Development of heterogeneous catalysts for transesterification of triglycerides

This paper describes a preliminary work done towards the development of new metallic heterogeneous catalysts to be used in the transesterification reaction of triglycerides, which is of considerable interest in the production of biodiesel. Biodiesel is a mixture of mono-alkyl esters of fatty acids, and is currently manufactured by transesterification of triglycerides with methanol using NaOH or KOH as liquid base catalyst. Catalysts as such are corrosive to the equipment, and as these catalysts are present in the liquid phase, must be neutralized after the completion of the reaction, typically using HCl, thus producing salt streams. Moreover, due to the presence of free fatty acids, it reacts to form soaps as unwanted by-products, hence requiring more expensive separation processes. Therefore, there is a great need for the development of industrial processes for biodiesel production using solid acid catalysts. The key benefit of using solid acid catalysts is that no polluting by-products are formed, and the catalysts do not have to be removed since they do not mix with the biodiesel product.