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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

S?ntese e caracteriza??o de biocombust?veis obtidos a partir do arroz e seus derivados

Silva, Tatiana de Oliveira Magalh?es da 15 January 2008 (has links)
Made available in DSpace on 2015-04-14T13:58:25Z (GMT). No. of bitstreams: 1 398972.pdf: 1270520 bytes, checksum: c981dc4ef6d67b9a25e1efbb0fef41df (MD5) Previous issue date: 2008-01-15 / Este trabalho apresenta um estudo comparativo entre sistemas catal?ticos para a rea??o de transesterifica??o dos ?leos de farelo de arroz. A transesterifica??o do ?leo do farelo de arroz refinado com metanol foi avaliada na presen?a de acido sulf?rico (H2SO4) e compostos de estanho como: cloreto de estanho (SnCl2. 2H2O), 2-etilhexanoato de estanho (Sn(C8H15O2)2), conhecido comercialmente como DBTDL. Os produtos das rea??es foram caracterizados atrav?s da analise comparativa entre os catalisadores, verificou-se uma melhor performance para o DBTDL, com rendimento de 99,9% , no tempo de 4h e rela??es molares de 480:100:5 entre ?lcool, ?leo e catalisador, respectivamente . Estes resultados demonstram a viabilidade do uso de compostos met?licos como catalisadores na obten??o de biodiesel, uma alternativa interessante a catalise acida e b?sica. Nas otimiza??es do processo, foram avaliadas alcoolizes com metanol e etanol, as razoes molares foram variadas e foram utilizados como ?leo de partida, alem dos ?leos refinados, tamb?m ?leos degomados e brutos.
2

Avalia??o f?sico-qu?mica e qu?mica dos ?leos e gorduras e seus efeitos na ingest?o in vivo

Lopes, ?tala Kariny Barroso 06 April 2015 (has links)
?rea de concentra??o: Qu?mica Org?nica. / Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-01-06T18:00:22Z No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) itala_kariny_barroso_lopes.pdf: 1856554 bytes, checksum: 93412cde269e6e1554cc9332b4babe65 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-01-07T11:43:35Z (GMT) No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) itala_kariny_barroso_lopes.pdf: 1856554 bytes, checksum: 93412cde269e6e1554cc9332b4babe65 (MD5) / Made available in DSpace on 2016-01-07T11:43:35Z (GMT). No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) itala_kariny_barroso_lopes.pdf: 1856554 bytes, checksum: 93412cde269e6e1554cc9332b4babe65 (MD5) Previous issue date: 2015 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / Diante do interesse e influ?ncia de ?leos e gorduras ingeridos na alimenta??o e seus efeitos no metabolismo e altera??es na composi??o corporal, o estudo visou caracterizar quimicamente ?leos e gorduras por CG-MS, FTIR e espectrometria UV/vis?vel (Fen?licos, Flavon?ides e Atividade Antioxidante (AA)), al?m de avaliar o efeito da suplementa??o em animais experimentais. Foram utilizados ?leos de Abacate (AB), C?rtamo (CA), Coco (CO), Linha?a (LI) e Pequi (PE), e Banha de Porco (BAN), Margarina (MAR), Manteiga (MAN) e Gordura Vegetal Hidrogenada (GVH). Os ?leos AB, CO, CA e LI tiveram maiores quantidades de fen?licos totais do que as gorduras BAN GVH, MAN e MAR. O CO apresentou maior quantidade de flavon?ides do que os ?leos LI, CA, AB e PE. A GVH apresentou maior quantidade de flavon?ides seguida da MAR, MAN e BAN. Os espectros de infravermelho mostraram a presen?a do grupo hidroxila na posi??o de estiramento 3650-3100nm, o que caracteriza a a??o AA nos ?leos e gorduras. Os cromatogramas identificaram as principais subst?ncias vol?teis dos ?cidos graxos como os ?cidos Capr?lico, L?urico, Miristico, Palm?tico, Este?rico, Ol?ico, Linol?ico, Eicosapentaen?ico e o Ela?dico. No ensaio biol?gico os animais receberam ra??o acrescida de 10% de cada ?leo e gordura, e o grupo controle recebeu apenas a ra??o. Na suplementa??o dos animais o coeficiente de ingest?o alimentar dos grupos AB, BAN,CA, LI, MAN e PE foram os maiores. Os grupos BAN, MAN, MAR e GVH apresentaram maior IMC que o grupo C, que por sua vez apresentou menor ?ndice que os grupos AB, CA, CO, LI e PE. Para o ?ndice de LEE os grupos AB, CA, CO, LI e PE tiveram maior ?ndice que GVH, MAN, MAR, BAN e C. O grupo MAN apresentou maior teor de glicose. Quanto a fra??o de triacilglicer?is e HDL-c os grupo BAN, GVH e MAN foram maiores em rela??o aos demais. Contudo pode se concluir que mesmo os ?leos e gorduras apresentando atividade antioxidante e presen?a de fen?licos e flavon?ides tendo efeitos ben?ficos para a sa?de, o consumo excessivo dos mesmos causa aumento do metabolismo lip?dico. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2015. / ABSTRACT Given the interest and influence of ingested fats and oils in food, its effects on metabolism and changes in body composition, this study aimed to characterize chemically oils and fats by GC-MS, FTIR spectrometry (phenolics, flavonoids and Antioxidade Activity), and to evaluate the effect of supplementation in experimental animals. Were used oils Avocado (AB), Safflower (CA), Coconut (CO), Flaxseed (LI) and Pequi (PE), and Lard (BAN), Margarine (MAR), Butter (MAN) and Hydrogenated Vegetable Fat (GVH). The AB, CO, CA and LI had higher amounts of total phenolics than the BAN GVH fats, MAN and MAR. The CO had higher amounts of flavonoids than the LI oils, CA, AB and PE. The GVH had higher amounts of flavonoids then the SEA, MAN and BAN. Infrared spectra showed the presence of the hydroxyl group in position 3650-3100nm stretch, which characterizes the EA action in oils and fats. The chromatograms identified the major volatile substances of fatty acids such as caprylic, lauric, myristic, palmitic, stearic, oleic, linoleic, elaidic and Eicosapentaenoic. In the biological test animals received diet plus 10% of each oil and fat, and the control group received only the diet. In supplementation of animals the intake of food coefficient of AB groups, BAN, CA, LI, MAN and PE were the greatest. The BAN groups, MAN, SEA and GVH had higher BMI than group C, which in turn showed a lower rate than the groups AB, CA, CO, LI and PE. For LEE index AB groups, CA, CO, LI and PE had higher rate than GVH, MAN, MAR, BAN and C. The MAN group had higher glucose content. As the fraction of triacylglycerol and HDL-c the BAN group, GVH and MAN was higher than the other. However it can be concluded that even the oils and fats presenting antioxidade activity and presence of phenolics and flavonoids with beneficial health effects, excessive consumption of these causes increased lipid metabolism.
3

