Made available in DSpace on 2014-12-17T15:41:58Z (GMT). No. of bitstreams: 1 JulioCTS_DISSERT.pdf: 2360843 bytes, checksum: 9fc8ef936717b3177303c0d0bd2e0718 (MD5) Previous issue date: 2012-04-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / It is known that the head office world energetics is leaning in the fossil fuels. However, the world panorama is changing quickly, for linked reasons to three of the humanity's great concerns in that century beginning: environment, global economy and energy. The biodiesel production is based on the transesterifica??o of vegetable oils or animal fats, using catalysts homogeneous or heterogeneous. The process of heterogeneous transesterifica??o presents lower conversions in comparison with the homogeneous, however, it doesn't present corrosion problems and it reduces to the occurrence of parallel reactions as saponification. In this sense, this work has for purpose the synthesis of a heterogeneous catalyst, KNO3/Al2O3, that soon afterwards was used in the reaction of transesterifica??o of the oil of the Helianthus annuus L. (sunflower). The solid materials (it supports and catalyst) they were analyzed by diffraction of ray-X (XRD) and electronic microscope of sweeping (MEV). After the analysis of Al2O3, a structure monophase amorphous tetragonal was verified, with characteristic patterns of that material, what could not be visualized in the difratograma of the catalyst. The biodiesel obtained with 4% wt. of KNO3/Al2O3 it was what obtained a better cinematic viscosity 8,3 mm2/s, comparing with the norms of ANP, and it also presented the best conversion tax in ethyl ?steres, in accordance with the quantitative measure starting from TG, that was of 60%. While the biodiesel with 6% wt. and with 8% wt. of KNO3/Al2O3 it was it that no transesterificou, because it was observed in the analysis termogravim?trica of those two materials, a single thermal event, that it corresponds the decomposition or volatilization of the triglycerides / Sabe-se que a matriz energ?tica mundial est? apoiada nos combust?veis f?sseis. No entanto, o panorama mundial est? mudando rapidamente, por motivos ligados a tr?s das grandes preocupa??es da humanidade nesse in?cio de s?culo: meio ambiente, economia global e energia. A produ??o de biodiesel ? baseada na transesterifica??o de ?leos vegetais ou gorduras animais, utilizando catalisadores homog?neos ou heterog?neos. O processo de transesterifica??o heterog?nea apresenta convers?es mais baixas em compara??o com o homog?neo, por?m, n?o apresenta problemas de corros?o e reduz ? ocorr?ncia de rea??es paralelas como saponifica??o. Neste sentido, este trabalho tem por finalidade a s?ntese de um catalisador heterog?neo, o KNO3/Al2O3, que em seguida foi utilizado na rea??o de transesterifica??o do ?leo da Helianthus annuus L.(girassol). Os materiais s?lidos (suporte e catalisador) foram analisados por difra??o de raios-X (DRX) e microsc?pio eletr?nico de varredura (MEV). Ap?s a an?lise da Al2O3, foi constatada uma estrutura monof?sica tetragonal amorfa, com padr?es caracter?sticos desse material, o que pode ser visualizado no difratograma do catalisador. O biodiesel obtido com 4% m/m de KNO3/Al2O3 foi o que obteve uma melhor viscosidade cinem?tica 8,3 mm2/s, comparando com as normas da ANP, e tamb?m apresentou a melhor taxa de convers?o em ?steres et?licos, em conformidade com a medida quantitativa a partir da TG, que foi de 60%. Enquanto o biodiesel com 6% m/m e com 8% m/m de KNO3/Al2O3 foi o que n?o transesterificou, pois foi observado na an?lise termogravim?trica desses dois materiais, um ?nico evento t?rmico, que corresponde a decomposi??o ou volatiliza??o dos triglicer?deos