- Highly Efficient Conversion of Renewable Levulinic Acid to?n-Butyl Levulinate Catalyzed by Sulfonated Magnetic Titanium Dioxide Nanotubes
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Abstract: A new solid acid catalyst Fe3O4@TNTs-SO3H was successfully prepared, characterized, and applied for efficient conversion of renewable levulinic acid to n-butyl levulinate, serving as a promising liquid fuel additive. This catalyst was demonstrated to show high catalytic activity and afford n-butyl levulinate with a yield of 94.6% under optimum conditions. Graphic Abstract: [Figure not available: see fulltext.]
- Mao, Fei-Feng,Zhao, Wenguang,Tao, Duan-Jian,Liu, Xianxiang
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- Esterification of levulinic acid to n-butyl levulinate over various acidic zeolites
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Levulinic acid (LA) has been recognized as a versatile building block for the synthesis of various organic chemicals as it contains ketone and carboxylic functional groups. Levulinate esters are important chemical feedstocks having potential applications either in flavouring and fragrance industries or biodiesel as blending component. The present work focuses on the synthesis of n-butyl levulinate by esterification of LA with n-butanol using various small and large pore zeolites. The preferential order to yield n-butyl levulinate was found to be: H-BEA > H-Y > H-ZSM-5 > H-MOR. Further, a study for optimizing the reaction conditions such as acid to n-butanol molar ratio, reaction time and catalyst concentration has been described. Under optimized reaction conditions, zeolite H-BEA has been found as most efficient catalyst with 82.2 % LA conversion and 100 % selectivity of n-butyl levulinate. Graphical Abstract: [Figure not available: see fulltext.] Scheme: Zeolite catalyzed esterification of levulinic acid
- Maheria, Kalpana C.,Kozinski, Janusz,Dalai, Ajay
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- Highly efficient metal salt catalyst for the esterification of biomass derived levulinic acid under microwave irradiation
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The esterification of levulinic acid (LA) to alkyl levulinates has been investigated in the presence of various metal salt catalysts under microwave irradiation. The reaction obtained 99.4% yield of methyl levulinate (ML) in the presence of Al2(SO4)3 catalyst in methanol solution under microwave conditions. The optimized reaction conditions were 110 °C and 10 minutes with a 20 mol% catalyst loading. Alcohols with longer carbon chains showed lower reactivities in the microwave electromagnetic field due to their poorer abilities to absorb and transmit microwave energy. Moreover, microwave irradiation provided a significantly higher reaction rate compared to conventional oil bath heating. LA aqueous solution was also converted to ML with high yields. The Al2(SO4)3 catalyst was successfully applied to the esterification of other biomass derived organic acids to their corresponding esters in high yields. Finally, the catalyst was recycled 5 times without much decrease in activity.
- Huang, Yao-Bing,Yang, Tao,Cai, Bo,Chang, Xin,Pan, Hui
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- Carbon nanotube/PTFE as a hybrid platform for lipase B fromCandida antarcticain transformation of α-angelica lactone into alkyl levulinates
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In this work an enzymatic method for the synthesis of alkyl levulinates from α-angelica lactone has been reported for the first time. Lipase B fromCandida antarcticawas immobilizedviainterfacial activation on the surface of a hybrid support, consisting of commercially available multi-walled carbon nanotubes (MWCNTs) and polytetrafluoroethylene (PTFE). Among the biocatalysts with various contents of PTFE in the support, the CALB/MWCNT-PTFE (0.10 wt%) biocatalyst with 22.5 wt% CALB loading was determined as the most active one in the model synthesis of then-butyl levulinate in toluene.n-Butyl levulinate was obtained quantitively after 120 min of the reaction under the selected reaction conditions (2-fold molar excess ofn-butanol, 0.150 g of biocatalyst per 1 mmol of α-angelica lactone, 20 °C). The yield ofn-butyl levulinate was found to be higher than that in the presence of accurate amounts of sulfuric acid or Novozyme-435. Additionally, the unique stability of the developed biocatalyst was demonstrated over 6 reaction cycles at 20 °C. The biocatalyst remained stable over 3 reaction cycles at 60 °C as well. The essence of the proposed approach lies in the possibility to overcome the equilibrium limitations occurring in the conventional Fisher esterification. The activity of the elaborated hybrid biocatalyst in the reactions non-specific for lipases is a clear proof of the versatility of the novel system.
- Boncel, Slawomir,Chrobok, Anna,Jurczyk, Sebastian,Kolanowska, Anna,Latos, Piotr,Szelwicka, Anna
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- Direct conversion of furfuryl alcohol to butyl levulinate using tin exchanged tungstophosphoric acid catalysts
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To decrease the dependence on crude oil, biomass derived liquid transportation fuels are highly desirable. Butyl levulinate is a potential cellulose-derived biofuel additive with properties similar to diesel and low water solubility. Herein we report a direct one-pot production of levulinic acid ester, butyl levulinate, from furfuryl alcohol by alcoholysis using n-butanol. The partial tin exchanged tungstophosphoric acid (TPA) supported on montmorillonite K-10 catalysts showed facile alcoholysis of furfuryl alcohol to levulinate ester under mild temperature conditions. Partially exchanging the H+ ion of TPA with Sn (x = 1) resulted in enhanced acidity of the catalyst and showed an increase in the catalytic activity as compared to TPA/K-10 catalyst. A series of tin exchanged tungstophosphoric acid (20 % w/w) supported on montmorillonite K-10 clay (Snx-TPA/K-10, where x = 0.5–1.5) were synthesized and thoroughly characterized by using XRD, FT-IR, UV-VIS, titration and SEM techniques. Among various catalysts, Sn1-TPA/K-10 was found to be the most active catalyst for butyl levulinate synthesis. Two different clay supports and varying tin loadings were used to study the effects on surface acidity as well as catalytic activity in butyl levulinate synthesis. Effects of different reaction parameters were studied and optimized to get high yields of butyl levulinate. Under mild reaction conditions at 110 °C, complete conversion of furfuryl alcohol with 98 % selectivity to butyl levulinate was achieved. The prepared catalyst could be recycled at least five times without significant loss of activity. The overall process is green and clean.
- Dicks, Jennifer Sarah,Keogh, John,Manyar, Haresh G.,Ranade, Vivek V.,Tiwari, Manishkumar S.
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- Solvent-free transesterification of methyl levulinate and esterification of levulinic acid catalyzed by a homogeneous iron(III) dimer complex
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Levulinic acid esters MeC(O)CH2CH2CO2R (LAE) are emerging bio-based chemicals used as solvents, additives and plasticizers. In this work a variety of levulinates (R= n-butyl, n-hexyl, n-octyl, 2-ethylhexyl, geranyl, 2-ethoxyethyl, benzyl, 2-octyl, cyclohexyl, menthyl) is obtained from the solvent-free transesterification of methyl levulinate (ML) and esterification of levulinic acid (LA), catalyzed by a dimeric complex of iron(III). The results are competitive with the few related reports of literature mainly based on heterogeneous catalysis. This first systematic study based on a homogeneous catalytic system therefore represents a significant extension within the field of biomass valorization.
