol were systematically studied. Under mild conditions, about 79.9% yield of n-butyl levulinate was achieved. In addition, the catalysts showed a stable catalytic performance after four consecutive cycles. Furthermore, no leaching of the active species was observed during the hot filtration testing, which can be attributed to the covalently linked –SO3H groups on the TNTs surface. In addition, the opened tubular nanostructure of the catalyst and the introduced strong Brønsted acid sites exhibited synergistic effects, which facilitated the selective conversion of the furfuryl alcohol to butyl levulinate.

Waste paper-derived magnetic carbon composite: A novel eco-friendly solid acid for the synthesis of n-butyl levulinate from furfuryl alcohol

Waste paper, a promising renewable source of cellulose, was successfully prepared into a magnetic carbonaceous solid acid (SMWP) via a facile and integrated impregnation-pyrolysis–sulfonation process. The resultant catalyst was confirmed to possess a porous structure with a high surface area, various oxygen-containing functional groups and contain Fe3O4 components. The SMWP catalyst also exhibited a high catalytic activity in the alcoholysis of furfuryl alcohol with n-butanol, up to 90.6% yield of n-butyl levulinate and 100% conversion of furfuryl alcohol was achieved by optimizing the reaction conditions. In comparison with other solid acids such as HZSM-5 zeolite and Nafion-212 resin, the better performance of SMWP could be explained by its strong acidity and good affinity to furfuryl alcohol, which results from the synergistic effect of SO3H, COOH and phenolic OH groups on the carbon surface. Moreover, the catalyst could be easily recycled with an external magnet and reused 7 times without a distinct loss of activity. The findings in this work provided an environmentally friendly manner for waste paper utilization and fuel additive production.

Catalytic conversion of furfuryl alcohol to n-hexyl levulinate using modified dendritic fibrous nanosilica

Dendritic fibrous nanosilica (DFNS) was used as an efficient support to prepare a series of Al/DFNS/Pr-SO3H catalysts with different Si/Al molar ratios. The textural properties, morphology, structural feathers, acidity, and heterogeneous nature of the catalysts were characterized. The Al/DFNS/Pr-SO3H catalysts were utilized in the synthesis of n-hexyl levulinate (nHL) from alcoholysis of furfuryl alcohol with n-hexanol. Among these catalysts, 40Al/DFNS/Pr-SO3H, a Lewis and Bronsted bi-functional solid acid catalyst, showed the highest catalytic performance and the reaction conditions were optimized in the presence of this catalyst. Under optimum reaction conditions, n-hexyl levulinate yield and furfuryl alcohol conversion were 93.5% and 99.9%, respectively. Also, reusability experiments affirmed that 40Al/DFNS/Pr-SO3H catalyst can be recycled and reused for four times with an insignificant decrease in yield of product.

Continuous Synthesis of Fuel Additives Alkyl Levulinates via Alcoholysis of Furfuryl Alcohol over Silica Supported Metal Oxides

Aiming at synthesizing alkyl levulinates via alcoholysis of furfuryl alcohol in continuous mode for the first time an attempt is made using cheapest and eco-friendly solid acid catalysts. Different silica supported solid acid catalysts containing the oxides of aluminium, tungsten, zirconium and titanium have been prepared. The nature, number and strength of surface acidic sites were evaluated by DRIFT spectroscopy with pyridine adsorption and NH3-TPD and also structural and textural features of the catalysts have been investigated by XRD and BET surface area techniques. Al2O3/SiO2 catalyst exhibited better activity with 100% conversion of furfuryl alcohol and 92.8% selectivity of methyl levulinate, which may be due to more number of surface acidic sites with large number of weak Lewis acidic sites. The catalytic activity of these solid acid catalysts is as follows: Al2O3/SiO2 > ZrO2/SiO2 > WO3/SiO2 > TiO2/SiO2. This is well correlated with the number of surface acidic sites. The stable catalytic activity during the 10 h time-on-stream study confirmed the sturdiness of Al2O3/SiO2 catalyst and also it is active for the selective formation of ethyl, n-propyl, n-butyl levulinates.

Alcoholysis of Furfuryl Alcohol into n-Butyl Levulinate Over SBA-16 Supported Heteropoly Acid Catalyst

In this work, n-butyl levulinate a potential renewable chemical in the energy sector and in the field of fine chemical synthesis has been synthesized via alcoholysis of furfuryl alcohol in batch process at atmospheric pressure over SBA-16 supported tungstophosphoric acid (TPA) catalyst. In order to characterize and correlate the catalytic activity, the wet impregnated TPA/SBA-16 catalysts were subjected to the physico chemical characterization techniques such as X-ray diffraction, N2-physisorption, SEM, TEM, FT-IR, NH3-TPD and pyridine adsorbed FT-IR analysis. The retention of 3D mesoporous structure and TPA structure even after impregnation was confirmed by XRD and N2-physisorption. The impregnation of TPA over SBA-16 creates the more number of available active acidic sites for the reactants. 25 wt% TPA/SBA-16 offers 97% selectivity to n-butyl levulinate with complete conversion of furfuryl alcohol in 3 h. Various reaction parameters were optimized to achieve the best catalytic activity. These results imply that the conversion of furfuryl alcohol to n-butyl levulinate go on with the formation of the intermediate 2-butoxymethylfuran. The recyclability of the catalyst and characterization of the spent catalyst was also studied. SBA-16 supported TPA catalyst is effective in the conversion of furfuryl alcohol to n-butyl levulinate at atmospheric pressure.

