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

Mechanical oil expression from selected oilseeds under uniaxial compression

Bargale, Praveen Chandra 01 January 1997 (has links)
Mechanical pressing of soybean is highly desirable as it provides, at low cost, non-contaminated, protein-rich, low-fat soyflour which can be further processed into nutritious edible foods. Unfortunately, mechanical pressing of this low-fat oilseed ($<$20%) yields only 50-70% of the available oil, in contrast to the solvent extraction method which recovers over 98% of the oil. The main focus of the study was to maximize the oil recovery from soybean using mechanical oil expression by applying two pretreatments, enzymatic hydrolysis and extrusion cooking of soybeans, and by varying the pressing conditions including three applied pressures (20, 40 and 60 MPa), three pressing temperatures (22, 60 and 90°C) and two sample sizes (10 and 20 g). To characterize the material properties affecting mechanical oil expression from soybean a mathematical simulation of uniaxial compression was developed which incorporated the time dependent variation of soybean properties. The mathematical simulation was based on Terznaghi's theory of consolidation for soils and was solved using measured values of the coefficients of permeability, volume change and consolidation. A compression-permeability test cell was specifically developed for these measurements. For validation of the model, in addition to extruded soy, sunflower seeds (oil content ca. 45%) were also compressed under the same pressing conditions. Improvements in oil recovery due to enzymatic pretreatment of soybean were small, while the extrusion pretreatment increased the oil recovery from only a trace for raw soybean to 90.6%. Such oil recovery using mechanical pressing of soybean has not been reported in the past. The measured values of oil recovery, coefficients of permeability, volume change and consolidation for soybean and sunflower seeds were found to vary significantly $(P<0.05)$ with time of pressing, applied pressure, pressing temperature and the size of the sample. For extruded soy samples, the developed model predicted the values of oil recovery versus pressing time with an average error of 15%, while for sunflower seed samples the average prediction error was 40%. The high error values were attributed to the presence of hulls in the sunflower seed samples, as well as error during measurement of the coefficient of permeability. The coefficient of consolidation was found to have the greatest influence on oil recovery. The incorporation of time dependent material properties in the developed simulation was demonstrated to give more accurate and consistent prediction in trends of oil recovery as compared to using constant material properties. The correlationship developed between the oilseed material properties and the oil recovery obtained from uniaxially compressed oilseeds would help researchers and designers to better evaluate the mechanical oil expression equipment and systems. To the extent that the developed model adequately predicted oil recoveries from both sunflower and soybean oilseeds, the model is expected to be applicable to other oilseeds as well.
2

Análises físico-químicas e otimização da prensagem de crambe em extrusora mecânica sob variações de temperatura e umidade relativa dos grãos / Physical-chemical analyzes and optimization of crambe pressing in mechanical extruder with variations in grain temperature and relactive moisture

