| Experimental apparatus were designed for the measurement of the temperature dependant viscosity, surface tension and density of methyl and ethyl esters used as biodiesel fuels. Models for predicting the critical properties, viscosity, surface tension, and density of methyl and ethyl ester biodiesel fuels, based on their fatty acid composition, were applied. The measured and predicted properties for three commercial methyl and ethyl ester biodiesel fuels were compared.; In order to obtain the kinematic viscosities of biodiesel fuels at temperatures up to 300°C or the boiling point of the lightest oil fraction, a modified Saybolt viscometer was designed. The viscometer was used to measure the efflux times for 60 ml of methyl esters of canola and soy and ethyl esters of fish-oil. The Modified Saybolt Viscometer was calibrated using standard oil. On average, the error in kinematic viscosity was less than 0.056 mm2/s. Measured kinematic viscosities were found to decrease with temperature according to a modified Andrade equation.; Pendant Drop tensiometry and Axisymmetric Drop Shape Analysis-Profile (ADSA-P) methods were used to measure the surface tension of biodiesel fuels with and error less than 5.00 mN/m on the average. From the measured data it was concluded that the surface tension of biodiesel fuels decrease with temperature. (Abstract shortened by UMI.)... |