Otimiza??o da s?ntese do AlSBA-15 para produ??o de biodiesel por transesteri-fica??o do ?leo de coco / Optimization of the synthesis of AlSBA-15 for production of biodiesel by transesterification of coconut oil

Rodrigues, Gic?lia 22 August 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-11-27T15:27:52Z No. of bitstreams: 1 GiceliaRodrigues_TESE.pdf: 4017865 bytes, checksum: c0fa528988ec3e75c837780c20f66c73 (MD5) / Approved for entry into archive by Elisangela Moura (lilaalves@gmail.com) on 2015-11-30T23:51:12Z (GMT) No. of bitstreams: 1 GiceliaRodrigues_TESE.pdf: 4017865 bytes, checksum: c0fa528988ec3e75c837780c20f66c73 (MD5) / Made available in DSpace on 2015-11-30T23:51:12Z (GMT). No. of bitstreams: 1 GiceliaRodrigues_TESE.pdf: 4017865 bytes, checksum: c0fa528988ec3e75c837780c20f66c73 (MD5) Previous issue date: 2014-08-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Atualmente, o Brasil conta com grande potencial e boas perspectivas futuras para a manuten??o e amplia??o de sua matriz energ?tica. S?o exemplos de alternativas para o futuro, os petr?leos oriundos do pr?-sal, energias e?licas, hidrel?tricas, nuclear, al?m dos biocombust?veis. O est?mulo ? produ??o e ao consumo de bicombust?vel favorece mundialmente a pol?tica de preserva??o ao meio ambiente, contribuindo na redu??o dos gases, poluentes, causadores do efeito estufa e redu??o das altera??es clim?ticas. A presen?a de catalisadores nos processos de produ??o de bicombust?veis desempenha um importante papel na melhoria da rotas de produ??o, tais como: taxa de rea??o, rendimento e seletividade de produtos e co-produtos de alto valor agregado. A tend?ncia atual das pesquisas nesse campo foca no aprimoramento desses processos com o uso de catalisadores heterog?neos, visto que catalisadores heterog?neos apresentam vantagens significativas, tais como: menor contamina??o dos produtos, facilidade de separa??o do catalisador do meio reacional, possibilidade de reaproveitamento do catalisador, diminui??o dos problemas de corros?o. Portanto, pesquisas est?o sendo desenvolvidas para obten??o de materiais mesoporosos, que s?o catalisadores heterog?neos, devido ao fato de que esses materiais apresentam facilidade de s?ntese e s?o economicamente vi?veis, apresentam poros relativamente grandes que facilitam a acessibilidade de ?cidos graxos no interior das part?culas, minimizando resist?ncias ao transporte de massa. Ap?s montada matriz experimental para a s?ntese do Al-SBA-15, foi realizado a s?ntese hidrot?rmica do Al-SBA-15 com diferentes raz?es de Si/Al variando as quantidades estequiom?tricas dos materiais precursores.Os testes catal?ticos foram a rea??o de transesterifica??o utilizando como m?tria-prima o ?leo de coco bruto e a pir?lise. As rea??es de transesterifica??o foram realizadas em um reator Parr de a?o inoxid?vel, modelo 4523, equipado com agitador mec?nico, indicadores de temperatura e press?o. O tratamento cin?tico referente aos dados da pir?lise do ?leo de coco puro e do ?leo de coco com AlSBA-15, realizou-se por meio da utiliza??o de curvas termogravim?tricas (TG) obtidas em uma termobalan?a modelo TGA/SDT Q600 da TA instruments, nas seguintes taxas de aquecimento: 5,10 e 20?C min-1. O ?leo de coco bruto apresentou com uma mat?ria-prima apropriada para obten??o do biodiesel via rota et?lica e o catalisador sintetizado com as condi??es experimentais I, apresentou as melhores condi??es para a s?ntese de biodiesel. Os aspectos visuais e as caracter?sticas f?sico-qu?micas dos produtos da rea??o, mostram que o catalisador AlSBA-15 favoreceu a rea??o. De acordo com as analises f?sico-qu?micas a ordem de estabilidade oxidativa do produto da rea??o de transesterifica??o foi: 1500?C +AlSBA-15 > 100?C> 100?C + AlSBA-15> 200?C + AlSBA-15. / Stimulus encouraging the production and consumption of biodiesel favors the policy of pre-serving the environment, contributing to the reduction of greenhouse gas reducing climate change. The current trend of research in this field focuses on improving these processes with the use of heterogeneous catalysts, seeing has significant advantages such as: low contamination of products, ease of separation of the catalyst from the reaction medium, possibili-ty of reuse of the catalyst, decreased corrosion problems. The objective of this research was to optimize the synthesis of AlSBA-15 for the production of biodiesel through transesterification process via ethyl route. For the optimization of hydrothermal synthesis of type AlSBA-15 catalyst has assembled a 23 factorial experimental matrix with eleven trials. The stoichiometric amounts of starting materials were varied according to different ratios Si / Al which is a factor in the experimental design, in addition to the time and temperature of aging of the synthesis gel. The material showed the best results of characterization (SBET = 591.7 (m2 / g), Vp = 0.83 (cm3 / g), Dp = 5.59 (nm), w = 6.48 (nm) was synthesized at 100 ? C for 24 hours, with a ratio Si / Al = 10.This material was applied as a heterogeneous catalyst in the reaction of ethyl transesterification as raw coconut oil in natura. Coconut oil presented suitable for obtaining biodiesel via ethyl route.The visual aspects and physical-chemical characteristics of the reaction products show that AlSBA-15 catalyst favored the reaction. According to physical-chemical analysis the order of oxidative stability of the product of the transesterification reaction was: catalytic reaction at 1500 ? C> non-catalytic reaction at 100 ? C> 100 ? C catalytic> catalytic reaction at 200 ? C Reaction. The results of oxidative stability and kinematic viscosity shows that the biodiesel produced in the catalytic sandblasting held at 150 ? C which was maintained within the ABNT NBR 7148, ABNT NBR 10441 and EN 14112.
4

Concentra??o do ?leo de girassol em compostos insaturados utilizando destila??o molecular

