Biodiesel production intensification via microwave irradiation-assisted transesterification of oil blend using nanoparticles from elephant-ear tree pod husk as a base heterogeneous catalyst

This study investigated the potential of a blend of neem-rubber seed oil together with calcined husk of elephant ear tree pod as catalyst for biodiesel production via transesterification aided with microwave irradiation. The essential process parameters involved in biodiesel production were optimized using central composite rotatable design combined with response surface methodology. The free fatty acid of the blend of neem and rubber seed oils in ratio 60:40 used in this work was effectively reduced from 17.76 to 0.67% using methanol/oil blend ratio of 25:1, catalyst [Fe-2(SO4)(3)] dosage of 10 wt.%, reaction time of 120 min and reaction temperature of 65 degrees C. The E. cyclocarpum pod husk ash was calcined at 700 degrees C for 4 h and characterized. The results obtained show that the calcined ash is rich in K, Mg, Ca and Fe, which was responsible for its high catalytic activity. The optimal condition established for the microwave-assisted transesterification of the Fe-2(SO4)(3)-pretreated oil blend was methanol/oil blend molar ratio of 11.44:1, catalyst dosage of 2.96 wt.% and reaction time of 5.88 min under microwave heating power of 150 W with a corresponding biodiesel yield of 98.77 +/- 0.16 wt.%. The fuel properties of biodiesel produced were within the standard specifications.