The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Arthur J Ragauskas - One of the best experts on this subject based on the ideXlab platform.
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phosphitylation and quantitative 31p nmr analysis of partially substituted biodiesel Glycerols
Fuel, 2009Co-Authors: Mate Nagy, Brian J Kerr, Cherie Ziemer, Arthur J RagauskasAbstract:The main step during biodiesel production is the catalytic transesterification of triglycerides. Glycerol and fatty acids are by-products of the biodiesel production and considered as contaminants in the final product. By selectively measuring the amount of fatty acids and Glycerol with different substitution levels, the yield of this step and the quality of the final biodiesel can be determined. This study examines the application of phosphitylation of Glycerol hydroxyl groups with 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane followed by P-31 NMR analysis to provide a rapid quantitative analytical technique for the determination of substitution patterns on partially esterified Glycerols, alcohols and the detection of fatty acids. P-31 NMR chemical shift data was established with a series mono and di-substituted esters of Glycerol, fatty acids and alcohols, then utilized to characterize commercial Glycerol and biodiesel samples. (C) 2009 Elsevier Ltd. All rights reserved.
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quantitative nmr analysis of partially substituted biodiesel Glycerols
Journal of Biobased Materials and Bioenergy, 2009Co-Authors: Mate Nagy, Teresa L Alleman, Thomas J Dyer, Arthur J RagauskasAbstract:Phosphitylation of hydroxyl groups in biodiesel samples with 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane followed by P-31-NMR analysis provides a rapid quantitative analytical technique for the determination of substitution patterns on partially esterified Glycerols. The unique P-31-NMR chemical shift data was established with a series mono and di-substituted fatty acid esters of Glycerol and then utilized to characterize an industrial sample of partially processed biodiesel.
Xingguo Wang - One of the best experts on this subject based on the ideXlab platform.
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solvent free enzymatic preparation of feruloylated monoacylGlycerols optimized by response surface methodology
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Liang Shan, Lixia Zhang, Xingguo WangAbstract:The ability of immobilized lipase B from Candida antarctica (Novozym 435) to catalyze the direct esterification of glyceryl ferulate (FG) and oleic acid for feruloylated monoacylGlycerols (FMAG) preparation in a solvent-free system was investigated. Enzyme screening and the effect of Glycerol on the initial reaction rate of esterification were also investigated. Response surface methodology (RSM) was used to optimize the effects of the reaction temperature (55-65 °C), the enzyme load (8-14%; relative to the weight of total substrates), oleic acid/(FG + Glycerol) (6:1-9:1; w/w), and the reaction time (1-2 h) on the conversion of FG and yield of FMAG. Validation of the RSM model was verified by the good agreement between the experimental and the predicted values of FG conversion and FMAG yield. The optimum preparation conditions were as follows: temperature, 60 °C; enzyme load, 8.2%; substrate ratio, 8.65:1 (oleic acid/(FG + Glycerol), w/w); and reaction time, 1.8 h. Under these conditions, the conversion of FG and yield of FMAG are 96.7 ± 1.0% and 87.6 ± 1.2%, respectively.
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Solvent-free synthesis of glyceryl ferulate using a commercial microbial lipase.
Biotechnology Letters, 2007Co-Authors: Liang Shan, Xingguo WangAbstract:A process was optimized for the enzymatic synthesis of glyceryl ferulate with a yield of up to 96% using a vacuum-rotary evaporation strategy under following conditions: 15 mmol Glycerol, 1.5 mmol ethyl ferulate, 170 mg Candida antarctica lipase, at 60°C for 10 h and under a vacuum of 10 mm Hg. The immobilized lipase can be used 10 times.
Jacek Stawinski - One of the best experts on this subject based on the ideXlab platform.
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a direct transformation of o silyl groups into o trichloroacetates a novel synthetic approach to protein kinase c ligands 1 oleoyl 2 acetyl and 1 hexadecyl 2 acetyl sn Glycerols
Tetrahedron Letters, 2005Co-Authors: Stephan D Stamatov, Martin Kullberg, Jacek StawinskiAbstract:A fluoride ion-promoted direct esterification of tert-butyldimethylsilyl- (TBDMS), or triisopropylsilyl (TIPS)-protected Glycerol derivatives by means of trichloroacetic anhydride (TCAA), followed by removal of the trichloroacetyl transient protection, provides a new, efficient entry to stereochemically pure 1-oleoyl-2-acetyl- and 1-O-hexadecyl-2-acetyl-sn-Glycerols.
Ivana Maria Pereira - One of the best experts on this subject based on the ideXlab platform.
