- Esterification of stearic acid by isomeric forms of butanol in a microwave oven under homogeneous and heterogeneous reaction conditions
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In this paper the influence of conventional and dielectric heating on the esterification of stearic acid by butanol has been studied. The influences of different isomeric forms of butanol, a catalyst and conditions of reaction (homogeneous versus heterogeneous) upon esterification have been investigated. The difference between conventionally or dielectrically heated reactions has been studied. For heterogeneous reactions a significant temperature enhancement effect is observed. This effect can be enlarged by the application of heat captors, which have been mixed or impregnated with catalyst. Further rate enhancements are realised by the use of a combination of microwave heating and ultrasound for heterogeneously catalysed reactions.
- Chemat, Farid,Poux, Martine,Galema, Saskia A.
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- Flow-through immobilization of Candida rugosa lipase on hierarchical micro-/macroporous carbon monolith
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Hierarchical micro-/macroporous carbon monoliths are prepared as enzyme carriers for flow-through process. The immobilization of Candida rugosa lipase on micro-/macroporous carbon monoliths is studied. Lipase is immobilized by physical adsorption which lipase solution is circulated through the micro-/macroporous carbon monolith. An accessibility of lipase to the surface inside the micro-/macroporous carbon monolith is enhanced by flow-through method which promotes enzyme-surface interaction and finally leads to rapid enzyme immobilization. After immobilization is conducted for 10 min, the maximum protein binding can be measured. In terms of substrate-immobilized lipase reactions, flowing of substrate through lipase immobilized micro-/macroporous carbon monolith promotes high efficiency in both reaction and product withdrawal. Moreover, at high flow rates of lipase solution in immobilization step, the lipase activity increases. Oxygenated surface of micro-/macroporous carbon monoliths support also demonstrates an interesting effect on lipase immobilization and biocatalyst activity. The initial reaction rate of lipase immobilized on oxygenated surface carbon monolith support has higher activity compared with normal surface.
- Luangon, Bordin,Siyasukh, Adisak,Winayanuwattikun, Pakorn,Tanthapanichakoon, Wiwut,Tonanon, Nattaporn
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- Hydrothermal saline promoted grafting: A route to sulfonic acid SBA-15 silica with ultra-high acid site loading for biodiesel synthesis
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A simple grafting protocol is reported which affords a ten-fold enhancement in acid site density of mesoporous sulfonic acid silicas compared to conventional syntheses, offering improved process efficiency and new opportunities for tailored supported solid acids in sustainable chemistry. This journal is
- Pirez,Lee,Manayil,Parlett,Wilson
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- Transesterification to biodiesel with superhydrophobic porous solid base catalysts
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Super combo: Superhydrophobic and porous solid bases are synthesized by co-polymerization of divinylbenzene (DVB) and 1-vinylimidazolate (VI). The materials show higher activities towards the transesterification of tripalmitin with methanol than conventional bases and VI mono-/polymer. Their performance is attributed to the synergy of superhydrophobicity combined with active VI sites. These catalysts also remain very active upon recycling.
- Liu, Fujian,Li, Wei,Sun, Qi,Zhu, Longfeng,Meng, Xiangju,Guo, Yi-Hang,Xiao, Feng-Shou
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- Synthesis and characterization of the n-butyl palmitate as an organic phase change material
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In this research, the n-butyl palmitate was synthesized using the esterification reaction of the PA with n-butanol. The 1H nuclear magnetic resonance and Fourier transform infrared illustrated that the hydroxyl group and carboxyl group disappeared, and the ester bond appeared after the reaction, explaining that n-butyl palmitate was successfully fabricated. The differential scanning calorimetry indicated that the phase-transition temperature and latent heat are 12.6?°C and 127.1?J?g?1, which was suited to use in low-temperature fields such as food, pharmaceutical, and biomedical. The thermogravimetric analysis suggested that it had great thermal stability during the phase change process. In addition, the thermal conductivity of the n-butyl palmitate was slightly higher than other fatty acid ester, and the 500 thermal cycles test results indicated that it had excellent thermal reliability. Therefore, the n-butyl palmitate is deduced to share great thermal energy storage ability in terms of latent heat thermal energy system applications.
