Transesterification of soybean oil using bovine bone waste as new catalyst

•Bovine bone waste can be convert to a potentially value added catalyst material.•Calcined bovine bone is an effective catalyst for soybean oil transesterification.•Only one calcination step is required to activate the bone waste.•Conversion of CaCO3 to CaO resulting in the catalytically active bone materials.•Bovine bone is commercial available, giving potential in industrial applications. Calcined bovine bone waste was employed to catalyze the transesterification reaction between soybean oil and methanol. The influence of various conditions on the efficiency of the transesterification was studied i.e. type of reactor, temperature, catalyst loading and methanol/oil ratio. The optimum yield of methyl ester (97%) was obtained by performing the closed-system transesterification at 65°C for 3h with catalyst loading of 8%wt and 6:1 methanol to oil ratio, using bone calcined at 750°C. Calcination of the commercial bovine bone at 650°C and above results in conversion of the calcium carbonate component to calcium oxide, with the major component being crystalline hydroxyapetite. Calcium oxide is believed to be responsible for the catalytic activity of the material. The reusability, low cost and low catalyst loading required (4%wt) may make bovine bone an attractive alternative to existing transesterification catalyst systems.