Electrical properties of mixtures of fatty acid methyl esters from different vegetable oils

Abstract

The dependence on temperature of the permittivity and conductivity of mixtures of Fatty Acid Methyl Esters (FAME) was determined between 300 K and 343 K, in the frequency range from 20 Hz to 2 MHz. Samples were made from oil of sunflower, corn, grape, chia, canola, jatropha, coconut and cottonseed. Permittivity fits very well to a linear function of temperature, the fitting parameters falling within a narrow range for all samples. Conductivity follows an Arrhenius dependence with activation energies between 0.202 eV and 0.252 eV. The results show that measurements of electrical properties, successfully used for the characterization of FAME from soybean oil, as reported in previous works, can also be employed in FAME obtained from different feedstocks. This generalization is relevant for laboratory and industrial characterization and quality control, and also for the application of "on line" measurements in automated production systems.