Vegetable oil methyl esters obtained by transesterification of vegetable oils are considered to be suitable alternative fuels for diesel engines. However, higher viscosity, surface tension and boiling temperatures of biodiesels may adversely affect spray characteristics as compared to those of diesel. Thus, spray characteristics of Jatropha Methyl Ester (JME) are studied by comparing them to those of diesel in a high-pressure chamber with optical access to simulate the actual in-cylinder conditions. Also, the effect of inner-nozzle cavitation on JME and diesel sprays is studied by utilizing two nozzles, one with sharp entry-radius and the other with larger entry-radius. Finally, spray characteristics of surrogate fuels such as n-dodecane and n-hexadecane are also studied. The first part of the work concerning precise measurements of inner-nozzle geometry revealed that one of the nozzles has a hole diameter of 190-µm and entry-radius of around 70-µm, while the other has a hole diameter of 208-µm and entry-radius of around 10-µm. Injection rate-shape and coefficient of discharge for JME and diesel flow through the two nozzles were then measured. It was observed that while the coefficients of discharge (Cd) are almost identical for JME and diesel, the nozzle with entry radius of 10-µm exhibited around 20% lower Cd than that of the entry-radius of 70-µm. This observation coupled with insight from complementary CFD simulations of inner-nozzle flow showed that the lower Cd of the nozzle with entry-radius of 10-µm could be attributed to inner-nozzle cavitation. The second part of the work involved measurement of non-evaporating spray characteristics including spray-tip penetration, spray-cone angle and droplet size measurement under realistic operating conditions using techniques such as Shadowgraphy and Particle/Droplet Imaging Analysis (PDIA). The non-evaporating spray of the fuels are studied by injecting them using a common-rail fuel injection system into the high-pressure chamber maintained at room temperature. Experimental results show that JME is associated with a slightly faster spray-tip penetration and narrow spray-cone angle indicating inferior spray atomization which is confirmed by around 5% larger droplet sizes. Slower spray-tip penetration, wider spray-cone angle and around 5% smaller droplet sizes are observed for the spray from the cavitating nozzle. Thus, the inner nozzle cavitation is observed to improve the atomization of diesel and JME sprays. The differences in spray characteristics of JME and diesel reduce as the injection pressure increases. The spray-tip penetrations of both surrogates are observed to almost match that of diesel. The third part of the work involved measurements of evaporating spray liquid length, vapour penetration and spread angle for JME, diesel and surrogates at conditions of 50 bar chamber pressure and 900 K temperature. It is observed that the JME exhibits around 16% longer liquid length than that of diesel. The liquid length of n-dodecane is significantly lower than that of diesel and liquid length of n-hexadecane is around 20% higher than that of n-dodecane mimicking the trend of JME and diesel. The liquid length of n-hexadecane is very close to that of diesel at all the three test conditions. Interestingly, the vapour penetration and spread angle for all the fuels is observed to be almost identical. As the cold spray and evaporating spray characteristics of n-hexadecane match well with those of diesel, n-hexadecane can be chosen as a pure component surrogate for diesel. Finally, an analytical model for predicting the spray vapour penetration is assessed with the experimentally-observed trends of penetration and spray spread angle. The model indicated that the effect of fuel density variation is compensated by the corresponding variation in injection velocity for a given injection pressure to result in a similar vapour penetration. Overall, the present work, in addition to studying the effect of fuel physical properties and cavitation on sprays, has generated a comprehensive experimental database on non-evaporating and evaporating sprays of biodiesel, diesel, and pure component surrogates, which would aid significantly in validation of CFD simulations.

