Darbo tikslas – ištirti rapsų aliejaus peresterinimo procesą naudojant biobutanolį, įvertinti gauto biodyzelino savybes ir poveikį aplinkai. Darbo objektas – rapsų aliejaus riebalų rūgščių butilesteriai, gauti po rapsų aliejaus peresterinimo biobutanoliu. Darbo metodai – rapsų aliejaus peresterinimas butanoliu atliktas biotechnologiniu metodu, naudojant biokatalizatorių Lipozyme TL IM. Peresterinimo laipsnis, butilesterių ir parcialinių gliceridų kiekis nustatyti plonasluoksnės ir dujų chromatografijos metodais. Gauto biodyzelino savybės įvertintos pagal standarte LST EN 14214 pateiktas metodikas. Variklio eksploataciniai ir deginių emisijų tyrimai VGT universitete atlikti 1992 m. gamybos ,,Audi-80‘‘ automobilio dyzeliniu varikliu. Variklio išmetamųjų dujų analizei naudotas išmetamųjų dujų analizatorius AVL DiCom 4000. Biologinis degalų suirimas atliktas taikant OECD 301 F ,,Manometrinės respirometrijos‘‘ metodą AL 606 prietaisu. Darbo rezultatai. Nustatytos optimalios 2 stadijų rapsų aliejaus peresterinimo butanoliu proceso sąlygos. Pagaminti rapsų aliejaus riebalų rūgščių butilesteriai (RBE) atitinka standarto LST EN 14214 reikalavimus. Grynų butilesterių atsparumą oksidacijai daugiau kaip 6 val. padidina antioksidantas – IONOL BF 200 (2000 ppm). Vasaros ir pereinamuoju laikotarpiu gryni butilesteriai ir jų mišiniai su žieminiu dyzelinu ir butanoliu tinkami naudoti be specialių priedų. Maišant rapsų aliejaus riebalų rūgščių butilesterius su žieminiu dyzelinu ir butanoliu... [toliau žr. visą tekstą] / Aim of the work – to analyze the process of rapeseed oil transesterification by using biobutanol, to evaluate the characteristics of the derived biodiesel and its impact on the environment. Object of research – butyl esters of rapeseed oil received after the transesterification of rapeseed oil using biobutanol. Research methods – transesterification of rapeseed oil using biobutanol has been performed by applying biotechnological method, using biocatalyst Lipozyme TL IM. The level of transesterification and quantity of butyl esters and partial glycerides has been determined by methods of thin-layer and gas chromatography. The characteristics of the derived biodiesel have been evaluated according to the methodology provided by standard LST EN 14214. The analysis of engine exploitation and environmental characteristics have been performed at VGT university on the diesel engine of 1992 “Audi-80”. For the analysis of exhaust gases of engine the gas analyzer AVL DiCom 4000 has been used. Degradation of biological fuel has been performed according to OECD 301 F “Manometric respirometry” using AL 606 device. Results of research. Optimal conditions of 2-stage rapeseed oil transesterification process using butanol. Were determined the produced butyl esters of rapeseed oil meet the requirements of LST EN 14214 standards. Antioxidant JONOL BF 200 increases the oxidative stability of pure butyl esters. In summer or during transition period pure butyl esters and their mixtures with... [to full text]

<p>The 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 &ordm / 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 &ordm / 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 &ordm / 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 &ordm / 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 &deg / 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 &ordm / 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.</p>

