The process of separation of these catalysts is facilitated because they do not need washing, which reduces the production of waste water and catalyst disposal at the end of the process. The recovered catalyst can also be reused. The application of heterogeneous catalysts can contribute to the decrease of biodiesel production costs and is of great importance for industrial operations. Different types of alumina supported potassium compounds have significant effects on the catalyst activity. The presence of the basic sites (K2O) formed on calcination of potassium compounds increases the basicity of the catalysts, providing high conversion to methyl esters.