Cabral, Tycianne Janynne de Oliveira 29 January 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-22T15:37:57Z No. of bitstreams: 1 TycianneJanynneDeOliveiraCabral_DISSERT.pdf: 2149439 bytes, checksum: 131d03398750f276cbe2491387456242 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-27T23:42:06Z (GMT) No. of bitstreams: 1 TycianneJanynneDeOliveiraCabral_DISSERT.pdf: 2149439 bytes, checksum: 131d03398750f276cbe2491387456242 (MD5) / Made available in DSpace on 2016-07-27T23:42:06Z (GMT). No. of bitstreams: 1 TycianneJanynneDeOliveiraCabral_DISSERT.pdf: 2149439 bytes, checksum: 131d03398750f276cbe2491387456242 (MD5) Previous issue date: 2016-01-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Os ?leos vegetais caracterizam-se como mat?rias-primas importantes no fornecimento de subst?ncias naturais de interesse das ind?strias farmac?uticas, aliment?cias e cosm?ticas. O ?leo de girassol destaca-se por apresentar em sua composi??o importantes ?cidos graxos insaturados, como o ?cido oleico (C18:1) e linoleico (C18:2), respons?veis por diversos benef?cios ? sa?de. O principal objetivo do presente trabalho ? a obten??o de fra??es enriquecidas em ?cidos graxos insaturados a partir do ?leo de girassol refinado. O ?leo em estudo foi caracterizado atrav?s da determina??o de algumas propriedades, como ?ndice de iodo, ?ndice de acidez e viscosidade. Uma transesterifica??o foi realizada a fim de transformar os triglicer?deos nos seus correspondentes ?steres met?licos de ?cidos graxos. Estes foram submetidos ao processo de destila??o molecular, por apresentar-se como uma alternativa eficiente para separa??o e purifica??o dessas subst?ncias, utilizando alto v?cuo e temperaturas reduzidas. As fra??es de ?steres obtidas foram analisadas por cromatografia gasosa. A t?cnica de planejamento de experimentos foi empregada a fim de avaliar as melhores condi??es para obten??o das fra??es de destilado, analisando algumas vari?veis, como temperatura do sistema de evapora??o e condensa??o. A temperatura do evaporador mostrou-se como a vari?vel de maior influ?ncia sobre o percentual de destilado obtido. As condi??es otimizadas para a resposta estudada foi de 100?C para temperatura do evaporador e de 10?C para a temperatura do condensador. O gr?fico de ?Split ratio? mostrou que para a menor vaz?o de alimenta??o (1mL/min) e maior temperatura do evaporador (110 ?C), foi obtida a maior fra??o de destilado. Foi realizado ainda, o estudo da influ?ncia da temperatura do evaporador sobre a concentra??o de compostos insaturados. A melhor condi??o de opera??o foi para a temperatura de 90?C, alcan?ando 82,22% de compostos insaturados. Foram obtidas as curvas de elimina??o dos compostos insaturados presentes na corrente de destilado. Os resultados da simula??o do processo de destila??o molecular do ?leo de girassol mostraram os perfis de concentra??o para tr?s diferentes vaz?es de alimenta??o. Foram obtidos os perfis de velocidade, temperatura e espessura do filme l?quido. A velocidade do filme aumenta ? medida que o fluido escorre pelas paredes do evaporador, atingindo um valor m?ximo no comprimento de 0,075 m. A espessura do filme diminui ao longo do percurso, uma vez que muitos compostos s?o volatilizados. O resultado do perfil de temperatura apresentou-se coerente com os reproduzidos pela literatura, mostrando-se constante ap?s atingir a temperatura m?xima de opera??o no comprimento de 0,15 m. Dessa forma, o presente trabalho permitiu caracterizar e concentrar, por meio da an?lise experimental, os compostos insaturados, bem como observar o comportamento do ?leo de girassol atrav?s da simula??o do processo. / Vegetable oils are characterized as important raw materials in the supplying of natural substances of interest pharmaceutical, food and cosmetic industry. Sunflower oil stands out for its important composition present in unsaturated fatty acids such as oleic acid (C18:1) and linoleic (C18:2), responsible for many health benefits. The main objective of this study is obtain enriched fractions in unsaturated compounds from refined sunflower oil. The oil used in this study was characterized by the determination of some properties, like iodine number, acid number and viscosity. A transesterification was done to transform the triglycerides into their corresponding methyl esters of fatty acids. These was submitted the molecular distillation process, for present as an efficient alternative to separation and purification of these substances, using high vacuum and low temperatures. Of the esters fractions that was obtained, were analyzed by gas chromatography. The experimental design technique was used to evaluate the influence of the temperature variation of evaporation and condensation system on the percentage obtained residue. The evaporator temperature proved to be the most influential variable on the studied response. The optimized conditions for the answer was studied at 100 ?C for evaporator temperature and 10 ?C for the condenser temperature. The graph of "split ratio" showed that for the lowest flow feed (1 mL/min) and higher evaporator temperature (110 ?C) was obtained in the largest fraction of distillate. It also used the study of the influence of evaporator temperature on the concentration of unsaturated compounds. The best operating conditions for temperature was 90 ?C reached 82.21 % of unsaturated compounds. Elimination curves of the unsaturated compounds present in the distillate stream were obtained. The simulation results of the molecular distillation process of sunflower oil showed the concentration profiles for three different feed flow rates. The speed, temperature and thickness profiles of the liquid film were obtained. The speed of the film increases as the fluid flows through the walls of the evaporator, reaching a maximum on length of 0.075 m. The film thickness decreases on the route, since many compounds are volatilized. The result of the temperature profile had to be consistent with the literature reproduced, being constant after reaching the maximum operating temperature in the length of 0.15 m. This study allowed characterizing and focusing, through experimental analysis, unsaturated compounds and observing the sunflower oil?s behavior through process simulation.
5

Extra??o de metais pesados de efluentes da ind?stria do petr?leo utilizando derivados de ?leos vegetais como extratantes

