Avalia??o da produ??o de biodiesel a partir de uma mistura de ?leos usando a Novozyme 435 como catalisador.

• Autor(a) principal: Neves, Camila Teixeira da Motta
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/5062
• topic: lipase, biodiesel; planejamento experimental; modelagem cin?tica; lipase, biodiesel; experimental design; kinetic modeling; Engenharia Qu?mica

The increasing on energy demand as well as environmental concern still motivates the study on biofuels production. Biodiesel has shown great potential for substitution of diesel, due to its ease of production and to the variety of raw materials available worldwide. Among the possible routes for the production of biodiesel, there is enzymatic transesterification that, despite the high cost of the biocatalyst, has the advantage of generating products with higher purity, its reusability and it also allows the use of low quality raw materials. This makes it possible to use a mixture of different raw materials in order to minimize production costs. Therefore, this study aimed to study the production of biodiesel from a mixture of soybean oil and frying oil, using the commercial lipase Novozyme 435 as a biocatalyst. For this, the influence of the lipase dosage (varying from 5 to 20%), the frying oil content in the mixture (varying from 0 to 100%) and the reaction time (varying from 4 to 10 h) on the methyl ester yield. The results obtained showed that Novozyme 435 was able to achieve high yields for the reaction. A maximum yield of 98.05% was obtained using a methanol to oil molar ratio of 3:1, 12.5% lipase, a mixture containing 50% frying oil, and 10 h of time reaction at 40 ? C. The lipase content was the factor that showed the greatest influence on the yield and, for lipase dosage above 13%, the oil blend characteristic does not influence the dependent variable. Therefore, it is possible to obtain high yields even using high contents of frying oil in the mixture. The operational stability of Novozyme 435 was also studied in the medium and it was observed that the lipase was able to maintain 94% of its activity after 5 cycles of reuse. Subsequently, the kinetic modeling of the reaction was performed. Two kinetic models were proposed, the Power Law and Eley-Rideal mechanism, and both correlated well the experimental data.