Dissertations / Theses on the topic 'Fatty acid methyl ester'
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Pisac, Claudia A. "An experimental study of combustion characteristics of fatty acid methyl ester biodiesel." Thesis, University of Hertfordshire, 2014. http://hdl.handle.net/2299/14641.
Full textDe, Castro Ana Maria. "Fatty acid methyl ester analysis of microbial communities in biofilters inoculated with different sources." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ28820.pdf.
Full textBollin, Patrick M. "The Production of Fatty Acid Methyl Esters in Lewis Acidic Ionic Liquids." University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1321507054.
Full textKling, Marcel Robert. "Synthesis of very long chain fatty acid methyl esters /." Title page, table of contents and abstract only, 1991. http://web4.library.adelaide.edu.au/theses/09PH/09phk65.pdf.
Full textKadisch, Marvin [Verfasser]. "Stabilizing whole-cell biocatalysts : En route to more efficient fatty acid methyl ester bioprocessing / Marvin Kadisch." Aachen : Shaker, 2017. http://d-nb.info/1149269103/34.
Full textChi, Lirong. "The production of methyl esters from vegetable oil/fatty acid mixtures." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0006/MQ45896.pdf.
Full textBahceci, Humeyra. "Fatty Acid Methyl Ester Analysis Of Bacterial Isolates From Salt Lake, Turkey And Characterization Of Their Extracellular Enzymes." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/12605483/index.pdf.
Full text#945
-amylase and protease. These enzymes were characterized in terms of enzyme activity, stability, optimum temperature and optimum pH. One of the isolates was identified as Bacillus pumilus, and two of them were identified as Bacillus subtilis. Other isolates were determined to be Bacillus licheniformis. All the isolates were determined to produce xylanase. Optimum temperatures and optimum pH values of xylanases were 50-55 °
C and pH 7.0-8.0. Xylanases were quite stable up to pH 8.0 and 70 °
C. Isolates were not significant cellulase producers. Four of the isolates did not produce any cellulase enzyme and the rest produced negligible amounts of cellulase. Therefore, xylanases from the isolates were promising for pulp and paper industry, which requires cellulase free and stable xylanases. All the isolates produced appreciable quantities of &
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-amylase. Optimum temperatures and optimum pH values of &
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-amylases 60-80 °
C and pH 7.0-8.0. &
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-Amylases were quite stable up to pH 9.0 and 80 °
C. &
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-Amylases from the isolates were promising for starch processing industry, which requires &
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-amylases stable at high temperatures and for detergent industry, which requires &
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-amylases stable at alkaline pH values. Considerable protease productions were achieved by all the isolates. TTG 2 was the best protease producer with 271 U/ml. Optimum temperatures and optimum pH values of proteases were 50-60 °
C and pH 7.0-7.4. Proteases were quite stable up to pH 9.0 and 80 °
C. Proteases from the isolates were promising for detergent and leather industry, in which proteases must be stable at alkaline pH values.
Banerjee, Sagarika. "EFFECTS OF LIVESTOCK ANTIBIOTICS ON NITRIFICATION, DENITRIFICATION, AND MICROBIAL COMMUNITY COMPOSITON IN SOILS ALONG A TOPOGRAPHIC GRADIENT." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_theses/43.
Full textKimmel, Tobias. "Kinetic investigation of the base catalyzed glycerolysis of fatty acid methyl esters." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=97339174X.
Full textSimpson, Michael J. "Synthesis of #DELTA#'9-desaturase inhibitors and related cyclopropenes." Thesis, University of Newcastle Upon Tyne, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239574.
Full textMcWilliams, Kevin Michael. "Coordination of internal olefins, specifically fatty acid methyl esters (FAMEs), by transition metals." [Ames, Iowa : Iowa State University], 2007.
Find full textJohansson, Katarina. "Fatty acid methyl esters as reactive diluents in solvent-borne thermally cured coil-coatings." Licentiate thesis, Stockholm, Chemical Science and Engineering, KTH, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4094.
Full textHamid, Samiyah. "Production and purification of fatty acid methyl esters from plant oils of different origin." Thesis, University of Greenwich, 2011. http://gala.gre.ac.uk/8056/.
Full textWestberg, Emilie. "Qualitative and Quantitative Analysis of Biodiesel Deposits Formed on a Hot Metal Surface." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-95617.
Full textJohansson, Katarina. "Thermally cured coil-coatings utilizing novel resins and fatty acid methyl esters as reactive diluents." Doctoral thesis, KTH, Fiber- och polymerteknik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4857.
Full textQC 20100817
Sekora, Nicholas Scott Lawrence Katheryn Kay Scott. "Identification of plant-parasitic nematodes using FAME analysis." Auburn, Ala, 2009. http://hdl.handle.net/10415/1806.
Full textNegi, Devender Singh. "Base catalyzed glycerolysis of fatty acid methyl esters: investigations towards the development of a continuous process." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980493404.
Full textScholten, Matthew John. "Enzymatic and chemical modification of fatty acid methyl esters: enzymatic catalysis of methyl linoleate using soybean lipoxygenase and chemical catalysis of methyl oleate Using Hypobromination." Thesis, University of Iowa, 2010. https://ir.uiowa.edu/etd/735.
Full textBabajide, Omotola Oluwafunmilayo. "Optimisation of biodiesel production via different catalytic and process systems." Thesis, University of the Western Cape, 2011. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_3380_1365754281.