Bressan, Rodrigo Techio 14 March 2018 (has links)
Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2018-04-25T12:59:47Z No. of bitstreams: 2 Rodrigo_Bressan2018.pdf: 2117464 bytes, checksum: 6d1c839df1e42cc2759414f1610b8f42 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-25T12:59:47Z (GMT). No. of bitstreams: 2 Rodrigo_Bressan2018.pdf: 2117464 bytes, checksum: 6d1c839df1e42cc2759414f1610b8f42 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-14 / Brazil started a great economic development, involving all sectors of the country, but mainly the energy sector. At this juncture, oil produced through vegetables, and extracted through presses, has great advantage in the production of energy, especially in remote regions that need energy self-sufficiency, or even in regions with crops suitable for oil extraction. The aim of the present work was to improve the mechanical pressing process in the mechanical press, evaluating the effect of the independent variables of extraction temperature and the moisture content added to the crambe grains in the crude oil extraction yield. chemical and physical properties of crude oil and cake. The completely randomized design (DIC) with three replications, thus, each mechanical extraction of oil and cake was divided into four relative moisture contents of water added to the sample (0, 2, 3,5 and 5 %) and four temperature (80, 100, 120 and 140 ˚C) for the extraction of crambe oil and cake. The vegetable oils were evaluated through acidity index, oil moisture, specific mass and viscosity, as well as bromatology with crude fiber, ethereal extract, crude protein, starches, ash content and cake moisture content. The data collected from the samples of pie and crude oil of the crambe seed were analyzed according to the test of variance indicating if there are effects of the treatments. The coefficient (R2) was determined as a statistical parameter that relates the variance of the experimental points. The temperature range of 140 to 160 oC and relative humidity content of 5% the yield of numerical oil will be maximum (22,63 %). And the second highest yield is in the temperature range of 120 to 140 oC with relative humidity content of 2,0 % (20,19 %). The minimum numerical pie yield is in the temperature range of 140 to 160 ℃ and a relative humidity of 5 % (77,36%). And the second lowest numerical yield of pie is in the range of 120 to 140 ℃ with relative humidity content of 2,0 % (79,80 %). The values of specific mass, kinematic viscosity at 40 oC, acidity index and oil moisture content were 837 kg m-3, 37,14 mm² s-1, 2,59 mg g-1 KOH and 0,176 %. And the values of pie, crude fiber, lipids, protein, carbohydrates and ash were respectively 12,45, 3,37, 19,23, 26,80, 36,53 and 5,04 % for higher numerical yield, as well being possible to optimize the process of optimization of mechanical extraction of crambe. / O Brasil iniciou um grande desenvolvimento econômico, envolvendo todos os setores do país, mas principalmente o setor da energia. Diante dessa conjuntura, o óleo produzido através de vegetais, e extraído através de prensas, tem grande vantagem na produção de energia, principalmente em regiões afastadas que necessitam de autossuficiência energética, ou ainda em regiões com culturas propícias a extração de óleo. Assim, o presente trabalho visou aperfeiçoar o processo de prensagem mecânica contínua em prensa mecânica, sendo avaliado o efeito das variáveis independentes de temperatura de extração e o teor de umidade adicionado aos grãos de crambe no rendimento de extração de óleo bruto, além da caracterização química e física do óleo bruto e da torta. O delineamento inteiramente casualizado (DIC) com três repetições, sendo assim, cada extração mecânica de óleo e torta foi dividida em quatro teores de umidade relativos de água adicionada a amostra (0 , 2 , 3,5 e 5 %) e quatro faixas de temperatura (80, 100, 120 e 140 ˚C) para a extração de óleo e torta de crambe. Foram avaliados os óleos vegetais através de índice de acidez, umidade do óleo, massa específica e viscosidade, além da bromatologia com fibra bruta, extrato etéreo, proteína bruta, amidos, teor de cinzas e umidade da torta. Os dados coletados das amostras de torta e óleo bruto da semente de crambe foram analisados segundo o teste de variância indicando se existem efeito dos tratamentos. Foi determinado o coeficiente (R2) como um parâmetro estatístico que relaciona a variância dos pontos experimentais. A faixa de temperatura de 140 a 160 ℃ e teor de umidade relativa de 5% o rendimento de óleo numérico será máximo (22,63 %). E o segundo maior rendimento está na faixa de temperatura de 120 a 140 ℃ com teor de umidade relativa de 2,0 % (20,19 %). O rendimento de torta numérico mínimo se dá na faixa de temperatura de 140 a 160 ℃ e teor de umidade relativa de 5% (77,36 %). E o segundo menor rendimento numérico de torta está na faixa de 120 a 140 ℃ com teor de umidade relativa de 2,0 % (79,80 %). Os valores de massa específica, viscosidade cinemática a 40 oC, índice de acidez e umidade do óleo para foram de 837 kg m-3, 37,14 mm² s-1, 2,59 mg g-1 de KOH e 0,176 %. E os valores de umidade de torta, fibra bruta, lipídeos, proteína, carboidratos e cinzas foram respectivamente 12,45, 3,37, 19,23, 26,80, 36,53 e 5,04 % para maior rendimento numérico, assim sendo possível otimizar o processo de otimização de extração mecânica de crambe.
3

Estudo das potencialidades do fruto do Ouricuri / Study of the potential of the fruit of Ouricuri