Pachycoris torridus (Scopoli, 1772) (Hemiptera: Scutelleridae) is the only representative of the Scutelleridae family of agricultural impact in Brazil. This bug is the main pest of Jatropha curcas (Linnaeus) (Euphorbiaceae), which produces raw material for the production of biodiesel. This study has as objective to evaluate bioecological and chemical aspects of P. torridus in herbivory of J. curcas. The experiments were performed using different methodologies, filed in literature, adapted to the particular insect pest, besides the development of new methodology that evaluated the attractiveness of J. curcas in different direction and distance. The research was developed in the Chemistry Laboratory of Natural Products of the Federal University of Alagoas (LPqRN/UFAL) and in Physiology Laboratory of the Agrarian Science Center (CECA/UFAL) and in the field (in the cities of Maceio and Rio Largo) during the period of May 2011 to January 2015. Younger seedlings were more susceptible to the attack even with smallest infestation, which the pest control must be done when there are signs of infestation in this stage. The sequence of behavioral categories which induced the sexual receptivity before intercourse was described in twelve steps. The intraspecific communication of P. torridus was brokered by emission of compound volatiles within a short distance, vibrational signals, sound and groping, driven by the male and recognized by the female. To make a difference between the patterns already known, the 30 new color patterns can be included in literature records, from number 28 to 57. Jatropha curcas releases kairomones long distances (200m) which isolatedly attracts P. torridus for hosting and herbivory. In the chemical evaluations, the compounds identified in the cuticle of P. torridus were: (E)-2-hexenal, (E)-4-(oxo)-2-hexenal, (E)-2-hexenyl acetate, (E)-2-octenal, undecane, dodecane, 1-tridecene, tridecane, (Z,Z)-2,7-Octadien-1-ol acetate, tetradecane and tetradecanal. Species adults P. torridus release content from metathoracic glands during courtship and copulation to attract the opposite sex, being able to empty their reservoir. That bug doesn’t secrete sexual pheromone and contents of their metathoracic glands submit double behavioral activity (alarm and attractiveness) at different concentrations. The rejection of the males to the females with new color patterns was caused by the presence of the chemical compound 1-Tridecene, as well as by increasing the concentration of the compound (E)-2-Octenal. / Fundação de Amparo a Pesquisa do Estado de Alagoas / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Pachycoris torridus (Scopoli, 1772) (Hemiptera: Scutelleridae) é o único representante da família Scutelleridae de impacto agrícola no Brasil. Esse percevejo é a principal praga da Jatropha curcas (Linnaeus) (Euphorbiaceae), a qual produz matéria-prima para obtenção de biodiesel. O presente trabalho visa avaliar aspectos bioecológicos e químicos de P. torridus na herbivoria de J. curcas. Os experimentos foram realizados por meio de variadas metodologias, protocoladas na literatura, adaptadas as particularidades do inseto-praga, além do desenvolvimento de nova metodologia que avaliou a atratividade de J. curcas em diferentes direção e distância. As pesquisas foram desenvolvidas no Laboratório de Química de Produtos Naturais da Universidade Federal de Alagoas (LPqRN/UFAL), no Laboratório de Fisiologia do Centro de Ciências Agrárias (CECA/UFAL) e no campo (em Maceió e Rio Largo), no período de maio de 2011 a janeiro de 2015. Mudas mais jovens foram mais suscetíveis ao ataque, mesmo com menor infestação, devendo ser feito o controle da praga quando ocorrerem sinais de infestação nessa fase. A sequência de categorias comportamentais que induziu a receptividade sexual antes da cópula foi descrita em doze etapas. A comunicação intraespecífica de P. torridus foi intermediada por emissão de compostos voláteis a curta distância, sinais vibratórios, sonoro e de tateamento, impulsionada pelo macho e reconhecida pela fêmea. Para diferenciar dos padrões já conhecidos, os 30 novos padrões cromáticos podem ser incluídos nos registros da literatura, a partir do no28 até 57. A espécie J. curcas emite cairomônios a longa distâncias (200m) que atraem isoladamente P. torridus para hospedagem e herbivoria. Nas avaliações químicas os compostos identificados na cutícula de P. torridus foram: (E)-2-Hexenal, (E)-4-(oxo)-2-Hexenal, Acetato de (E)-2-hexenila, (E)-2-Octenal, Undecano, Dodecano, 1-Trideceno, Tridecano, Acetato de (Z,Z)-2,7-octadien1-ol, Tetradecano e Tetradecanal. Adultos da espécie P. torridus liberam conteúdo das glândulas metatorácicas durante a corte e cópula, para atrair o sexo oposto, chegando a esvaziar seu reservatório. Esse percevejo não secreta feromônio sexual e o conteúdo de suas glândulas metatorácicas apresentam dupla atividade comportamental (alarme e atratividade) em concentrações diferentes. A rejeição dos machos as fêmeas com novos padrões cromáticos foi ocasionada pela presença do composto químico 1-Trideceno, bem como pelo aumento na concentração do composto (E)-2-Octenal.