- Ma, Liyun,Guo, Chuigen,Ou, Rongxian,Wang, Qingwen,Li, Liping
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- Charge-remote and charge-proximate fragmentation processes in alkali- cationized fatty acid esters upon high-energy collisional activation. A new mechanistic proposal
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The effect of the metal ion on the high-energy collision-induced dissociation (CID) of alkali metal-cationized n-butyl and methyl ester derivatives of palmitic and oleic acid was examined. The results show that the alkali metal ion has a pronounced effect and does not act as a mere 'spectator' ion with respect to the fragmentation process. While C-H cleavage is a dominant process for [M + Li]+ as well as [M + Na]+ precursor ions, C- C cleavage is also significant for the [M + Na]+ ions. Homolytic mechanisms involving the formation of a transient biradical cation are proposed which enable us to rationalize in a straightforward manner all product ions formed by both charge-remote and charge-proximate fragmentations. The mechanistic proposal is discussed in view of available knowledge on electron impact, CID and related processes. In order to predict how the alkali metal ion could affect the reactivity of the postulated biradical state formed following electronic excitation of the alkali metal-cationized molecules, quantum chemical calculations were performed on methyl and n-butyl acetate as model substances. The decreased spin density at the carbonyl oxygen atom in the biradical state may provide an explanation for the greater tendency towards C-C cleavage reactions of the sodium-cationized fatty acid esters relative to the corresponding lithium complexes.
- Claeys, Magda,Nizigiyimana, Liberata,Van Heuvel, Hilde Den,Vedernikova, Irina,Haemers, Achiel
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- Activation of enzyme nanogel in organic solvents by PEG-substrate joint imprinting
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A substrate or polyethyleneglycol (PEG) imprinted lipase nanogel displayed increased apparent activity in organic solvents by 2.5-4.7 folds, compared to native lipase. It enabled a one-step synthesis of chloramphenicol palmitate with a yield of ~99% and purity of ~99%, indicating that the imprinted lipase nanogel is an appealing catalyst in organic media. This journal is
- Wang, Rui,Zhang, Yifei,Ge, Jun,Liu, Zheng
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- Development and Validation of a Novel Free Fatty Acid Butyl Ester Gas Chromatography Method for the Determination of Free Fatty Acids in Dairy Products
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Accurate quantification of free fatty acids in dairy products is important for both product quality control and legislative purposes. In this study, a novel fatty acid butyl ester method was developed, where extracted free fatty acids are converted to butyl esters prior to gas chromatography with flame ionization detection. The method was comprehensively validated to establish linearity (20-700 mg/L; R2 > 0.9964), limits of detection (5-8 mg/L), limits of quantification (15-20 mg/L), accuracy (1.6-5.4% relative error), interday precision (4.4-5.3% relative standard deviation), and intraday precision (0.9-5.6% relative standard deviation) for each individual free fatty acid. A total of 17 dairy samples were analyzed, covering diverse sample matrices, fat content, and degrees of lipolysis. The method was compared to direct on-column injection and fatty acid methyl ester methods and overcomes limitations associated with these methods, such as either column-phase absorption or deterioration, accurate quantification of short-chain free fatty acids, and underestimation of polyunsaturated free fatty acid.
- Mannion, David T.,Furey, Ambrose,Kilcawley, Kieran N.
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p. 499 - 506
(2019/01/08)
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- Characterization, performance, and applications of a yeast surface display-based biocatalyst
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This work demonstrates the efficacy and cost effectiveness of yeast surface display (YSD) as a method for producing and purifying enzyme catalysts. Lipase B from Candida antarctica (CalB) and lipase from Photobacterium lipolyticum sp. M37 (M37L) were individually displayed on the surface of yeasts via fusion with alpha-agglutinin. The enzyme is produced, purified, and immobilized in a single step. The population expressing the enzyme was quantified by flow cytometry. After lyophilization, the hydrolytic activity of the biocatalyst was assayed with p-nitrophenyl butyrate and p-nitrophenyl palmitate substrates. Esterification reactions involving octanoic acid and either butanol or octanol were used to evaluate esterification activity. The lyophilized YSD biocatalyst hydrolytic activity matched or exceeded commercial lipase (Novozym 435) immobilized on acrylic resin at equal catalyst loading, and achieved esterification levels 10-50% that of Novozyme 435. Factoring in the cost of production, the YSD biocatalyst represents a considerable savings over traditionally prepared and purchased enzyme catalysts. This promises to significantly expand the catalytic applications of immobilized lipases, and immobilized enzymes more generally, in commercial processes. This journal is
- Eby,Peretti
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p. 19166 - 19175
(2015/06/15)
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- Use of metal-accumulating plants for implementing chemical reactions
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The use of metal-accumulating plants for implementing chemical reactions.
