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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

Avalia??o da efici?ncia de catalisadores comerciais na obten??o de biodiesel de algod?o (Gossipium hisutum L.)

Carvalho, Ricardo Henrique Rocha de 02 March 2009 (has links)
Made available in DSpace on 2014-12-17T15:01:18Z (GMT). No. of bitstreams: 1 RicardoHRC.pdf: 2184332 bytes, checksum: 733eb5ecd4a020c789e1bdb3062d808d (MD5) Previous issue date: 2009-03-02 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The increasing demand for energy and the environment consequences derived from the use of fossil energy, beyond the future scarcity of the oil that currently is the main power plant of the world, it stimulated the research around the production of biodiesel. In this work the synthesis of biodiesel of cotton in the methyl route was carried through, for had been in such a way used catalyst commercial homogeneous, Na-Methylat and the K-Methylat, aiming to the evaluation of the efficiency of them. An experimental planning 23 was elaborated aiming to evaluate the influence of the variable (molar reason oil/alcohol, % of catalyst and temperature) in the process as well as indicating the excellent point of operation in each case. The biodiesel was analyzed by gaseous chromatography, indicating a conversion of 96,79% when used Na-Methylat? as catalytic, and 95,65% when the K-Methylat? was used. Optimum result found with regard to the conversion was obtained at the following conditions: molar reason oil/alcohol (1:8), temperature of 40?C and 1% of catalyst Na-Methylat, reaching a 96,79% conversion, being, therefore, above of the established for the European norm (96.5%). The analysis of regression showed that the only significant effect for a confidence level of 95%, was of the changeable temperature. The variance analysis evidenced that the considered model is fitted quite to the experimental response, being statistically significant; however it does not serve inside for make forecasts of the intervals established for each variable. The best samples were analyzed by infra-red (IR) that identified the strong bands of axial deformation C=O of methylic ester, characterized through analyses physicochemical that had indicated conformity with the norms of the ANP, that with the thermal and rheological analyses had together evidenced that biodiesel can be used as combustible alternative in substitution to diesel / A crescente demanda por energia e as conseq??ncias ambientais derivadas do uso de energia f?ssil, al?m da futura escassez do petr?leo, que atualmente ? a principal fonte de energia do mundo, impulsionaram as pesquisas em torno da produ??o de biodiesel. Neste trabalho foi realizada a s?ntese do biodiesel de algod?o pela rota met?lica, fazendo-se uso de catalisadores comerciais homog?neos, Na-Methylat? e K-Methylat?, visando ? avalia??o da efici?ncia destes. Um planejamento experimental 23 com ponto central em triplicata foi elaborado visando avaliar a influ?ncia das vari?veis (raz?o molar ?leo/?lcool, % de catalisador e temperatura), bem como indicar o ponto ?timo de opera??o em cada caso. Os biodieseis foram analisados por cromatografia gasosa, indicando uma convers?o de 96,79% quando utilizado o Na-Methylat? como catalisador, e 95,65% quando se utilizou o K-Methylat?. O melhor resultado encontrado com rela??o ? convers?o se deu nas seguintes condi??es: raz?o molar ?leo/?lcool (1:8), temperatura de 40?C e 1% de catalisador Na-Methylat, alcan?ando uma convers?o de 96,79%, estando, portanto, acima do estabelecido pela norma europ?ia (96,5%). A an?lise de regress?o submetida mostrou que o ?nico efeito significativo para um n?vel de 95% de confian?a, foi o da vari?vel temperatura. A an?lise de vari?ncia constatou que o modelo proposto se mostra muito bem ajustado ?s respostas experimentais, sendo significativo sob o ponto de vista estat?stico, por?m n?o serve para fins preditivos dentro dos intervalos estabelecidos para cada vari?vel. As melhores amostras foram analisadas por infravermelho que identificou as bandas fortes de deforma??o axial C=O do ?ster met?lico, caracterizadas atrav?s de an?lises f?sico-qu?micas que indicaram conformidade com as normas da ANP, que juntamente com as an?lises t?rmicas e reol?gicas constataram que o biodiesel pode ser utilizado como combust?vel alternativo em substitui??o ao diesel

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