Submitted by Lúcia Brandão (lucia.elaine@live.com) on 2015-07-15T16:05:00Z No. of bitstreams: 1 Tese - Cristiane Daliassi Ramos de Souza.pdf: 2429333 bytes, checksum: 3abea0012ee786e4320f226b2f591475 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-20T15:48:37Z (GMT) No. of bitstreams: 1 Tese - Cristiane Daliassi Ramos de Souza.pdf: 2429333 bytes, checksum: 3abea0012ee786e4320f226b2f591475 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-20T15:54:41Z (GMT) No. of bitstreams: 1 Tese - Cristiane Daliassi Ramos de Souza.pdf: 2429333 bytes, checksum: 3abea0012ee786e4320f226b2f591475 (MD5) / Made available in DSpace on 2015-07-20T15:54:42Z (GMT). No. of bitstreams: 1 Tese - Cristiane Daliassi Ramos de Souza.pdf: 2429333 bytes, checksum: 3abea0012ee786e4320f226b2f591475 (MD5) Previous issue date: 2012-11-10 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Jatropha curcas L. is a vegetable species that supplies great amount of oil, but due to its toxicity cannot be used to feed human beings. It is a promising alternative for Biodiesel production. This Thesis had the purpose of perform analytic, thermal and energy studies for the oil extracted from oleaginous species Jatropha curcas L., cultivated in the State of Amazonas. The study was also done for byproducts such as fruit peels, seed peels and the cake originated by biofuel productive chain. To reach the proposed objective, the experimental activities were started with the sampling of the whole fruits in a plantation located in Itacoatiara city-Amazonas. Six independent samplings were done in different months and all the samples were submitted to physical characterization to evaluate size and weight for all parts of the fruit. The process to obtain the oil was done by two methods: mechanical extraction and chemical extraction (Soxhlet system). The chemical extraction was performed for all available samples and the best efficiency was the 50.21%, although all the extractions have presented good results (43-48%). The mechanical process was just performed for the 2010 crop presenting a satisfactory efficiency (33.14%). Then, the oil extracted by the two processes was characterized by several physical-chemical parameters. The oxidative stability by Rancimat was measured for the oils and the result was around 12 hours, this value is considered satisfactory when compared with other species. The fatty acid profile was analyzed by gas chromatography, which indicated the presence of higher concentrations of oleic and linoleic acids. The palmitic, stearic, arachidic and palmitoleic acids were also detected, however in smaller concentrations. The evaluation for thermal and energy potential was done for the oil and byproducts using TG/DTA, immediate analysis and superior heat power techniques. The results of thermal analysis for the oils obtained by chemical and mechanical extraction indicated thermal stability temperature about 180 and 217°C, respectively. Energy evaluation for byproducts was done by immediate analysis and high values for volatile materials were found (65-78%). These values characterize a fuel that can be easy and quickly burned during the combustion process. The results of PCS for the obtained oils presented high values (34-39 MJ/kg), which are close to the ones measured for diesel. For the byproducts, the results were between 17 and 21 MJ/kg, close and even superiors to the literature values for other agricultural residues showing, therefore, great applicability for use in energy generation processes. Finally, reactions with the Jatropha curcas L. oil were made to