Full textThe production of biodiesel (methyl esters) from vegetable oils represents analternative means of producing liquid fuels from biomass, and one which is growing rapidly in commercial importance and relevance due to increase in petroleum prices and the environmental advantages the process offers. Commercially, biodiesel is produced from vegetable oils, as well as from waste cooking oils and animal fats. These oils are typically composed of C14-C20 fatty acid triglycerides. In order to produce a fuel that is suitable for use in diesel engines, these triglycerides are usually converted into the respective mono alkyl esters by base-catalyzed transesterification with short chain alcohol, usually methanol. In the first part of this study, the transesterification reactions of three different vegetable oils
sunflower (SFO), soybean (SBO) and waste cooking oil (WCO) with methanol was studied using potassium hydroxide as catalyst in a conventional batch process. The production of biodiesel from waste cooking oil was also studied via continuous operation systems (employing the use of low frequency ultrasonic technology and the jet loop reactor). The characterisation of the feedstock used and the methyl ester products were determined by different analytical techniques such as gas chromatography (GC), high performance liquid chromatography (HPLC) and thin layer chromatography (TLC). The effects of different reaction parameters (catalyst amount, methanol to oil ratio, reaction temperature, reaction time) on methyl ester/FAME yield were studied and the optimum reaction conditions of the different process systems were determined. The optimum reaction conditions for production of methyl esters via the batch process with the fresh oil samples (SFO and SBO) were established as follows: a reaction time of 60 min at 60 º
C with a methanol: oil ratio of 6:1 and 1.0 KOH % wt/wt of oil
while the optimum reaction conditions for the used oil (WCO) was observed at a reaction time of 90 min at 60 º
C, methanol: oil ratio of 6:1 and 1.5% KOH wt/wt of oil. The optimum reaction conditions for the transesterification of the WCO via ultrasound technology applied in a continuous system in this study were: a reaction time of 30 min, 30 º
C, 6:1 methanol/oil ratio and a 0.75 wt% (KOH) catalyst concentration. The ultrasound assisted transesterification reactions performed at optimum conditions on the different oil samples led to higher yields of methyl esters (96.8, 98.32 and 97.65 % for WCO, SFO and SBO respectively) compared to methyl esters yields (90, 95 and 96 % for WCO, SFO and SBO respectively) obtained when using conventional batch procedures. A considerable increase in yields of the methyl esters in the ultrasound assisted reaction process were obtained at room temperature, in a remarkably short time span (completed in 30 min) and with a lower amount of catalyst (0.75 wt % KOH) while the results from the continuous jet loop process system showed even better results, at an optimum reaction condition of 25 min of reaction, a methanol: oil ratio of 4:1 and a catalyst amount of 0.5 wt%. This new jet loop process allowed an added advantage of intense agitation for an efficient separation and adequate purification of the methyl esters phase at a reduced time of 30 min. The use of homogeneous catalysts in conventional processes poses many disadvantages
heterogeneous catalysts on the other hand are attractive on the basis that their use could enable the biodiesel production to be more readily performed as a continuous process resulting in low production costs. Consequently, a solid base catalyst (KNO3/FA) prepared from fly ash (obtained from Arnot coal power station, South Africa) and a new zeolite, FA/Na-X synthesized from the same fly ash were used as solid base catalysts in the transesterification reactions in the conversion of a variety of oil feedstock with methanol to methyl esters. Since fly ash is a waste product generated from the combustion of coal for power generation, its utilization in this manner would allow for its beneficiation (as a catalytic support material and raw material for zeolite synthesis) in an environmentally friendly way aimed at making the transesterification process reasonably viable. Arnot fly ash (AFA) was loaded with potassium (using potassium nitrate as precursor) via a wet impregnation method while the synthesized zeolite FA/Na-X was ion exchanged with potassium (using potassium acetate as precursor) to obtain the KNO3/FA and FA/K-X catalysts respectively. Several analytical techniques were applied for characterization purposes. The results of the XRD and XRF showed that the AFA predominantly contained some mineral phases such as quartz, mullite, calcite and lime. The high concentration of CaO in AFA was apparent to be beneficial for the use of fresh fly ash as a support material in the heterogeneous catalysed transesterification reactions. XRD characterisation of KNO3/FA results indicated that the structure of KNO3/FA gradually changed with the increase in KNO3 loading. The catalyst function was retained until the loading of KNO3 was over 10 %. IR spectra showed that the KNO3 was decomposed to K2O on the fly ash support during preparation at a calcination temperature of 500 º
C. The CO2-TPD of the KNO3/FA catalysts showed that two basic catalytic sites were generated which were responsible for high catalytic abilities observed in the transesterification reactions of sunflower oil to methyl esters. On the other hand, XRD results for the as- received zeolite synthesized from AFA showed typical diffraction peaks of zeolite NaX. SEM images of the FA /NaX showed nano platelets unique morphology different from well known pyramidal octahedral shaped crystal formation of faujasite zeolites and the morphology of the FA /KX zeolite did not show any significant difference after ion exchange. The fly ash derived zeolite NaX (FA /NaX) exhibited a high surface area of 320 m2/g. The application of the KNO3/FA catalysts in the conversion reactions to produce methyl esters (biodiesel) via transesterification reactions revealed methyl ester yield of 87.5 % with 10 wt% KNO3 at optimum reaction conditions of methanol: oil ratio of 15:1, 5 h reaction time, catalyst amount of 15 g and reaction temperature 160 °
C, while with the use of the zeolite FA/K-X catalyst, a FAME yield of 83.53 % was obtained for 8 h using the ion exchanged Arnot fly ash zeolite NaX catalyst (FA/KX) at reaction conditions of methanol: oil ratio of 6:1, catalyst amount of 3 % wt/wt of oil and reaction temperature of 65 º
C. Several studies have been carried out on the production of biodiesel using different heterogeneous catalysts but this study has been able to uniquely demonstrate the utilization of South African Class F AFA both as a catalyst support and as a raw material for zeolite synthesis
these catalyst materials subsequently applied sucessfully as solid base catalysts in the production of biodiesel.
