- Evolution Process and Controlled Synthesis of Humins with 5-Hydroxymethylfurfural (HMF) as Model Molecule
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Elucidation of the chemical structure and formation mechanism of humins is a requisite to further improve the efficiency of acid-catalyzed biomass conversion. Through a low-temperature approach, the key intermediates resulting in the formation of 5-hydroxymethylfurfural (HMF)-derived humins were captured, revealing multiple elementary reactions such as etherification, esterification, aldol condensation, and acetalization. Through humin characterization, it was found out that the aldol condensation moiety between aldehyde group and levulinic acid is critical to justify the characteristic IR peaks (1620 and 1710 cm?1) and aromatic fragments from pyrolysis GC–MS. Based on the investigations by means of HPLC–MS/MS, IR, pyrolysis GC–MS, and SEM, the structural models of humins at different temperatures were proposed, which are comprised of the elementary reaction types confirmed by the key intermediates. Humin structures with varying content of aldol condensation could be controllably synthesized under different reaction conditions (temperature and time), demonstrating the evolution process of HMF-derived humins.
- Shen, Haiyan,Shan, Haozhe,Liu, Li
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- Selective oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran over intercalated vanadium phosphate oxides
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The selective oxidation of 5-hydroxymethylfurfural (5-HMF) to 2,5-diformylfuran (DFF) was studied over vanadium phosphate oxide (VPO)-based heterogeneous catalysts in the liquid phase. The selectivity to DFF was highly increased when using intercalated vanadium phosphate oxides under mild conditions (1 atm of oxygen, 110°C) in an aromatic solvent. We found that the length of the intercalated ammonium alkyl chain had no clear influence on the catalytic performances, and a maximum yield of 83% could be achieved over C14VOPO4 and C14VOHPO4 after 6 h of reaction. Recycling of the catalyst was successfully performed, and we further obtained some insights in the reaction pathway: while the desired oxidation reaction indeed proceeded over the catalyst, the formation of by-products was linked to the presence of free radicals in solution.
- Grasset, Fabien L.,Katryniok, Benjamin,Paul, Sebastien,Nardello-Rataj, Veronique,Pera-Titus, Marc,Clacens, Jean-Marc,De Campo, Floryan,Dumeignil, Franck
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- Production of 5-(formyloxymethyl)furfural from biomass-derived sugars using mixed acid catalysts and upgrading into value-added chemicals
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In this work, 5-(formyloxymethyl)furfural (FMF) has been produced from biomass-derived hexose sugars within a biphasic reaction mixture consisting of aqueous formic acid (85%), a strong Br?nsted acid catalyst, and 1,2-dichloroethane as an organic extractant. Using a combination of aqueous hydrobromic acid and formic acid, under optimized condition (80 °C, 8 h, 10 wt% substrate loading), 68% isolated yield of FMF was obtained from fructose. FMF has been demonstrated as a renewable chemical building block for the synthesis of renewable chemicals of commercial significance such as 5-methylfurfural, 2,5-diformylfuran, and 2,5-furandicarboxylic acid in good to excellent isolated yields.
- Dutta, Saikat
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- Oxidation of 5-hydroxymethylfurfural to maleic anhydride with molecular oxygen
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5-Hydroxymethylfurfural (HMF) was converted to maleic anhydride in 52% yield via selective oxidation with molecular oxygen using VO(acac)2 as catalyst in liquid phase. The Royal Society of Chemistry.
- Du, Zhongtian,Ma, Jiping,Wang, Feng,Liu, Junxia,Xu, Jie
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- Toward an Integrated Conversion of 5-Hydroxymethylfurfural and Ethylene for the Production of Renewable p-Xylene
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The use of biomass as a solution to satisfy the pressing needs for a fully sustainable biocommodity industry has been explored for a long time. However, limited success has been obtained. In this study, a highly effective two-stage procedure for the direct preparation of para-xylene (PX) from 5-hydroxymethylfurfural (HMF) and formic acid in one pot is described; these chemicals are two of the major bio-based feedstocks that offer the potential to address urgent needs for the green, sustainable production of drop-in chemical entities. The use of a robust, efficient heterogeneous catalyst, namely, bimetallic Pd-decorated Au clusters anchored on tetragonal-phase zirconia, is crucial to the success of this strategy. This multifunctional catalytic system can not only facilitate a low-energy-barrier H2-free pathway for the rapid, nearly exclusive formation of 2,5-dimethylfuran (DMF) from HMF but also enable the subsequent ultraselective production of PX by the dehydrative aromatization of the resultant DMF with ethylene. With increasing pressure around the world to move toward a bio-based economy, it is essential that industrially important commodity chemicals can be readily accessed from biomass resources. Para-xylene (PX) synthesis is one such target that is being actively pursued through the development of several biorefinery schemes based on integrated biomass processing. Significant progress has recently been achieved either in the selective synthesis of biorenewable PX from Diels-Alder-like coupling of ethylene with 2,5-dimethylfuran (DMF) or making DMF from 5-hydroxymethylfurfural (HMF) using hydrogen as the terminal reductant. However, a green and direct conversion of HMF, an essential feedstock source for future biorefinery schemes, into PX has yet to be developed. We have established an integrated process that directly converts HMF to PX in a highly compact and hydrogen-independent manner, thereby providing a new perspective on the potential of advanced biorefinery technologies. Cao and colleagues describe an alternative strategy for producing para-xylene through a more sustainable method than the current bio-based approaches. The strategy relies on an integrated conversion of 5-hydroxymethylfurfural with formic acid and ethylene, made possible by the use of a single multifunctional catalyst based on bimetallic Pd-decorated Au deposited on tetragonal-phase zirconia. The proposed process is particularly appealing because it is fully fossil independent, implying a viable and greener biorefinery scheme.
- Tao, Lei,Yan, Tian-Hao,Li, Wenqin,Zhao, Yi,Zhang, Qi,Liu, Yong-Mei,Wright, Mark M.,Li, Zhen-Hua,He, He-Yong,Cao, Yong
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supporting information
p. 2212 - 2227
(2018/10/02)
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- EFFICIENT METHOD FOR PREPARING 2,5-DIMETHYLFURAN
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The present disclosure provides methods to make liquid fuels from renewable, carbon neutral precursors. Specifically, methods to prepare 2,5-dimethylfuran from a source of fructose or other carbohydrates using a one-pot synthesis are provided. In some embodiments, the disclosed methods avoid the isolation of intermediates, and employ “green” reagents like formic acid and acetic acid.
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Page/Page column 12
(2011/11/06)
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- Efficient production of the liquid fuel 2,5-dimethylfuran from fructose using formic acid as a reagent
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Three in one: New reagents are needed to generate liquid fuels from biomass, but the reagents must serve multiple roles. For the conversion of fructose into the title compound 1, formic acid serves three roles: assists in the isomerization/dehydration, serves as an H2 source for hydrogenation, and helps deoxygenate the alcohol functional groups.
- Thananatthanachon, Todsapon,Rauchfuss, Thomas B.
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supporting information; experimental part
p. 6616 - 6618
(2010/11/04)
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