Multi-objective optimisation of transesterified Jatropha curcas oil using response surface methodology and grey relational analysis

Abstract

A mathematical model for Jatropha curcas oil transesterification is proposed at five various process parameters, namely catalyst concentration, reaction time, stirrer speed, ratio of methanol to oil and extraction temperature. A three-level-five-factorial Box–Behnken is used for the design of the experiment. Analysis of variance of the experimental results at the confidence level of 95% proved that the ratio of methanol to oil and catalyst concentration are the important process parameters in transesterification and the values that are predicted were nearly equal to that of the experimental values that validate the credibility of the model. The grey relational analysis is used for the optimisation of the process parameters to minimise the transesterified Jatropha oil viscosity and to maximise the yield of Jatropha curcas biodiesel.