Avaliação do efeito do teor do álcool etílico em um sistema ternário etanol/biodiesel/diesel

Abstract

The increasing concern about climate change and the need to reduce dependence on fossil fuels have driven the search for more sustainable energy alternatives. One way to reduce emissions is by adding oxygenated compounds such as biodiesel and alcohols to diesel fuel. However, this addition can lead to phase separation between the fuels and have serious consequences for engine performance. In this context, this study aimed to evaluate the effect of ethanol content on the miscibility of components in mixtures containing ethanol + biodiesel + diesel through the study of liquid-liquid equilibrium. The results from ternary phase diagrams revealed that the amount of water present in ethanol has a significant effect on the miscibility of the mixture components, with larger biphasic regions observed in systems with lower ethanol content. For the 95% ethanol diagram, the reliability of experimental data on equilibrium lines was assessed through the Othmer-Tobias and Hand correlations, which showed correlation coefficients (R²) of 0.99668 and 0.99505, respectively. The results obtained from the NRTL and UNIQUAC thermodynamic models demonstrated excellent agreement with the experimental data, with a deviation of only 1.78% for the NRTL model and 0.78% for the UNIQUAC model.