Santana, Dulcin?ia de Castro 25 July 2008 (has links)
Made available in DSpace on 2014-12-17T15:01:46Z (GMT). No. of bitstreams: 1 DulcineiaCS.pdf: 1697403 bytes, checksum: 0f7cd236e54bc771afdfff455ddc2e54 (MD5) Previous issue date: 2008-07-25 / The study of a promising alternative for the treatment of produced water from the oil industry envisaging its reuse was the focus of this work. Millions of liters of water are generated per day, containing heavy metals in low concentrations (< 0,15 mg/L for Pb, <0,04 mg/L for Cd, <0,04 mg/L for Ni). The technology applied to extract these metals from aqueous phase was the solvent extraction and the extratants used were vegetable oils originated from coconut oil. They can be used in natural form or as derivatives, known as MAC - Mixture of Carbox?lics Acids. The determination of the heavy metal con?centrations in a complex matrix was made by using the atomic absorption spectrometry technique (AAS). On the bench tests using synthetics aqueous solutions containing metals, vegetable oils showed no power to extract the metals studied. The extractant MAC was selective for the Pb> Cd> Ni, in the concentration of 8% in the same organic phase. In this condition, the lower efficiency of extraction obtained was 92% for the Pb, 69% for the Cd, in the range of pH ranging from 6 to 8. An experimental planning was conducted for continuous tests. The device used was called MDIF Misturador-Decantador ? Invers?o de Fases and the aqueous phase was produced water from P?lo Indutrial de Guamar?/RN . No correlation between the studied variables (concentration of metal, concentration of extratant and agitation in the mixing chamer) could be obtained, because of possible factors which occurred as: variation in the composition of the studied sample, phenomena of precipitation and complexation of metals in the reservoir of feed, solubility of extratant / O estudo de uma promissora alternativa para o tratamento de ?guas produzidas da ind?stria do petr?leo visando a sua reutiliza??o foi o foco deste trabalho. S?o milh?es de litros de ?gua/dia descartados ao mar, atrav?s de emiss?rios submarinos, contendo metais pesados em baixas concentra??es (< 0,15 mg/L de Pb, <0,04 mg/L de Cd, <0,04 mg/L de Ni). A tecnologia utilizada para extrair esses metais da fase aquosa foi a extra??o por solvente e os extratantes estudados foram ?leos vegetais in natura e derivados do ?leo de coco, denominada MAC Mistura de ?cidos Carbox?licos. A determina??o da concentra??o dos metais pesados em matriz complexa foi realizada utilizando o EAA Espectr?metro de Absor??o At?mica. Nos ensaios de bancada realizados, com solu??es sint?ticas contendo metais, os ?leos vegetais n?o apresentaram poder de extra??o dos metais estudados. J? o extratante MAC foi seletivo para o Pb > Cd > Ni na concentra??o de 8% do mesmo na fase org?nica. Nesta condi??o, a menor efici?ncia de extra??o obtida foi de 92% para o Pb, 69% para o Cd, na faixa de pH variando de 6 a 8. Um planejamento experimental foi realizado para os ensaios em regime cont?nuo. O equipamento utilizado foi o MDIF - Misturador Decantador ? Invers?o de Fases e a fase aquosa utilizada foi a ?gua produzida proveniente da sa?da do SAO Separador ?gua ?leo do P?lo Industrial de Guamar?/RN. Nenhuma correla??o entre as vari?veis estudadas, concentra??o do metal, concentra??o do extratante e agita??o na c?mara de mistura pode ser obtida devido a poss?veis fatores ocorridos como: varia??o na composi??o da amostra estudada, fen?menos de precipita??o e complexa??o de metais no reservat?rio de alimenta??o, solubiliza??o do extratante
6

Isolamento dos constituintes do Tegumento da Castanha de Caj? (TCC) e avalia??o do seu potencial como antioxidante natural / Isolation of the constituents of cashew nut integument (CNI) and evaluation of its potential as a natural antioxidant

Oliveira, Nat?lia de Freitas 25 April 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-04-27T20:56:01Z No. of bitstreams: 1 NataliaDeFreitasOliveira_TESE.pdf: 17307152 bytes, checksum: 67b914f696cbef8db6c64e30f9b3221b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-04-27T21:01:53Z (GMT) No. of bitstreams: 1 NataliaDeFreitasOliveira_TESE.pdf: 17307152 bytes, checksum: 67b914f696cbef8db6c64e30f9b3221b (MD5) / Made available in DSpace on 2017-04-27T21:01:53Z (GMT). No. of bitstreams: 1 NataliaDeFreitasOliveira_TESE.pdf: 17307152 bytes, checksum: 67b914f696cbef8db6c64e30f9b3221b (MD5) Previous issue date: 2016-04-25 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / O caj? (Anacardium occidentale L.) ? uma das principais fontes de renda dos produtores rurais da regi?o Nordeste do Brasil. A castanha de caj? ? constitu?da por tr?s partes: casca, am?ndoa e uma pel?cula marrom conhecida como tegumento (TCC). ?leos vegetais brutos possuem diferentes constituintes que s?o indesej?veis ao produto final, uma vez que podem ocasionar a oxida??o no ?leo. Fatores como a degrada??o oxidativa s?o de extrema import?ncia para o aumento do tempo de estocagem de ?leos e gorduras. Neste trabalho procurou-se isolar os diferentes tipos de metab?litos secund?rios do tegumento; elaborar e otimizar uma metodologia para o refino dos ?leos de canola e girassol; e avaliar o potencial antioxidante do extrato do tegumento da castanha de caj? na estabilidade oxidativa (EO) de ?leos vegetais. A abordagem fitoqu?mica demonstrou que o tegumento ? rico em diversos metab?litos, como os alcal?ides, sais de am?nio e os compostos fen?licos (taninos). Os ?leos foram analisados em quatro grupos de amostras: industrial, bruto, degomado e neutralizado. Os ?leos neutralizados de canola e girassol apresentaram acidez livre (IA) abaixo dos ?leos industrializados, bem como os ?ndices de iodo (II) e per?xido (IP). Atrav?s dos resultados obtidos, verificou-se que o processo de refino adotado resultou em um produto com padr?o semelhante ao ?leo industrializado e dentro das normas. O teste de oxida??o acelerada, Schaal Oven Test, e as an?lises IA, IP, absortividade espec?fiva (AE) em 232 e 270nm, dienos (DC) e trienos conjugados (TC), e EO em PetroOxy foram realizados, observando-se que as adi??es de antioxidantes naturais nos ?leos vegetais asseguraram a estabilidade oxidativa ap?s o envelhecimento acelerado em estufa. Evidenciou-se, tamb?m, que o ?leo de canola foi mais est?vel e resistente a longos per?odos de estocagem. O uso dos extratos metan?licos de tegumento (MDF) forneceu melhores resultados de IA, IP, DC em rela??o ao controle e ao antioxidante sint?tico BHA. O per?odo de indu??o avaliado pelo PetroOxy foi aumentado com a adi??o dos antioxidantes naturais do TCC, demonstrando que sua a??o antioxidante em ?leos vegetais o torna um potencial composto bioativo natural. / The cashew (Anacardium occidentale L.) is one of the main sources of income for farmers in the Northeast region of Brazil. The cashew nut is composed of thee main parts: peel, almond, and a brown film known as integument (CNI). Crude vegetable oils have different constituents which are undesirable in the end product, causing oil oxidation. Factors such as oxidative degradation are extremely important to increase the shelf life of oils and fats. This research was developed aiming to: identify and isolate different types of secondary metabolites from the integument; develop and optimize a methodology for refining canola and sunflower oils; and evaluate the antioxidant potential of the integument extract in oxidative stability (OS) of vegetable oils. The phytochemical approach showed that the integument is rich in various metabolites such as alkaloids, ammonium salts, phenolic compounds (tannins). The oils were analyzed in four groups of samples: industrial oil, crude oil, degummed oil, and neutralized oil. The values of acidity contente (AV) obtained for the canola and sunflower neutralized oils were lower than the ones for industrial oils, as well as for iodine index (II) and peroxide index (PV). The results showed that the adopted refining process resulted in na oil with similar properties of the industrial one and in accordance with Brazilian standards. The accelerated oxidation test, Schaal Oven Test, and the AV, PV, especific absorty (EA) analysis, at 232 and 270nm, and OS (PetroOxy) were performed and it was observed that the addition of the natural antioxidants in vegetable oils ensured oxidative stability after accelerated aging in stove. It is also evident that the canola oil is more stable and resistant to long periods of storage. The use of integument methanolic extracts (IME) provided better results for AV, PV, DC in relation to the control and the synthetic antioxidante (BHA). The induction period measured by PetrOxy was increased with the addition of natural antioxidants from CNI, demonstrating that this product presents antioxidant action for vegetable oils, allowing it?s use as a natural bioactive compound.
7