obtain biofuels through the methylic and ethylic transesterification and thermal cracking. The results for transesterification process were excellent, with efficiency above 90%, however, the physical-chemical evaluation showed that the methylic Biodiesel was the only one in conformity with the Resolution 14/2011 from ANP. A satisfactory efficiency of 75% was obtained for bio-oil. / O pinhão manso é uma espécie vegetal que fornece grande quantidade de óleo e por sua toxidade não pode ser usado na alimentação humana, podendo se transformar em uma alternativa promissora na produção de Biodiesel. Esta Tese teve a finalidade de realizar um estudo analítico, térmico e energético do óleo extraído da espécie oleaginosa pinhão manso (Jatropha curcas L.), cultivada no Estado do Amazonas, assim como dos co-produtos, tais como, cascas do fruto, cascas da semente e torta, presentes na cadeia produtiva de biocombustíveis. Para atingir o objetivo proposto, as atividades experimentais foram iniciadas com a coleta dos frutos na plantação localizada em Itacoatiara-AM. Foram feitas seis coletas em diferentes meses e todas as amostras foram submetidas à caracterização física avaliando o tamanho e a massa para todas as partes do fruto. Em seguida realizou-se o processo de obtenção do óleo, utilizando dois métodos, a extração mecânica e a extração com solvente (Método Soxhlet). A extração com solvente foi realizada para todas as amostras coletadas e o melhor rendimento obtido foi de 50,21%, apesar de ter obtido bons resultados em todas as extrações (43-48%). O processo mecânico foi realizado apenas com o lote da safra de 2010 apresentando um rendimento satisfatório (33,14%). Posteriormente, o óleo extraído foi caracterizado por diversos parâmetros físico-químicos. A estabilidade oxidativa por Rancimat foi realizada para o óleo do pinhão manso ficando em torno de 12 horas, um valor considerado satisfatório quando comparado com outras espécies. O perfil de ácidos graxos foi analisado por cromatografia gasosa, o qual indicou a presença de altas concentrações dos ácidos oléico e linoléico. Os ácidos palmítico, esteárico, araquídico e palmitoléico também foram detectados, porém em concentrações menores. A avaliação do potencial térmico e energético foi realizada para o óleo e os co-produtos utilizando as técnicas de TG/DTA, análise imediata e PCS. Os resultados da análise térmica dos óleos, obtidos via extração química e mecânica, indicaram uma temperatura de estabilidade térmica em torno de 180C e 217C, respectivamente. Na avaliação energética dos co-produtos realizada pela análise imediata houve destaque para o teor de materiais voláteis, que apresentou valores elevados (65-78%), o que caracteriza um combustível mais fácil e rapidamente queimado durante o processo de combustão. Os resultados do PCS para os óleos obtidos apresentaram valores elevados (34-39 MJ/kg) e próximos ao diesel. Para os co-produtos, os resultados ficaram entre 17 e 21 MJ/kg, próximos e até superiores aos valores reportados na literatura para outros resíduos agrícolas mostrando, portanto grande aplicabilidade para utilização em processos de geração de energia. Por fim foram realizadas reações com o óleo de pinhão manso para obter biocombustíveis através da transesterificação metílica e etílica e do craqueamento térmico. Os resultados da transesterificação mostraram-se excelentes, com rendimentos acima de 90%, entretanto a avaliação físico-química mostrou que apenas o Biodiesel metílico ficou em conformidade com a Resolução 14/2011 da ANP. O Bio-óleo obteve um rendimento satisfatório (75%).

