- Catalytic dehydration of levoglucosan to levoglucosenone using Br?nsted solid acid catalysts in tetrahydrofuran
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We studied the production of levoglucosenone (LGO) via levoglucosan (LGA) dehydration using Br?nsted solid acid catalysts in tetrahydrofuran (THF). The use of propylsulfonic acid functionalized silica catalysts increased the production of LGO by a factor of two compared to the use of homogeneous acid catalysts. We obtained LGO selectivities of up to 59% at 100% LGA conversion using solid Br?nsted acid catalysts. Water produced during the reaction promotes the solvation of the acid proton reducing the activity and the LGO production. Using solid acid catalysts functionalized with propylsulfonic acid reduces this effect. The hydrophilicity of the catalyst surface seems to have an effect on reducing the interaction of water with the acid site, improving the catalyst stability.
- Oyola-Rivera, Oscar,He, Jiayue,Huber, George W.,Dumesic, James A.,Cardona-Martínez, Nelson
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- Catalytic fast pyrolysis of cellulose to prepare levoglucosenone using sulfated zirconia
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Sulfated zirconia was employed as catalyst for fast pyrolysis of cellulose to prepare levoglucosenone (LGO), a very important anhydrosugar for organic synthesis. The yield and the selectivity of LGO were studied in a fixed-bed reactor at different temperatures and cellulose/catalyst mass ratios. The experiments of catalyst recycling were also carried out. The results displayed that from 290 to 400 °C, the liquid and solid accounted for more than 95 wt % of products, and the higher temperature led to more liquid and less solid products. The introduction of SO42-/ZrO2 could promote cellulose conversion and LGO production. The temperature had a similar effect on the yield and selectivity of LGO at different cellulose/catalyst mass ratios. The maximum yield was obtained at 335 °C. Although the structure of the parent ZrO2 was retained after recycles, which was confirmed by X-ray diffraction and N2 adsorption-desorption measurements, the activity of SO42-/ZrO2 could only be partially recovered by simply calcination. The catalytic activity decrease could be mainly attributed to SO42- leaching, and the activity could be restored by further impregnation of H2SO4. It′s not diamond, it′s zirconia: SO42-/ZrO2 is an efficient catalyst for the production of levoglucosenone by fast pyrolysis of cellulose admixing catalysts. The optimal temperature for preparation of levoglucosenone is in the range of 320-350 °C. In the presence of the SO42-/ZrO2, the levoglucosenone content of pyrolysis liquid is greatly increased at 335 °C compared to pure cellulose.
- Wang, Zhi,Lu, Qiang,Zhu, Xi-Feng,Zhang, Ying
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- Leather-Promoted Transformation of Glucose into 5-Hydroxymethylfurfural and Levoglucosenone
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The search for efficient catalysts frequently leads to new homogeneous and heterogeneous catalysts of increasing complexity, and sometimes common, natural, or hybrid natural/synthetic materials that could be used in catalysis are overlooked. For example, the leather industry has produced robust Cr-containing materials for centuries by chemical treatment of animal hides with chromium salts. Herein, the use of chromium-tanned leather as a heterogeneous catalyst for glucose dehydration to 5-hydroxymethylfurfural (5-HMF) and levoglucosenone (LGO) is reported. Four pieces of waste leather were obtained from shoe soles and a belt, characterized by a range of techniques including FTIR spectroscopy, SEM, BET surface area measurements, XRD, and X-ray photoelectron spectroscopy, and their catalytic activity was evaluated. The activity of the scrap leather pieces compares favorably to those of many recently reported catalysts for the preparation of 5-HMF, but additionally results in significant quantities of LGO. Overall, the results demonstrate that waste leather is an outstanding material for use in catalysis.
- Bobbink, Felix D.,Huang, Zhangjun,Menoud, Florent,Dyson, Paul J.
