Orientador: Rubens Maciel Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-01T13:16:30Z (GMT). No. of bitstreams: 1 Santos_MarcelaG.Motados_M.pdf: 3608818 bytes, checksum: dd58239af4dfd4bf4e0e40b36a9134e5 (MD5) Previous issue date: 2000 / Resumo: Desde a terceira década do século XX, tem-se realizado o processo de extração de oleaginosas utilizando como solvente o hexano. Como esta substância é tóxica e altamente inflamável, tem-se intensificado a procura por solventes que produzam óleo de boa qualidade utilizando tecnologias limpas minimizando o prejuízo ao meio ambiente e também ao ambiente de produção. É neste contexto que está sendo estudada a substituição do hexano por solventes supercríticos, que são não só solventes efetivos para a extração, mas também apresentam uma série de peculiaridades que os tornam mais vantajosos em relação aos solventes líquidos, geralmente usados. Além das características inerentes aos meios supercríticos, o dióxido de carbono tem-se tornado um solvente potencial para a substituição do hexano por ser não tóxico, não inflamável, por apresentar condições supercríticas relativamente brandas (temperatura crítica de 31°C e pressão crítica de 73.8 bar), além de estar disponível a baixo custo. O objetivo deste trabalho é estudar o comportamento de uma planta de extração supercrítica. Além disso será realizada a análise de sensibilidade paramétrica para a avaliação do comportamento de determinadas variáveis na performance do processo, baseada nos conceitos do planejamento fatorial. Neste trabalho é apresentado um modelo que usa parâmetros experimentais para avaliar políticas de controle e otimização. Partindo deste modelo foi realizada a análise de sensibilidade paramétrica, que possibilitou estudar tanto os efeitos principais das perturbações nas variáveis como os efeitos de interação destas variáveis. A partir disso foi possível determinar as variáveis de maior influência no processo, e, desta forma, determinar estratégias de otimização do processo. Além disso foi avaliada também a estabilidade da solução numérica do modelo apresentado para o método de solução utilizado / Abstract: Since the third decade of the century XX, it has been accomplishing the extraction process of oleaginous for hexane. As this substance is toxic and highly flammable, it has been intensifying the search of solvents that produce oil of good quality using clean technologies, minimizing the damage to the environment and production envirenment. It is in this context that is being studied the substitution of the hexane by supercritical solvents, which are not just effective solvents for the extraction of oil of seeds, but they also present a series of peculiarities they turn them more advantageous in relation to the liquid solvents, generally used. Besides the inherent characteristics to the supercritical means, the carbon dioxide has been proving a potential solvent for the substitution of the hexane for being not toxic, not flammable, to present supercritical conditions relatively mild (critica I temperature of 31°C and critica I pressure of 73.8 bar), besides being at a low cost available.The objective of this work is to study the behavior of a supercritical extraction plant. Besides the parametric sensibility analysis is accomplished for the evaluation of the behavior of certain variables in the precess performance, based on the concepts of the factorial designo. In this work a model is presented that uses experimental parameters for evaluations of control politics and optimization. Starting from this model took place the parametric sensitivity analysis, which facilitated to study the principal and interaction effects of perturbations in certain variables. Starting frem that it was possible to determine the variables of larger influence in the process, and, this way, to determine strategies of the process optimization. Besides the stability of the numeric solution of the model for the used solution method was also evaluated. / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

The slow yet steady expansion of the global economies, has led to an increased demand for energy and fuel, which would eventually lead to shortage of fossil fuel resources in the near future. Consequently, researchers have been investigating other fuels like biodiesel. Biodiesel refers to the monoalkyl esters which can be derived from a wide range of sources like vegetable oils, animal fats, algae lipids and waste greases. Currently, biodiesel is largely produced by the conventional route, using an acid, a base or an enzyme catalyst. Drawbacks associated with this route result in higher production costs and longer processing times. Conversely, supercritical transesterification presents several advantages over conventional transesterification, such as, faster reaction rates, catalyst free reaction, less product purification steps and higher yields. This work focused on the supercritical transesterification of cooking oil, soybean in particular. The experimental investigation was conducted using methanol at supercritical conditions. These conditions were milder in terms of pressure than those reported in literature. A batch setup was designed, built and used to carry out the supercritical transesterification reactions. The biodiesel content was analyzed using gas chromatography-mass spectrometry to calculate reaction yields. Methyl ester yield of 90% was achieved within 10 minutes of reaction time using supercritical transesterification. A maximum yield of 97% was achieved with this process in 50 minutes of reaction time. Two key factors, temperature and molar ratio were studied using variance analysis and linear regression and their significance on the biodiesel yield was determined. The kinetic tendency of the reaction was investigated and the values of rate constants, activation energy and the pre-exponential factor were estimated.