abstract: Second-generation biofuel feedstocks are currently grown in land-based systems that use valuable resources like water, electricity and fertilizer. This study investigates the potential of near-shore marine (ocean) seawater filtration as a source of planktonic biomass for biofuel production. Mixed marine organisms in the size range of 20µm to 500µm were isolated from the University of California, Santa Barbara (UCSB) seawater filtration system during weekly backwash events between the months of April and August, 2011. The quantity of organic material produced was determined by sample combustion and calculation of ash-free dry weights. Qualitative investigation required density gradient separation with the heavy liquid sodium metatungstate followed by direct transesterification and gas chromatography with mass spectrometry (GC-MS) of the fatty acid methyl esters (FAME) produced. A maximum of 0.083g/L of dried organic material was produced in a single backwash event and a study average of 0.036g/L was calculated. This equates to an average weekly value of 7,674.75g of dried organic material produced from the filtration of approximately 24,417,792 liters of seawater. Temporal variations were limited. Organic quantities decreased over the course of the study. Bio-fouling effects from mussel overgrowth inexplicably increased production values when compared to un-fouled seawater supply lines. FAMEs (biodiesel) averaged 0.004% of the dried organic material with 0.36ml of biodiesel produced per week, on average. C16:0 and C22:6n3 fatty acids comprised the majority of the fatty acids in the samples. Saturated fatty acids made up 30.71% to 44.09% and unsaturated forms comprised 55.90% to 66.32% of the total chemical composition. Both quantities and qualities of organics and FAMEs were unrealistic for use as biodiesel but sample size limitations, system design, geographic and temporal factors may have impacted study results. / Dissertation/Thesis / M.S.Tech Technology 2011

Neste trabalho foi realizado o estudo de transformações de óleo de soja com o catalisador VO(acac)2 em meio homogêneo e heterogêneo. Estes processos catalíticos estão de acordo com os conceitos de química limpa, no sentido de economia de reagentes e diminuição de subprodutos, enquanto que a matéria-prima, óleo vegetal, foi escolhida por ser de fonte renovável, sustentável e abundante no Rio Grande do Sul e no Brasil. A reação de transesterificação do óleo de soja foi realizada através do sistema VO(acac)2 e VO(acac)2 suportado em uma argila celadonita, cujo depósito localiza-se na região de Ametista do Sul – RS. O sistema heterogêneo foi caracterizado pelas técnicas de DRX, BET, BJH, ATG, FTIR, CHN, MEV/EDS e ICP/OES. O teor de vanádio impregnado na argila foi de 1,06 %. O melhor rendimento das reações de transesterificação foi de 36 % e 30 % para os sistemas homogêneo e heterogêneo, respectivamente, para as condições de 2 % em mol e 5 % em mol de vanádio, a 65 ºC de temperatura e 48 horas de reação. Alguns testes foram realizados em reações de epoxidação. Do sistema celadonita/VO(acac)2 foi obtido conversão de 44 %, 15 % de monoepóxido e 34 % de seletividade, em 3 horas de reação. A avaliação quantitativa das reações foi realizada por RMN de 1H. / This work presents the study of soybean oil reactions with VO(acac)2 in homogeneous and heterogeneous catalytic systems. The catalytic systems follow the green chemistry principles of economy of reagents and reduction in sub-products of the reaction while the starting material, soybean oil, was chosen as a renewable source, sustainability of its crop and abundancy. Soybean oil transesterification reactions were done with the catalytic system VO(acac)2 and VO(acac)2 supported in celadonita, which is a mineral found in Ametista do Sul / RS. The heterogeneous system was characterized by the XRD, BET, BJH, TGA, FTIR, CHN, SEM/EDX and ICP/OES techniques. The amount of vanadium impregnated in the clay it was 1,06%. The best conditions for transesterification reaction gave 36 % yield for homogeneous system and 30 % yield for heterogeneous system, using 2 % molar and 5 % molar of vanadium, respectively, at 65 ºC of temperature and 48 hours of reaction. Some tests on epoxidation reactions were performed. With celadonita/VO(acac)2 system it was obtained a conversion of 44%, 15% of monoepoxide and 34 % of selectivity after 3 hours of reaction. The quantitative evaluation of the reactions was made by 1H NMR.