Testud, Blandine. "Les huiles végétales comme plateforme pour la conception de nouveaux polyesters hyper-ramifiés." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0365/document.
Full textThe aim of this thesis was to use vegetable oils as a platform for the design of more sustainable polyesters of hyperbranched architecture. For that purpose, the approach by polycondensation of ABn-type monomers (n ≥ 2) was favored. Plant oils and/or fatty acid methyl esters were chemically modified to synthesize multifunctional precursors featuring ester (A) and alcohol moieties (B). Simple, safe and efficient chemical transformations were considered to provide industrial perspectives to this work. Two main platforms of ABn-type monomers were developed by (1) acid hydrolysis of epoxidized vegetables oils and (2) thiol-ene/metathesis coupling reactions. The subsequent polycondensation of these oily-derived monomers, performed in bulk, gave access to novel renewable hyperbranched polyesters. The branching density as well as the thermo-mechanical properties of these materials were adjusted by designing and selecting the chemical structure of the fatty acid-based monomers. Finally, an exploratory work was carried out regarding the post-functionalization of both the core and the periphery of these hyperbranched polyesters with the aim at tuning their properties and thus opening the scope of their applications, from commodity plastics to advanced materials
Saleh, Jehad. "A Membrane Separation Process for Biodiesel Purification." Thesis, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/19730.
Full textLancaster, Sarah Renee. "Soil microbial response to glyphosate-base cotton pest management systems." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2636.
Full textLane, Matthew S. "THE EFFECT OF GLYPHOSATE ON SOIL MICROBIAL COMMUNITIES." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1301068421.
Full textBule, Maria João Galvão Morgado. "Produção de biodiesel por catálise enzimática em sistemas descontínuo e contínuo a partir de óleo de cardo." Master's thesis, ISA, 2014. http://hdl.handle.net/10400.5/6804.
Full textThe aim of this study is the biodiesel production from cardoon seed oil (Cynara cardunculus, L.) by enzymatic catalysis in batch and continuous systems. The biodiesel (fatty acid methyl esters - FAME) was obtained by transesterification of the crude cardoon oil with methanol, in a biphasic organic/aqueous system, catalyzed by the lipase/acyltransferase from Candida parapsilosis immobilized in synthetic resins (Accurel MP1000 and Lewatit VP OC 1600). This enzyme, when biphasic media, catalyses preferentially transesterification over hydrolysis, conversely to the behaviour of conventional lipases. In batch system, the highest FAME yield (about 97%) was obtained with the enzyme immobilized in Lewatit VP OC 1600 after 24h of reaction, with an oil concentration of 10% (m/v) in the emulsion. The Fame production system was implemented in a packed-bed continuous reactor. The highest FAME yield (about 20%) was obtained with the enzyme immobilized in Accurel MP 1000 with an oil concentration of 20% (m/v) in the emulsion. In this essay, the enzyme demonstrated a good operational stability, remaining active about 15 days, when the FAME production stopped.
Nguyen, van Cuong. "Maîtrise de l'aptitude technologique des oléagineux par modification structurelle : applications aux opérations d'extraction et de transestérification in-situ." Thesis, La Rochelle, 2010. http://www.theses.fr/2010LAROS308/document.
Full textThe present work has concerned the impact of Instant - Controlled Pressure Drop (DIC) texturing on both operations of oil extraction and in-situ transesterification, carried out with the rapeseed and the kernels of Jatropha Curcas. A fundamental analysis proved the importance of the reactive or solvent diffusion within the solid matrix. By texturing the natural product, the whole operation can be intensified. The process is revealed through three characteristics, which are the effective diffusivity, the starting accessibility, and the yields of extraction. Also, the kinetics and yield of fatty acid methyl ester of in-situ transesterification are discovered. A phenomenological study allowed determining the value of these characteristics versus DIC operating parameters (saturated steam pressure P and treatment time t).A 2 h solvent extraction of DIC treated material allowed the total oil yields to be improved by 153% for colza and 112% for jatropha, the effective diffusivity (Deff) can reach up to 8.014*10-12 m2/s as against 0.715*10-12 m2/s for colza untreated by DIC, and up to 5.90*10-12 m2/s as against 2.42*10-12 m2/s for the untreated jatropha. The rate of initial accessibility of products treated by DIC can reach up to 80.53% as against 26.71% for untreated colza and can reach up to 92.58% as against 75.91% for the product untreated jatropha. In the case of in situ transesterification, the total yield of fatty acid methyl esters (FAME total) obtained from the DIC treated products is systematically higher than that of untreated colza and jatropha raw material. The reaction time was decreased to 30 - 45 min instead of 120 min in the case of colza, and to 15 min instead of 60 min in the case of jatropha kernel
Timmons, Michael Douglas. "EXPLORATIONS IN HOMEOVISCOUS ADAPTATION AND MASS SPECTRAL ANALYSIS OF MEMBRANE LIPIDS." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_diss/74.