- Melchiorre, Massimo,Amendola, Raffaele,Benessere, Vincenzo,Cucciolito, Maria E.,Ruffo, Francesco,Esposito, Roberto
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- Production of n-butyl levulinate over modified KIT-6 catalysts: comparison of the activity of KIT-SO3H and Al-KIT-6 catalysts
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The catalytic activity of propylsulfonic acid-functionalized mesoporous silica (KIT-SO3H) was compared to the performance of alumina-incorporated KIT-6 (Al-KIT-6) in the esterification reaction of the biomass-derived levulinic acid with n-butanol. The catalysts were prepared by functionalization of the silica support with propylsulfonic acid (Pr-SO3H) by post-synthesis grafting using 3-mercaptopropyltrimethoxysilane as a propyl-thiol precursor followed by oxidation. In addition, Al-KIT-6 was synthesized according to in situ synthesis. Catalysts were characterized using various techniques such as XRD, nitrogen adsorption/desorption, SEM, TGA, ICP-OES, FT-IR and elemental analysis. It is evident that increases in catalyst loading, butyl alcohol-to-levulinic acid ratio and reaction temperature significantly enhance the butyl levulinate yield. The reusability and stability of catalysts were evaluated, and it was found that while esterification reaction by KIT-SO3H compound catalyzed under milder conditions, the stability of Al-KIT-6 catalyst was better.
- Najafi Chermahini, Alireza,Assar, Matin
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- Continuous Synthesis of Fuel Additives Alkyl Levulinates via Alcoholysis of Furfuryl Alcohol over Silica Supported Metal Oxides
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Abstract: 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.
- Chada, Raji Reddy,Koppadi, Kumara Swamy,Enumula, Siva Sankar,Kondeboina, Murali,Kamaraju, Seetha Rama Rao,Burri, David Raju
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- Zirconium Exchanged Phosphotungstic Acid Catalysts for Esterification of Levulinic Acid to Ethyl Levulinate
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Abstract: Zirconium exchanged phosphotungstic acid catalysts were prepared and studied for esterification of levulinic acid with ethanol. The catalysts were characterized by powder XRD, BET surface area, Raman spectroscopy, FT-infrared spectroscopy, Temperature programmed desorption of NH3 and Pyridine adsorbed FT-IR analysis. The presence of Zr resulted in the generation of strong Lewis acidic sites. Among all the catalysts the catalyst with partially exchanged Zr (Zr0.75TPA) showed higher activity due to the present of stronger Br?nsted and Lewis acidic sites. The Zr0.75TPA catalyst exhibits amazing reusability with constant activity. Graphic Abstract: Zr exchanged TPA is active in the esterification of levulinic acid into ethyl levulinate.[Figure not available: see fulltext.].
- Pasha, Nayeem,Lingaiah,Shiva, Raj
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- Catalytic upgrading of α-angelica lactone to levulinic acid esters under mild conditions over heterogeneous catalysts
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Butyl levulinate was prepared starting from α-angelica lactone and butanol over Amberlyst 36. Different reaction conditions were optimized, which resulted in full conversion and 94% selectivity toward the ester at 75°C. A reaction network analysis reveals pseudo-butyl levulinate and levulinic acid as intermediates in the preparation of butyl levulinate. The mild protocol was successfully applied for different alcohols and compared with the esterification of levulinic acid. Overall, this study identifies α-angelica lactone as a better candidate than levulinic acid for the heterogeneously catalysed preparation of levulinic acid esters. A catalyst screening shows that also zeolites and zirconia-based catalysts are able to catalyse the reaction. However, the transformation of the intermediate pseudo-butyl levulinate into butyl levulinate requires acid sites of sufficient strength to proceed.
- Al-Shaal, Mohammad G.,Ciptonugroho, Wirawan,Holzh?user, Fabian J.,Mensah, Joel B.,Hausoul, Peter J. C.,Palkovits, Regina
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- Titanate nanotubes-bonded organosulfonic acid as solid acid catalyst for synthesis of butyl levulinate
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In this study, titanate nanotubes-bonded organosulfonic acid (TNTs-SO3H) was prepared and employed as an efficient heterogeneous catalyst for esterification of levulinic acid with n-butanol. Two reaction products pseudo n-butyl levulinate (pseudo-BL) and n-butyl levulinate (BL) were detected by GC-MS. The catalyst showed 86.8% conversion of levulinic acid with 99.7% selectivity towards n-butyl levulinate. TNTs-SO3H exhibited strong acidic sites and high stability even after seven cycles of usage and would be well expected to be a potential candidate for alkyl levulinate production.
- Zhou, Shuolin,Jiang, Dabo,Liu, Xianxiang,Chen, Yiping,Yin, Dulin
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- Hydrothermal carbon enriched with sulfonic and carboxyl groups as an efficient solid acid catalyst for butanolysis of furfuryl alcohol
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Carbonaceous material (GC-PTSA-AC) functionalized with both high density of SO3H and COOH groups was prepared by one-step hydrothermal carbonization of glucose with p-toluenesulfonic acid and acrylic acid. This novel carbon could be used directly for the alcoholysis of furfuryl alcohol and n-butanol without any post-modification, and it was found to be more efficient than the monofunctional hydrothermal carbon only decorated with SO3H or COOH groups. The reason was attributed to the larger amount of COOH groups on GC-PTSA-AC, cooperating with the SO3H active sites to facilitate the butanolysis reaction.
- Yang, Jinfan,Zhang, Hongyu,Ao, Zhifeng,Zhang, Sufeng
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- Synthesis of Butyl Levulinate Based on Α-Angelica Lactone in the Presence of Easily Separable Heteropoly Acid Catalysts
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A series of choline (Ch)-exchanged heteropoly acids (HOCH2CH2N(CH3)3)xH(6?x)P2W18O62 [abbreviated as ChxH(6?x)P2W18O62, x=1–6] was synthesized and used as catalysts for the reaction of α-angelica lactone (alpha-AL) with n-butanol to form butyl levulinate (BL). The solubility of ChxH(6?x)P2W18O62 in the reaction mixture was temperature dependent: The catalysts were soluble under the reaction conditions and precipitated upon cooling of the reaction mixture. This facilitated recovery of the catalysts from the liquid phase. Importantly, an increase of the Ch content caused a decrease of the catalyst solubility. Catalytic activity of ChxH(6?x)P2W18O62 for the reaction with n-butanol appeared to be in good agreement with the concentration of Br?nsted-acidic sites. The results suggest that the reaction proceeded through formation of pseudo-butyl levulinate as intermediate. Ch2H4P2W18O62 exhibited the best balance between catalytic activity and temperature-dependent solubility. The yield of BL reached 79.4 % at full conversion of alpha-AL at a moderate temperature of 75 °C in an open system. ChxH(6?x)P2W18O62 could be successfully reused five times without significant loss of activity.
