Estudo termodinâmico do biodiesel de coco babaçu: Propriedade físico-químicas e equilíbrio líquido-líquido

Abstract

The biodiesel was developed for use in substitution of petroleum diesel, fuel with large participation in Brazilian carrier matrix. For understanding the behavior of the biodiesel chain constituents, the objectives of this work include the study of the liquid-liquid equilibrium (LLE) of the compounds involved in the production and calculation of thermodynamic properties of mixtures containing biodiesel. The ternary systems studied were: babassu coconut methyl biodiesel + methanol + glycerol and babassu coconut ethyl biodiesel + ethanol + glycerol, at temperatures of 20 ° C and 40 ° C, atmospheric pressure, using titration and densimetric techniques. Where it has been observed that the influence of temperature on phase behavior may be negligible. Alcohol alteration modifies the behavior of the heterogeneous region of the system. The thermodynamic consistency of the data was verified by the Hand correlation. The thermodynamic models of activity coefficient, NRTL, UNIQUAC and UNIFAC, were used to correlate the experimental data of LLE in the systems studied, and were satisfactory. In addition, density and viscosity data of binary mixtures were obtained at specified temperature intervals for the entire mass composition range of the babassu coconut ethyl biodiesel + ethanol (293,15K to 333,15K) and babassu coconut methyl biodiesel + methanol (293.15K at 323.15K), by densimetric and viscosimetric techniques. As expected, was observed that the density and viscosity are inversely proportional to the temperature, where the former relates linearly and the latter logarithmically.