La réaction de transestérification des huiles végétales avec de l'éthanol permet la production d’esters éthyliques dont les applications industrielles sont, à ce jour, essentiellement cosmétiques ou alimentaires. Pour ouvrir le champ des applications aux biocarburants (pour substituer les carburants actuels issus de ressources fossiles), il est apparu nécessaire de développer un procédé de transestérification plus performant pour être économiquement rentable. Selon le schéma réactionnel et les propriétés thermocinétiques du système, les limites des procédés batchs existants pourraient être franchies en utilisant des procédés continus. Le système étudié est complexe en raison des changements d’équilibres de phase notamment et de la présence simultanée de différents phénomènes (mélange, transferts de chaleur et de matière, réactions principales et compétitives) qui doivent être précisément contrôlés. Pour concevoir correctement un procédé continu et acquérir de nombreuses données, les microréacteurs apparaissent comme un outil approprié à cette transposition. Dans ce travail, nous avons transposé la réaction batch dans un dispositif microstructuré continu (tube PFA de diamètre interne 508 μm) induisant un meilleur contrôle des transferts de chaleur et de matière. L’étude de l’influence des conditions de fonctionnement (débits des réactifs, rapport molaire initial huile/éthanol, température…) a permis de trouver des paramètres réactionnels favorables qui permettent d’atteindre des conversions et rendements élevés. Dans ces conditions, nous avons montré qu’il est possible d’acquérir des données cinétiques dès les premières secondes de réaction, ce qui n’était pas réalisable en réacteur batch conventionnel. Pour acquérir ces données en batch et en microréacteurs, nous avons développé une méthode d’analyse en ligne par spectroscopie proche infrarouge en s’appuyant sur la chromatographie en phase gazeuse comme méthode de référence. Des modèles PLS ont alors été établis pour quantifier en ligne les teneurs en composés majoritaires lors de la réaction de transestérification de l’huile de tournesol hautement oléique avec l’éthanol. A partir de ces données, les phénomènes mis en jeu ont été modélisés et les constantes cinétiques ainsi que les coefficients de transfert de cette réaction ont été déterminés. Le modèle a ensuite été utilisé pour simuler des réactions avec d’autres conditions opératoires et il nous a permis de travailler sur la séparation des produits de la réaction. / Transesterification reaction of vegetable oil with ethanol leads to ethyl esters, used to date for applications principally in food and cosmetic industry. To open the application field to biofuels (to substitute current fuels resulting from fossil resources), process efficiency has to be developed to be economically profitable. According to the reaction scheme and thermokinetic properties, limits of current batch processes can be overcome by carrying out continuous processes. The studied system is complex due in particular to phase equilibrium changes as well as simultaneous presence of various phenomena (mixing, heat and mass transfers, principal and competitive reactions) which have to be precisely controlled. Therefore, microreactors appear as the appropriate tool for transposition to a continuous process and acquisition of numerous data. In this work, batch reaction was transposed to a micro-scaled continuous device (PFA tube of 508 μm internal diameter), inducing better heat and mass transfer. Study of the influence of the operational conditions (reactants flow, initial ethanol to oil molar ratio, temperature...) revealed the favourable reaction parameters necessary to reach high conversions and yields. In these conditions, we showed the possibility of acquiring kinetic data at the first seconds of the reaction, which was not feasible in a conventional batch process. To acquire data in batch and microreactors, an on-line analysis method by Near InfraRed (NIR) spectroscopy was developed by using gas chromatography as a reference method. PLS models were then set up to quantify the major compounds contents on-line during the transesterification reaction of high oleic sunflower oil with ethanol. These data were used to model occurring phenomena and to determine kinetic constants and transfer coefficients. The model was subsequently used to simulate reactions with other operational conditions and also to work on the separation of reaction products.