Santos, Luana Tássia Souza dos 09 October 2015 (has links)
The ouricuri (Syagrus coronata) features high oil content, is a rustic tree, resilient, adaptable and persistent. From these features it is possible that she is a promising raw material for biofuel production, through the use of its oil for biodiesel production and enzyme Peel by fermentation for production of second-generation ethanol. This paper proposes the study of drying of the almonds of ouricuri in balance three drying temperatures (100, 80 and 60° C) for the purpose of analyzing the behavior of water loss in these temperatures and study the processes of oil extraction. Mechanical extractions were carried out (in hydraulic press and electric press) and solvent. On mechanical extraction by hydraulic press, used the following pressures: 165; 247.5; 330; 412.5 and 495 kgf/cm ². The extraction with a 495 pressure kgf/cm ² in volume showed the highest amount of oil extracted, with 52 ml 100 g of almond oil. In mechanics, for electric press, were used the following pressures: 165; 247.5 and 330 kgf/cm ². The extraction with a 247.5 pressure kgf/cm ² was the best in terms of efficiency, reaching 75% approximate. In solvent extraction variables were evaluated: time (4:00 and 2); average diameter (1.015 mm and 1.435 mm); and the solvent (hexane and ethanol), analysed statistically observed the influence of these variables. The time was determination on income, because in 2:00 had already been taken from virtually the whole almond oil. The average diameter of 1.015 mm provided an almond 1.57% increase on the amount of oil extracted with solvent ethanol 1.435 mm income higher than that presented in hexane 4.42%. From these results it was possible to develop a model of solvent extraction process in light of the significant variables. The oil extracted was characterized according to the humidity, density, pH and acidity index. The oil density performed over the limit allowed by the ANP. The bark and ouricuri fiber went through the acid and hydrothermal pretreatment, where were characterized according to pH, residual sugars total (ART),° Brix, acidity and moisture. The value of fiber ART indicated the possibility of being subject to subsequent steps of enzymatic hydrolysis and fermentation for obtaining second-generation ethanol. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O ouricuri (Syagrus coronata) apresenta alto teor de óleo, é uma árvore rústica, resistente, adaptável e perene. A partir dessas características é possível que ela seja uma matéria-prima promissora para produção de biocombustíveis, através do uso do seu óleo para produção de biodiesel e pela fermentação enzimática da casca para produção de etanol de segunda geração. Este trabalho propõe o estudo da secagem das amêndoas do ouricuri em balança de secagem em três temperaturas (100, 80 e 60ºC) com a finalidade de analisar o comportamento da perda de água nessas temperaturas e estudar os processos de extração do óleo. Foram realizadas extrações mecânicas (em prensa hidráulica e prensa elétrica) e por solvente. Na extração mecânica por prensa hidráulica, foram utilizadas as seguintes pressões: 165; 247,5; 330; 412,5 e 495 kgf/cm². A extração com uma pressão de 495 kgf/cm² em termos de volume apresentou maior quantidade de óleo extraído, com 52 ml de óleo em 100 g de amêndoa. Na extração mecânica, por prensa elétrica, foram utilizadas as seguintes pressões: 165; 247,5 e 330 kgf/cm². A extração com uma pressão de 247,5 kgf/cm² foi a melhor em termos de eficiência, chegando a aproximados 75%. Na extração por solvente foram avaliados as variáveis: tempo (2 e 4h); diâmetro médio (1,015 mm e 1,435 mm); e o solvente (hexano e etanol), analisadas estatisticamente observou-se a influência dessas variáveis. O tempo não representou determinação sobre o rendimento, pois em 2 horas já havia sido extraído praticamente todo o óleo da amêndoa. O diâmetro médio de 1,015 mm da amêndoa proporcionou um aumento de 1,57% sobre a quantidade de óleo extraída com 1,435 mm. O solvente etanol apresentou rendimento superior ao hexano em 4,42%. Através desses resultados foi possível desenvolver um modelo do processo de extração por solvente em função das variáveis significantes. O óleo extraído foi caracterizado de acordo com a umidade, densidade, pH e índice de acidez. A densidade do óleo se apresentou acima do limite permitido pela ANP. A casca e a fibra do ouricuri passaram pelo pré-tratamento ácido e hidrotérmico, onde foram caracterizadas de acordo com pH, açucares redutores totais (ART), °Brix, acidez e umidade. O valor do ART da fibra indicou a possibilidade de ser submetida a etapas posteriores de hidrólise enzimática e fermentação para obtenção de etanol de segunda geração.
4