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- Unravelling the catalytic influence of naturally occurring salts on biomass pyrolysis chemistry using glucose as a model compound: A combined experimental and DFT study
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Fast pyrolysis is an efficient thermochemical decomposition process to produce bio-oil and renewable chemicals from lignocellulosic biomass. It has been suggested that alkali- and alkaline-earth metal (AAEM) ions in biomass alter the yield and composition of bio-oil, but little is known about the intrinsic chemistry of metal-catalyzed biomass pyrolysis. In this study, we combined thin-film pyrolysis experiments and density functional theory (DFT) calculations to obtain insights into AAEM-catalyzed glucose decomposition reactions, especially forming major bio-oil components and char. Experiments reveal the difference in the yield and composition of bio-oil of metal-free and AAEM complexed glucose. Metal-free glucose produced 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DHMDHP) as the predominant compound in bio-oil, while 1,6-anhydroglucofuranose (AGF) was dominant in Na(i)/glucose, levoglucosan (LGA) in K(i)/glucose, levoglucosenone (LGO) in Ca(ii)/glucose and furfural in Mg(ii)/glucose. To evaluate the stereoelectronic basis of metal ions in altering pyrolysis reaction kinetics, the reaction mechanisms of AGF, LGA, 5-hydroxymethylfurfural (5-HMF), furfural, 1,5-anhydro-4-deoxy-d-glycerohex-1-en-3-ulose (ADGH), LGO, and char formation were investigated using DFT calculations. DFT results showed that the presence of Ca(ii) and Mg(ii) ions catalyzed furfural and LGO formation, while alkali ions decatalyzed the formation of these products. Conversely, Na(i) and K(i) ions catalyzed the concerted dehydrative ring closure of glucofuranose during AGF formation. For ADGH, AAEMs showed an anti-catalytic effect. We also described a novel route for char formation via coupling between 1,2-anhydroglucopyranose and a carbonyl compound. The presence of alkali ions catalyzed char formation. Thus, the atomistic insights obtained from DFT calculations assist in understanding the observed change in experimental yields of individual bio-oil compounds governing their composition.
- Arora, Jyotsna S.,Ansari, Khursheed B.,Chew, Jia Wei,Dauenhauer, Paul J.,Mushrif, Samir H.
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- Production of levoglucosenone and 5-hydroxymethylfurfural from cellulose in polar aprotic solvent-water mixtures
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We demonstrate a process to produce levoglucosenone (LGO) and 5-hydroxymethylfurfural (HMF) from cellulose in up to 65% carbon yield using sulfuric acid as catalyst and a solvent consisting of a mixture of tetrahydrofuran (THF) with water. In pure THF, LGO is the major product of cellulose dehydration, passing through levoglucosan as an intermediate. Increasing the water content (up to 5 wt%) results in HMF as the major product. HMF is formed both by glucose dehydration and direct dehydration of LGA. The maximum combined yield of LGO and HMF (~65 carbon%) is achieved in the presence of 1-2.5 wt% H2O, such that comparable amounts of these two co-products are formed. THF gave the highest total yields of LGO and HMF among the solvents investigated in this study (i.e., THF, diglyme, tetraglyme, gamma-valerolactone (GVL), cyclopentyl methyl ether (CPME), 1,4-dioxane, and dimethyl sulfoxide (DMSO)). Furthermore, the rate of LGO and HMF degradation in THF was lower than in the other solvents. LGO/HMF yields increased with increased strength of the acid catalyst (H2SO4 > H3PO4 > HCOOH), and HMF was produced more selectively than LGO in the presence of hydrochloric acid. Techno-economic analysis for LGO and HMF production from cellulose shows that the lowest LGO/HMF production costs are less than $3.00 per kg and occur at a cellulose loading and water content of 2-3% and 1.5-2.5% respectively.
- He, Jiayue,Liu, Mingjie,Huang, Kefeng,Walker, Theodore W.,Maravelias, Christos T.,Dumesic, James A.,Huber, George W.
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- Synergetic Effect of Br?nsted/Lewis Acid Sites and Water on the Catalytic Dehydration of Glucose to 5-Hydroxymethylfurfural by Heteropolyacid-Based Ionic Hybrids
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The effective dehydration of glucose to 5-hydroxymethylfurfural (HMF) has attracted increasing attention. Herein, a series of sulfonic-acid-functionalized ionic liquid (IL)–heteropolyacid (HPA) hybrid catalysts are proposed for the conversion of glucose to HMF. A maximum total yield of HMF and levoglucosan (LGA; ≈71 %) was achieved in the presence of pyrazine IL-HPA hybrid catalyst [PzS]H2PW in THF/H2O–NaCl (v/v 5:1). The mechanism of glucose dehydration was studied by tailoring the Br?nsted/Lewis acid sites of the hybrid catalysts and altering the solvent composition. It was found that water and heteropolyanions have a significant effect on the reaction kinetics. Heteropolyanions are able to stabilize the intermediates and promote the direct dehydration of glucose and intermediate LGA to HMF. A small amount of water could facilitate the conversion of glucose to LGA and suppress the dehydration of LGA to levoglucosenone. In addition, the synergetic effect of Br?nsted/Lewis acid sites and a little water was conducive to accelerated proton transfer, which improved the yield of HMF from glucose dehydration.
