Conversion of Karanja oil to biodiesel using modified heterogeneous base catalyst

In the recent times, biodiesel production from various non‐edible oil sources has received a lot of attention. Karanja oil is chosen mainly due to its availability and low cost. It is a nitrogen fixing tree cultivated to enhance soil quality. Transesterification of Karanja oil to biodiesel using a basic solid modified heterogeneous catalyst has been discussed in the present study. Aluminum nitrate Al(NO3)3 impregnated on calcined marble (Al(NO3)3/calcined marble), prepared by wet impregnation method (25%), is used as a modified heterogeneous base catalyst. Surface morphology of the synthesized catalyst is determined using a scanning electron microscope (SEM) analyzer and the composition of various elements present in the prepared catalyst is analyzed using energy dispersive spectrometer (EDS analyzer). 67.56 (wt/wt) of calcium oxide (CaO) is observed for calcined marble and 78.19 (wt/wt %) of CaO has been noticed for impregnated catalyst (Al(NO3)3/calcined marble). A maximum biodiesel yield of 96.5% and a conversion of 97.43% was obtained at an optimum methanol:oil molar ratio of 9:1 (mol/mol), 4 (wt %) of catalyst concentration and 1.5 (h) reaction time respectively. The entire composition of formed biodiesel is determined using gas chromatography–mass spectrometry (GC–MS) analyzer and conversion of Karanja oil to biodiesel is measured using 1H‐nuclear magnetic resonance (NMR) analyzer.