Transesterification of Animal fat to biodiesel over calcined solid sodium silicate catalyst

There is a great interest in biomass resources for fuel production as they are renewable, available in abundance and eco-friendly. Animal fat is associated with high free fatty acids content (FFA) that can reduce the quality and yield of biodiesel. As a result this catalyst selection is crucial to avoid soap formation during biodiesel production. Therefore this research evaluates the feasibility of transesterification of animal fat, (beef tallow) to biodiesel over sodium silicate catalyst in a batch reactor. Brunauer, Emmett and Teller (BET) analysis was used to determine the pore sizes, pore volume and the surface area of the catalyst. Scanning electron microscope (SEM) was used to determine the surface morphology of the catalyst and Fourier transform infrared (FTIR) was used to determine the chemical functionalities of the catalyst. The operating variables that were investigated in this study are: the effect of reaction time, reaction temperature and catalyst amount on the biodiesel yield. The catalyst activity and recovery were also investigated. Maximum catalyst recovery of 82% from catalyst amount of 1 g was achieved, from which a biodiesel yield of 15.5% was obtained compared to the 17.1% biodiesel yield obtained for 1 g catalyst amount. Therefore, sodium silicate catalyst is recyclable and can maintain its activity for a number of cycle.