The ability of natural zeolite and synthetic ion-exchange resin for ammonia removal from aqueous solution was studied through batch experiments. The results showed that both zeolite and ion-exchange resin were effective (up to 87% of removal) in eliminating ammonia from aqueous solution. Factorial design and response surface methodology were applied to evaluate and optimize the effects of pH, dose, contact time, temperature and initial ammonia concentration. Low pH condition was preferred with the optimum pH found to be 6 for both zeolite and ion-exchange resin. High dose generated high removal rate and low exchange capacity. Results of factorial design and response surface methodology showed that temperature was not a significant parameter. The model prediction was in good agreement with observed data (R2 = 0.969 for zeolite and R2 = 0.957 for resin, respectively). For zeolite, the optimum Qe was 22.90 mg/g achieved at pH=7 and initial ammonia concentration of 3000 mg/L. For ion-exchange resin, Qe of 28.78 mg/g was achieved at pH=6 and initial TAN concentration of 3000 mg/L. The reaction kinetics for both of them followed the Pseudo-second order kinetic model (R2=0.998 and R2=0.999, respectively). Equilibrium data were fitted to Langmuir and Freundlich isotherm models with Freundlich model providing a slightly better predication for zeolite (R2=0.992) and Langmuir providing more accurate prediction for ion-exchange resin (R2=0.996). The ion-exchange resin can be completely regenerated by 2N H2SO4.

The application of Ultrasound (US) irradiation to remove ammonia nitrogen from aqueous solutions, including synthetic solution and landfill leachate, at 20 kHz was investigated in this thesis. Batch experiments were carried out using two synthetic solutions with initial ammonia concentrations of 3000 and 5000 mg TAN/L in addition to two leachates from new and old landfills. The results of testing showed that US irradiation is an effective treatment technology for the removal of aqueous ammonia. More specifically, it was found that increasing sonication time and pH increased ammonia removal. The maximum observed removal of ammonia was 87.4% at a pH of 11 and sonication time of 25 minutes. Also, it was found that volatilization of ammonia to the atmosphere accounted for 0-7% of removal, the thermal effect of US accounted for 21.1-52.7%, and the non-thermal effect of US accounted for 44.5-78.8% (depending on pH and sonication time). Results of factorial design and response surface methodology showed that pH, energy output (kJ), and the interaction between the two were significant parameters. The predicted two factor interaction (2FI) model was in close agreement to the observed data (R2 = 0.94) and produced an optimum ammonia removal of 87% at a pH of 10.9 and energy output of 94.8 kJ. Analysis of variance tests showed that there were no significant differences in the percent removal of ammonia due to the non-thermal effects of US across all four solutions (synthetic and leachate) indicating that US irradiation is a non-selective treatment method for ammonia removal.