Made available in DSpace on 2017-07-10T17:59:31Z (GMT). No. of bitstreams: 1 Carolline Rodrigues Ranucci.pdf: 1478673 bytes, checksum: dbf05cf901d293b1091d138f2695fb5f (MD5) Previous issue date: 2015-09-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The increase in global energy demand has contributed to the search for alternative energy sources aimed at reducing the dependency on fossil fuels. The airline industry increasingly invests in the development of a less dependent on fossil fuel sources, that is from renewable sources and to maintain the original composition of fossil kerosene (jet fuel-1), preventing changes are needed in aircraft engines. An alternative is the production of so-called Biokerosene from oil intended for energy purposes. In this context, there are the jatropha oil (Jatropha curcas L.), babassu (Orbignya phalerata) and palm kernel (Elaeis guineenses) who present themselves as strong potential for the production of bio-kerosene. The objective of this study was to obtain an alternative aviation biofuel to fossil kerosene (jet fuel-1) from the transesterification reaction by homogeneous catalysis, esters were subjected to vacuum fractional distillation process, and the fractions that showed higher contents of minor carbon chains compounds were mixed with fossil commercial kerosene in the proportions of 5, 10 and 20% (biokerosene/kerosene). Also mixtures of the methyl esters of kerosene were performed in the same proportions. Some quality specifications determined by the standard of ANP No. 38 of 28.07.2011 DOU 29.07.2011, as the kinematic viscosity, calorific value, density and flash point were tested for both the methyl esters and bio-kerosene as to their mixtures to fossil kerosene. Mixtures up to 20% bio-kerosene jatropha, babassu and palm kernel in the evaluated quality parameters only the calorific value did not meet the established limits, lying below this by a very small margin. Based on these results, it has been found feasible to carry blends of Jatropha Biokerosene, babassu oil and palm kernel prepared by this method with commercial jet fuel up to 10% (v/v), and if the range of acceptability of parameters is larger this percentage can reach up to 20%. The characterization of mixtures of methyl esters/kerosene confirmed that the biofuels obtained by the proportion between 10 and 20%, has properties comparable with the commercial aviation fuel available. / O aumento da demanda energética mundial tem contribuído para a busca de fontes alternativas de energia que visem à redução na dependência de combustíveis fósseis. O setor aéreo investe cada vez mais no desenvolvimento de um combustível menos dependente de fontes fósseis, que seja de origem renovável e que mantenha a composição original do querosene fóssil (QAV-1), evitando que sejam necessárias modificações nos motores das aeronaves. Uma alternativa está na produção do denominado bioquerosene a partir de oleaginosas destinadas para fins energéticos. Nesse contexto, tem-se os óleos de pinhão manso (Jatropha curcas L.), babaçu (Orbignya phalerata) e palmiste (Elaeis guineenses) que se apresentam como forte potencial para a produção de bioquerosene. O objetivo deste trabalho foi estudar a obtenção de um biocombustível de aviação alternativo ao querosene fóssil (QAV-1), a partir da reação de transesterificação por catálise homogênea, os ésteres obtidos foram submetidos ao processo de destilação fracionada a vácuo, e as frações que apresentaram maiores teores de compostos de cadeias de carbono menores foram misturadas ao querosene fóssil comercial nas proporções de 5, 10 e 20% (bioquerosene/querosene). Também foram realizadas misturas dos ésteres metílicos com o querosene nas mesmas proporções. Algumas especificações de qualidade determinadas pela Norma da ANP Nº 38, de 28.07.2011 DOU 29.07.2011, como a viscosidade cinemática, poder calorífico, massa específica e ponto de fulgor, foram testadas tanto para os ésteres metílicos e bioquerosene quanto para as suas misturas ao querosene fóssil. As misturas de até 20% de bioquerosene de pinhão manso, babaçu e palmiste nos parâmetros de qualidade avaliados apenas o poder calorífico não atendeu os limites estabelecidos, encontrando-se abaixo deste por uma margem muito pequena. Com base nestes resultados, verificou-se ser viável realizar misturas de bioquerosene de pinhão manso, babaçu e palmiste preparadas por este método com querosene de aviação comercial em até 10% (v/v), e caso a faixa de aceitabilidade dos parâmetros seja ampliada, este percentual pode chegar a até 20%. As caracterizações das misturas dos ésteres metílicos/querosene confirmaram que o biocombustível obtido pela proporção entre 10 e 20%, possui propriedades comparáveis com o combustível de aviação comercial disponível.