Substitui??o da suplementa??o da ractopamina por ?leo de c?rtamo e coco em dietas para su?nos em termina??o / Replacement of ractopamine supplementation by safflower and coconut oil in diets for pigs in termination

Costa, Clara Viviane Silva da 28 July 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-01-16T17:59:55Z No. of bitstreams: 1 ClaraVivianeSilvaDaCosta_DISSERT.pdf: 2160720 bytes, checksum: 6f0b40fd44b02d69cd2f7b13af06ba85 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-01-22T11:22:59Z (GMT) No. of bitstreams: 1 ClaraVivianeSilvaDaCosta_DISSERT.pdf: 2160720 bytes, checksum: 6f0b40fd44b02d69cd2f7b13af06ba85 (MD5) / Made available in DSpace on 2018-01-22T11:22:59Z (GMT). No. of bitstreams: 1 ClaraVivianeSilvaDaCosta_DISSERT.pdf: 2160720 bytes, checksum: 6f0b40fd44b02d69cd2f7b13af06ba85 (MD5) Previous issue date: 2017-07-28 / Objetivou-se avaliar a substitui??o da suplementa??o da ractopamina pelo uso dos ?leos de c?rtamo e coco na dieta de su?nos em termina??o. Foram utilizados 24 su?nos machos castrados mesti?os com peso m?dio de 78,00 ? 8,76 kg, distribu?dos em delineamento em blocos casualizados, com quatro tratamentos e seis repeti??es. Os tratamentos constitu?ram de Ra??o Basal (RB); RB + 10 ppm de ractopamina; RB + 4g de ?leo de coco e RB + 4g de ?leo de c?rtamo. Avaliou-se os par?metros de desempenho, peso dos ?rg?os, caracter?sticas de carca?a, qualidade da carne e perfil de ?cidos graxos por cromatografia gasosa. Os animais alimentados com ractopamina e o ?leo de c?rtamo apresentaram melhor convers?o alimentar. O maior ganho de peso foi observado (p ? 0,05) nos animais suplementados com o ?leo de coco e a ractopamina. Em rela??o ao peso dos ?rg?os, observou-se redu??o (p ? 0,05) no peso do est?mago dos animais suplementados com o ?leo de coco. Constatou-se redu??o significativa (p ? 0,05) na espessura de toucinho no ponto 3 dos animais suplementados com ?leo de c?rtamo e para ?rea de olho de lombo houve efeito significativo (p ? 0,05) nos alimentados com ractopamina. Os demais par?metros de carca?a n?o foram observados (p > 0,05) diferen?a entre os tratamentos utilizados. Nas avalia??es do perfil de ?cidos graxos, observou-se maior concentra??o (p ? 0,05) de C12:0 e C14:0 no tecido adiposo dos su?nos suplementados com ?leo de coco. No m?sculo Longissimus dorsi houve o enriquecimento com ?-9, redu??o do C18:1n9t nos animais suplementados com ?leo c?rtamo e eleva??o de C16:1 nos suplementados com ?leo de coco. Recomenda-se a utiliza??o do ?leo de c?rtamo em substitui??o a ractopamina, por apresentar melhor convers?o alimentar, reduzir a espessura de toucinho e promover o enriquecimento da carne com ?-9. / This study aimed to evaluate the replacement of supplementation of ractopamine by the use of safflower and coconut oils in pig diet termination. 24 crossbred barrows were used with an average weight of 78.00 ? 8.76 kg, distributed in a randomized block design with four treatments and six replications. The treatments constituted of Basal Ration (BR); BR + 10 ppm of ractopamine; BR + 4g of coconut oil and BR + 4g of safflower oil. Assessed the performance parameters, organ weight, carcass characteristics, meat quality and profile of fatty acids by gas chromatography. Animals fed ractopamine and safflower oil showed better feed conversion. The highest weight gain was observed (p ? 0.05) in the animals supplemented with coconut oil and ractopamine. In relation to the weight of the organs, it was observed reduction (p ? 0.05) in the stomach weight of animals supplemented with coconut oil. There was a significant (p ? 0.05) reduction in the backfat thickness at point 3 of the animals supplemented with safflower oil and in the loin eye area there was a significant effect (p ? 0.05) on the ractopamine fed. The other carcass parameters were not observed (p > 0.05) difference between the treatments used. In the evaluation of the fatty acid profile, a higher concentration (p ? 0.05) of C12:0 and C14:0 was observed in the adipose tissue of the pigs supplemented with coconut oil. In the longissimus muscle dorsi there was the enrichment with ?-9, reduction of C18:1n9t in animals supplemented with oil safflower and elevation of C16:1 in supplemented with coconut oil. The use of safflower oil is recommended to replace the ractopamine, for presenting better feed conversion, reduce the backfat thickness and promote meat enrichment with ?-9.
8

Uma perspectiva da modelagem QSPR para triagem/desenho de catalisadores para a s?ntese de carbonatos oleoqu?micos