Current prices and demand for petroleum hydrocabons have generated an increase of oil spills around the country and the world. Health and environmental impacts associated to these organic pollutants represent a huge concern for the general public, leading the public and private sector to develop new technologies and methods to minimize or eliminate those risks. Ex-Situ bioremediation through biopiles, as a main remediation technique to treat a wide range of hydrocarbons, has been a topic of considerable research interest over the last years. It provides an economical and environmental solution to restore the environment to background levels. Nevertheless, successful bioremediation under cold climate conditions is of considerable concern in countries like Canada, as low temperatures can delay the rate of bioremediation of oil hydrocarbons, thus limiting the operation of soil treatment facilities to certain times of the year. Recent research has found out that bioremediation could be conducted even at low or cold temperatures with larger periods of times. And even more, the addition of petroleum degrading microorganisms (bioaugmentation) and nutrients or biosurfactants (biostimulation) could enhance the process in some cases. In the present study, a comprehensive assessment of bioaugmentation and biostimulation strategies for ex-situ bioremediation of petroleum contaminated soil under cold climate conditions is proposed. Field scale biopiles were constructed and subjected to different concentrations of commercial microbial consortia and mature compost, as bioaugmentation and biostimulation strategies, in a soil treatment facility at Moose Creek, Ontario over a period of 94 days (November 2012 to February 2013). Assessment and comparison of the biodegradation rates of total petroleum hydrocarbons (TPH) and their fractions were investigated. Furthermore, a response surface methodology (RSM) based on a factorial design to investigate and optimize the effects of the microbial consortia application rate and amount of compost on the TPH removal was also assessed. Results showed that biopiles inoculated with microbial consortia and amended with 10:1 soil to compost ratio under aerobic conditions performed the best, degrading 82% of total petroleum hydrocarbons (TPHs) with a first-order kinetic degradation rate of 0.016 d_1, under cold temperature conditions. The average removal efficiencies for TPHs after 94 days for control biopiles, with no amendments or with microbial consortia or compost only treatments were 48%, 55%, and 52%, respectively. Statistical analyses indicated a significant difference (p < 0.05) within and between the final measurements for TPHs and a significant difference between the treatment with combined effect, and the control biopiles. On the other hand, the modeling and optimization statistical analysis of the results showed that the microbial consortia application rate, compost amendment and their interactions have a significant effect on TPHs removal with a coefficient of determination (R2) of 0.88, indicating a high correlation between the observed and the predicted values for the model obtained. The optimum concentrations predicted via RSM were 4.1 ml m-3 for microbial consortia application rate, and 7% for compost amendment to obtain a maximum TPH removal of 90.7%. This research contributes to provide valuable knowledge to practitioners about cost-effective and existing strategies for ex-situ bioremediation under cold weather conditions.

Orientador: Roy Edward Bruns / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T11:44:59Z (GMT). No. of bitstreams: 1 Rodrigues_MarlonCasagrande_M.pdf: 2084739 bytes, checksum: 4206c434cf21dfc145d73ca304a9981b (MD5) Previous issue date: 2011 / Resumo: Nos últimos anos a emissão de ruído tem sido decisiva para aceitação de veículos no mercado, não somente devido a legislação, mas também no que diz respeito a satisfação do cliente. Por este motivo as empresas fabricantes de veículos e ou motores de combustão interna tem sido obrigadas a dar uma atenção especial as emissões de ruído para poderem competir com suas concorrentes. Neste trabalho realizou-se estudo da influencia dos parâmetros de injeção de combustível do motor MWM 6.12 TCE no nível de ruído emitido pelo motor Diesel na condição de marcha lenta, por meio da técnica de planejamento multivariado de experimentos. Foram escolhidas duas técnicas de medição indireta de ruído (ruído de combustão e aceleração na saia do bloco) para serem utilizadas como variável resposta do planejamento de experimentos. Para verificação da eficácia dos planejamentos realizou-se ensaios qualitativos e quantitativos de ruído propriamente dito. Foi feito um planejamento fatorial fracionário 28-4 para fazer uma triagem de oito fatores de acordo com seus efeitos nas respostas aceleração na saia do bloco e ruído de combustão. Os fatores com efeitos mais significativos, pressão do rail, ponto de injeção principal, ponto de pré-injeção 2 e debito da pré-injeção 2, foram investigados usando um planejamento composto central e superfícies de respostas foram determinadas para cada uma das respostas. Os resultados mostraram que apenas a variável resposta vibração na saia do bloco apresentou resultados satisfatórios para esta condição especifica do motor tanto nos testes quantitativos como qualitativos (redução de 2 dB e melhora na qualidade sonora respectivamente). Apos verificação da influencia dos parâmetros de injeção no ruído emitido verificou-se também a influencia destas alterações no consumo de combustível e emissões dos gases de escape e foi observado que existem influencias significativas nas emissões dos gases de escape / Abstract: In recent years the noise level has been decisive for acceptance of vehicles on the market, not only because of legislation but also with regard to customer satisfaction. For this reason the manufacturers of vehicles and internal combustion engines have been forced to give special attention to the emission of noise to compete with their competitors. In this work, the influences of fuel injection parameters on the noise level of the MWM 6.12 TCE diesel engine emitted under low idle condition were determined using multivariate statistical design of experiments. Two techniques for the indirect measurement of noise, combustion noise and engine crankcase vibration, were chosen as the response variables for the experimental design. To check design effectiveness both qualitative and quantitative noise measurements were carried out. A 28-4 fractional factorial design was performed to screen eight factors according to their effects on engine crankcase vibration, and combustion noise. The factors with the most significant effects, rail pressure, pre-injection point, main injection point and the pre-injection delivery, were investigated using a central composite design and response surfaces were determined for each response. The results showed that only the engine crankcase vibration showed satisfactory results for this particular engine condition in both the quantitative and qualitative analyses (reduction of 2 dB and an improvement in sound quality, respectively). After verification of the influences of the injection parameters on the noise the influences of these changes on fuel consumption and exhaust emissions were also analyzed. Significant influences were observed on the exhaust gas emissions / Mestrado / Projetos / Mestre em Engenharia Automobilistica

