Optimization of biodiesel yield from non-food karanja seed oil: Characterization and assessment of fuel properties

Abstract

In the present research work, a non-conventional oil i.e., karanja (Pongamia pinnata L.) seed oil was selected to synthesize biodiesel through base catalyzed transesterification reaction. To minimize the FFA (free fatty acid) value of oil, esterification of oil using H2SO4 was carried out before the transesterification. The esterified oil was then subjected to transesterification with methanol in the presence of KOH, yielding karanja oil methyl esters (KOMEs) along with glycerol as a side-product. The transesterification was carried out under optimized reaction parameters such as alcohol to oil molar ratio of 6:1, temperature of 60 °C, KOH concentration of 1.00%, reaction time of 120 min, stirring rate of 750 rpm and maximum KOMEs yield of 95.4% was achieved. Different functional groups in KOMEs were traced via FTIR whereas GC-MS profiling was investigated to characterize different fatty acids in KOMEs. Moreover, fuel characteristics of KOMEs were determined and matched with standards. The findings of this research work support the use of Pongamia pinnata seed oil as a viable non-conventional/non-food oil feedstock for production of good quality biodiesel with value-added perspectives.

Keywords

• Karanja oil
• Optimized transesterification
• FTIR
• GC-MS
• Oleic acid
• Fuel properties