Abstract:
This study focused on the production of biodiesel from the non-edible karanja oil (Pongamia pinnata). Two steps esterification process i.e. acid esterification and alkaline esterification was followed due to the high fatty acids (9.5%) content in karanja oil. Acid esterification process reduced the fatty acid percentage to 1.25% and further alkaline transesterification produced methyl esters.
Both homogeneous and heterogeneous catalysts were used for the esterification process. Different heterogeneous catalysts such as K2CO3/MgO, K2CO3/CaO, Al2O3/MgO, and Al2O3/CaO were prepared and the reactions conditions i.e. oil to methanol ratio, reaction time, reaction temperature, catalyst weight percentage were optimized for higher fatty acid methyl eaters (FAME) content. The maximum FAME content of 97.16% was obtained in presence of K2CO3/MgO catalyst (4wt.%) at the oil to methanol mole ration of 1:15.
The physico-chemical properties of the heterogeneous catalysts were characterized by specific surface area (BET) and X-ray diffraction study. Kinetic experiments were conducted to determine the reaction order and activation energy for the formation of biodiesel following Levenspiel method. Kinetic results suggested pseudo-first order reaction. The variation of reaction rate constant with catalyst weight percentage were also determined it showed linear variation up to 8wt.% of the catalyst used for the reaction.
