- Catalytic acetalization of glycerol to biofuel additives over NiO and Co3O4 supported oxide catalysts: experimental results and theoretical calculations
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A series of NiO and Co3O4 supported oxide catalysts was synthesized and investigated in the acetalization of glycerol with butyraldehyde to biofuels production. The catalysts were characterized by XRD, N2 sorption, FTIR and Raman spectroscopy, SEM-EDS and HRTEM techniques. The influence of the catalysts mass, glycerol to butyraldehyde molar ratios, reaction temperature and presence of solvent were deeply investigated. The dispersion of Ni and Co oxides gave distinct effects on the catalytic performances of the solids with AlTi and CeMn being actives in all conditions tested. The mechanistic aspect of the reaction was investigated by density functional theory (DFT). Among the catalysts, the high acidity of the Co/CeMn and Ni/CeMn promoted the acetalization of glycerol more efficiently to produce 4-methanol-2-propyl-1,3-dioxolane, in spite of the glycerol oligomers formation. The correlation of the structure, acidity, morphology and texture of the solids with the catalytic performance was illustrated for solventless acetalization of glycerol with butyraldehyde reaction. The theoretical calculations by DFT studies revealed a more favorable route to 1,3-dioxolane production.
- Bezerra, Jo?o R.,Campos, Adriana,Duarte, Gian,Oliveira, Alcineia C.,Oton, Lais F.,Saraiva, Gilberto D.,Tehuacanero-Cuapa, Samuel,de Sousa, Francisco F.
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- Structure–Activity Relationships of WOx-Promoted TiO2–ZrO2 Solid Acid Catalyst for Acetalization and Ketalization of Glycerol towards Biofuel Additives
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Abstract: WOx-promoted TiO2–ZrO2 solid acid catalyst was prepared and applied in the catalytic acetalization and ketalization of glycerol with carbonyl compounds to produce biofuel additives. The presence of WOx promoter and TiO2 remarkably improved the catalytic activity of ZrO2. Approximately, 100% glycerol conversion was evidenced with non-bulky aliphatic aldehydes and ketones like, propanol and cyclohexanone. The physical characterization of WOx-promoted TiO2–ZrO2, revealed a higher formation of tetragonal crystalline phase of ZrO2, over monoclinic. The total surface acidity and the ratio of Br?nsted to Lewis acidic site concentrations were determined by NH3-TPD and pyridine-chemisorbed FTIR spectroscopy, respectively. A considerably higher concentration of Lewis acidic sites, ~ 213.29?μmol/gm, was evidenced on the WOx-promoted TiO2–ZrO2 catalyst surface. Catalytic activity study revealed a direct correlation between the surface Lewis acidic site concentration and the activity of catalyst. This significant observation indicated the key role of Lewis acidic sites in this catalytic process. The WOx-promoted TiO2–ZrO2 catalyst was also considerably stable and showed good performance in the acetalization/ketalization of glycerol with other substituted carbonyl compounds. Graphic Abstract: The WOx-promoted TiO2–ZrO2 solid acid catalyst exhibits superior catalytic performance for acetalization and ketalization of glycerol with carbonyl compounds to produce biofuel additives. [Figure not available: see fulltext.].
- Baithy, Mallesham,Mukherjee, Deboshree,Rangaswamy, Agolu,Reddy, Benjaram M.
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- Conversion of platform chemical glycerol to cyclic acetals promoted by acidic ionic liquids
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The condensation of glycerol, a platform chemical from renewable materials, with benzaldehyde to generate cyclic acetals was investigated using acidic ionic liquid as catalyst. Evidence was presented that the product mixture of 4-hydroxymethyl-2-phenyl-1,3-dioxolane and 5-hydroxyl-2-phenyl-1,3-dioxane, with cis and trans two stereo-isomers for each one identified by 1H NMR were obtained. Further modification of reaction conditions promoted by N-butyl-pyridinium bisulfate ([BPy]HSO4) led to the totally cyclic acetals with 99.8% yield at room temperature. A micro water-removal reactor constituted by ionic liquids was proposed, which favourably shifted the condensation equilibrium to the product side by transferring the produced water out of the organic phase in time, so that the water-carrying agent or reactive distillation was avoided. Moreover, the product separation made this methodology more accessible to sustainable green biomass chemistry.
- Wang, Bo,Shen, Yue,Sun, Jiankui,Xu, Feng,Sun, Runcang
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p. 18917 - 18923
(2014/05/20)
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- Acetals Esters Produced from Purified Glycerin for Use and Application as Emollients, Lubricants, Plasticizers, Solvents, Coalescents, Humectant, Polymerization Monomers, Additives to Biofuels
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It refers to a new group of acetal monoesters and diesters which have in its structure the ester function and cyclic ethers that give these products excellent properties as solvency, plasticity in polymers, solubility in polar and nonpolar means, spreadab
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Paragraph 0050
(2014/12/09)
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- Features of synthesis of 4-hydroxymethyl-1,3-dioxolanes from glycerol and aldehydes
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Specific features of reaction of glycerol with aldehydes, compared to ketones, were revealed, and formation of 4-hydroxymethyl-1,3-dioxolanes from glycerol and lower aldehydes (acetaldehyde, propionaldehyde, and butyraldehyde) was examined. The products were isolated, and their physicochemical characteristics were determined.
- Shevchuk,Podgornova,Piskaikina
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p. 853 - 856
(2007/10/03)
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