A Review on Application of Heterogeneous Catalyst in the Production of Biodiesel from Vegetable Oils

Biodiesel has been considered as one of the interesting alternative and environmentally benign fuels. The development of environmental friendly heterogeneous catalyst for the esterification/transesterification process seems to be promising route and the reason why it is more preferred to conventional homogeneous and enzymatic catalyzed reactions is discussed. However, investigation on heterogeneous catalyst for biodiesel production is extensively carried out based on previous research studies. In order to reduce cost of biodiesel production, evaluation and characterization of heterogeneous catalytic materials before and after its preparation provide facts on the process that have significant impact on the desired activity and selectivity properties. This review study provides a comprehensive overview of common process techniques usually employ in producing biodiesel. Different materials that serve as sources of heterogeneous catalysts to transesterify oils or fats for production of biodiesel with emphasis on selection criteria of solid catalytic materials are also highlighted. The potential heterogeneous catalyst that could be derived from anthill, various methods of preparing solid catalysts, as well as reusability and leaching analysis are discussed in details