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-09-25T14:32:33Z No. of bitstreams: 1 ADRIANA ALMEIDA SILVA - TESE (PPGEP) 2008.pdf: 8434650 bytes, checksum: 7ca7e24f622bbd49778d99a13f342587 (MD5) / Made available in DSpace on 2018-09-25T14:32:33Z (GMT). No. of bitstreams: 1 ADRIANA ALMEIDA SILVA - TESE (PPGEP) 2008.pdf: 8434650 bytes, checksum: 7ca7e24f622bbd49778d99a13f342587 (MD5) Previous issue date: 2008-12-19 / Nas últimas décadas uma quantidade substancial de pesquisas foi realizada a fim de encontrar novas fontes de energia renovável e sustentável para substituir o diesel de petróleo. Uma fonte alternativa promissora de energia é o biodiesel, que é um combustível renovável que pode ser produzido a partir dos óleos e gorduras animais/vegetais ou mesmo ácidos graxos reciclados da indústria de alimentos. Os catalisadores heterogêneos podem melhorar os métodos de síntese eliminando os custos adicionais associados aos catalisadores homogêneos e minimizando a produção de poluentes. As argilas ativadas têm atraído atenção como catalisadores para uma variedade de reações ácidas. O comportamento físico-químico dos minerais argilosos tem sido estudado devido a sua relação como adsorvente e/ou propriedades catalíticas. Diante do exposto verifica-se a necessidade de desenvolver estudos sobre a utilização de argilas como catalisador na produção do biodiesel, tornando-se, portanto, fundamental conhecer a estabilidade e propriedades do biodiesel produzido a partir desses catalisadores. Visando avaliar a eficiência das argilas como catalisadores no processo de transesterificação deste combustível, foram estudados nesse trabalho 27 tipos de argilas, fornecidas pela empresa BENTONISA- Bentonita do Nordeste S.A, para produção do biodiesel na rota etílica e metílica, utilizando óleo de soja. Inicialmente foi realizada uma pré-seleção das argilas, utilizando as análises de umidade e pH, onde foram escolhidos 15 tipos de amostras, as mesmas foram submetidas a ensaios nos sistemas reacionais S1 e S2 e utilizando as técnicas de cor do óleo (aspecto visual) e viscosidade, optou-se pelos dois melhores catalisadores argilosos (A23 e A24) a serem testados no sistema padrão para produção do biodiesel, denominado S3. Os catalisadores A23 e A24 foram caracterizados por : fluorescência de raios-X (FRX); difração de raios-X (DRX); espectroscopia de absorção no infravermelho (IV); microscopia eletrônica de varredura (MEV); energia dispersiva de raios-X (EDS) e área específica pelo método BET. O óleo de soja e o biodiesel formado foram caracterizados através das seguintes técnicas: composição química, umidade, acidez, densidade 20ºC, glicerol total e viscosidade 40ºC, teor de éster, teor de álcool e cromatografia gasosa. Os resultados mostraram que é possível obter o biodiesel a partir de catalisadores argilosos. / In the last decades a substantial amount of research has been undertaken to find new sources of renewable and sustainable energy to replace Diesel. A promising alternative energy source is biodiesel, which is a renewable fuel produced from vegetable oils and animal fats or even from recycled fat from the food industry. Heterogeneous catalysts can improve the synthesis methods eliminating additional costs associated with the homogeneous catalysts and minimizing the production of pollutants. Activated clays have attracted attention as catalysts for a variety of acid reactions. The physical and chemical behavior of clay minerals has been studied because of their property as adsorbent and / or catalysts. Therefore the need to develop studies on the use of clays as a catalyst in the production of biodiesel, making it, therefore, necessary to know the stability and properties of biodiesel produced by these catalysts. To evaluate the efficiency of clays as catalysts in the transesterification process of this fuel, 27 types of clay supplied by the company BENTONISA- Bentonite Nordeste SA, were studied in this work. The biodiesel was produced on the ethyl and methyl route, using soybean oil as raw material. The initial preselection for the clays was carried out on moisture and pH analysis, whereby 15 samples were selected. These were submitted to the testing systems in the S1 and S2, using the techniques of oil color (visual aspect) and viscosity. The two best clay catalysts (A23 and A24) were chosen to be tested in the standard system for production of biodiesel called S3. The catalysts A23 and A24 were characterized by: FRX; XRD; IR, SEM, EDS and BET. The soybean oil and biodiesel were characterized by the following techniques: chemical composition, moisture, acidity, density 20ºC, viscosity 40ºC, total glycerol, ester content, alcohol content and gas chromatography. The results showed that it is possible to get biodiesel from clay catalysts.