Potencial do óleo de soja residual como matéria-prima para a produção de biodiesel

Abstract

One of the measures to minimize the environmental damages affected by humanity is the use of fuels that have a sustainable characteristic, such as biodiesel. The diversity of raw materials in the process is a great advantage, within the options of inputs for the production of biodiesel, the reuse of residual oil is highlighted because it is a correct disposal, avoiding contamination of effluents. The most used process for biodiesel production is the transesterification reaction of animal oils or fats with a primary alcohol in the presence of a catalyst. The present work explores the production of biodiesel with residual oil, through the transesterification process, using ethyl and methyl alcohol. A factorial design with two levels and three variables was carried out, resulting in 8 experiments, to produce soybean biodiesel by homogeneous catalysis. The fixed parameters were: oil/alcohol molar ratio of 1/8, amount of catalyst of 1.5% of the oil mass and reaction time of 60 min. The variables were: type of alcohol (methanol and ethanol), type of catalyst (KOH and NaOH) and reaction temperature (28 °C and 50 °C). Of the 8 experiments carried out, 2 reached a yield greater than 96.5%, the minimum yield required by the National Agency of Petroleum, Natural Gas and Biofuels (ANP) for the commercialization of biodiesel. The highest yield, 99%, was found in the reaction using methanol as alcohol, KOH as catalyst and temperature of 50 °C. Physical-chemical analyzes of density, viscosity and acidity index were also carried out for the residual oil and the obtained biodiesel. The values found for biodiesel in the analyzes are within the values acceptable by the ANP.