Property modification of jatropha oil biodiesel by blending with other biodiesels or adding antioxidants

The feasibility of biodiesel production from jatropha (Jatropha curcas) oil was investigated with respect to the biodiesel blending properties and its oxidation stability with antioxidants. The JME (jatropha oil methyl esters) had the cetane number of 54, cold filter plugging point of −2 °C, density of 881 kg/m³ at 15 °C, ester content of 99.4 wt.%, iodine value of 96.55 g I₂/100 g, kinematic viscosity of 4.33 mm²/s at 40 °C, and oxidation stability of 3.86 h. Furthermore, the JME was blended with palm oil biodiesel and soybean oil biodiesel at various weight ratios and evaluated for fuel properties as compared to the relevant specifications. In addition, several antioxidants at concentrations between 100 and 1000 ppm were studied for their potential to improve the oxidation stability of the JME. The relationship between the IP (induction period) in the measurement of the oxidation stability associated with the antioxidant consumption in the JME was described by first-order reaction rate kinetics. Moreover, the ln IP (natural logarithm of the IP) at various concentrations of pyrogallol showed a linear relationship with the test temperature. The oxidation stability at ambient temperatures was predicted on the basis of an extrapolation of the temperature-dependent relationship.