Iron Oxide Catalysts Supported on Porous Silica for the Production of Biodiesel from Crude Jatropha Oil

A heterogeneous catalyst, FeO x /SiO2, prepared by the pore-filling method, was found to be active in the transesterification of crude Jatropha oil with methanol. When the transesterification reaction was carried out with a reaction temperature of 220 °C, a catalyst amount of 15 wt%, a methanol/oil molar ratio of 218:1, and a reaction time of 3 h, the yield of fatty acid methyl esters (FAME) in the product exceeded 99.0 %, and met with EN standards for allowable contents of glycerine and mono-, di-, and tri-glycerides. The correlation between the FAME production activity and measured acidity of the FeO x /SiO2 catalysts showed that the transesterification reaction was promoted via the acidic function of these catalysts, which are less inhibited by coexisting free fatty acids in the feedstock triglycerides.