- Yi, Xiaohu,Al-Shaal, Mohammad G.,Ciptonugroho, Wirawan,Delidovich, Irina,Wang, Xiaohong,Palkovits, Regina
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- Recognizing soft templates as stimulators in multivariate modulation of tin phosphate and its application in catalysis for alkyl levulinate synthesis
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Catalyst synthesis is an art where an inefficient material can be remarkably converted into a highly active and selective catalyst by adopting a suitable synthetic strategy to tune its properties during synthesis. The underlying principle of the strategy presented here is the integration of tailoring the structural and chemical behavior of tin phosphates with tuned catalytic active centers directed by employing different structure directing agents (SDAs) and the attempt to understand this in detail. It is demonstrated how soft templates can be effectively used for their so far unknown utilization of tuning the active sites in phosphate containing catalysts. We found that, by using an appropriate synthesis strategy, it is possible to tune and control explicitly both the catalyst morphology and the nature of active sites at the same time. The 31P MAS NMR study revealed that employing SDAs in the synthesis strongly influenced the nature and amount of phosphate species in addition to porosity. The resultant different nanostructured SnPO catalysts were investigated for one-pot synthesis of alkyl levulinates via alcoholysis of furfuryl alcohol. Among the catalysts, SnPO-P123 exhibited greater butyl levulinate yield via alcoholysis of furfuryl alcohol with n-butanol and the study was extended to synthesize different alkyl levulinates. Importantly, the active sites in the SnPO-P123 catalyst responsible for the reaction were elucidated by a study using 2,6-lutidine as a basic probe molecule. This study therefore provides an avenue for rational design and construction of highly efficient and robust nanostructured SnPO catalysts to produce alkyl levulinates selectively. This journal is
- Manjunathan, Pandian,Shanbhag, Dhanush Y.,Vinu, Ajayan,Shanbhag, Ganapati V.
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- Efficient conversion of levulinic acid or furfuryl alcohol into alkyl levulinates catalyzed by heteropoly acid and ZrO2 bifunctionalized organosilica nanotubes
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A series of heteropoly acid and ZrO2 bifunctionalized organosilica nanotubes (PW12/ZrO2-Si(Et)Si-NTs) were fabricated via a P123 single-micelle-templated sol-gel co-condensation route and carefully adjusted Si-to-Zr molar ratio and acidity in the initial gel mixture. The morphological characteristics, textural properties, Bronsted and Lewis acidity, and structural integrity of the incorporated Keggin units, as well as the formation of the carbon/silica framework, were well characterized. The PW12/ZrO2-Si(Et)Si-NTs hybrid nanocatalysts were applied in the synthesis of alkyl levulinates by esterification of levulinic acid and ethanolysis of furfuryl alcohol, and the obtained excellent catalytic activity was explained in terms of the strong Bronsted and Lewis acidity, unique hollow tubular nanostructure, and hydrophobic surface of the hybrid nanocatalysts; additionally, the catalysts could be reused at least three times without significant loss of activity. Finally, the possible reaction mechanism of the PW12/ZrO2-Si(Et)Si-NTs-catalyzed esterification and ethanolysis reactions were put forward.
- Sun, Yingnan,Guo, Yihang,Song, Daiyu,An, Sai
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- Clean synthesis of alkyl levulinates from levulinic acid over one pot synthesized WO3-SBA-16 catalyst
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The present work highlights the application of solid acid catalyst to produce alkyl levulinate from levulinic acid in continuous mode under vapor phase conditions. In this context, tungsten oxide incorporated SBA-16 catalysts were prepared by one pot direct synthesis method and evaluated for the titled reaction. Under optimized reaction conditions, 3 wt% WO3-SBA-16 catalyst delivered complete conversion of levulinic acid with 95% selectivity towards ethyl levulinate. The synthesized catalysts were characterized to know the physico-chemical features by various techniques, namely, X-ray diffraction, N2 physisorption, temperature programmed reduction of hydrogen (H2-TPR), temperature programmed desorption of ammonia (NH3-TPD), DR-UV–vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The characterization results suggest that, the superior catalytic activity can be ascribed due to the enhanced acidity of SBA-16 obtained through incorporation of tungsten oxide and easy of accessibility for the dispersed active sites through uniform pore channels. The constant catalytic activity in 10 h time on study shows the sturdiness of the catalyst and the spent catalyst can be regenerated several times. Moreover, various alkyl levulinates (methyl, n-propyl, and n-butyl) were synthesized with more than 90% selectivity over this catalyst.
- Enumula, Siva Sankar,Gurram, Venkata Ramesh Babu,Chada, Raji Reddy,Burri, David Raju,Kamaraju, Seetha Rama Rao
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- Alcoholysis of Furfuryl Alcohol into n-Butyl Levulinate Over SBA-16 Supported Heteropoly Acid Catalyst
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Abstract: 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. Graphical Abstract: [Figure not available: see fulltext.] SBA-16 supported TPA catalyst is effective in the conversion of furfuryl alcohol to n-butyl levulinate at atmospheric pressure.
- Siva Sankar, Enumula,Saidulu Reddy,Jyothi, Yadagiri,David Raju, Burri,Rama Rao, Kamaraju Seetha
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- Efficient conversion of biomass-derived furfuryl alcohol to levulinate esters over commercial α-Fe2O3
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An efficient process for the production of levulinate esters from biomass-derived furfuryl alcohol in liquid alcohol over commercial α-Fe2O3 was firstly investigated. Among the catalysts we tested, α-Fe2O3, a cheap, commercially available and environmentally benign catalyst, exhibited a remarkable catalytic performance for the transformation and gives levulinate esters in good yield compared to the previous studies. The corresponding esters such as methyl levulinate, ethyl levulinate and butyl levulinate were obtained in high yields under optimized reaction conditions. Several influence factors for the formation of levulinate esters were also discussed. A plausible reaction mechanism for the formation of levulinate ester from furfuryl alcohol was proposed. From the viewpoint of practice and economy, the present study provides a potential application for the efficient synthesis of fine chemicals from biomass-derived compounds over cheap, commercially available and environmentally benign catalysts.
- Ren, Dezhang,Fu, Jun,Li, Lu,Liu, Yunjie,Jin, Fangming,Huo, Zhibao
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- TTAB mediated synthesis of Meso-H-BEA and its application in the production of n-butyl levulinate
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The present work is focusing on the improvement of catalytic characteristics of zeolite. In the present endeavor, zeolite H-BEA has been modified using sol-gel route by making use of tetradecyltrimethyl ammonium bromide (TTAB) surfactant as a structure directing agent. The synthesized mesozeolite was characterized by SEM, HRTEM, 29Si and 27A1 MAS-NMR, small and wide-angle XRD, FT-IR, TGA, NH3-TPD, ICP-OES and BET surface area analysis. The synthesized material was found to exhibit mesoporosity along with microporosity of parent H-BEA. The utility of modified H-BEA as heterogeneous catalyst was demonstrated in the production of value added chemical, n-butyl levulinate from biomass derived feedstock, levulinic acid (LA) via esterification reaction. n-butyl levulinate is one of the significant industrial chemical and has wide use as plasticizing agent, solvent and odorous substance. Various process variables such as molar ratio (LA to n–butanol), catalyst concentration (%) and reaction time (h) were optimized by response surface methodology (RSM), using the Box–Behnken Design (BBD). Analysis of variance (ANOVA) has been performed to investigate the suitability and significance of the quadratic model.
- Morawala, Dhara H.,Lathiya, Dharmesh R.,Dalai, Ajay K.,Maheria, Kalpana C.
