Statistical optimization of biolubricant production from Jatropha curcas oil using trimethylolpropane as a polyol

This paper presents the optimization and modeling of transesterification of Jatropha curcas methyl ester (JME) with trimethylolpropane (TMP) as a polyol in the presence of potassium hydroxide catalyst. The optimization of the transesterification reaction was carried out using 2³ response surface methodology experimental design studying the effect of temperature (109.77-160.23 °C), reaction time (20 minutes to 3.68 hours) and catalyst concentration (0.73 to 1.73 % w/w) at a constant mole ratio of JME to TMP of 3.9: 1 under vacuum condition. The results of effect of process variables revealed that an optimum condition for the biolubricant synthesis was at a temperature of 120 °C, reaction time of 3 hours and catalyst concentration of 0.8 % w/w optimum was obtained. The percentage yield of biolubricant was 96.95 % as against 98.09 % predicted by the model. The statistical analyses of the data lead to development of the second order quadratic polynomial regression model which establishes the relationship between biolubricant yield and the process variables. The model was able adequately to predict the biolubricant yield with a co efficient of determination (R) of 0.9068.