Made available in DSpace on 2017-07-10T18:08:12Z (GMT). No. of bitstreams: 1 Andreia Fatima Zanette.pdf: 1763321 bytes, checksum: 2ac6f2e4fb36ec4d7935446c7ec228f6 (MD5) Previous issue date: 2010-02-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The search for renewable sources of energy had increased intensely through the last years. By this way, biofuels are starting to play an important role as an alternative in opposition to fossil fuels. Biodiesel can be obtained by a transesterification reaction of oils with a short alcohol chain. In this regard, the species Jatropha curcas has been showing many advantages due its good quality of its extracted oil, yet it does not rival with food production. The use of heterogeneous catalysts presents itself as a promising alternative to the homogeneous catalysts, reducing biodiesel production costs, because the process of separation of the reaction results is simpler, there s not soap production, besides the possibility of re-using the catalyst. In this sense, the objective of this study was to valuate the efficiency of the following heterogeneous catalysts: resins, zeolites, clays, hydrotalcites, aluminas, and niobium oxide in the esters of fatty acids production, using methanol and Jatrophas curcas oil as substrates. For this finality, were made experimentation in a batch reactor in order to reach the catalysts screening in the following operational conditions: oil to methanol molar ratio of 1:9, 6 hours of reaction, 5 % (w/w) catalysts, at 6 °C to 120 °C. Results showed that an increasing in the temperature conduces an increment in the reaction s efficiency. Were selected two catalysts that presented the highest efficiency: clayl KSF and the resin Amberlyst 15, the both are commercial catalysts. A DCCR 23 complete experimental planning was made with this both catalysts to maximize the percentage of esters in the reaction. Independent variables and valuated levels in the planning were: temperature between 80 °C and 180 °C, oil to methanol molar ratio at 1:4 to 1:14, and catalyst percentage of 1 to 20% (w/w). Reaction conditions for a maximum efficiency in esters were: oil to methanol molar ratio of 1:12, 5 % (w/w) of catalyst, 160 °C and 6 hours of reaction, for both catalysts, obtaining a percentage of 70 % for clay and 60 % for the resin. It was also made a study of these catalysts re-utilization in five successive experiments in a batch reactor in the optimized reaction conditions for the both catalysts. It was observed an efficiency decrease in the number of the catalyst using cycles. In the fifth cycle the reaction efficiency was 37,5 % with the clay KSF and 25,2 % with the resin Amberlyst 15. As well, was searched the characterization of the catalysts about the area and the diameter of their pores by means of nitrogen isotherms and the application of the BET and BJH methods, which identified that the products present microporous and mesoporous. Yet, experiments were made to obtain the reaction kinetics in a batch reactor in the optimized conditions of the reaction. A simplified kinetic model was proposed, which described the reaction kinetics nicely. / A busca por fontes renováveis de energia tem-se intensificado nos últimos anos. Desta forma, os biocombustíveis estão adquirindo um papel relevante como alternativa aos combustíveis fósseis. O biodiesel pode ser obtido pela reação de transesterificação de óleos com um álcool de cadeia curta. Neste cenário, a espécie Jatropha curcas tem mostrado vantagens pela boa qualidade do óleo extraído, além de não competir com a alimentação. O emprego de catalisadores heterogêneos apresenta-se como alternativa promissora aos catalisadores homogêneos, reduzindo os custos da produção de biodiesel, pois o processo de separação dos produtos da reação é mais simples, não há a formação de sabão, além da possibilidade de reutilização do catalisador. Neste contexto, o objetivo do presente trabalho foi avaliar a eficiência dos seguintes catalisadores heterogêneos: resinas, zeólitas, argilas, aluminas, hidrotalcitas e óxido de nióbio na produção de ésteres de ácidos graxos, utilizando metanol e óleo de pinhão manso como substratos. Para esse fim, foram realizados experimentos num reator batelada visando ao screening do catalisador nas seguintes condições operacionais: razão molar óleo:metanol de 1:9, 6 horas de reação, 5 % (m/m) de catalisador, nas temperaturas de 60 °C e 120 °C. Na temperatura de 60 °C o maior rendimento em ésteres foi de 18 %, e até 40 % na temperatura de 120 °C. Os resultados mostraram que um aumento na temperatura conduz a um incremento no rendimento da reação. Foram selecionados dois catalisadores que apresentaram o maior rendimento, a argila KSF e a resina Amberlyst 15, ambos