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- Efficient conversion of renewable levulinic acid to n-butyl levulinate catalyzed by ammonium and silver co-doped phosphotungstic acid
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Ammonium and silver co-doped phosphotungstic acid was developed as novel efficient catalyst for the synthesis of n-butyl levulinate. The catalyst was characterized by element analysis, FT-IR, XRD and Hammett indicator method. Among them, (NH4)0.5Ag0.5H2PW12O40 exhibited the highest catalytic activity, and the yield of n-butyl levulinate could reach up to 99.0% within 2 h. The results showed that the activity of (NH4)0.5Ag0.5H2PW12O40 was higher than that of single Ag+ or NH4+ doped H3PW and other representative catalysts reported by literatures. In addition, (NH4)0.5Ag0.5H2PW12O40 performed good reusability for this reaction.
- Zhou, Xi,Li, Ze Xian,Zhang, Chao,Gao, Xue Ping,Dai, You Zhi,Wang, Gong Ying
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- Efficient alcoholysis of furfuryl alcohol to n-butyl levulinate catalyzed by 5-sulfosalicylic acid
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It is urgent to study the utilization of biomass energy to solve the environmental problems caused by the excessive use of fossil fuels. In this study, a rapid and efficient route for the conversion of furfuryl alcohol (FA) into n-butyl levulinate (BL) has been catalyzed by 5-sulfosalicylic acid. The nearly complete conversion of FA and a considerable 99.7% selectivity of BL are obtained under the optimal conditions. Based on the experimental results, a possible mechanism for the alcoholysis of FA is proposed. The present study provided a promising way for alkyl levulinates synthesis over economical and environmentally benign catalysts.
- Zhao, Wenguang,Ding, Hui,Tian, Yi,Xu, Qiong,Liu, Xianxiang
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- Enhanced heterogeneous catalytic conversion of furfuryl alcohol into butyl levulinate
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We study the catalytic condensation of furfuryl alcohol with 1-butanol to butyl levulinate. A screening of several commercial and as-synthesized solid acid catalysts shows that propylsulfonic acid-functionalized mesoporous silica outperforms the state-of-the-art phosphotungstate acid catalysts. The catalyst is prepared via template-assisted sol-gel polycondensation of TEOS and MPTMS. It gives 96 % yield (and 100 % selectivity) of butyl levulinate in 4h at 110 °C. Reaction profiles before and after a hot filtration test confirm that the active catalytic species do not leach into the solution. The catalyst synthesis, characterization, and mode of operation are presented and discussed. Sour cat: Screening several commercial and as-synthesized solid acid catalysts in the condensation of furfuryl alcohol with 1-butanol to afford butyl levulinate shows that the best catalyst is a sulfonic acid-functionalized mesoporous silica, allowing a significant improvement over the state-of-the-art. The catalyst selectively affords n-butyl levulinate in relatively short time at 110 °C.
- Demmacarà, Piera,Ciriminna, Rosaria,Shiju,Rothenberg, Gadi,Pagliaro, Mario
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- Efficient conversion of furfuryl alcohol to ethyl levulinate with sulfonic acid-functionalized MIL-101(Cr)
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Catalytic ethanolysis of furfuryl alcohol (FA) to ethyl levulinate (EL) with MIL-101(Cr)-SO3H, prepared by simple one-pot hydrothermal treatment, is presented for the first time. The as-prepared catalyst with high surface area, hydrothermal and chemical stability, good dispersion, and feasible accessibility of -SO3H Br?nsted acid sites was found to show superior performance to other sulfonic acid-functionalized solid catalysts. Besides the special textural properties, the obtained good catalytic activity of 79.2% EL yield and 100% FA conversion were also dependent on the density and strength of the Br?nsted acid and the reaction parameters. A slight loss of catalytic activity after five consecutive recycles and the hot filtration experiment confirmed the good stability of MIL-101(Cr)-SO3H. Two coexisting reaction paths for the ethanolysis of FA to EL catalyzed by MIL-101(Cr)-SO3H were proposed, wherein 2-ethoxymethylfuran (2-EMF) was observed to be the dominant intermediate.
- Liu, Xiao-Fang,Li, Hu,Zhang, Heng,Pan, Hu,Huang, Shan,Yang, Kai-Li,Yang, Song
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- One pot synthesis of WOx/mesoporous-ZrO2 catalysts for the production of levulinic-acid esters
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WOx/mesoporous-ZrO2 (WmZr) has been successfully prepared by one-pot evaporation induced self-assembly. The resulting textural properties are highly affected by the additions of WO3 and calcination temperatures. XRD and Raman spectroscopy were used to investigate the crystalline structures and surface states of the materials. Surface acidity was studied employing NH3-TPD and DRIFT spectroscopy with pyridine adsorption. Catalysts loaded with 20-25 wt.% WO3 and calcined at 800 °C exhibited the highest surface acidity with the greatest amount of Br?nsted acid sites. The catalysts were tested in the esterification of levulinic acid (LA) with 1-butanol (1-BuOH). Pseudo- (p-BL) and normal-butyl levulinate (n-BL) were observed as the only products. The highest conversion of LA (64-67%) as well as a selectivity of n-BL of up to 97% could be achieved applying a catalyst with 20 wt.% WO3 loading calcined at 800 °C. A clear correlation between catalyst activity and the relative ratio of Br?nsted and Lewis acid sites could be confirmed.
- Ciptonugroho, Wirawan,Al-Shaal, Mohammad G.,Mensah, Joel B.,Palkovits, Regina
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- Esterification of levulinic acid with butanol over ion exchange resins
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Alkyl levulinates are biobased chemicals with a great number of applications and great biofuel potential for blending to conventional diesel or gasoline. The present work focuses on the liquid-phase synthesis of butyl levulinate (BL) by esterification of levulinic acid (LA) with 1-butanol (BuOH) using a set of acidic ion-exchange resins. Experiments were performed at 80 °C and 2.5 MPa in a batch reactor by using an initial molar ratio AL/BuOH of 1/3 and a catalyst loading of 0.8%. It has been found that BL could be successfully obtained over ion-exchange resins with a selectivity higher than 99.5%. LA conversions ranged from 64% (Amberlyst 46, macroreticular, surface sulfonated) to 94% (Dowex 50Wx2, gel-type resin, conventionally sulfonated) at 8 h reaction time. By comparing their catalytic behavior, it was seen that resins morphology plays a very important role in the synthesis of BL making easier the access of reactants to acid sites. Accessibility of LA and BuOH to acid centers was high over highly swollen and low polymer density resins. Thus, gel-type resins with low divinylbenzene (DVB) content have been found as the most suitable to produce BL, e.g. Dowex 50Wx2, Dowex 50Wx4 and Purolite CT224. Among them, Dowex 50Wx2 (2% DVB) is the most efficient catalyst tested.
