Produção e caracterização de biodiesel utilizando óleo de fritura residual: uma sequência didática de atividade experimental problematizada

Abstract

The planet's climatic situation is a major concern today and the replacement of fossil fuels with biofuels is one of the alternatives to reduce air pollution. These fuels can be obtained, for example, through the transformation of vegetable oil used for frying into biodiesel, in addition to the fact that the raw material used in the production of this biofuel is from a renewable source and the production technique is sustainable, contributing to the reduction of disposal of used oil in the environment. This theme leads to the discussion of several concepts and demonstrates the importance of its approach at school, seeking to bring scientific knowledge closer to the student's daily life. This work aimed to plan a problematic experimental activity proposal related to the production of biodiesel as a teaching strategy. The applied methodology was divided into two stages, the first stage being carried out in the laboratory with the characterization of the physical-chemical properties of residual frying oils, such as pH, specific mass and moisture content. As well as, the production and characterization of the biodiesel obtained, analyzing its acidity, specific mass, aspect analysis, corrosivity to copper and combustion. In the second stage of the work, a proposal for an experimental activity was elaborated, problematized with the theme of biodiesel. In the laboratory stage, it was important to determine the properties of the residual frying oil before carrying out the transesterification reaction, as it allowed analyzing the quality of the oil to obtain biodiesel. Through the results obtained regarding these properties, it was possible to verify that the fried oils analyzed, in general, were in an acceptable range, not compromising their use to obtain biodiesel. The biodiesel production method used proved to be effective for obtaining biodiesel, however, taking great care in the preparation of the residual oil and in the reaction time with the reagents used. According to the results obtained during the conduct of this research, the residual frying oil can be converted into biodiesel presenting physico-chemical characteristics allowed by the current legislation, with a concrete possibility of using residual frying oils to obtain biodiesel.