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-08-16T12:27:26Z No. of bitstreams: 1 AMANDA SANTANA PEITER - TESE (PPGEQ) 2017.pdf: 4504888 bytes, checksum: 524c2d78079fab537fef86ee47f99f28 (MD5) / Made available in DSpace on 2018-08-16T12:27:26Z (GMT). No. of bitstreams: 1 AMANDA SANTANA PEITER - TESE (PPGEQ) 2017.pdf: 4504888 bytes, checksum: 524c2d78079fab537fef86ee47f99f28 (MD5) Previous issue date: 2017-09-15 / O consumo de combustíveis derivados do petróleo aumenta a cada ano, o que resulta no aumento da poluição atmosférica. Devido a isso a economia mundial necessita de fontes alternativas de energia. O biodiesel existe como alternativa ao diesel. Biodiesel pode ser obtido a partir da reação de transesterificação, na qual os triglicerídeos presentes nos óleos vegetais ou gorduras animais reagem com álcool de cadeia curta na presença de um catalisador para obter os ésteres de ácidos graxos. Neste trabalho foi encontrada a cinética da reação de transesterificação de óleo de soja com metanol e com etanol, na presença de hidróxido de sódio, para produzir biodiesel. Para o biodiesel metílico a cinética foi de primeira ordem e para o etílico a cinética foi de segunda ordem. Esses dados da cinética foram utilizados para fazer simulações das reações. A técnica de fluidodinâmica computacional CFD permite um estudo profundo e detalhado, inclusive análises de campos de velocidade e pressão, sem a necessidade de técnicas experimentais avançadas de análise ou custos financeiros para montagem de planta piloto. Essa técnica é desenvolvida principalmente em pacotes comerciais como o Ansys, que oferece diversas interfaces gráficas e modelos. Neste trabalho foi criada a geometria e a malha para o tanque com os diferentes impelidores e inseridas as condições da reação para encontrar os resultados. O modelo utilizado foi o de turbulência k- ε, a cinética foi considerada de primeira ordem para o metanol e de segunda ordem para o etanol e o sistema considerado monofásico e multicomponente. A simulação para o etanol não se mostrou satisfatória, pois as frações mássicas simuladas não tiveram o comportamento semelhante ao experimental. Já para as reações com metanol, as frações mássicas obtidas pela simulação ficaram bem próximas as encontradas experimentalmente, mostrando que a simulação foi satisfatória. / The consumption of fuels derived from petroleum increases every year, resulting in increased air pollution. Because of this the world economy needs alternative sources of energy. Biodiesel exists as an alternative to diesel. Biodiesel can be obtained from the transesterification reaction in which the triglycerides present in vegetable oils or animal fats react with short chain alcohol in the presence of a catalyst to obtain the fatty acid esters. In this work the kinetics of the reaction of transesterification of soybean oil with methanol and with ethanol in the presence of sodium hydroxide to produce biodiesel was found. For the methyl biodiesel the kinetics was of first order and for the ethyl the kinetics was of second order. These kinetic data were used to simulate the reactions. The CFD computational fluid dynamics technique allows in-depth and detailed study, including velocity and pressure field analyzes, without the need for advanced experimental analysis techniques or financial costs for pilot plant assembly. This technique is mainly developed in commercial packages such as Ansys, which offers several graphical interfaces and models. In this work the geometry and the mesh were created for the tank with the different impellers and the conditions of the reaction were inserted to find the results. The k-ε turbulence model was used, kinetics was considered first-order for methanol and second-order for ethanol and the system considered single-phase and multicomponent. The simulation for the ethanol was not satisfactory, since the simulated mass fractions did not have the behavior similar to the experimental one. As for the reactions with methanol, the mass fractions obtained by the simulation were very close to those found experimentally, showing that the simulation was satisfactory.