- Tejero,Ramírez,Fité,Tejero,Cunill
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- Synthesis of n-Butyl Levulinate Using Mesoporous Zeolite H-BEA Catalysts with Different Catalytic Characteristics
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Abstract: The present work focuses on the utilization of waste biomass for the improvement of key catalytic properties of conventional zeolite H-BEA. In the present endeavor, zeolite H-BEA has been modified using cetyltrimethyl ammonium bromide (CTAB) and rice husk (a waste biomass resource), via desilication post synthetic route, which is not reported so far. The synthesized mesoporous zeolite H-BEA catalysts have been characterized by various characterization techniques such as, SEM, 27Al and 29Si MAS-NMR, wide and low angle XRD, ICP-OES, FT-IR, TGA, NH3-TPD and BET surface area. The resultant mesoporous zeolite materials (MCCK and MCRK) exhibited bimodal porosity as well as improved physicochemical properties, and the utility of these modified zeolites as heterogeneous catalysts has been demonstrated in the production of n-butyl levulinate via levulinic acid (LA) esterification. The catalytic material, which has been modified using CTAB and rice husk, is found to exhibit better catalytic activity towards the synthesis of n-butyl levulinate (95.6%) as compared to other zeolite counterparts under the optimised reaction conditions, which is attributed to its enhanced surface area and lower Si/Al ratio as compared to other catalysts under study.
- Morawala, Dhara H.,Dalai, Ajay K.,Maheria, Kalpana C.
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- Heteropoly acid supported on silicalite–1 possesing intracrystalline nanovoids prepared using biomass – an efficient and recyclable catalyst for esterification of levulinic acid
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Researchers prepared silicalite-1 containing intracrystalline nanovoids under hydrothermal synthesis conditions by adding corn stem pith powder into the zeolite synthesis gel. The nanovoids found to increase the external surface area of the zeolite and, when HPA was supported, it was loaded onto these nanovoids which improved dispersion of HPA and accesssiblity of acid sites. X-ray photoelectron spectroscopy and 31 31P- MAS NMR indicated interfacial bond formation between the silicalite-1 surface and HPA which would facilitate dispersion.
- Manikandan,Cheralathan
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- Utilization of renewable resources: Investigation on role of active sites in zeolite catalyst for transformation of furfuryl alcohol into alkyl levulinate
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A bio-derived furfuryl alcohol transformation into various high-value chemicals is a growing field of interest among researchers. This study reports an exclusive investigation of the porosity and active sites responsible for the efficient alcoholysis of furfuryl alcohol to alkyl levulinate by the aid of zeolite catalyst. Alkyl levulinate is a promising platform chemical potentially used as a fuel additive and also for the production of chemicals. A detailed study using well-characterized HZSM-5 catalyst on the influence of acidity and post synthesis modification like desilication, dealumination, metal ion exchange and phosphate modification revealed the most desired type of acid sites required to catalyze this reaction. Among the HZSM-5 catalysts tested, HZSM-5 (SAR 95) showed the best performance of ≥ 99 % furfuryl alcohol conversion and 85 % butyl levulinate selectivity under optimum conditions. The catalyst exhibited good recyclability additionally addressing all the challenges reported in the previous literature fulfilling the green chemistry principles.
- Vaishnavi,Sujith,Kulal, Nagendra,Manjunathan, Pandian,Shanbhag, Ganapati V.
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- Assessment of ion exchange resins as catalysts for the direct transformation of fructose into butyl levulinate
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The transformation of fructose into butyl levulinate in aqueous 1-butanol (initial molar ratio 1-butanol/fructose 79, and butanol/water 1.19) has been studied in a discontinuous reactor at 80?120 °C and 2.0 MPa over 8 sulfonic polystyrene-DVB ion exchange resins as catalysts (catalyst loading 0.85–3.4 %). Resins swell greatly in the reaction medium and the reaction takes place mainly in the swollen gel-phase. Swollen resins in water have been characterized by analysis of ISEC data, and spaces originated in the gel phase upon swelling are described in terms of zones of different polymer density. A relationship has been found between the morphology of swollen resins and ester production. Swollen resins with low polymer density show the highest butyl levulinate yield. Dowex 50Wx2 was the most effective because it creates the largest and widest spaces in the gel-phase when swelling. Consequently, it better accommodates the proton-transfer-reaction mechanisms.
- Ramírez, Eliana,Bringué, Roger,Fité, Carles,Iborra, Montserrat,Tejero, Javier,Cunill, Fidel
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- Esterification of levulinic acid over Sn(II) exchanged Keggin heteropolyacid salts: An efficient route to obtain bioaditives
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In this paper, we describe a process to add value to the biomass derivatives (i.e., levulinic acid), converting it to bioadditives over solid Sn(II) exchanged Keggin heteropolyacid salts. These solid catalysts are an attractive alternative to the traditional soluble and corrosive Br?nsted acid catalysts. Among Sn(II) heteropoly salts, the Sn1.5PW12O40 was the most active and selective catalyst, achieving high conversions (ca. 90 %) and selectivity (90–97 %) for alkyl esters and angelica lactone, the main reaction products. The impacts of the main reaction parameters (i.e., catalyst load, temperature, and the molar ratio of alcohol to acid) were investigated. The use of renewable raw material, and an efficient and recyclable catalyst are the main positive features of this process. The Sn1.5PW12O40 catalyst was easily recovered and reused without loss activity.
- Da Silva, Márcio José,Chaves, Diego Morais,Teixeira, Milena Galdino,Oliveira Bruziquesi, Carlos Giovani
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- Conversion of levulinic acid to γ-valerolactone over Zr-containing metal-organic frameworks: Evidencing the role of Lewis and Br?nsted acid sites
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Zr-containing UiO-66 and MOF-808 are evaluated for converting levulinic acid (LA) into γ-valerolactone (GVL) through various routes: (i) Step-wise esterification of LA to n-butyl levulinate (nBuL) and Meerwein-Ponndorf-Verley (MPV) reduction to GVL; (ii) One-pot two-steps esterification with n-butanol followed by MPV reduction with sec-butanol; and (iii) direct conversion of LA into GVL through a tandem reaction. Selection of this multistep complex reaction evidences the participation of the different acid sites (Lewis or Br?nsted) of the material in each individual step: Br?nsted-induced acid sites catalyze esterification reaction efficiently, while Lewis acid sites are the preferred sites for the MPV step. Sulfation of MOF-808 is used to enhance the Br?nsted acidity of MOF-808, which improves the performance for esterification. However, the sulfate groups introduced are detrimental for the MPV step, since they reduce the intra-pore space available to form the required bulky transition state. These results evidence the need to find the best equilibrium between Br?nsted and Lewis acid sites to optimize the outcome of this multistep reaction.
- Cirujano, F. G.,Guarinos, J. M.,Llabrés i Xamena, F. X.,Rapeyko, A.
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- Eco-Friendly Natural Clay: Montmorillonite Modified with Nickel or Ruthenium as an Effective Catalyst in Gamma-Valerolactone Synthesis
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Ni/Ru metals supported on cheap and available support montmorillonite K10 were used for the selective hydrogenation of levulinic acid to γ-valerolactone. Different loadings of the metals were applied by the impregnation method, and detailed characterization was performed (UV–VIS, XRD, TPR, TPD, particle size distribution, SEM, XRF). Metals’ homogeneous distribution on the surface was confirmed. The selectivity to the desired product was almost independent on the used material. A detailed study of the influence of solvents on the studied reaction was also performed—protic alcohol-based solvents caused the formation of levulinic and valeric acid esters in the reaction mixture. The selectivity was influenced mainly by the alcohol structure (the highest selectivity obtained using isopropyl alcohol and sec-butanol). Mainly the solvent’s donor number (except ethanol) influenced the reaction rate. The prepared catalysts are promising, available, and cheap materials for the studied reaction. Solvent may significantly influence the yield of γ-valerolactone. Graphic Abstract: [Figure not available: see fulltext.].