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Page/Page column 45
(2015/10/28)
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- USE OF COMPOSITIONS OBTAINED BY CALCINING PARTICULAR METAL-ACCUMULATING PLANTS FOR IMPLEMENTING CATALYTICAL REACTIONS
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The use of metal-accumulating plants for implementing chemical reactions especially catalytical reactions.
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Paragraph 0744-0747
(2016/01/25)
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- Synthesis of carboxylic acid esters in the presence of micro- and mesoporous aluminosilicates
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The catalytic properties of zeolites HY, HBeta, and HZSM-12 and of mesoporous amorphous aluminosilicate in liquid-phase esterification of aliphatic (monobasic C1-C18, dibasic C6, C10) and aromatic (benzoic, trimellitic, phthalic) carboxylic acids with butanol were studied. Zeolite HBeta appeared to be the most active catalyst. Procedures were developed for preparing esters in the presence of zeolitic catalyst HBeta, ensuring 100% selectivity of ester formation at 90-98% conversion of the acid.
- Grigor'Eva,Suleimanova,Agliullin,Kutepov
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p. 773 - 779
(2015/01/30)
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- Application of Sulfonic Acid Functionalised Hybrid Silicas Obtained by Oxidative Cleavage of Tetrasulfide Bridges as Catalysts in Esterification Reactions
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Hybrid materials with tetrasulfide bridges were synthesised by co-condensation between bis[3-(triethoxysilyl)propyl]tetrasulfide and either tetraethyl orthosilicate or 1,4-bis(triethoxysilyl)benzene under acidic conditions in the presence of Brij-76 as a structure-directing agent. They were post-modified by treatment with H2O2 for 3h or 24h. A progressive loss of the mesostructure in the resulting materials was observed upon increasing the S content in the synthesis mixtures. Thus, only those samples with the lowest tetrasulfide content could be considered as periodic mesoporous organosilicas. This effect was even more pronounced upon oxidation. The oxidised materials exhibited a considerable acidity, particularly those with the two precursors in approximately equal amounts. All sulfonic acid functionalised materials were used as catalysts in the esterification of acetic acid with ethanol, and they exhibited a comparable or very similar activity to that of Amberlyst-15. Several mesoporous and microporous hybrid materials were selected and compared to this commercial resin in the transformation of more hydrophobic substrates. Some of these hybrid materials were especially attractive for the transformation of benzyl alcohol and various secondary alcohols.
- Lopez, Maria Isabel,Esquivel, Dolores,Jimenez-Sanchidrian, Cesar,Romero-Salguero, Francisco Jose
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p. 1002 - 1010
(2013/05/09)
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- Well-dispersed sulfated zirconia nanoparticles as high-efficiency catalysts for the synthesis of bis(indolyl)methanes and biodiesel
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Well-dispersed sulfated zirconia nanoparticles were synthesized with poly(N-vinylpyrrolidone) as a surfactant. The resultant sulfated zirconia nanoparticles are characterized by SEM, XRD, FT-IR and XPS. These nanoparticles were directly used as catalysts for the synthesis of bis(indolyl)methanes and biodiesel via electrophilic substitution reaction of indole with various aldehydes and the esterification of long-chain free fatty acids and exhibited excellent catalytic activity. The mechanism of the formation of the synthesized zirconia nanoparticles was also proposed.
- Chen, Guochang,Guo, Cun-Yue,Qiao, Hongbin,Ye, Mingfu,Qiu, Xiaoning,Yue, Caibo
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- Specific enzyme-catalyzed hydrolysis and synthesis in aqueous and organic medium using biocatalysts with lipase activity from Aspergillus niger MYA 135
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In the present study, the specific hydrolytic activity of three biocatalysts such as the constitutive mycelium-bound lipase, the induced mycelium-bound lipase and the lyophilized induced supernatant from A. niger MYA 135 was evaluated in both aqueous and organic media.A direct correlation between activity in water and n-hexane was not observed for the same hydrolytic reaction. The n-hexane/water activity ratio (RO/A) was applied to characterize the activity in organic medium. The three biocatalysts showed RO/A values higher than 1 for hydrolysis of long-chain fatty acid esters, demonstrating a higher specific hydrolytic activity in organic solvent than in water. A different behavior was observed during hydrolysis of middle-chain fatty acid esters, which was higher in aqueous medium (R O/Adw) observed in a reaction mixture containing propanol and p-nitrophenyl laurate. Finally, both p-nitrophenyl caprate (C10) and p-nitrophenyl laurate (C12) were preferentially methanolized by the lyophilized induced supernatant, being this lipase activity the most specific biocatalyst preparation under transesterification conditions. A selectivity-based analysis of each lipase preparation toward transesterification or hydrolysis in organic medium was evaluated as well. Springer Science+Business Media, LLC 2012.
