Made available in DSpace on 2015-04-14T13:58:56Z (GMT). No. of bitstreams: 1 444965.pdf: 19735321 bytes, checksum: 848931c529752f1baa29108987cfc311 (MD5) Previous issue date: 2012-11-09 / Biodiesel is a synthetic fuel usually produced by the transesterification reaction. This study was undertaken to monitor the kinetics of the transesterification reaction between soybean oil and methanol catalyzed by potassium methoxide. A series of reactions was monitored with a laser spectrometer used to analyze the absorption and scattering of light in real-time. The objectives of this study aimed to determine when the reaction came in chemical equilibrium. This objective was achieved by observing an arbitrary time interval, experimentally obtained from the graph of electrical resistance versus time, allowing optimize reaction time, by using a monitoring system that combined the information received through multiple sensors. Determine if the optical phenomenon observed during the reaction could be described by Euclidean geometry and whether it was related with the internal conical diffraction. It was found that it is not related to the internal conical diffraction, however, depending on the scale applied to observe the optical phenomenon it can be described by the Euclidean geometry. The goal of developing analytical instrumentation was achieved by constructing a non-invasive laser spectrometer. / O biodiesel ? um combust?vel sint?tico, geralmente produzido a partir da rea??o de transesterifica??o. Este trabalho foi desenvolvido para monitorar a cin?tica da rea??o de transesterifica??o entre o ?leo de soja e o metanol, catalisada por met?xido de pot?ssio. Uma s?rie de rea??es foi monitorada com um espectr?metro laser, utilizado para analisar a absor??o e o espalhamento da luz em tempo-real. Os objetivos deste trabalho visaram determinar quando a rea??o entrou em equil?brio qu?mico. Atingiu-se este objetivo atrav?s da observa??o de um intervalo arbitr?rio de tempo, obtido experimentalmente a partir do gr?fico da resist?ncia el?trica em fun??o do tempo, permitindo otimizar o tempo de rea??o atrav?s da utiliza??o de um sistema de monitoramento que combinava as informa??es recebidas atrav?s de v?rios sensores. Determinar se o fen?meno ?ptico observado durante a rea??o poderia ser descrito pela geometria Euclidiana e se o mesmo tinha rela??o com a difra??o c?nica interna. Constatou-se que o mesmo n?o apresenta rela??o com a difra??o c?nica interna, por?m, dependendo da escala utilizada para observar o fen?meno ?ptico, ele pode ser descrito pela geometria Euclidiana. O objetivo de desenvolver instrumenta??o anal?tica foi alcan?ado atrav?s da constru??o de um espectr?metro laser n?o invasivo.