Full textStewart, Gaynelle. "Engineering Saccharomyces ceresisiae for the Secretion of an Extracellular Lipase." ScholarWorks@UNO, 2007. http://scholarworks.uno.edu/td/577.
Full textJohnson, Michael Ben. "Microalgal Biodiesel Production through a Novel Attached Culture System and Conversion Parameters." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/32034.
Full textMaster of Science
Louis, Kévin. "Synthèse et fonctionnalisation d'aldéhydes issus de la coupure d'esters gras insaturés." Thesis, Poitiers, 2013. http://www.theses.fr/2013POIT2290/document.
Full textA high interest has been devoted to the use of renewable carbon in the chemical industry. The goal of this work is the substitution of fossil oils by vegetable oils to synthesize bio sourced monomers for polyesters and polyamides production. The synthesis of methyl 9-oxononanoate as a platform molecule from fatty acid methyl esters of rapeseed oil was carried out in solvent free ozonolysis at room temperature. Intermediary ozonides was reduced to aldehydes by catalytic hydrogenation under H2 pressure and in the presence of Pd(5)/C catalyst giving a 92% carbonyl yield. This process was applied to a wide range of unsaturated esters with a chain length within 9 and 13 carbon atoms. This process allows the selective conversion of renewable materials to value added chemicals, in mild conditions and in the presence of a recyclable catalyst. Moreover, the co products are non toxic and valuable. Hydrogenation of aldehyde group was performed in the presence of methanol at 50°C under hydrogen pressure. Raney Nickel and Pd(5)/C exhibit a yield to methyl 9 hydroxynonanoate higher than 90%. Reductive amination of the aldehyde functional group was investigated with success in the presence of NH3(g) and Pd(5)/C at 50°C in methanol to produce primary amino ester. The amount of ammoniac is directly correlated to the selectivity of the reaction. As a consequence a minimum amount of 3 eq. of ammoniac is required to avoid the formation of secondary amino-ester
Sendžikienė, Eglė. "Žemės ūkio kilmės riebalinių atliekų panaudojimas biodyzelino gamyboje." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2005. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2005~D_20051108_124439-95751.
Full textKasumba, John. "Organic Chemical Characterization Of Primary And Secondary Biodiesel Exhaust Particulate Matter." ScholarWorks @ UVM, 2015. http://scholarworks.uvm.edu/graddis/358.
Full textAlbuquerque, Anderson dos Reis. "Autoxidação de ésteres metílicos de ácidos graxos: estudo teórico-experimental." Universidade Federal da Paraíba, 2010. http://tede.biblioteca.ufpb.br:8080/handle/tede/7179.
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In this work, computational chemistry calculations and thermal analysis experiments were performed in order to determine the oxidative stability of four fatty acid methyl esters (stearate, oleate, ricinoleate and linoleate), whose fatty chains may be inserted in oils and biodiesel. In the computational chemistry investigation the sequence of stabilities, based on the dissociation energy of the C-H bond was: C18:2 < C18:1 < C18:1;12-OH < C18:0, for the B3LYP 6-31G(d) and MP2 6-311++G(2d,p); and C18:2 < C18:1;12-OH < C18:1 < C18:0, for the B3LYP 6-311++G(2d,p). The spin density analysis allowed stating that the ricinoleate hydroxyl does not act as a pro-oxidizing, as the radicals formed in C-12 or OH are not stabilized by the unsaturation in C9, showing, thus, the behavior of a secondary alkyl alcohol in relation to these sites, whereas their allylic hydrogen display an energy similar to the oleate hydrogens. In the experimental investigation carried out TG, it was possible to observe the formation of hydroperoxides by means of the mass gain in an oxygen atmosphere for oleate, linoleate and ricinoleate, but only volatilization for the stearate. In this investigation, a small heating rate (2 ºC/min) was utilized. The kinetic calculations based on PDSC, in the dynamic and isothermal modes showed that the oxidation susceptibility is quite dependent of temperature, atmosphere and the method employed, being more critical in relation to the methyl ricinoleate. In the dynamic mode, in an air atmosphere at 110ºC, the relative susceptibility was 1 : 17 : 17 : 226 (C18:0 : C18:1 : C18:1;12-OH : C18:2). In an O2 atmosphere this proportion was 1 : 11 : 1 : 102. In the isothermal mode PDSC, at the same temperature, the proportion was 1 : 1230 : 1585 : 23001 in an air atmosphere, and 1 : 33 : 40 : 445 in an O2 atmosphere. Performing a structure/property relationship, the oxidation temperature determined at a heating rate of 10 ºC/min was shown to be strongly correlated with the BDE (C-H) obtained by DFT and MP2, confirming the relationship between the first exothermic event of PDSC in the dynamic mode and the C-H bond strength. Therefore, PDSC is shown as a accelerated testing technique able to determine the true oxidative stability of lipids, as it supplies information on the rate controlling step of auto-oxidation (L-H + R1● → L● + R1-H), whereas the Rancimat method does not supply such information. Ternary ester blends were made and their oxidative stabilities were assessed by means of PDSC in a synthetic air atmosphere. Four equations were obtained with high linear correlation coefficients (R2 > 0.98). A biodiesel representation model was also developed, expressing its main oxidation sites and molecular descriptors for several physico-chemical properties. This representation is expressed by the molecular formula Ca Hb H*c Hd** He***(O2)f (0H)g and shows as one of its advantages the easy display of biodiesel data, what makes more evident the study of structure/property relationship. Its application for the four FAME s and twenty-three blends allowed determining the oxidation temperature (OT) in an air atmosphere, based on the descriptors for allylic hydrogen (H*) and bis-allylic hydrogens (H**). From such model a program in language C was elaborated, whose input is the FAME mole fraction and whose output is the OT in a synthetic air atmosphere. Keywords: Auto-oxidation, FAME (fatty acid methyl esters), Biodiesel, PDSC, DFT.
