Otimização da produção e caracterização físico-química de ésteres metílicos e etílicos produzidos a partir do óleo de Buriti (Mauritia flexuosa)

Abstract

World energy demand has steadily grown over the years, and the world's largest energy source for many segments still comes from fossil fuels. These fuels have resulted in environmental disasters and severe air pollution, resulting in poor air quality. Unlike other countries, where fossil fuels are used mainly to generate electricity, in Brazil the main consumption is for transportation, with mineral diesel being the most consumed fuel. That said, it is necessary to produce a renewable and less polluting fuel, such as biodiesel, for the total or partial replacement of diesel. The present work aimed to optimize the conditions for obtaining biodiesel from Buriti vegetable oil, the most common palm in Brazil, in order to obtain better conversion yield, optimize the reagent consumption and improve its physicochemical characteristics. The choice of Buriti oil aimed to classify this palm tree as another oilseed in biodiesel production, diversifying the raw materials used for its production, promoting the development and the number of family farmers benefited from its use in the North, Northeast and Semiarid. From Buriti oil, the transesterification reaction was optimized by homogeneous alkaline catalysis, using KOH as catalyst, obtaining methyl and ethyl esters. For methyl esters, the best reaction condition was obtained with an oil: methanol molar ratio of 1:10, 3% catalyst and 40 min reaction time, with an ester content of 98.82%. In the case of ethyl esters, the highest percentage yield of esters was obtained with an oil: ethanol molar ratio of 1:18, 3% catalyst and 60 min reaction time, 98.06%, being the catalyst the most determinant variable in the positive results obtained. Concerning the chemical physical characteristics analyzed, the results obtained for the methyl and ethyl esters respected the ranges required by the regulatory standard, except for the acid number, which presented values higher than the maximum limit required for both esters. However, such a problem can be solved by pre-treatment of Buriti crude oil. According to the results obtained and the social issues involved, Buriti oil is promising for the production of methyl and ethyl esters, given the satisfactory conversion of triglycerides to esters and their physicochemical properties, within current regulations.