Biodiesel Production from Pongamia Pinnata and its Characterization using GC-MS, NMR and FT-IR Spectral Studies

Biodiesel synthesis from the pongamia oil seed and its characterization is elaborated in this paper. A double stage transesterification i.e. acid catalysed transesterification and base catalysed esterification are adopted to reduce the free fatty acids content and conversion of triglycerides into methyl esters. In this process, H₂SO₄, NaOH and methanol are used at the methanol/oil molar ratio of 7:1. By this process, 95% of pongamia biodiesel is obtained. The physiochemical properties like calorific value, Cetane number, density, kinematic viscosity, flash point, fire point etc. are analysed and it is found to be within the ASTM standards. GC-MS analysis indicated the existence of 14 prominent fatty acids with oleic acid as the major constituent. 13C and 1H NMR results supported the GC-MS data and it also confirmed the conversion efficiency of converting the vegetable oil into PBD as 87.23%. The shifting and appearance of major peaks in the FT-IR spectrum confirmed the formation of FAMEs from the triglycerides.