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Estudo de alguns parametros para precipitação de glicerol atraves de complexação com zinconio em vinhaças de alcool carburante e de aguardente e em lixivias fracas de sabvaria
[s.n.], 2018Co-Authors: Ivana Maria PereiraAbstract:Orientador: Roberto Herminio MorettiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de AlimentosResumo: Neste trabalho avaliaram-se diferentes parâmetros, à nivel de laboratório, para precipitar glicerol de vinhaça mista da produção de álcool carburante e vinhaça de caIdo de cana da produção de aguardente, bem como de lixívias fracas de saboaria, através da complexação do glicerol com zircônio e posterior separação por centrifugação e decantação natural. Os processos utilizados consistiram do aquecimento dos efluentes (vinhaças "in natura" e pré-concentrada ou lixívias) com compostos de zircônio dando formação a uiït complexo glicerol-zircônio que precipita em meio alcalino. O precipitado foi então separado por centrifugação ou por decantação natural. Os precipitados após aquecimento a pH ácido liberam o glicerol, que pode então ser destilado. As variáveis estudadas foram: pH de precipitação do camplexo glicerol-zircônia; concentração de zircônio; compostos de zircônio (cloreto, nitrato e hidróxido); processo de separação de Precipitado e tempo de decantação natural. Os resultados mostraram que a pH 9.0 obteve-se a melhor precipitação do complexo glicerol-zircônio conseguindo-se uma maior concentração de glicerol no precipitado com menor perda de zircônio no sobrenadante para todos os efluentes empregados. A maior eficiência na concentração de glicerol foi obtida com hidróxido de zircônio para os dois processos de separação de precipitada e com todos os efluentes estudados, A decantação natural foi um processo de separação de precipitado melhor que a centrifugação quando utilizou-se hidróxido de zírcônio, tanto para as vinhaças quanto para a lixívia. O tempo ótimo de decantação foi de 3 horas. As concentrações ótimas de zircônio, quando foi empregado hidróxido e utilizando a decantação como processo de separação, foram de 1.6 %. (m/v) para vinhaça mista da produção de álcool carburante e vinhaça de aguardente. Para vinhaça mista pré-concentrada e lixívia fraca, esta concentração foi de 2.0% (m/v)Abstract: In this research, the different parameters involved in the precipitation of Glycerol from fuel alcohol stillage (vinasse) distilled alcoholic liquor stillage and from a watery lye resulting from soap production, using complexing of the Glycerol by zirconium and subsequent separation by centrifugation and by naturaI decantation were evaluated. The process used consisted of heating those effluents (unconcentrated and pre-concentrated vinasse or lye) with zirconium compounds, thus forming a Glycerol zirconium complex that precipitated in an alkaline medium. The precipitate separated by centrifugation or decantation. After heating under acid conditions the precipitates released the Glycerol, wich couId then be distilled. The variables studied were: pH for complex precipitation; zirconium concentration; zirconium compounds (chloride, nitrate and hydroxide); precipitate separation process and natural decantation time. The resuIts showed that, with all the effluents studied, the optimum ph for the precipitation of the Glycerol- zirconium cotmplex was 9.0 in order to obtain the highest Glycerol concentration in the precipitate with lower loss o-f zirconium in the supernatant, In all cases the most efficient compound for Glycerol concentration was zirconium hydroxide. Natural, decantation was a better process for precipitate separation than centrifugation when the compound used was zirconium hydroxide both for stillages and for the watery lye. The optimum sedimentation time was three hours. The optimum zirconium concentration was 1,6% when using hydroxide zirconium and decantation as the precipitate separation process for the unconcentrated sugar cane stillages resuIting from fuel alcohol production and resulting from distilled alcoholic liquor, and 2.0 % for the pre-concentrated sugar cane stillages resuIting from fuel alcohol production and for the watery lyeMestradoMestre em Tecnologia de Alimento
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Estudo de alguns parametros para precipitação de glicerol atraves de complexação com zinconio em vinhaças de alcool carburante e de aguardente e em lixivias fracas de sabvaria