catalisadores comerciais. Foi realizado um planejamento experimental completo DCCR 23 com estes dois catalisadores a fim de maximizar o teor de ésteres da reação. As variáveis independentes e níveis avaliados no planejamento foram: temperatura entre 80 e 180 °C, razão molar óleo:metanol de 1:4 a 1:14, e teor de catalisador de 1 a 20 % (m/m). As condições reacionais para um máximo de rendimento em ésteres foram: razão molar óleo:metanol de 1:12, 5 % (m/m) de catalisador, 160 °C e 6 horas de reação, para ambos os catalisadores, obtendo um teor de ésteres de 70 % para a argila e de 60 % para a resina. Também foi realizado um estudo da reutilização destes catalisadores em cinco experimentos consecutivos em um reator batelada nas condições reacionais otimizadas para os dois catalisadores. Observou-se um decréscimo do rendimento com o número de ciclos de utilização do catalisador. No quinto ciclo o rendimento da reação foi de 37,5% para a argila KSF e de 25,2 % para a resina Amberlyst 15. Também foi realizada a caracterização dos catalisadores quanto à área e o diâmetro dos poros por meio das isotermas de nitrogênio e aplicação dos métodos BET e BJH. Os resultados obtidos mostraram que os materiais avaliados apresentam microporosos e mesoporosos.Também foram realizados experimentos para a obtenção da cinética da reação em um reator batelada nas condições otimizadas da reação. Um modelo cinético simplificado foi proposto, o qual descreveu satisfatoriamente a cinética da reação.

Atomization of fuel is an important pre-requisite for efficient combustion in devices such as gas turbines, liquid propellant rocket engines, internal combustion engines and incinerators. The overall objective of the present work is to explore air-assisted atomization strategies for high viscosity fuels and liquids. Air-assisted atomization is a twin-fluid atomization method in which energy of the gas is used to assist the atomization of liquids. Broadly, three categories of air-assisted injection, i.e., effervescent, impinging jet and pre-filming air-blast are studied. Laser-based diagnostics are used to characterize the spray structure in terms of cone angle, penetration and drop size distribution. A backlit direct imaging method is used to study the macroscopic spray characteristics such as spray structure and spray cone angle while the microscopic characteristics are measured using the Particle/droplet imaging analysis (PDIA) technique. Effervescent atomization is a technique in which a small amount of gas is injected into the liquid at high pressure in the form of bubbles. Upon injection, the two-phase mixture expands rapidly and shatters the liquid into droplets and ligaments. Effervescent spray characteristics of viscous fuels such as Jatropha and Pongamia pure plant oils and diesel are studied. Measurements are made at various gas-to-liquid ratios (GLRs) and injection pressures. A Sauter Mean Diameter (SMD) of the order of 20 µm is achieved at an injection pressure of 10 bar and GLR of 0.2 with viscous fuels. An image-based method is proposed and applied to evaluate the unsteadiness in the spray. A map indicating steady/unsteady regime of operation has been generated. An optically accessible injector tip is developed which has enabled visualization of the two-phase flow structure inside the exit orifice of the atomizer. An important contribution of the present work is the correlation of the two-phase flow regime in the orifice with the external spray structure. For viscous fuels, the spray is observed to be steady only in the annular two-phase flow regime. Unexpanded gas bubbles observed in the liquid core even at an injection pressure of 10 bar indicate that the bubbly flow regime may not be beneficial for high viscosity oils. A novel method of external mixing twin-fluid atomization is developed. In this method, two identical liquid jets impinging at an angle are atomized using a gas jet. The effect of liquid viscosity (1 cP to 39 cP) and surface tension (22 mN/m to 72 mN/m) on this mode of atomization is studied by using water-glycerol and water-ethanol mixtures, respectively. An SMD of the order of 40 µm is achieved for a viscosity of 39 cP at a GLR of 0.13 at a liquid pressure of 8 bar and gas pressure of 5 bar. It is observed that the effect of liquid properties is minimal at high GLRs where the liquid jets are broken before the impingement as in the prompt atomization mode. Finally, a pre-filming air-blast technique is explored for transient spray applications. An SMD of 22 µm is obtained with diesel at liquid and gas pressures as low as 10 bar and 8.5 bar, respectively. With this technique, an SMD of 44 µm is achieved for Jatropha oil having a viscosity 10 times higher than that of diesel.