Santos, Victor Hugo Jacks Mendes dos 29 May 2018 (has links)
Submitted by PPG Engenharia e Tecnologia de Materiais (engenharia.pg.materiais@pucrs.br) on 2018-08-27T20:28:46Z No. of bitstreams: 1 Uma perspectiva da modelagem QSPR para triagem-desenho de catalisadores para a s?ntese de carbona.pdf: 5038129 bytes, checksum: cd9bae4ba9eacd711c360bc304996732 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-08-28T12:42:24Z (GMT) No. of bitstreams: 1 Uma perspectiva da modelagem QSPR para triagem-desenho de catalisadores para a s?ntese de carbona.pdf: 5038129 bytes, checksum: cd9bae4ba9eacd711c360bc304996732 (MD5) / Made available in DSpace on 2018-08-28T13:11:11Z (GMT). No. of bitstreams: 1 Uma perspectiva da modelagem QSPR para triagem-desenho de catalisadores para a s?ntese de carbona.pdf: 5038129 bytes, checksum: cd9bae4ba9eacd711c360bc304996732 (MD5) Previous issue date: 2018-05-29 / To date, only a small number of organocatalysts have been applied to produce oleochemical carbonates, while the description of new catalysts system still limited. This work presents a preliminary perspective of Quantitative Structure-Property Relationship (QSPR) modeling to assist in the targeted choice/design of active organocatalysts to produce cyclic carbonates. The QSPR was developed by applying the molecular descriptors (2D) to model the structure-property relationship between the organocatalysts features and its activity to produce oleochemical carbonates. From the virtual screening, a total of 122 catalysts have their activity predicted and the best molecular targets are proposed. The principal molecular features (organic structure, molecular arrangement, carbon chain size and substituent type) were identified through data mining, while the principal component analysis (PCA) proved to be suitable to perform the exploratory analysis of the molecules set. In addition, is presented the first report of the application of cetyltrimethylammonium bromide (CTAB) as a new catalyst to produce oleochemical carbonate derived from soy, canola and rice oils. The reactions were performed in a 50 cm3 stainless steel autoclave at 120?C, for 48 hours, without stirring, 5 MPa (p, CO2), 2 g of epoxidized oil, 4 mL of butanol and 5 mol% of CTAB. From the proposed method, all reactions showed more than 98% of epoxide conversion to cyclic carbonate for all the vegetable oil. In this way, the QSPR modelling can be applied to reduce the costs and time in the organocatalysts screening/design for the cyclic carbonates synthesis from CO2 and epoxides. / At? o momento, apenas um pequeno n?mero de organocatalisadores foram aplicados para produ??o de carbonatos oleoqu?micos, enquanto a descri??o de novos sistemas de catalisadores ainda ? limitada. O presente trabalho apresenta uma perspectiva preliminar da modelagem por Rela??o Quantitativa Estrutura-Propriedade (QSPR) para auxiliar na escolha/desenho de novos organocatalisadores para produ??o de carbonatos c?clicos. O QSPR foi desenvolvido aplicando os descritores moleculares (2D) para modelar a rela??o estrutura-propriedade entre as caracter?sticas dos organocatalisadores e sua atividade para produ??o de carbonatos oleoqu?micos. A partir da triagem virtual, um total de 122 catalisadores tiveram sua atividade prevista e os melhores alvos moleculares s?o propostos. As principais caracter?sticas moleculares (estrutura org?nica, arranjo molecular, tamanho da cadeia de carbono e tipo de substituinte) foram identificadas atrav?s da minera??o de dados, enquanto a an?lise de componentes principais (PCA) mostrou-se adequada para realizar a an?lise explorat?ria do conjunto de mol?culas. Al?m disso, ? apresentado o primeiro relato da aplica??o do brometo de cetiltrimetilam?nio (CTAB) como um catalisador para a produ??o de carbonato oleoqu?mico derivados dos ?leos de soja, canola e arroz. As rea??es foram realizadas em uma autoclave de a?o inoxid?vel de 50 cm3 a 120 ? C, durante 48 horas, sem agita??o, 5 MPa (p, CO2), 2 g de ?leo epoxidado, 4 mL de butanol e 5% molar de CTAB. A partir do m?todo proposto, todas as rea??es apresentaram mais de 98% de convers?o de ep?xido em carbonato c?clico para todos os ?leos vegetais. Desta forma, a modelagem QSPR pode ser aplicada para reduzir os custos e tempo na sele??o/desenho de organocatalisadores para a s?ntese de carbonatos c?clicos a partir de CO2 e ep?xidos.
9

Produ??o de biodiesel por rotas et?licas e met?licas promovidas por irradia??o de micro ? ondas oriundas de um forno dom?stico n?o modificado