Estudo da extração mecânica de bixina das sementes de urucum em leito de jorro

Cunha, Fabiano Guimarães e 25 April 2008 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The interest and the consumption of natural dyes have been increasing over the last years. The urucum seeds have a dye located in their external layer called bixin. The spouted bed, since it is an inexpensive equipment and because of its simple operation, can be an excellent alternative for mechanical extraction of the bixin from the surface of the urucum seeds, on small and average country properties. However, despite having some interesting fluidodinamics characteristics for the related application, such as an intense movement of particles and an effective gas-solid contact, the spouted bed presents some restrictions that have limited its application. This work had as objective to study the effect of the variables: use of the draft, the load of the urucum seeds and the air velocity on the process of the mechanical extraction of the bixin in a spouted bed. The computational fluidodinamics technique (CFD) was used to describe numerically the behavior both of the urucum seeds and the air inside the spouted bed. By means of the results obtained it was possible to achieve the operational conditions that maximize the efficiency of removal and allow the attainment of a product with the appropriate quality. From the experimental planning, carried through in order to study the effect of the load of the seeds, the air flow and the presence of the draft in the mechanical extraction of the bixin from urucum seeds, it was possible to get to the conclusion that the presence of the "draft" was the variable that had the highest effect in all the studied answer variables (mass of extracted powder, productivity and bixin concentration). Since the presence of the draft showed to be the variable that governs the attrition kinetics, the effect of the distance from the draft base to the spouted bed base (ht) was studied, in view of the maximization of the dyeing production. The experimental results showed that the distance from the draft base to the spouted bed base (ht) that most favors the mechanical extraction of the bixin in spouted bed was the one of 4cm. The results of the simulation through CFD also helped in the understanding of the best performance for the configuration of the spouted bed using a draft, placed at ht = 4 cm. Through the simulations, it was also possible to get values of velocity for the condition of minimum spouting, close to the experimental values, with relative errors of about 4%. / O interesse e o consumo dos corantes naturais têm aumentado muito nos últimos anos. As sementes do urucum possuem um corante situado nas partes externas denominado bixina. O leito de jorro por se tratar de um equipamento barato e de operação simples, pode ser uma excelente alternativa para extração mecânica da bixina da superfície das sementes de urucum, em pequenas e médias propriedades rurais. Entretanto, apesar de apresentar algumas características fluidodinâmicas interessantes para a referida aplicação, tais como um intenso movimento das partículas e um efetivo contato gás-sólido, o leito de jorro apresenta algumas restrições, que tem limitado a sua utilização. Este trabalho teve como objetivo estudar os efeitos das variáveis: uso do tubo draft, a carga de sementes e a velocidade do ar no processo na extração mecânica da bixina em leito de jorro. A técnica da fluidodinâmica computacional (CFD) foi utilizada para descrever numericamente a fluidodinâmica do escoamento das sementes de urucum e do ar no leito de jorro. Por meio dos resultados obtidos foi possível obter as condições operacionais que maximizam a eficiência de remoção e permitem a obtenção de um produto com a qualidade adequada. A partir do planejamento experimental realizado para estudar o efeito da carga de sementes, da vazão do ar e da presença do draft na extração mecânica da bixina, foi possível concluir que a presença do draft foi a variável que teve o maior efeito em todas as respostas estudadas (massa de pó extraído, produtividade e concentração de bixina). Uma vez que a presença do tubo interno mostrou ser a variável que governa a cinética de atrição, foi estudado o efeito da distância do tubo à base do leito (ht), tendo em vista a maximização da produção do corante. Os resultados experimentais mostraram que a distância do draft à base (ht) que mais favorece a extração mecânica da bixina em leito de jorro é de 4cm. Os resultados da simulação por CFD ajudaram na compreensão do melhor desempenho para a configuração do leito de jorro com tubo draft e ht = 4 cm. Com as simulações também foi possível obter valores de velocidade para a condição de jorro mínimo próximo dos valores experimentais, com erros relativos na ordem de 4%. / Mestre em Engenharia Química

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