Biofuels in civil aviation is actively studied in recent years to identify potential alternative jet fuels to meet stringent environmental regulations imposed to tackle degraded air quality caused by fossil fuel combustion. In this context, the aviation industry prefers to develop ‘drop-in’ fuels which may not require substantial modifications in existing jet engine technologies. The thesis aims at evaluating the atomization characteristics of camelina- and jatropha-derived drop-in biofuels discharging from simplex swirl atomizer used in aircraft gas turbine engines. The test fuels are characterized in detail and all fuels meet current ASTM D7566 specifications. The experiments are conducted by discharging fuel spray into quiescent atmospheric air in a fuel spray booth to obtain spray characteristics such as fuel discharge behaviour, spray cone angle, breakup behaviour of swirling fuel sheet and spray drop size distribution. The characteristics of sheet breakup are deduced from the captured images of biofuel sprays and the measurements of spray droplet size distribution are obtained using Spraytec (laser-diffraction instrument). A systematic comparison is made between the biofuel sprays and the 100% Jet A-1 (conventional aviation kerosene) sprays to evaluate the drop-in feature of the biofuels. All the measured spray characteristics of the biofuel sprays follow the Jet A-1 both in qualitative and quantitative terms which ensure the drop-in nature of the tested biofuels. The minor differences observed in the comparison of the quantitative spray measurements are attributed to the variation in the fuel properties. This claim is supported using the predictions obtained from the liquid film breakup model and the empirical correlation reported in the literature for the determination of sheet breakup characteristics and mean drop size for sprays discharging from simplex swirl atomizers.

Seed-oil based biodiesel production particularly biodiesel production from the nonedible oil seed bearing plant - Jatropha curcas L. - is a key strategic direction outlined in the biofuels strategy of the Government of Ethiopia. The main objective underlying the strategy include substitution of imported diesel oil used in the road transport sector while at the same time contributing to the local and global greenhouse gasses (GHG) reduction efforts. In this study the environmental benefits and costs of production and use of Jatropha biodiesel in the road transport sector of Ethiopia is assessed using a life cycle analysis (LCA) methodology. The analysis focused on determining the potential environmental impacts and net non-renewable energy saving potential of biodiesel from Jatropha oil-seeds using the following metrics: (i) Net Greenhouse Gas (GHG) reduction, and (ii) Net Energy Balance (NEB) relative to diesel oil. The study shows that the net GHG emissions reduction potential of Jatropha Methyl Ester (JME) is highly influenced by the magnitude of initial carbon loss occurring in the process of conversion of different land uses to Jatropha plantation, and less so on other unit processes of JME production system analysed. The NEB of JME relative to use of diesel oil per functional unit of one GJ is less sensitive to impacts of land use change and is generally positive. Where no land use change impacts is considered, or where Jatropha is grown on lands with low carbon stock such as grasslands, substitution of diesel oil with JME in Ethiopia can provide GHG emission reduction of about 43%, and for each MJ of JME produced the nonrenewable energy requirement will be 0,38 MJ. Production of JME by converting lands with high above ground, below ground and/or soil carbon stocks such as shrub lands or well stocked forest lands will result in net loss of carbon and require ecological carbon payback time of 50 to hundreds of years. The impact of introducing and use of JME-diesel oil blends by Anbassa City Bus Services Enterprise (ACBSE) bus fleets shows that, displacement of diesel oil with JME that have positive GHG reduction potential, will also contribute to the reduction of air pollutants and improvement of ambient air quality in Addis Ababa. Two key recommendations of this research work are that to ensure environmental sustainability of biodiesel production from Jatropha seeds (i) land availability and land suitability assessment for estimating the potential available land for Jatropha (and other oil-seed bearing plants) shall be conducted, and (ii) minimum requirements on GHG reduction and NEB requirements on biodiesel shall be established. / Environmental Sciences / M. Sc. (Environmental Management)