2017Co-Authors: Ivana Maria PereiraAbstract:Resumo: Neste trabalho avaliaram-se diferentes parâmetros, à nivel de laboratório, para precipitar glicerol de vinhaça mista da produção de álcool carburante e vinhaça de caIdo de cana da produção de aguardente, bem como de lixívias fracas de saboaria, através da complexação do glicerol com zircônio e posterior separação por centrifugação e decantação natural. Os processos utilizados consistiram do aquecimento dos efluentes (vinhaças "in natura" e pré-concentrada ou lixívias) com compostos de zircônio dando formação a uiït complexo glicerol-zircônio que precipita em meio alcalino. O precipitado foi então separado por centrifugação ou por decantação natural. Os precipitados após aquecimento a pH ácido liberam o glicerol, que pode então ser destilado. As variáveis estudadas foram: pH de precipitação do camplexo glicerol-zircônia; concentração de zircônio; compostos de zircônio (cloreto, nitrato e hidróxido); processo de separação de Precipitado e tempo de decantação natural. Os resultados mostraram que a pH 9.0 obteve-se a melhor precipitação do complexo glicerol-zircônio conseguindo-se uma maior concentração de glicerol no precipitado com menor perda de zircônio no sobrenadante para todos os efluentes empregados. A maior eficiência na concentração de glicerol foi obtida com hidróxido de zircônio para os dois processos de separação de precipitada e com todos os efluentes estudados, A decantação natural foi um processo de separação de precipitado melhor que a centrifugação quando utilizou-se hidróxido de zírcônio, tanto para as vinhaças quanto para a lixívia. O tempo ótimo de decantação foi de 3 horas. As concentrações ótimas de zircônio, quando foi empregado hidróxido e utilizando a decantação como processo de separação, foram de 1.6 %. (m/v) para vinhaça mista da produção de álcool carburante e vinhaça de aguardente. Para vinhaça mista pré-concentrada e lixívia fraca, esta concentração foi de 2.0% (m/v).Abstract:In this research, the different parameters involved in the precipitation of Glycerol from fuel alcohol stillage (vinasse) distilled alcoholic liquor stillage and from a watery lye resulting from soap production, using complexing of the Glycerol by zirconium and subsequent separation by centrifugation and by naturaI decantation were evaluated. The process used consisted of heating those effluents (unconcentrated and pre-concentrated vinasse or lye) with zirconium compounds, thus forming a Glycerol zirconium complex that precipitated in an alkaline medium. The precipitate separated by centrifugation or decantation. After heating under acid conditions the precipitates released the Glycerol, wich couId then be distilled. The variables studied were: pH for complex precipitation; zirconium concentration; zirconium compounds (chloride, nitrate and hydroxide); precipitate separation process and natural decantation time. The resuIts showed that, with all the effluents studied, the optimum ph for the precipitation of the Glycerol- zirconium cotmplex was 9.0 in order to obtain the highest Glycerol concentration in the precipitate with lower loss o-f zirconium in the supernatant, In all cases the most efficient compound for Glycerol concentration was zirconium hydroxide. Natural, decantation was a better process for precipitate separation than centrifugation when the compound used was zirconium hydroxide both for stillages and for the watery lye. The optimum sedimentation time was three hours. The optimum zirconium concentration was 1,6% when using hydroxide zirconium and decantation as the precipitate separation process for the unconcentrated sugar cane stillages resuIting from fuel alcohol production and resulting from distilled alcoholic liquor, and 2.0 % for the pre-concentrated sugar cane stillages resuIting from fuel alcohol production and for the watery lye
Liang Shan - One of the best experts on this subject based on the ideXlab platform.
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solvent free enzymatic preparation of feruloylated monoacylGlycerols optimized by response surface methodology
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Liang Shan, Lixia Zhang, Xingguo WangAbstract:The ability of immobilized lipase B from Candida antarctica (Novozym 435) to catalyze the direct esterification of glyceryl ferulate (FG) and oleic acid for feruloylated monoacylGlycerols (FMAG) preparation in a solvent-free system was investigated. Enzyme screening and the effect of Glycerol on the initial reaction rate of esterification were also investigated. Response surface methodology (RSM) was used to optimize the effects of the reaction temperature (55-65 °C), the enzyme load (8-14%; relative to the weight of total substrates), oleic acid/(FG + Glycerol) (6:1-9:1; w/w), and the reaction time (1-2 h) on the conversion of FG and yield of FMAG. Validation of the RSM model was verified by the good agreement between the experimental and the predicted values of FG conversion and FMAG yield. The optimum preparation conditions were as follows: temperature, 60 °C; enzyme load, 8.2%; substrate ratio, 8.65:1 (oleic acid/(FG + Glycerol), w/w); and reaction time, 1.8 h. Under these conditions, the conversion of FG and yield of FMAG are 96.7 ± 1.0% and 87.6 ± 1.2%, respectively.
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Solvent-free synthesis of glyceryl ferulate using a commercial microbial lipase.
Biotechnology Letters, 2007Co-Authors: Liang Shan, Xingguo WangAbstract:A process was optimized for the enzymatic synthesis of glyceryl ferulate with a yield of up to 96% using a vacuum-rotary evaporation strategy under following conditions: 15 mmol Glycerol, 1.5 mmol ethyl ferulate, 170 mg Candida antarctica lipase, at 60°C for 10 h and under a vacuum of 10 mm Hg. The immobilized lipase can be used 10 times.
