Selected physical properties of liquid biofuels

Abstract

The goal of this study was the determination of basic physical properties such as density, calorific value and rheological properties of liquid biofuels. Biofuels on the base of bioethanol and rapeseed methyl ester were chosen. Following control samples were selected: diesel oil without admixture of methyl esters and commercially available diesel oils with small amount of methyl ester admixture (6.2 and 6.5%). Dynamic viscosities of individual samples were measured in the range from -10°C to 50°C. Then dependence of shear rate on shear stress was measured at temperatures -10, 0, 20 and 40°C. The most of samples showed the Newtonian behaviour. However, samples with high content of methyl esters or pure methyl esters showed thixotropy behaviour at the low temperature.

Keywords

• rheology
• thixotropy
• density
• methyl ester