Metrological Approach in the Study of Biodiesel Viscosity Variation with Temperature

In this article, we study the relation between viscosity and temperature of several biodiesel types (soybean, sunflower, corn, castor bean, and animal fat based) in a metrological point of view. All the biodiesel types were obtained by a transesterification reaction with methanol in the presence of an alkaline base as a catalyst. The biodiesels had their viscosities measured using capillary viscometers following Brazilian standards, in temperatures ranging from 20°C to 40°C. An extra study was performed with another beef tallow biodiesel (transesterified with ethanol) with temperatures up to 100°C. For all the measurements, the uncertainties were calculated. Even though there have been many studies on biodiesel on recent years, most of these do not have a metrological focus. This study shows the behavior of the biodiesel viscosity in a temperature range of 20°C to 40°C, and also how its composition influences the viscosity.