- ?erveny, Libor,Trejbal, Ji?í,Vaňková, Michaela,Vrbková, Eva,Vysko?ilová, Eli?ka
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- Catalytic conversions of isocyanate to urea and glucose to levulinate esters over mesoporous α-Ti(HPO4)2·H2O in green media
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We have described a facile solvothermal synthesis of a sheet-like α-Ti(HPO4)2·H2O nanomaterial. The material comprises 10.7 nm nanoparticles along with ordered mesopores throughout its hexagonal building blocks. The material possesses a bandgap of 3.86 eV and works as an efficient catalyst for the selective synthesis of ureas from a broad range of isocyanates in the presence of H2O at room temperature with a high product yield (up to 93%) and a TOF value up to 15.25 h-1. The α-Ti(HPO4)2·H2O nanomaterial also catalytically converts glucose to levulinic acid (LA) and subsequently LA to alkyl levulinates in the presence of different alcohols with a high product yield (up to 98%) and a TOF value up to 43.00 h-1. Furthermore, all the reactions are performed under green and facile catalytic conditions without using any hazardous solvent. The α-Ti(HPO4)2·H2O catalyst material was also found to be reusable for manifold cycles for all the reactions, keeping its catalytic efficiency along with its structural and morphological characteristics unaffected, supporting its industrial relevance.
- Hazra Chowdhury, Arpita,Hazra Chowdhury, Ipsita,Biswas, Surajit,Chakrabortty, Pekham,Islam, Sk. Manirul
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p. 16452 - 16460
(2020/10/14)
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- Inexpensive and tuneable protic ionic liquids based on sulfuric acid for the biphasic synthesis of alkyl levulinates
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Alkyl levulinates are bio-derived chemicals, increasingly popular for their uses as solvents, additives and intermediates. However, efficient and recyclable catalysts for their synthesis are still the subject of intensive research. In this study, a wide range of alkyl levulinates was synthesized under mild conditions (room temperature, atmospheric pressure), using inexpensive and efficient Br?nsted acidic ionic liquids (ILs) based on sulfuric acid and off-the-shelf bases. Acidity of the ILs was closely related to their activity. The ILs could be easy separated and recycled, without significant changes in conversion or selectivity over 10 cycles (yields ca. 90–95%). Under optimized conditions, a 99% yield of pentyl levulinate (model reaction) was achieved. The method was demonstrated to be efficient in the synthesis of levulinates of C1-C16 linear, branched and cyclic alcohols. This innovative, green route to alkyl levulinates fits well within the sustainable development strategy.
- Chrobok, Anna,Gillner, Danuta,Matuszek, Karolina,Przypis, Marta,Swad?ba-Kwa?ny, Ma?gorzata
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- A New Sulfonic Acid-Functionalized Organic Polymer Catalyst for the Synthesis of Biomass-Derived Alkyl Levulinates
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Abstract: Alkyl levulinates are important biobased chemicals with great fuel-blending properties and good reactivity. In this work, a new functionalized nitrogen-containing organic polymer bearing sulfonic acid groups (PDVTA-SO3H) was successfully prepared and studied for the esterification of levulinic acid with alcohols to produce alkyl levulinates. The results showed that this sulfonic acid-functionalized organic polymer possessed high catalytic activity, and the yield of n-butyl levulinate reached 97.4% under the mild conditions. PDVTA-SO3H exhibited strong acidic sites and high stability, and would be well expected to be a potential candidate better than some commercial sulfonic solid catalysts for alkyl levulinates production. The catalyst had been reused without any treatment for five times and the results proved its potential for industrial applications. Graphic Abstract: A new sulfonic acid-functionalized organic polymer showed high activity in the conversion of biomass derived levulinic acid into alkyl levulinates.[Figure not available: see fulltext.]
- Tian, Yi,Zhang, Ruoqi,Zhao, Wenguang,Wen, Sha,Xiang, Yanping,Liu, Xianxiang
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p. 3553 - 3560
(2020/05/22)
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- AQUIVION perfluorosulfonic acid resin for butyl levulinate production from furfuryl alcohol
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This study reports the sustainable production of butyl levulinate (BL) from furfuryl alcohol (FA), a highly abundant biomass derived platform obtained from C5 sugars in hemicellulose. FA upgrading is performed adopting a robust and easily recyclable commercial perfluorosulfonic acid resin, Aquivion P87S, used as cylinder shaped pellets. This approach avoids the use of corrosive and harmful mineral acids allowing a simple separation of the catalyst from the reaction mixture, reducing the cost of equipment materials and disposal or neutralization issues, also resulting in reduced solvent dehydration. Moreover, FA alcoholysis to BL involves butanol as a sustainable reaction medium, also readily obtained from biomass. The catalyst remains stable up to 6 recycles. Furthermore, the absence of heavy by-products and the stability of the catalyst allowed us to perform successive additions of the substrate to the reaction medium to increase the BL concentrations up to 0.66 M (13 wt%).
- Bernal, Hilda Gómez,Oldani, Claudio,Funaioli, Tiziana,Raspolli Galletti, Anna Maria
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p. 14694 - 14700
(2019/09/30)
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- Catalytic synthesis of levulinate esters over zirconia and its modified forms coated on honeycomb monoliths: Green synthesis
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A series of solid acid catalysts such as ZrO2, Mo(VI)/ZrO2 and W(VI)/ZrO2 have been coated on honeycomb monoliths as well as synthesized in the powder forms and used as catalytic materials for synthesis of ethyl levulinate from levulinic acid and ethanol. These solid acids were characterized by BET, NH3-TPD/n-butyl amine back titration, FTIR, PXRD and SEM techniques. Effects of various reaction parameters towards the reaction performance were studied. The performance of the catalyst was tested based on nature of the catalyst (honeycomb coated or powder form), reaction time (1 to 5 h), molar ratio (1:1 to 1:12 levulinic acid to ethanol) and reusability of the catalytic material. An excellent yield (86-88 %) of ethyl levulinate was obtained under optimized conditions. An attempt is made to correlate the activity of the catalysts in this esterification reaction with their surface characteristics. The honeycomb monoliths coated with zirconia and its modified forms were found to be ecofriendly, cost-effective and reusable catalytic materials compared to their powder forms.
- Serrao, Reena Saritha,Mohamed Shamshuddin,D'Souza, Joyce
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p. 1993 - 1999
(2019/08/08)
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- Esterification and ketalization of levulinic acid with desilicated zeolite β and pseudo-homogeneous model for reaction kinetics
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To maximize the production of esters (E), keto (K) and keto-ester (KE) by esterification and ketalization of levulinic acid (LA) has been reacted using diols such as 1,2-propane diol (PDOL),1,2-ethane diol (EDOL), and 1,2,3-propane triol or glycerol (TRIOL) with desilicated Hβ. This work aims to assess the conversion and selectivity for the production of esters using conventional and microwave-irradiated (MWI) reactors. Catalysts characterizations were performed using NH3-temperature programme desorption, Brunauer, Emmett and Teller surface area (BET), Barrett, Joyner, and Halenda (BJH), scanning electron microscope, transmission electron microscope, and dynamic light scattering. Operating parameters such as reaction temperature (170–180°C), reaction time (20–80?min), feed composition (LA:PDOL/EDOL/TRIOL, 1:8/10/12), and microwave energy (300–500 watt) have been systematically investigated. Note that 99–100% conversion was achieved with the product selectivity of E (40%), K (30%), and KE (30%) with1,2-EDOL; E (56%), K (2%), and KE (17%) with 1,2-PDOL; E (69%), K(0%), and KE (22%) with TRIOL using D-Hβ as a solid catalyst in an MWI reactor. Reaction paths and kinetics were studied using pseudo-homogeneous (PH) model.