Made available in DSpace on 2016-01-26T18:56:02Z (GMT). No. of bitstreams: 1 Andreia Olivo.pdf: 894633 bytes, checksum: 2ac23611f96154423617674d30caf247 (MD5) Previous issue date: 2013-11-05 / The industries effluents treatments was employed in order to reduce the organic material until appropriate level, and subsequently, returns it to the environment, without damages, or reuse itself in the same process. The slaughter-house industry is characterized by consuming a large amounts of water in the production processes, producing a wastewater with high concentrations of organic material, that can be verified by high levels of Biochemical Oxygen Demand (BOD5) and high levels of Chemical Oxygen Demand (COD). Increasingly, these companies search new techniques that are less harmful to the environment in order to eliminate or minimize the impacts. Thus, considering the importance of slaughter-house industry to the economy for Presidente Prudente-SP region and the environmental impact of this activity, the present study was done to optimize the wastewater treatment produced by these industries. To perform this study the concentration of nutrients, pH and oxygen concentration were systematic changed to gain a greater efficiency in the biological wastewater treatment system, employing a factorial design study. The wastewater treatment was carried out in a bench scale through an aerobic biological reactor. Analyzes were performed to characterize the effluent from the reactor by kinetic profiles and the obtain results were employed in the experimental design. These COD and BOD data were used as responses in the experimental design. It was verified an average COD removal of 79.3% and an average BOD5 removal of 76.7% for BOD5. All experiments represent a first order kinetics, and the maximum removal rate reaches 99%. This study demonstrated that a correct variation of nutrient concentration, pH and oxygen concentration values can optimize the organic matter removal. / O tratamento de efluentes, gerados pelas indústrias, tem como intuito diminuir a matéria orgânica até atingir níveis adequados, para posteriormente, devolve-lo ao meio ambiente sem prejudicá-lo ou reaproveitá-lo no próprio processo. A indústria frigorífica se caracteriza por consumir grande quantidade de água nos processos produtivos, gerando efluentes líquidos com altas concentrações de matéria orgânica que pode ser verificado por elevados níveis de Demanda Bioquímica de Oxigênio (DBO5) e Demanda Química de Oxigênio (DQO). Cada vez mais estas empresas buscam o emprego de novas técnicas que sejam menos agressivas ao meio ambiente seguindo a tendência de eliminar ou minimizar os impactos ambientais. Desta forma, tendo em vista a importância da indústria frigorífica para a economia da região de Presidente Prudente - SP e o impacto ambiental causado por esta atividade econômica, o presente trabalho buscou otimizar o tratamento de efluentes gerados em um frigorífico. Para se realizar este estudo foram alteradas a concentração de nutrientes, pH e concentração de oxigênio, visando uma maior eficiência dentro do sistema de tratamento biológico de efluentes, por meio do planejamento fatorial. O tratamento de efluentes foi realizado em escala de bancada através de um reator biológico aeróbio. Foram realizadas análise de caracterização do efluente e acompanhamento do reator para a realização de perfis cinéticos e obtenção dos resultados para a aplicação do planejamento experimental. Como respostas foram utilizadas os dados de DQO e de DBO após o tratamento do efluente coletado. Verificou-se uma remoção média para a DQO de 79,3% e de 76,7% para a DBO5. Todos os experimentos apresentaram uma cinética de primeira ordem, sendo que a taxa de remoção máxima alcançou 99%. Este estudo demonstrou que a variação correta dos valores de concentração de nutrientes, pH e concentração de oxigênio pode otimizar a remoção da matéria orgânica.