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-08-17T13:19:35Z No. of bitstreams: 1 CARLOS EDUARDO PEREIRA - TESE (PPGEQ) 2017.pdf: 6340687 bytes, checksum: a5c8d06008238c03161add19b46e0a44 (MD5) / Made available in DSpace on 2018-08-17T13:19:35Z (GMT). No. of bitstreams: 1 CARLOS EDUARDO PEREIRA - TESE (PPGEQ) 2017.pdf: 6340687 bytes, checksum: a5c8d06008238c03161add19b46e0a44 (MD5) Previous issue date: 2017-08-02 / A peneira molecular MCM-41 é considerada promissora como suporte para os óxidos metálicos em processo de refino de petróleo, adsorventes e catalisadores. Os catalisadores heterogêneos apresentam grande potencial de viabilizar a produção de biodiesel através da reação de transesterificação. A síntese da peneira molecular MCM-41 foi realizada a partir da água deionizada, brometo de cetiltrimetilamônio, hidróxido de amônio, etanol e ortossilicato de tetraetila. O óxido de zircônia foi obtido pelo método sol-gel a partir do oxicloreto de zircônio com hidróxido de amônio à temperatura ambiente e ativado por calcinação a 550 e 700°C. Em seguida o óxido de zircônia ativado foi sulfatado, seco e calcinado a 400 °C. A zircônia sulfatada foi incorporada a peneira molecular MCM-41 por impregnação via úmida, com diferentes proporções mássicas (10, 20, 30, 40, 50%). Verifica-se que a partir das análises de difração de raio X a formação da peneira molecular MCM-41 confirmou a estrutura hexagonal e a fase mesoporosa. Observou-se formação das fases, tetragonal e monoclínica do óxido de zircônia. Através da espectroscopia de absorção na região do infravermelho com transformada de Fourier foi possível detectar picos referentes a presença de íons sulfatos bidentados ligado a superfície da zircônia. As propriedades texturais apresentaram estruturas com poros bimodais após o processo de incorporação da zircônia sulfatada. As micrografias do óxido de zircônia ativadas a 550 e 700 °C apresentaram tricas em sua superfície antes e após de incorporação da zircônia sulfatada. O potencial catalítico foi avaliado na reação transesterificação do óleo de soja por rota metílica. O catalisador com óxido de zircônia ativado a 700 °C e sulfatado e incorporado a peneira molecular com 40% (em peso) apresentou maior conversão de ésteres metílicos 83,8%. No entanto, esta conversão não especifica o óleo obtido como biodiesel de acordo com a norma da Agência Nacional de Petróleo, Gás Natural e Combustíveis. Assim como o índice de acidez. Porém os resultados de densidade e viscosidade estão de acordo com a especificação estabelecida pelas normas. / The MCM-41 molecular sieve is considered promising as a support for the petroleum refining metal oxides, adsorbents and catalysts. Heterogeneous catalysts have great potential to make viable the production of biodiesel through the transesterification reaction. The synthesis of the MCM-41 molecular sieve was performed from deionized water, cetyltrimethylammonium bromide (CTABr), ammonium hydroxide (NH4OH), ethanol and tetraethyl orthosilicate (TEOS). The zirconium oxide was obtained by the sol-gel method from zirconium oxychloride with ammonium hydroxide at room temperature, the material was activated at 550 and 700 °C, and thereafter, sulphated. The material was then activated using the calcination process at 550 and 700 ° C and sulfated. The sulfation process was carried out with a 0.5 mol.L-1 sulfuric acid solution and allowed to stand for 30 minutes, dried for 12 h at 120 ° C and calcined at 400 ° C. The process of incorporation of ZS into the MCM-41 molecular sieve was done using different mass proportions (10, 20, 30, 40 and 50%) in relation to the mass of the MCM-41 molecular sieve, by wet method. It was verified from the analyzes of X-ray diffraction, the adsorption of nitrogen (BET method) and Fourier transform infrared spectroscopy (FTIR) the crystalline and textural properties which confirmed the molecular sieve obtainment and the presence of the tetragonal and monoclinic phases of the sulfated zirconia in the mesoporous structure. The micrographs of activated zirconium oxide at 550 and 700 °C and sulphated showed dispersed particles with the presence of cracks on its surface, after the incorporation there were no modifications in the structure. The catalytic activity was evaluated by the transesterification reaction of the soybean oil via the methyl route, using all the catalysts which were synthesized. The results showed that the catalyst 50_ZS/MCM-41_550 °C showed a greater conversion of methyl esters of 81.4% with the predominant tetragonal phase. The catalyst with the zirconium oxide activated at 700 °C obtained a conversion of 83.8% to the 40_ZS/MCM-41_700 °C catalyst, with the predominant monoclinic phase. However, the ester content of the oil samples was below the value established by the National Agency of Petroleum, Natural Gas and Fuels (ANP). The density and kinematic viscosity of the catalysts under study X_ZS/MCM-41 were in the range of the established standard. The acidity index was above the specified values, confirmed by the high percentage of free fatty acids in the oil.