Nesse trabalho, cálculos de química computacional e experimentos de análise térmica foram realizados para determinar a estabilidade oxidativa de quatro ésteres metílicos de ácidos graxos (estearato, oleato, ricinoleato e linoleato), cuja cadeia graxa pode estar inserida em óleos e biodiesel. Na investigação por química computacional a seqüência de estabilidade com base na energia de dissociação da ligação C-H foi: C18:2 < C18:1 < C18:1;12-OH < C18:0, para o B3LYP 6-31G(d) e MP2 6-311++G(2d,p); e C18:2 < C18:1;12-OH < C18:1 < C18:0, para o B3LYP 6-311++G(2d,p). A análise da densidade de spin permitiu afirmar que a hidroxila do ricinoleato não age como pró-oxidante, pois os radicais formados no C-12 ou OH não são estabilizados pela insaturação no C9, comportando-se, portanto, como um álcool alquílico secundário em relação a esses sítios, enquanto que seus hidrogênios alílicos possuem energia próxima aos do oleato. Na investigação experimental por TG foi possível observar a formação dos hidroperóxidos através do ganho de massa em atmosfera de oxigênio para o oleato, linoleato e ricinoleato, mas apenas volatilização para o estearato. Para tanto, uma pequena taxa de aquecimento (2 ºC/min) foi utilizada. Os cálculos cinéticos obtidos por PDSC nos modo dinâmico e isotérmico mostraram que a susceptibilidade relativa à oxidação é bastante dependente da temperatura, da atmosfera e do método empregados, sendo mais crítica em relação ao ricinoleato de metila. No modo dinâmico, em atmosfera de ar à 110ºC, a susceptibilidade relativa foi de 1 : 17 : 17 : 226 (C18:0 : C18:1 : C18:1;12-OH : C18:2). Em atmosfera de O2 essa proporção foi de 1 : 11 : 1 : 102. Na PDSC modo isotérmico nessa mesma temperatura a proporção foi de 1 : 1230 : 1585 : 23001 em atmosfera de ar, e 1 : 33 : 40 : 445 em atmosfera de O2. Fazendo uma relação estrutura-propriedade, a temperatura de oxidação na taxa de aquecimento de 10 ºC/min mostrou-se bastante correlacionada com a BDE (C-H) obtidas por DFT e MP2, confirmando a relação entre o primeiro evento exotérmico da PDSC no modo dinâmico e a força da ligação C-H. Nesse sentido, a PDSC apresenta-se como a técnica de ensaio acelerado capaz de determinar a verdadeira estabilidade oxidativa de lipídeos, pois fornece informações sobre a etapa contraladora da velocidade de autoxidação (L-H + R1● → L● + R1-H), enquanto que o método Rancimat não fornece essa informação. Foram realizadas misturas ternárias dos ésteres e verificadas suas estabilidades oxidativas por PDSC em atmosfera de ar sintético. Quatro equações foram obtidas com elevada correlação linear (R2 > 0.98). Foi desenvolvido também um modelo de representação do biodiesel expressando seus principais sítios de oxidação e descritores moleculares para diversas propriedades físico-químicas. Essa representação é dada pela fórmula molecular Ca Hb H*c Hd** He***(O2)f (0H)g e tem como uma das vantagens a simplificação de apresentação dos dados para biodieseis, o que torna mais palpável o estudo de relação estrutura-propriedade. Sua aplicação para os quatro FAMEs e vinte e três misturas permitiu determinar a temperatura de oxidação (OT) em atmosfera de ar com base nos descritores para hidrogênios alílicos (H*) e bis-alílicos (H**). A partir desse modelo foi elaborado um programa em linguagem C, tendo como dados de entrada a fração molar dos FAMEs e como saída a OT em atmosfera de ar sintético.
Mayer, Júlia Gonçalves. "Comparação da análise de ácidos graxos TRANS em biscoito por cromatografia gasosa acoplada a espectrometria de massas (cg-em) e por espectroscopia no infravermelho com transformada de fourier e reflectância total atenuada (FT-IR-ATR)." Niterói, 2018. https://app.uff.br/riuff/handle/1/5892.