Made available in DSpace on 2016-07-18T17:46:19Z (GMT). No. of bitstreams: 1 Andreia Olivo.pdf: 894633 bytes, checksum: 2ac23611f96154423617674d30caf247 (MD5) Previous issue date: 2013-11-05 / The industries effluents treatments was employed in order to reduce the organic material until appropriate level, and subsequently, returns it to the environment, without damages, or reuse itself in the same process. The slaughter-house industry is characterized by consuming a large amounts of water in the production processes, producing a wastewater with high concentrations of organic material, that can be verified by high levels of Biochemical Oxygen Demand (BOD5) and high levels of Chemical Oxygen Demand (COD). Increasingly, these companies search new techniques that are less harmful to the environment in order to eliminate or minimize the impacts. Thus, considering the importance of slaughter-house industry to the economy for Presidente Prudente-SP region and the environmental impact of this activity, the present study was done to optimize the wastewater treatment produced by these industries. To perform this study the concentration of nutrients, pH and oxygen concentration were systematic changed to gain a greater efficiency in the biological wastewater treatment system, employing a factorial design study. The wastewater treatment was carried out in a bench scale through an aerobic biological reactor. Analyzes were performed to characterize the effluent from the reactor by kinetic profiles and the obtain results were employed in the experimental design. These COD and BOD data were used as responses in the experimental design. It was verified an average COD removal of 79.3% and an average BOD5 removal of 76.7% for BOD5. All experiments represent a first order kinetics, and the maximum removal rate reaches 99%. This study demonstrated that a correct variation of nutrient concentration, pH and oxygen concentration values can optimize the organic matter removal. / O tratamento de efluentes, gerados pelas indústrias, tem como intuito diminuir a matéria orgânica até atingir níveis adequados, para posteriormente, devolve-lo ao meio ambiente sem prejudicá-lo ou reaproveitá-lo no próprio processo. A indústria frigorífica se caracteriza por consumir grande quantidade de água nos processos produtivos, gerando efluentes líquidos com altas concentrações de matéria orgânica que pode ser verificado por elevados níveis de Demanda Bioquímica de Oxigênio (DBO5) e Demanda Química de Oxigênio (DQO). Cada vez mais estas empresas buscam o emprego de novas técnicas que sejam menos agressivas ao meio ambiente seguindo a tendência de eliminar ou minimizar os impactos ambientais. Desta forma, tendo em vista a importância da indústria frigorífica para a economia da região de Presidente Prudente - SP e o impacto ambiental causado por esta atividade econômica, o presente trabalho buscou otimizar o tratamento de efluentes gerados em um frigorífico. Para se realizar este estudo foram alteradas a concentração de nutrientes, pH e concentração de oxigênio, visando uma maior eficiência dentro do sistema de tratamento biológico de efluentes, por meio do planejamento fatorial. O tratamento de efluentes foi realizado em escala de bancada através de um reator biológico aeróbio. Foram realizadas análise de caracterização do efluente e acompanhamento do reator para a realização de perfis cinéticos e obtenção dos resultados para a aplicação do planejamento experimental. Como respostas foram utilizadas os dados de DQO e de DBO após o tratamento do efluente coletado. Verificou-se uma remoção média para a DQO de 79,3% e de 76,7% para a DBO5. Todos os experimentos apresentaram uma cinética de primeira ordem, sendo que a taxa de remoção máxima alcançou 99%. Este estudo demonstrou que a variação correta dos valores de concentração de nutrientes, pH e concentração de oxigênio pode otimizar a remoção da matéria orgânica.

In this thesis, the design of experiment is studied. Firstly, a theoretic background in mathematical statistics necessary for understanding is built (chapter 2). The design of experiment is then presented in chapters 3 and 4. Chapter 3 is divided into several subchapters in which its brief history is provided as well as its complex theoretic description (basic principles, steps for planning, etc.). Chapter 4 deals with particular types of the design of experiment (Factorial experiments or Response surface design). Simple examples are provided to illustrate the theory in chapters 3 and 4. Last part of the thesis is strictly practical and focuses on an application of the theory for particular data sets and its evaluation (chapter 5).

In the past few decades, brake pad-rotor interface friction studies have gained high importance in the automotive industry. The goal of these studies has been to improve the design to maximize the contact area and performance in brakes. In these studies, friction coefficient has always assumed to be the same for linear and rotational motion. In our study, we show that the rotational and linear friction process have different friction coefficients. We use semi-metallic and ceramic brake material pads reduced into brake samples using scaling laws of physics. The samples were mounted on the Universal Mechanical Tester and experimented for linear and rotational friction process against Pearlitic Gray cast iron rotor. From results, it proved friction coefficients of linear movement is always higher than the rotational movement. The linear friction coefficient was found to be 43% higher on an average than the rotational friction coefficient in both the materials tested at 1MPa and 10 mm/s. These results will help industry in gaining better fundamental understanding about the friction coefficients of rotor- brake contact interfaces.