Optimization of the dual stage procedure of biodiesel synthesis from Neem oil using RSM based Box Behnken design

Abstract

ABSTRACT Non-edible Neem oil was abundantly available in India with an estimated current annual production of 100 thousand tons per annum thus making it a strong candidate as a biodiesel feedstock. The major problem of Neem oil is its high free fatty acid (FFA) content (4.2%). The present study comprises of optimization of the dual-stage process of biodiesel synthesis from Neem oil using the Box–Behnken Design. The optimal process variables for esterification was pronounced as alcohol to oil molar ratio of 7.4:1, 0.89 wt% of H2SO4 catalyst, reaction temperature of 41°C and reaction duration of 88 minutes yielding Neem oil with optimum FFA value of 1.91% and the predicted FFA value was 1.73%. The optimized Neem Biodiesel yield of 96.39% was achieved with alcohol to oil molar ratio of 7.1:1 and 1.02 wt% of KOH catalyst at a reaction temperature of 41°C in 98 minutes reaction duration. The predicted Biodiesel yield was reported 97.14% at these reaction conditions. These results reveal a reliable forecast of the acid esterification process and alkali transesterification process by response surface methodology. The characteristics of synthesized Biodiesel meet the ASTM D6751 and EN14214 standards thus making it as a suitable power source for Diesel engines.