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Os métodos analíticos utilizados para medir o percentual de ácido graxo trans (AGT) em alimentos envolvem cromatografia em fase gasosa com detecção de ionização de chama (CG-DIC), espectrometria de massas (CG-EM) e espectroscopia no infravermelho com transformada de Fourier e refletância total atenuada (FT-IR-ATR). O presente estudo teve como objetivo investigar a viabilidade e a aplicabilidade do uso das técnicas de FT-IR-ATR, sem extração, com extração prévia da gordura e após hidrólise e metilação dos ácidos graxos, para avaliar o conteúdo de AGT em biscoitos recheados e comparar os resultados obtidos com os encontrados para a determinação de ácido elaídico pela técnica de CG-EM. Foram escolhidas 9 marcas de biscoitos recheados sabor chocolate e 1 pacote de gordura vegetal hidrogenada, para ser usada como padrão secundário para análise de AGT por FT-IR-ATR. As amostras foram analisadas, inicialmente, quanto aos seus conteúdos de umidade e lipídeos totais. Para todas as amostras não foi observada concentração de umidade superior a 6,03 g/100 g. Os lipídeos totais variaram de 12,51±0,58 a 23,84±0,09 g/100 g. A presença de AGT foi identificada por FT-IR-ATR pela visualização da banda próxima a 966 cm−1 e confirmada com adição de padrão às amostras. Ao analisar as amostras de biscoito homogeneizadas e sem outro preparo, não foi viável a utilização do método de FT-IR-ATR, visto que a absorção de radiação infravermelha de substâncias da amostra se sobrepõe à absorção na região das ligações duplas trans, o que demonstra que a matriz do alimento pode influenciar na análise. Quanto a presença dos AGT, ácido elaídico (C18:1, n-9 trans) foi identificado e confirmado em todas as amostras através de CG-EM. Ao comparar a quantificação pelos métodos CG-EM e FT-IR-ATR em amostras de extratos e na forma de ácidos graxos metilados (FAME), foram observadas concentrações baixas de ácido elaídico/ácidos graxos trans (de 0,03±0,01 a 0,86±0,01 g/100 g de biscoito) obtidas pelos diferentes métodos. Não foram encontradas diferenças significativas entre as concentrações de AGT determinadas pelos três métodos testados para oito das nove amostras analisadas. O presente trabalho mostrou que a técnica de FT-IR-ATR, analisando o extrato lipídico e as amostras em forma de FAME foi adequado para estimar os teores de AGT em biscoito recheado de chocolate, visto que proporciona uma análise mais rápida, com um menor número de etapas e menor consumo de reagentes em relação às análises por CG-EM
The analytical methods used to measure the percentage of trans fatty acids in foods involve gas chromatography with flame ionization detection (GC-FID), mass spectrometry (GC-MS) and attenuated total reflectance fourier transform infrared spectroscopy (ATR-FT-IR). The aim of the present study was to investigate the feasibility and applicability of ATR-FT-IR techniques, without extraction, with previous extraction of fat and after hydrolysis and methylation of fatty acids to evaluate the content of TFA in filled biscuits, and compare the results obtained with those found for the determination of elaidic acid by the CG-MS technique. Were chosen 9 marks of chocolate filled biscuit and 1 packet of hydrogenated vegetable fat to be used as a secondary standard for AGT analysis by ATR-FT-IR. The samples were initially analyzed for their moisture contents and total lipids. For all samples, no moisture content higher than 6.03 g/100 g. Total lipids ranged from 12.51 ± 0.58 to 23.84 ± 0.09 g/100g. The presence of TFA was identified by ATR-FT-IR through the visualization of the band near 966 cm−1 and confirmed with addition of standard to the samples. When analyzing the homogenized cookie samples and without further preparation, the use of the ATR-FT-IR method was not feasible because the absorption of infrared radiation from sample substances overlaps the absorption in the region of the trans double bonds, which demonstrates that the food matrix may influence the analysis. Regarding the presence of TFA, elaidic acid (C18: 1, n-9 trans) was identified and confirmed in all samples by GC-MS. When comparing quantification by GC-MS and ATR-FT-IR in samples of extracts and in the form of fatty acids methly esters (FAME), low concentrations of elaidic acid / trans fatty acids were observed (0.03 ± 0.01 to 0.86 ± 0.01 g / 100 g of biscuit) obtained by the different methods. No significant differences were found between the concentrations of TFA determined by the three methods tested for eight of the nine samples analyzed. The present study showed that the ATR-FT-IR technique, analyzing the lipid extract and the samples in the form of FAME, was adequate to estimate the TFA contents in chocolate filled biscuit, because it provides a faster analysis with a smaller number of steps and lower toxic chemicals in relation to GC-MS analyzes
Šinkūnienė, Dovilė. "Lipase selection and application for fatty acid ester synthesis." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140210_082745-97488.