One pot selective transformation of biomass derived chemicals towards alkyl levulinates over titanium exchanged heteropoly tungstate catalysts

Alkyl levulinates were produced from biomass derived carbohydrates (glucose, fructose) and platform chemicals (5-hydroxy methyl furfural, furfuryl alcohol and levulinic acid) under feasible reaction condition using titanium modified heteropoly tungstate catalysts. Titanium exchanged heteropoly tungstophosphoric acid (TPA) with variation in titanium content were prepared and various spectroscopic methods were used to characterize these catalysts. The exchange of Ti in TPA essentially created new Lewis acidic sites. The existence of both Lewis and Bronsted acid sites of titanium containing TPA Keggin were directing the selective synthesis of alkyl levulinates from different starting materials. The partially exchanged Ti0.75TPA catalyst yielded about 92–98% of alkyl levulinates from 5-hydroxy methylfurfural, furfuryl alcohol and levulinic acid, whereas 63 and 21% yield was achieved by the alcoholysis of fructose and glucose respectively. Different types of alkyl levulinates were also synthesized from alcoholysis of furfuryl alcohol. The reaction conditions were optimized to achieve maximum yield of alkyl levulinates. The catalyst was easily separated and reused without any loss in activity.

Selective conversion of furfuryl alcohol into butyl levulinate over zinc exchanged heteropoly tungstate supported on niobia catalysts

Selective synthesis of butyl levulinate by alcoholysis of furfuryl alcohol with n-butanol was achieved over of zinc exchanged tungstophosphoric acid supported on niobia catalysts. These catalysts were prepared and characterized by powder X-ray diffraction, FT-Infra red spectroscopy, pyridine adsorbed-FT-IR, temperature programmed desorption of ammonia, Laser Raman spectroscopy. The characterization results confirmed that the primary structure of Keggin ion of tungstophosphoric acid remained intact after exchange of its protons with zinc and subsequent dispersion on niobia. The exchange of Zn ions with the protons of heteropoly tungstate resulted in the creation of Lewis acidic sites. The catalysts were active for the synthesis of butyl levulinates under mild conditions within short reaction time. The activity of the catalysts related to the acidity of the catalysts which was dependent on the amount of Zn exchanged to the heteropoly tungstate on niobia. Reaction conditions were optimized and about 94% yield of n-butyl levulinate was achieved. The catalysts are reusable without any appreciable loss in activity.

Efficient synthesis of butyl levulinate from furfuryl alcohol over ordered mesoporous Ti-KIT-6 catalysts for green chemistry applications

Here we describe the synthesis of butyl levulinate by alcoholysis of furfuryl alcohol with n-butanol over a series of titanium incorporated mesoporous KIT-6 molecular sieve catalysts prepared by a simple sol–gel treatment.

Microwave-assisted alcoholysis of furfural alcohol into alkyl levulinates catalyzed by metal salts

The alcoholysis of furfuryl alcohol with different alcohols was carried out by using metal salt catalysts under microwave conditions, achieving high alkyl levulinates’ yields in a short reaction time.

Integrated Catalytic Process to Directly Convert Furfural to Levulinate Ester with High Selectivity

Levulinic acid is an important platform molecule from biomass-based renewable resources. A sustainable manufacturing process for this chemical and its derivatives is the enabling factor to harness the renewable resource. An integrated catalytic process to directly convert furfural to levulinate ester was developed based on a bifunctional catalyst of Pt nanoparticles supported on a ZrNb binary phosphate solid acid. The hydrogenation of furfural and the following alcoholysis of furfuryl alcohol were performed over this catalyst in a one-pot conversion model. Mesoporous ZrNb binary phosphate was synthesized by a sol-gel method and had a high surface area of 170.1 m(2) g(-1) and a large average pore size of around 8.0 nm. Pt nanoparticles remained in a monodisperse state on the support, and the reaction over Pt/ZrNbPO4 (Pt loading: 2.0 wt%; Zr/Nb, 1:1) gave a very high selectivity to levulinate derivatives (91% in total). The sustainability of this conversion was greatly improved by the process intensification based on the new catalyst, mild reaction conditions, cost abatement in separation and purification, and utilization of green reagents and solvents.