- Umrigar, Vaishali,Chakraborty, Mousumi,Parikh, Parimal
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p. 299 - 308
(2019/02/01)
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- PROCESS FOR THE PREPARATION OF LEVULINATE ESTERS
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The present invention is directed to a process for synthesizing at least one levulinate ester, said process comprising the reaction of furfuryl alcohol polymer with at least one other alcohol in the presence of water and at least one catalyst, said catalyst comprising at least one metal selected from bismuth, gallium, aluminum, tin and iron and said furfuryl alcohol polymer being obtainable by condensation of furfuryl alcohol at a temperature of at least 50℃.
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Page/Page column 11
(2018/07/22)
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- Selective Levulinic Acid Hydrogenation in the Presence of Hybrid Dendrimer-Based Catalysts. Part I: Monometallic
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Hybrid Ru-containing catalysts, based on poly(propylene imine) (PPI) dendrimers, immobilized in silica pores, were synthesized and characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The synthesized Ru catalysts proved their efficiency in the selective hydrogenation of levulinic acid and its esters at 80 °C, 30 bar of H2, and 50 % volume substrate concentration in water. Quantitative yields of γ-valerolactone were obtained for both micro- and mesoporous Ru catalysts within 2 h with catalytic activity as high as 1610 h?1. The reaction rate and selectivity on γ-valerolactone were found to depend on several factors such as carrier structure, temperature, presence of water, and substrate/Ru ratio. The novelty of these hybrid materials is the presence of both weak acid (SiO2) and organic base centers (dendrimer amino groups), enhancing the dispersion of Ru nanoparticles. The presence of amino groups in the catalyst stabilizes the Ru nanoparticles during the synthesis and promotes the adsorption of levulinic acid on the surface of Ru nanoparticles during the reaction. Synthesized hybrid Ru catalysts can be reused several times without significant loss of activity.
- Maximov, Anton L.,Zolotukhina, Anna V.,Mamedli, Adila A.,Kulikov, Leonid A.,Karakhanov, Edward A.
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p. 222 - 233
(2017/11/27)
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- MoO3 supported on ordered mesoporous zirconium oxophosphate: An efficient and reusability solid acid catalyst for alkylation and esterification
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A series of molybdenum oxide supported on ordered mesoporous zirconium oxophosphate (MoO3/M-ZrPO) materials with different MoO3 loadings (0–20 wt%) and calcination temperatures (500–900 °C) have been designed, synthesized and employed as solid acid catalysts in alkylation and esterification. The XRD, TG-DSC, H2-TPR, N2-physisorption and TEM characterizations were taken to investigate the structural properties and states of introduced MoO3 species. The influence of MoO3 loadings and calcination temperatures in catalytic performance was detailedly investigated and optimal catalytic activity was reached at 10 wt% MoO3 loadings and treated at 700 °C. Moreover, MoO3/M-ZrPO catalysts exhibited outstanding catalytic performance in Friedel-Crafts alkylation of different aromatic compounds and esterification of levulinic acid with 1-butanol. Furthermore, it was noteworthy that the catalyst had superior reusability and no noticeable declines were observed in catalytic performance even after seven runs.
- Miao, Zhichao,Li, Zhenbin,Zhao, Jinping,Si, Weijiang,Zhou, Jin,Zhuo, Shuping
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- Method for synthesizing levulinate
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The invention relates to a method for synthesizing levulinate. The method comprises the following step: catalyzing levulinic acid and alcohol to be subjected to esterification reaction by utilizing aloading type PDA-SO3H solid acid catalyst, so as to obtain the levulinate. According to the method provided by the invention, the loading type PDA-SO3H solid acid catalyst is used as the catalyst, canbe recycled and also can be used for more efficiently catalyzing the generation of the levulinate. The method directly takes the levulinic acid and the alcohol as raw materials and the levulinate issynthesized through one-step reaction; the selectivity of a product is higher than 99.9 percent and the yield is high; when the alcohol is enough, the conversion rate of the levulinic acid reaches 87percent or more.
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Paragraph 0041-0046; 0056; 0061; 0069-0073
(2018/12/02)
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- PROCESS FOR THE PREPARATION OF LEVULINATE ESTERS
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The present invention is directed to a process for synthesizing at least one levulinate ester, said process comprising a step of introducing furfuryl ether into a reaction medium and a step of conversion of furfuryl ether into levulinate ester in the presence of water and at least one catalyst, said catalyst comprising at least one metal selected from bismuth, gallium, aluminum, tin and iron.
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Page/Page column 11
(2018/07/29)
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- Facile and high-yield synthesis of methyl levulinate from cellulose
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Efficient production of chemicals from cellulose provides sustainable routes for the utilization of natural renewable resources to meet the requirements of human society. Herein, we reported a highly efficient and simple metal salt catalyst, Al2(SO4)3, for cellulose conversion to methyl levulinate (ML) under microwave conditions. A highest ML yield of 70.6% was obtained at 180 °C within a very short time of 40 min. The introduction of water could reduce humin/coke formation and solvent consumption, and could also switch the reaction pathway via the more reactive intermediate glucose. Kinetic and mechanistic studies of the subreactions showed that both cellulose hydrolysis and alcoholysis pathways were involved in the cellulose conversion to ML, with the former as the main route in the presence of water. The Lewis acid species [Al(OH)x(H2O)y]n+ and the Br?nsted acid species H+, generated by in situ hydrolysis of Al2(SO4)3, were responsible for the reaction conversions. The reaction with microwave heating showed accelerated reaction rates of 25 times the reaction with conventional oil heating, and even more times for the rates of glucose and methyl glucoside (MG) dehydration, resulting in higher reaction selectivity toward ML production. The catalyst was also successfully recycled and applied to the conversion of cellulose to other alkyl levulinates, as well as the conversion of raw biomass to ML with high yields. The homogeneous nature of Al2(SO4)3, together with its high efficiency and excellent recyclability, make it a potential catalyst for the large-scale production of ML in industry.
