Biodiesel Synthesis from Pongamia pinnata oil over Modified CeO2 Catalysts

This study investigates the use of CeO2, ZrO2, MgO and CeO2-ZrO2, CeO2-MgO, CeO2-ZrO2-MgO mixed oxides as solid base catalysts for the transesterification of Pongamia pinnata oil with methanol to produce biodiesel. SO4(2-)/CeO2 and SO4(2-)/CeO2-ZrO2 were also prepared and used as solid acid catalysts for esterification of Pongamia pinnata oil (P-oil) to reduce the % of free fatty acid (FFA) in P-oil. These oxide catalysts were prepared by an incipient wetness impregnation method and characterized by techniques such as NH3-TPD for surface acidity, CO2-TPD for surface basicity and powder X-ray diffraction for crystalinity. The effect of nature of the catalyst, methanol to P-oil molar ratio and reaction time in esterification as well as in transesterification was investigated. The catalytic materials were reactivated & reused for five reaction cycles and the results showed that the ceria based catalysts have reasonably good reusability both in esterification and transesterification reaction. The test results also revealed that the CeO2-ZrO2 modified with MgO could have potential for use in the large scale biodiesel production.