Full textLipazių atranka ir taikymas riebalų rūgščių esterių sintezei Lipazės yra intensyviai tiriama fermentų grupė dėl jų gebos katalizuoti platų spektrą sintezės reakcijų. Disertacinio darbo tikslas buvo ištirti ir optimizuoti riebalų rūgščių esterių sintezės, panaudojant lipazes, būdus. Tirta fermento preparato paruošimo (imobilizavimo), fermento bei substratų pasirinkimo bei reakcijos sąlygų ir priedų įtaka riebalų hidrolizės, biodyzelino, fenetiloktanoato (kvapiojo esterio) sintezės reakcijų eigai ir išeigai. Pirmą kartą ištirtos Lietuvoje paruoštos Enterobacter aerogenes lipazės savybės, ji imobilizuota ant gamtinės kilmės nešiklių. Komercinių lipazių katalizuojamų reakcijų sąlygų įtakai nustatyti ir reakcijos išeigai optimizuoti naudota atsako paviršiaus metodologija. Tiriant reakcijos priedų įtaką acilgrupės migracijai ir biodyzelino sintezės reakcijai, nustatyta, kad perspektyvus priedas yra silikagelis. Lipazių specifiškumas ženkliai skiriasi skirtingoms acilglicerolių klasėms ir regioizomerams, šių žinių pagrindu buvo pasiūlyta dviejų etapų biodyzelino sintezės katalizė.
Bacha, Kenza. "Interaction entre les carburants diesel et biodiesel et les composants du système d'injection diesel." Thesis, Mulhouse, 2016. http://www.theses.fr/2016MULH4471.
Full textDiesel injection system must withstand more severe operating conditions (pressure, temperature), and be compatible with the evolution of diesel fuel, such as the introduction of Fatty Acid Methyl Esters (FAME) and use of different additives, which may affect the durability of the vehicle, following the formation of deposits. The objective of this work is to understand the mechanisms of deposit formation from fuel oxidation and determine the major parameters involved in deposit-substrate interactions (surface condition, materials, geometry, temperature...). Two studies were discussed. The first study focuses on the liquid phase accelerated oxidation of Diesel fuel, FAME and mixtures (Diesel / FAME) using PetroOxy device, the oxidation kinetic was determined for the different fuels and characterization of oxidation products was carried out using the (FTIR-ATR, ATG / DTG and GC / MS). The second study was dedicated to the reproduction of deposit on different substrates (aluminum, stainless steel, PEEK, aluminum coating on gold, silcoklean coating on stainless steel) using the Micro Coking device, and characterization of the deposit obtained in each case using (FTIR-ATR, ATG / DTG, XPS and FEG). The results of this work permit to determine the impact of FAME nature and FAME concentration on fuel oxidation stability; an hypothesis was proposed to explain deposit formation
Kouakou, Cédric. "Etude approfondie de la cristallisation des carburants et des combustibles, impact des nouvelles bases." Thesis, Pau, 2014. http://www.theses.fr/2014PAUU3017/document.
Full textThe concerns about greenhouse effect have encouraged the use of biodiesels to replace petroleum-derived diesel fuel. Indeed, the European Union has issued a Directive 2003/30/EC, which mandates the use of biofuels in a percentage ranging from 5.75% in 2010 to 20.00% in 2020 (calculated on the basis of energy content) for all transportation fuels marketed within the member states. First-generation biodiesels made from vegetable oils or animals fats are blended with petroleum diesel to fuel the engines. Besides, the refining schemes were modified to produce more heavy petroleum cuts in order to satisfy the growing demand of diesel fuel. However, the resulting diesel are more exposed to operability problems as the Fatty Acid Methyl Esters and the heavy normal paraffins may solidified in the tank and filters when the temperature drops down during the winter seasons. Thus the study of the solid-liquid phase equilibria of these blends may be useful to predict the temperature of apparition of the solidified material, known as the cloud point. In this work, we collected the melting data of the pure biodiesel components (Fatty Acid Methyl Esters) and we studied the phase change temperature of real diesel samples (petroleum diesel and biodiesel blends). Then, we have developed a thermodynamic model in order to compute the solid-liquid phase equilibria of all these kind of fluids involved in the diesel fuel formulation. Comparisons were made with the experimental phase change measurements and with the cloud point normalized measurement methods (ASTM D5771 et D7689). Finally, we have correlate the phase change temperature calculated by the thermodynamic model with the normalized cloud point, so as this important data could be obtain by a predictive tool
Bentley, David James. "Cyclic peptides : total synthesis of stephanotic acid methyl ester and approaches toward moroidin." Thesis, University of Exeter, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425241.
Full textZhao, Peng. "The Attempted Synthesis of Carba-Nicotinic Acid Mononucleotide Methyl Ester using the Zincke Reaction." University of Toledo Health Science Campus / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=mco1488576282701401.
Full textFalahati, Hamid. "The Characterization of Bimodal Droplet Size Distributions in the Ultrafiltration of Highly Concentrated Emulsions Applied to the Production of Biodiesel." Thesis, University of Ottawa (Canada), 2010. http://hdl.handle.net/10393/19585.
Full textNatural Sciences and Engineering Research Council of Canada (NSERC)
Hikosaka, Tomoyuki, Yasunori Hatta, Hidenobu Koide, Akina Yamazaki, Fumihiro Endo, Hitoshi Okubo, Tsutomu Nara, and Katsumi Kato. "Space Charge Behavior in Palm Oil Fatty Acid Ester (PFAE) by Electro-optic Field Measurement." IEEE, 2009. http://hdl.handle.net/2237/14538.
Full textKoide, Hidenobu, Keizo Kawanishi, Katsumi Kato, Hitoshi Okubo, Naoki Hayakawa, and Hiroki Kojima. "Charge behavior in Palm Fatty Acid Ester Oil (PFAE) / pressboard composite insulation system under voltage application." IEEE, 2012. http://hdl.handle.net/2237/20736.