Neste trabalho foi realizado o estudo de transformações de óleo de soja com o catalisador VO(acac)2 em meio homogêneo e heterogêneo. Estes processos catalíticos estão de acordo com os conceitos de química limpa, no sentido de economia de reagentes e diminuição de subprodutos, enquanto que a matéria-prima, óleo vegetal, foi escolhida por ser de fonte renovável, sustentável e abundante no Rio Grande do Sul e no Brasil. A reação de transesterificação do óleo de soja foi realizada através do sistema VO(acac)2 e VO(acac)2 suportado em uma argila celadonita, cujo depósito localiza-se na região de Ametista do Sul – RS. O sistema heterogêneo foi caracterizado pelas técnicas de DRX, BET, BJH, ATG, FTIR, CHN, MEV/EDS e ICP/OES. O teor de vanádio impregnado na argila foi de 1,06 %. O melhor rendimento das reações de transesterificação foi de 36 % e 30 % para os sistemas homogêneo e heterogêneo, respectivamente, para as condições de 2 % em mol e 5 % em mol de vanádio, a 65 ºC de temperatura e 48 horas de reação. Alguns testes foram realizados em reações de epoxidação. Do sistema celadonita/VO(acac)2 foi obtido conversão de 44 %, 15 % de monoepóxido e 34 % de seletividade, em 3 horas de reação. A avaliação quantitativa das reações foi realizada por RMN de 1H. / This work presents the study of soybean oil reactions with VO(acac)2 in homogeneous and heterogeneous catalytic systems. The catalytic systems follow the green chemistry principles of economy of reagents and reduction in sub-products of the reaction while the starting material, soybean oil, was chosen as a renewable source, sustainability of its crop and abundancy. Soybean oil transesterification reactions were done with the catalytic system VO(acac)2 and VO(acac)2 supported in celadonita, which is a mineral found in Ametista do Sul / RS. The heterogeneous system was characterized by the XRD, BET, BJH, TGA, FTIR, CHN, SEM/EDX and ICP/OES techniques. The amount of vanadium impregnated in the clay it was 1,06%. The best conditions for transesterification reaction gave 36 % yield for homogeneous system and 30 % yield for heterogeneous system, using 2 % molar and 5 % molar of vanadium, respectively, at 65 ºC of temperature and 48 hours of reaction. Some tests on epoxidation reactions were performed. With celadonita/VO(acac)2 system it was obtained a conversion of 44%, 15% of monoepoxide and 34 % of selectivity after 3 hours of reaction. The quantitative evaluation of the reactions was made by 1H NMR.

Biodiesel is now considered as an important option for full or partial diesel fossil replacement. At the same time, biodiesel is a renewable and an environmentally friendly fuel. This work has as goal to employ residual vegetable oils for biodiesel production and evaluate its viability as raw material. For that, some initial steps were considered in order to get a correct planning for the project: i) gathering and purification of the raw material; ii) determination of the physico-chemical properties of the residual oils; iii) choice of the catalytic system based on the quality of the raw material; iv) biodiesel production; and v) evaluation of the properties of the biofuel produced. The results of the frying oils characterization are in agreement with the requirements, not compromising their use for obtaining biodiesel. The biodiesel production was conducted by basic and acid catalysis in the presence of methanol or ethanol, as alcoholysis agents. The best results, in biodiesel production, were obtained for methanolysis conducted in the presence of basic catalyst. The results presented here show a concrete possibility of the use of frying oil as raw material for obtaining biodiesel, even if the sample has been collected in small establishments. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O biodiesel constitui, nos dias atuais, uma importante alternativa de substituição para o diesel fóssil, sendo ao mesmo tempo um combustível renovável e ambientalmente correto. O presente trabalho teve como objetivo empregar resíduos de óleos comestíveis para a obtenção de biodiesel e avaliar sua viabilidade como matéria prima. Para tanto, algumas etapas foram realizadas: (i) coleta e purificação adequadas da matéria-prima; (ii) determinação das propriedades físico-químicas dos óleos residuais; (iii) escolha do sistema catalítico a ser empregado, em função da qualidade desses; (iv) obtenção do biodiesel; e (v) avaliação da propriedade desse biocombustível. Através dos resultados obtidos para os óleos de fritura foi possível constatar que os mesmos, de uma maneira geral, atendem às necessidades, não comprometendo sua utilização para obtenção de biodiesel. A obtenção de biodiesel foi conduzida por catálise básica e ácida, na presença de metanol ou etanol, como agentes de alcoólise. Os melhores resultados, em termos de rendimento em éster, foram obtidos para a metanólise conduzida em presença de catalisador básico. Os resultados aqui apresentados permitem visualizar uma possibilidade concreta da utilização de óleos de fritura como matéria-prima para a obtenção de biodiesel, mesmo que a coleta tenha sido realizada em pequenos estabelecimentos.