- Romero, Cintia M.,Pera, Licia M.,Loto, Flavia,Baigori, Mario D.
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p. 1361 - 1368
(2013/01/15)
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- Synthesis of short chain alkyl esters using cutinase from Burkholderia cepacia NRRL B2320
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Short chain alkyl esters are well appreciated for fruity flavors they provide. These are mainly applied to the fruit-flavored products like jam, jelly, beverages, wine and dairy. Cutinase from Burkholderia cepacia NRRL B 2320 was found to be active in catalyzing the synthesis of alkyl esters in organic solvent. The optimal temperature range for the enzyme catalyzed synthesis was found to be from 35 °C to 40 °C. The maximum conversion (%) during synthesis of ester was obtained for butyric acid (C4) and valeric acid (C5) with butanol reflecting the specificity of the enzyme for short-chain length fatty acids. In case of alcohol specificity, butanol was found to be most preferred substrate by the enzyme and conversion (%) decreased with increasing carbon chain length of alcohol used in the esterification reaction. The kinetic analysis for the synthesis of butyl butyrate by varying concentration of one substrate at a time (butanol or butyric acid), showed that Ping-Pong Bi Bi model with acid inhibition and influence of initial water is most suitable model for the prediction of the reaction kinetics.
- Dutta, Kasturi,Dasu, Veeranki Venkata
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experimental part
p. 150 - 156
(2012/07/01)
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- PRODUCTION OF DETERGENT RANGE ALCOHOLS
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This invention relates to a process for the production of a mixture of detergent-range alcohols having an average of between 8 and 20 carbon atoms per molecule. The process includes the steps of providing a hydrocarbon stream containing olefins and paraffins in which more than 5% by volume of olefin molecules in the hydrocarbon stream have a total number of carbon atoms which is different from the total number of carbon atoms of the most abundant two carbon numbers of olefins in the hydrocarbon stream; reacting the hydrocarbon stream with CO and an alcohol in the presence of a catalyst in a hydroesterification reaction to form a hydrocarbon stream containing esters and paraffins; separating esters from the hydrocarbon stream containing esters and paraffins; and subjecting the esters to a hydrogenation reaction to provide the mixed alcohol product.
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(2009/01/24)
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- Process for producing fatty acid alkyl ester composition
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An object of the present invention is to solve a problem of separation and recovery of catalysts present in an alkali metal catalytic method currently often used, a problem of excess consumption of a catalyst by a free fatty acid in a raw material, and other problems, and to solve a problem of the presence of a large excess amount of alcohol in a conventional supercritical methanol method, and to provide a method for producing a fatty acid alkyl ester composition in a reaction system containing water and free fatty acid present. The present invention has attained the above-mentioned object by provided a method for producing a fatty acid alkyl ester composition using fats and oils containing a fatty acid glyceride and/or fatty acid, wherein alcohol and/or water is allowed to co-exist with the above-mentioned fats and oils and the reaction is conducted under conditions of a temperature of 100° C. to 370° C. and a pressure of 1 to 100 MPa.
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(2008/06/13)
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- An eco-friendly method for the synthesis of aryl and alkyl esters of carboxylic acids using acid activated Indian bentonite
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Esterification of various carboxylic acids with phenol and alcohols has been achieved using acid activated Indian bentonite (AAIB) as catalyst. The catalyst is versatile, and the reaction is found to work well for primary, secondary and tertiary alcohols. The yields are very good under specific reaction conditions.
- Vijayakumar,Iyengar, Pushpa,Nagendrappa, Gopalpur,Prakash, B. S. Jai
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p. 922 - 925
(2007/10/03)
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- A CONVENIENT METHOD FOR ENZYMATIC BENZYL-ALKYL TRANSESTERIFICATION UNDER MILD NEUTRAL CONDITIONS
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Lipases from Candida cylindracea and from Pseudomonas fluorescens efficiently catalyse the benzyl to alkyl transesterification in organic solvents under mild conditions in nearly quantitative yields.
- Gutman, Arie L.,Shkolnik, Eleonora,Shapira, Michal
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p. 8775 - 8780
(2007/10/02)
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