- Zhao, Pingping,Cui, Hongyou,Zhang, Yunyun,Zhang, Yuan,Wang, Yong,Zhang, Yali,Xie, Yujiao,Yi, Weiming
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p. 824 - 832
(2018/10/31)
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- High-pressure fast-pyrolysis, fast-hydropyrolysis and catalytic hydrodeoxygenation of cellulose: Production of liquid fuel from biomass
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A lab-scale, high-pressure, continuous-flow fast-hydropyrolysis and vapor-phase catalytic hydrodeoxygenation (HDO) reactor has been successfully designed, built and tested with cellulose as a model biomass feedstock. We investigated the effects of pyrolysis temperature on high-pressure cellulose fast-pyrolysis, hydrogen on high-pressure cellulose fast-hydropyrolysis, reaction pressure (27 bar and 54 bar) on our reactor performance and candidate catalysts for downstream catalytic HDO of cellulose fast-hydropyrolysis vapors. In this work, a liquid chromatography-mass spectrometry (LC-MS) method has been developed and utilized for quantitative characterization of the liquid products. The major compounds in the liquid from cellulose fast-pyrolysis (27 bar, 520 °C) are levoglucosan and its isomers, formic acid, glycolaldehyde, and water, constituting 51 wt%, 11 wt%, 8 wt% and 24 wt% of liquid respectively. Our results show that high pressures of hydrogen do not have a significant effect on the fast-hydropyrolysis of cellulose at 480 °C but suppress the formation of reactive light oxygenate species like glycolaldehyde and formic acid at 580 °C. The formation of permanent gases (CO, CO2, CH4) and glycolaldehyde and formic acid increased with increasing pyrolysis temperature in the range of 480 °C-580 °C in high-pressure cellulose fast-pyrolysis, in the absence of hydrogen. Candidate HDO catalysts Al 2O3, 2% Ru/Al2O3 and 2% Pt/Al 2O3 resulted in extents of deoxygenation of 20%, 22% and 27%, respectively, but led to carbon loss to gas phase as CO and CH4. These catalysts provide useful insights for other candidate HDO catalysts for improving the extent of deoxygenation with higher carbon recovery in the liquid product.
- Venkatakrishnan, Vinod Kumar,Degenstein, John C.,Smeltz, Andrew D.,Delgass, W. Nicholas,Agrawal, Rakesh,Ribeiro, Fabio H.
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p. 792 - 802
(2014/02/14)
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- Mechanocatalysis for biomass-derived chemicals and fuels
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Heterogeneous catalysis cannot be easily applied to solids such as cellulose. However, by mechanically grinding the correct catalyst and reactant, it is possible to induce solid-solid catalysis or mechanocatalysis. This process allows a wide range of solids to be effectively utilized as feedstock for commercially relevant compounds. Here we show a set of structural and physical parameters important for the implementation of catalysts in mechanocatalytic processes and their application in the catalytic depolymerization of cellulose. Using the best catalysts, which possess high surface acidities and layered structures, up to 84% of the available cellulose can be converted to water-soluble compounds in a single pass. This approach offers significant advantages over current methods - less waste, insensitivity to feedstock, multiple product pathways, and scalability. It can be easily integrated into existing biorefineries - converting them into multi-feedstock and multi-product facilities. This will expand the use of non-food polysaccharide sources such as switch grass.
- Hick, Sandra M.,Griebel, Carolin,Restrepo, David T.,Truitt, Joshua H.,Buker, Eric J.,Bylda, Caroline,Blair, Richard G.
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experimental part
p. 468 - 474
(2010/08/06)
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- Inhibition of acid-catalyzed depolymerization of cellulose with boric acid in non-aqueous acidic media
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Boric acid inhibited the acid-catalyzed depolymerization of cellulose in sulfolane, a non-aqueous medium, at high temperature. Formation of the dehydration products such as levoglucosenone, furfural, and 5-hydroxymethyl furfural were also effectively inhibited. Similar inhibition was observed for cellooligosaccharides and starch, although the glucosidic bonds in methyl glucopyranosides and methyl cellobioside were cleaved to form α-d-glucofuranose cyclic 1,2:3,5-bisborate.
- Kawamoto, Haruo,Saito, Shinya,Saka, Shiro
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p. 249 - 255
(2008/09/19)
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- 3-Oxidopyrylium Adducts from the Pyrolysis of Cellulose
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The major product from pyrolysis of acid-doped cellulose is levoglucosenone (1) which is now shown to undergo, under the conditions of its formation, deformylation to 3-oxidopyrylium (2).Five dimers of this ylide (2), and an adduct (17) of it and levoglucosenone (1), have now been isolated from the product of phosphoric acid-catalysed pyrolysis of cellulose.Sealed tube pyrolysis of (1) yielded the adduct (17) and its isomer (18).
- Furneaux, Richard H.,Mason, Jennifer M.,Miller, Ian J.
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p. 1923 - 1928
(2007/10/02)
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