- Huang, Yao-Bing,Yang, Tao,Lin, Yu-Ting,Zhu, Ying-Zhi,Li, Li-Cheng,Pan, Hui
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p. 1323 - 1334
(2018/03/26)
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- MFI Acid Catalysts with Different Crystal Sizes and Porosity for the Conversion of Furanic Compounds in Alcohol Media
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Solid acid catalysts possessing MFI topology and different crystal sizes and porosities were explored for the conversion of carbohydrate-biomass-derived α-angelica lactone and 5-(hydroxymethyl)furfural, in 1-butanol at T=120–170 °C, to give levulinate esters and furanic ethers. Micro/mesoporous microcrystalline catalysts were prepared by post-synthesis base/acid treatments of ZSM-5 zeolite; the influence of the desilication (base) conditions on the material properties was investigated. A nanocrystalline ZSM-5 sample was synthesised by using hydrothermal, dynamic conditions and used as a reference material. A comparison of the catalytic performances of materials featuring different morphological, textural, and acid properties highlights a complex interplay between the acid and textural properties. The best-performing catalyst (MZS0.6) was obtained by post-synthesis-treatment; fairly good catalytic stability was confirmed by catalyst recycling, contact tests, and characterisation of the spent catalyst. MZS0.6 was compared with the macrorecticular ion-exchange resin Amberlyst-15, chosen as a benchmark solid acid catalyst, in the two reaction systems.
- Antunes, Margarida M.,Lima, Sérgio,Fernandes, Auguste,Magalh?es, Ana L.,Neves, Patrícia,Silva, Carlos M.,Ribeiro, Maria F.,Chadwick, David,Hellgardt, Klaus,Pillinger, Martyn,Valente, Anabela A.
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p. 2747 - 2759
(2017/07/28)
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- A biomass sugar preparation of levulinic acid ester
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The invention discloses a method for preparing acetyl propionate from biomass sugar. The method comprises the following steps: reacting for 3-6 hours in an alcohol solution of 190-210 DEG C by taking the biomass sugar and magnetic zirconium phosphate solid acid as a catalyst to obtain acetyl propionate, wherein a molar ratio of P to Zr in the magnetic zirconium phosphate solid acid is 1-3, the alcohol is methanol, alcohol, propyl alcohol or butyl alcohol; a mass ratio of the magnetic zirconium phosphate solid acid to the biomass sugar is (0.4-2) to 1. According to the method disclosed by the invention, raw materials are renewable resources, and the acetyl propionate is directly prepared by adopting the magnetic solid acid which is easy to prepare, easy to separate and capable of recycled through catalysis one-step process. The method is simple in process, safe to operate, relatively low in equipment requirement and low in production cost, and is an environment-friendly production process.
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Paragraph 0026-0027
(2017/08/25)
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- A catalytic biomass sugar directly alcoholysis method of preparing levulic ester
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The invention belongs to the technical field of compound synthesis, and particularly relates to a method for preparing ethyl levulinate by catalyzing biomass sugar to be directly alcoholyzed. According to the method disclosed by the invention, Al3 salt is used as a catalyst. The method for preparing the ethyl levulinate by catalyzing biomass sugar to be directly alcoholyzed is not only moderate in reaction condition and strong in substrate universality, but also high in yield of the ethyl levulinate.
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Paragraph 0021-0022; 0067-0068; 0069-0070
(2017/02/23)
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- Carbonized glycerol nanotubes as efficient catalysts for biofuel production
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Highly acidic, functionalized, carbonized glycerol nanotubes successfully synthesized via a simultaneous carbonization and acidification have been identified as efficient and stable solid acid catalysts for biofuel production from glycerol and levulinic acid.
- Viswanadham, Nagabhatla,Debnath, Suman,Saxena, Sandeep K.,Al-Muhtaseb, Ala'A H.
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p. 41364 - 41368
(2016/05/19)
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- A solid acid catalysis process for high-yield preparation levulic ester (by machine translation)
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The invention discloses a solid acid catalysis process for high-yield preparation levulic ester, belonging to the field of organic synthesis. The invention will be 1 parts by weight of a sugar, 10-100 parts by weight alcohol, 0.01-0.2 parts by weight of acid and B 0.1-1 parts by weight of a L acid mix, 130-190 °C reaction under the temperature 1-20h, aminolevulinic acid methyl ester solution obtained; the L acid as tin-containing molecular sieve, B acid as SBA-15-SO 3 H, Carbon-SO 3 H or Amberlyst-15 a in. Raw material carbohydrate is cheap and easy to obtain, for the acid L, B acid can be repeated using a catalytic effect to be reduced is not obvious, the one-step process for preparing the laevulinic acid ester compound, can be widely applied to food additive, essence, chemical reaction intermediates and gasoline, diesel fuel additive and other industries. (by machine translation)
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Paragraph 0045; 0046
(2017/02/24)
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- Influence of butanol isomers on the reactivity of cellulose towards the synthesis of butyl levulinates catalyzed by liquid and solid acid catalysts
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Butyl esters of levulinic acid form an interesting class of bio-based compounds that can be used, for example, as fuel additives. Their preparation mainly proceeds through the esterification of levulinic acid while the few reported studies on their direct synthesis from cellulose give limited information. In the present work, we studied for the first time in detail the influence of butanol isomers on the non-catalyzed cellulose liquefaction and the acid catalyzed formation of butyl levulinates from cellulose. In the absence of catalysts there was no influence of the alcohol class on liquefaction which reached 70-85% after 2 hours at 300 °C. In the presence of catalysts, we showed that the class of the alcohol had a significant influence on the butyl levulinate yield. With primary alcohols yields of 50% were obtained in the presence of H2SO4 (200 °C, 30 min). This level of yield can be considered as very interesting for these kinds of one-pot transformations involving cellulose. With secondary alcohols, yields less than 20% were obtained while no butyl levulinate was formed with tertiary alcohols. We also report for the first time this transformation in the presence of solid acids. Insoluble Cs2HPW12O40 or sulfated zirconia catalyzed the reaction heterogeneously despite deactivation leading to limited yields of 13% (200 °C, 1 hour). We finally show that water in butanol had an ambivalent role in enhancing the cellulose reactivity but limiting the esterification step and found that 5-7 wt%/butanol of water was the optimum amount.
- Démolis, Alexandre,Eternot, Marion,Essayem, Nadine,Rataboul, Franck
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p. 3747 - 3754
(2016/05/09)
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- A fructose-based biomass catalytic conversion systems furan derivatives
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A method for preparing furan derivatives by catalytic conversion of fructose-based biomass is characterized by: taking biomass such as fructose, cane sugar, inulin and the like as raw materials, taking low-boiling-point alcohols comprising aliphatic alcohols or alicyclic alcohols all with six or less than six carbon atoms as a solvent, and under the effect of a catalyst, performing reactions comprising hydrolysis, dehydration, etherfication and the like for coupling so as to obtain furan derivatives such as 5-alkoxymethyl furfural, levulinate esters, 5-hydroxymethylfurfural and the like. The method has the advantages of high raw material utilization rate, high in-situ coupling efficiency in the dehydration and etherfication reactions, and easily separated and purified system.
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Paragraph 0023
(2017/02/09)
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- Indium(III) triflate promoted synthesis of alkyl levulinates from furyl alcohols and furyl aldehydes
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A facile protocol for the alcoholysis of furfuryl alcohol into levulinate esters has been developed employing low catalyst loadings of indium(III) triflate. This method provides a rapid and efficient route for the synthesis of these useful materials. The alcoholysis reactions of 5-hydroxymethylfurfural (HMF), furfural and furfural dimethylacetal were also investigated under these reaction conditions.
- Kean, Jacqueline R.,Graham, Andrew E.
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p. 175 - 179
(2015/02/19)
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