Miranda, S?vio Eduardo Oliveira 29 October 2011 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:46Z No. of bitstreams: 5 edu.pdf: 1793374 bytes, checksum: 659bf4622f25b099b1d7c3bd613d8f8a (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T11:06:41Z (GMT) No. of bitstreams: 5 edu.pdf: 1793374 bytes, checksum: 659bf4622f25b099b1d7c3bd613d8f8a (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T11:06:41Z (GMT). No. of bitstreams: 5 edu.pdf: 1793374 bytes, checksum: 659bf4622f25b099b1d7c3bd613d8f8a (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / Neste trabalho est? descrito uma nova metodologia para a produ??o de biodiesel (?steres met?licos ou et?licos de ?cidos graxos) a partir do emprego de diversos ?leos vegetais na sua forma ?bruta?, assim como ?leos residuais oriundos de processo de fritura e tamb?m gordura animal (sebo) como material de partida. Al?m deste desafio, procurou-se realizar as rea??es de transesterifica??es em um processo acelerado por irradia??o das micro-ondas obtidas a partir de um forno de micro-ondas dom?stico, o qual n?o sofreu adapta??es, tais como: inser??o de um sistema de agita??o e tamb?m de refluxo, para ser utilizado em rea??es qu?micas. O primeiro passo do trabalho incluiu a utiliza??o dos diferentes ?leos vegetais brutos, isto ?, desprovidos de processo de refino e de degomagem, para a produ??o de biodiesel. Para tanto foi necess?rio o desenvolvimento de uma metodologia que permitisse a purifica??o desses ?leos vegetais brutos, pois estes podem conter subst?ncias, como a ?gua, os ?cidos graxos livres (AGL) e os ?steres de f?sforos (fosfat?dicos) que s?o inibidoras do processo de transesterifica??o. Na busca por uma t?cnica que permitisse a pr?via purifica??o desses ?leos vegetais, foram testados e obtidos excelentes resultados, quando foi realizada a sua filtra??o em s?lica gel 60 Mesh. A polaridade dessa s?lica oriunda dos grupos silan?is permitiu com grande ?xito a reten??o de AGL e dos ?steres de f?sforo, al?m do seu alto poder de adsor??o, reduzindo de maneira significativa o teor de ?gua presente nesses ?leos vegetais. O fator limitante para o emprego da s?lica gel comercial nos processos de purifica??o das diversas oleaginosas foi o seu alto custo, o que tornava invi?vel o processo de purifica??o. Ap?s diversos estudos e tentativas de encontrar um processo que substitu?sse a s?lica gel comercial anteriormente empregada, foi realizado a s?ntese de uma nova s?lica gel a partir do emprego de areia de constru??o e de carbonatos, sendo um processo simples e de baixo custo. Os resultados obtidos no processo de purifica??o dos ?leos vegetais brutos empregando s?lica gel ?sint?tica? foram similares aos da s?lica gel ?comercial?, o que levou o emprego desse processo de purifica??o de maneira sistem?tica no preparo de mat?ria-prima (reagentes) para posterior transesterifica??o. Os bons resultados permitiram testes dessa nova metodologia de purifica??o em ?leos e gorduras residuais (OGR) oriundos de processos de fritura. Nesses ?leos foram encontrados um n?mero bem maior de subprodutos (impurezas) que podem inibiriooooooo65t\azs NM de maneira parcial ou total o processo de transesterifica??o. Dessa forma, a purifica??o dos OGR tornou-se um grande desafio para a s?lica gel ?sint?tica?. Entre as impurezas contidas nesses ?leos residuais, podemos destacar os AGL, ?gua e os produtos oriundos da degrada??o oxidativa e t?rmica (per?xidos, alde?dos, cetonas, furanos, mon?meros c?clicos e n?o c?clicos) dos ?leos vegetais. Os OGR foram purificados com excelentes resultados por filtra??o sob s?lica gel ?sint?tica? em um processo realizado a temperatura ambiente. Al?m dos ?leos residuais puros, nesse processo foi obtida a gordura animal, a qual ficou retida sobre a s?lica sint?tica dentro do funil de filtra??o. Essa gordura animal foi posteriormente purificada por filtra??o a 60 ?C tamb?m em s?lica gel sint?tica e assim como o ?leo residual utilizada como material de partida na s?ntese de biodiesel. Vale ressaltar que os bons resultados alcan?ados no processo de purifica??o sob s?lica gel sint?tica e a necessidade crescente de mat?ria-prima (?leos vegetais), incentivou a amplia??o do programa de coleta de ?leo e gorduras residuais (OGR) na cidade de Diamantina/MG, intitulado como ?Doe Energia? e implantado em 2006. Tanto os ?leos vegetais brutos, como os ?leos residuais e a gordura animal purificados em s?lica gel sint?tica foram transesterificados a biodiesel (met?lico ou et?lico) em alcoolatos (metanolatos e etanolatos) previamente preparados ?in situ? a partir da solubiliza??o de NaOH ou KOH em metanol ou etanol. Neste processo ocorreu a adi??o do alcoolato sobre o material de partida, sendo a rea??o conduzida sob irradia??o de micro-ondas dom?stica a 240 W durante dez minutos e acompanhada por cromatografia em camada delgada (CCD). Os produtos da rea??o (biodiesel e glicerina) foram separados por decanta??o em funil de separa??o, sendo o biodiesel (et?lico ou met?lico) posteriormente lavado at? pH neutro, seco em Na2SO4 e purificados por destila??o a press?o reduzida. A caracteriza??o do biodiesel produzido foi realizada por m?todos espectrom?tricos como a RMN1H e 13C, al?m disso, o controle de qualidade do biodiesel produzido foi realizado empregando t?cnicas anal?ticas seguindo as normas preconizadas pela Ag?ncia Nacional de Petr?leo, G?s Natural e Biocombust?veis (ANP). A glicerina foi purificada, atrav?s de um pr?vio tratamento com adi??o de ?cido sulf?rico ou clor?drico, gerando o AGL, biodiesel e sulfatos ou cloretos de metais alcalinos como co-produtos. Alguns desses sais como o sulfato de s?dio foi posteriormente purificados por recristaliza??o e utilizados como dessecantes para o pr?prio biodiesel. A efici?ncia da metodologia empregando irradia??o de micro-ondas dom?stica, levou ao estudo do seu uso em rea??es in situ, ou seja, transesterifica??o direta das sementes e dos frutos de oleaginosas, tais como a soja e a mamona. Esse processo consiste em uma desidrata??o pr?via dos frutos ou sementes a uma temperatura de 80 ?C durante 8 horas. O alcoolato preparado foi adicionado sobre os frutos ou sementes triturados e secos e a mistura foi agitada com o aux?lio de um agitador mec?nico a 7500 rpm durante 10 minutos a temperatura ambiente, a fim de homogeneizar a mistura reacional. Essa mistura foi levada a um forno de micro-ondas dom?stico e irradiada a 240 W durante 10 minutos em um processo acompanhado por CCD. Ap?s esse per?odo a massa reacional foi filtrada sob v?cuo, a fim de eliminar o res?duo vegetal s?lido (torta). A solu??o resultante foi transferida para um funil de separa??o, onde ocorreu ap?s poucos minutos, a separa??o do biodiesel (fase superior) da glicerina (fase inferior) por simples decanta??o. Os produtos foram separados por decanta??o e tanto a glicerina como o biodiesel (et?lico ou met?lico) foram purificados e caracterizados. O rendimento em biodiesel foi de aproximadamente 96% no emprego de sementes de soja e de 97% empregando sementes de mamona. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2011. / ABSTRACT This work described a new methodology for the production of biodiesel (methyl or ethyl esters of fatty acids) from the use of various vegetable oils in its "raw" as well as waste oil from the frying process and also animal fat (tallow) as starting material. In addition to this challenge, we tried to carry out the reactions transesterification in a process accelerated by microwave irradiation obtained from a domestic microwave oven, which has not undergone changes, such as insertion of an agitation system and also reflux for used in chemical reactions. The first step of the work included the use of different crude oils, this is, devoid of the process of refining and degumming, for the production of biodiesel. For this purpose it was necessary to develop a methodology that allows the purification of crude vegetable oils, as they may contain different substances such as water, free fatty acids (FFA) and esters of phosphorus (Phosphatidic) which are inhibitors of the transesterification process. In the search for a technique that allowed the prior purification of vegetable oils have been tested and achieved excellent results when your filtration was performed on silica gel 60 Mesh. The polarity of this coming from the silica silanol groups with great success allowed the retention of FFA and phosphorus esters, in addition to its high adsorption, significantly reducing the water content present in these oils. The limiting factor for the commercial use of silica gel in the purification processes of other crops was the high cost, which made impossible the purification process. After several studies and attempts to find a process to replace the previously used commercial silica gel was carried out the synthesis of a new silica gel from the use of construction sand and carbonates, with a simple and low cost. The results obtained in the purification process of crude vegetable oils using silica gel "synthetic" were similar to those of silica gel "commercial", which led to the use of this purification process in a systematic manner in the preparation of raw materials (reagents) for subsequent transesterification. The good results allowed testing of this new method of purification of waste oils and fats (WOF) from the frying process. These oils have been found a much larger number of products (impurities) in a manner that can inhibit the partial or total transesterification process. Thus, the purification of WOF has become a major challenge for the silica gel "synthetic". Among the residual impurities contained in these oils, we can highlight the FFA, water and products from thermal and oxidative degradation (peroxides, aldehydes, ketones, furans, cyclic and non cyclic monomers) of vegetable oils. The WOF with excellent results were purified by filtration on silica gel "synthetic" in a process performed at room temperature. Besides the pure residual oils, this process was obtained animal fat, which was held on the synthetic silica into the filter funnel. This fat was then purified by filtration at 60 ?C also on silica gel and synthetic as well as the residual oil is also used as starting material in the synthesis of biodiesel. It is noteworthy that the good results achieved in the purification process in synthetic silica gel and the increasing need of raw material (vegetable oils) has encouraged the expansion of the program to collect waste oil and fats (WOF) in the Diamantina / MG city, titled as "Energy Donate" and implemented in 2006. Both crude vegetable oils, such as waste oils and animal fat purified on silica gel synthesis was transesterified biodiesel (methyl or ethyl) in alcoholates (metanolatos and ethanolate) previously prepared "in situ" from the solubilization of NaOH or KOH in methanol or ethanol. This process was the addition of alcoholates on the starting material, and the reaction was conducted under microwave irradiation of a 240 W home for ten minutes and accompanied by thin layer chromatography (TLC). The reaction products (biodiesel and glycerol) were separated by decanting funnel separation, and biodiesel (methyl or ethyl) subsequently washed until neutral, dried on Na2SO4 and purified by distillation at reduced pressure. The characterization of the biodiesel produced was performed by spectrometric methods such as RMN 1H and 13C, in addition, the quality control of biodiesel was carried out using analytical techniques following the standards recommended by the National Petroleum, Natural Gas and Biofuels Agency (ANP). The glycerin was purified through a previous treatment with sulfuric acid or hydrochloric acid, generating the FFA, biodiesel or chlorides and sulfates of alkali metals as co-product. Some of these salts such as sodium sulfate was further purified by recrystallization and used as desiccants for their own biodiesel. The efficiency of the methodology using a household microwave irradiation, led to the study of their use in reactions in situ, that is, direct transesterification of seeds and fruits of oilseeds such as soybeans and castor beans. This process consists of a prior dehydration of fruits or seeds at a temperature of 80 ?C for 8 hours. The alcoholates prepared was added on the fruits or seeds crushed and dried mixture was stirred with the aid of a mechanical stirrer at 7500 rpm for 10 minutes at room temperature in order to homogenize the reaction mixture. This mixture was brought to a domestic microwave oven and irradiated at 240 W for 10 minutes in a process monitored by TLC. After this time the reaction mass was filtered under vacuum to remove the solid waste plant (cake). The resulting solution was transferred to a separatory funnel, which occurred a few minutes, after the separation of biodiesel (upper phase) of glycerin (lower phase) by simple decantation. The products were separated by decantation and glycerin as much biodiesel (methyl or ethyl) have been purified and characterized. The yield of biodiesel was approximately 96% in the use of soybean and 97% employing castor beans.
10