Full textHuq, Abul Fatha Md Anisul. "Interfacial and Solvent Processing Control of Phenyl-C61-Butyric Acid Methyl Ester (PCBM) Incorporated Polymer Thin Films." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1427746818.
Full textBaltazar, Maria de Fatima Monginho. "Studies of the enzymology of fatty acid oxidation and of methyl ketone production in Aspergillus niger." Thesis, University of Hull, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265127.
Full textKerman, Ipek. "Synthesis And Characterization Of Poly(oxalic Acid Dithiophen-3-yl Methyl Ester) And Thiophene Ended Poly-&." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605014/index.pdf.
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-caprolactone (PCL) and oxalic acid dithiophen-3-yl methyl ester (ODME) and their copolymers with both pyrrole and thiophene were achieved. Chemical structure of the precursor polymer and monomer were investigated Redox behavior of polymer and monomers were determined by Cyclic Voltammetry (CV). Structural characterization of samples were carried out by 1H, 13C Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Conductivities of the films were measured by using four probe technique. Thermal analyses of conducting copolymers were investigated via Differential Scanning Calorimetry (DSC) and Thermal Gravimetry Analysis (TGA). The morphologies of the copolymer films were examined by Scanning Electron Microscopy (SEM). Electrochromic and spectroelectrochemical behavior of the copolymers were investigated, and their ability of employment in device construction has been examined.
Koide, H., T. Hikosaka, Y. Hatta, A. Yamazaki, F. Endo, K. Kato, T. Nara, S. Yamamoto, and H. Okubo. "Charge Behavior in Palm Fatty Acid Ester Oil (PFAE) / Pressboard Insulation System under Flow Condition in Power Transformers." IEEE, 2008. http://hdl.handle.net/2237/12075.
Full textStarr, Christopher Daniel. "Fatty acid derived ester related gene expression, activities, and volatiles for on-tree ripening and storage of apples." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/c_starr_091409.pdf.
Full textTitle from PDF title page (viewed on Jan. 8, 2010). "Program in Molecular Plant Sciences." Includes bibliographical references (p. 61-68).
Silva, Raquel Filipa Maia da. "Produção de Biodiesel por catálise enzimática a partir de óleo de cardo." Master's thesis, ISA/UTL, 2011. http://hdl.handle.net/10400.5/4073.
Full textThis work aimed the production of biodiesel from cardoon seed oil (Cynara cardunculus L.) by enzymatic catalysis. The oil was extracted from cardoon seeds from two different crops, 2007 and 2009, and had a free fatty acid (FFA) content of 4.5% and 1.6%, respectively. The effect of FFA content in the enzymatic reaction kinetics was, therefore, investigated. The biodiesel (fatty acid methyl esters - FAME) were obtained by transesterification of crude oil whit methanol in a biphasic organic/aqueous system in the presence of a biocatalyst (enzyme). The lipase/acyltransferase from Candida parapsilosis was used in free form and immobilized in syntetic resins (Accurel MP1000 and Eupergit C) at different concentrations from 0.13% to 2.65% in the reaccion. Using an amount of 0.28% of enzyme in the free form, a maximum yield of 97% of FAME was obtained after 24h of reaction. In the production of fatty acid methyl esters using immobilized lipase/acyltransferase a lower yield of approximately 40% was obtained, but the recovery and reuse of the enzyme in different studies is possible. The FFA content in cardoon oils did not affect enzymatic catalysis
Meheust, Hélène. "New fatty acid-based polyesters as viscosity control additives for lubricants." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0291.
Full textThe aim of this thesis was to promote the use of polyesters from oleaginous resources as viscosity control additives for lubricants. The hydroxyl-acid type monomers were polymerized through polycondensation route. First, poly(methyl ricinoleate) and its homologous poly(methyl-12-hydroxystearate) were synthesized in a large range of molecular weights and their use as thickeners of lubricant oils was demonstrated. Secondly, comb polyesters derived from poly(methyl ricinoleate) were designed via thiol-ene addition and polycondensation process. The effect of the polyester architecture on their behavior in solution was investigated and revealed that comb polymers are the most suitable for applications that required a thickening efficiency and a pour point depressant effect. Then, comb (co)poly(9-alkyl 12-hydroxystearate)s with various pendant alkyl chains were designed in order to control their solubility in a mineral oil, the Yubase 4+, and to limit the oil viscosity decrease of these oils with temperature. Finally, the behavior in dodecane of two comb (co)poly(9-alkyl 12-hydroxystearate)s revealed that the polymer chains tend to aggregate at low temperature and to disaggregate with the temperature increase. This phenomenon is in accordance with one of the oil Viscosity Index Improver behaviors, described in literature
Grayson, John David. "Improvement of Yellow Perch Larvae Culture via Live Food Enrichment with Polyunsaturated Fatty Acids." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1417720966.
Full textMa, Tiezheng. "Oxidation Kinetics of Methyl Linoleate and α-Linolenate in Bulk and Oil-in-water Emulsion Systems." Kyoto University, 2014. http://hdl.handle.net/2433/188751.
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新制・課程博士
博士(農学)
甲第18313号
農博第2038号
新制||農||1020(附属図書館)
学位論文||H26||N4820(農学部図書室)
31171
京都大学大学院農学研究科食品生物科学専攻
(主査)教授 安達 修二, 教授 河田 照雄, 教授 保川 清
学位規則第4条第1項該当