The effects of storage time on fuel properties of Jatropha biodiesel blends

This study investigates the effects of storage time on fuel properties of biodiesel made from Jatropha oil and its blends with mineral diesel at different percentage compositions. The influence of storage stability on selected fuel properties such as kinematic viscosity, density, pour, cloud and flash points for Jatropha biodiesel and its blends at varying storage times were investigated using standard test methods. The biodiesel obtained through trans-esterification of Jatropha oil was blended with mineral diesel to obtain fractional samples of B20 (20% biodiesel blend), B40 (40% biodiesel blend), B60 (60% biodiesel blend) and B100 (100% neat biodiesel). Results show that kinematic viscosity and density increase for each blend over the 12 weeks of storage period. Flash, cloud and pour points decrease for each blend over the period of study. B20 was observed to be the optimum blend mix as its fuel properties were relatively unchanged over the storage period when compared to that of mineral diesel. It can be implied from the research that while properties like kinematic viscosity and density deteriorate with time; flash, cloud and pour points are observed to have improved with storage time.