Constribui??o t?cnica de um sistema de emuls?o inversa a base de ?leos vegetais para fluidos de perfura??o

Silva Neto, Miguel Arcangelo da 27 September 2002 (has links)
Made available in DSpace on 2014-12-17T15:01:19Z (GMT). No. of bitstreams: 1 MiguelASN.pdf: 491289 bytes, checksum: be60500500779f6a3fd87b90108feb8c (MD5) Previous issue date: 2002-09-27 / The developments in formulating drilling fluids to apply in petroleum fields are based on new technologies and environmental challenges, where the technical performance of a developed drilling fluid is used to produce a minimum environmental impact, showing great economy in costs. It is well known that the potential use of oil-based drilling fluids is limited because these fluids when discharged in the sea do not disperse as much as water-based ones and may form waterproof films in the seabed, having a profound effect on plants and animals living in this environment. The current works have been made in investigating fluids called pseudofluids, which are synthetic ester-based, n-paraffin-based and other fluids formed from inverse emulsion. In this research the principal parameters involved in inverse emulsion process were studied, in laboratory scale, using esters as main component. Others commercial drilling fluids were used as comparative samples, as well as samples from laboratory and field where these drilling fluids are being applied. Concentrations of emulsifier and organophilic clay, which are viscosity donor, were varied to verify the influence of these parameters, in different oil/water ratios (55/45, 60/40, 65/35, 70/30, and 75/25). The salt concentration (NaCl) is an indicative parameter of stability and activity of an esterbased fluid. In this research the salt concentration was varied in 10,000, 20,000, and 50,000 ppm of NaCl. Some rheological properties of the produced fluids were studied, such as: initial gel, plastic viscosity, yield point, and apparent viscosity. Through the obtained rheological measures, the existence of two systems could be verified: fluid and flocculated. It could be noticed that the systems were influenced, directly, by the oil/water ratio and emulsifier, organophilic clay and NaCl concentrations. This study showed the viability to use an ester obtained from a regional vegetable product baba?u coconut oil to obtain an efficient and environmental safe drilling fluid / O desenvolvimento atual e futuro, em campos de petr?leo, baseia-se em novas tecnologias e desafios ao meio ambiente, onde se utiliza principalmente a performance t?cnica de um fluido de perfura??o que produza o m?nimo impacto ambiental, mostrando ainda, uma ?tima economia nos custos desses desenvolvimentos. Sabe-se que o potencial de continuidade de fluidos de perfura??o a base de ?leo est? limitado e, por conseguinte, o avan?o ambiental tem sido na investiga??o de fluidos chamados pseudo-fluidos, ou seja, fluidos sint?ticos base ?ster, ?ster, n-parafina e outros fluidos de emuls?o inversa, os quais est?o em estudo. Neste trabalho estudou-se em n?vel de laborat?rio as principais vari?veis envolvidas no processo de emuls?o inversa usando ?steres como componente principal, utilizando-se amostras comparativas de outros fabricantes, como tamb?m amostras provenientes de laborat?rio e de campo onde est?o sendo utilizados estes fluidos de perfura??o. As concentra??es de emulsificante ou argila organof?lica, que ? doadora de viscosidade, foram variadas para verificar a influ?ncia destes par?metros a diferentes raz?es ?leo/?gua (55/45, 60/40, 65/35, 70/30 e 75/25), mantendo-se constante os demais componentes do fluido. A concentra??o do sal, que ? um par?metro indicador de estabilidade e da atividade em fluido a base ?ster, foi variada em 10.000, 20.000 e 50.000 ppm de NaCl. Algumas propriedades reol?gicas dos fluidos assim produzidos foram estudadas, tais como: gel inicial, viscosidade pl?stica, limite de escoamento e viscosidade aparente. A partir das medidas reol?gicas obtidas, p?de-se verificar a exist?ncia de dois sistemas: fluido e floculado. P?de-se perceber que os resultados obtidos foram influenciados diretamente pela raz?o ?leo/?gua e pelas concentra??es do emulsificante, da argila organof?lica e do NaCl. Este estudo consolidou importantes conhecimentos que abrir?o portas para o sucesso de novas pesquisas, tornando-se fundamental a viabiliza??o de coloc?-lo posteriormente no mercado de trabalho do Brasil

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