Synthesis of biodiesel via homogeneous Lewis acid catalyst

The use of classical alkaline catalysts in the transesterification of waste fats and oils to obtain fatty methyl esters (FAME) poses great difficulties due to the presence of large amounts of free fatty acids (FFA). This paper studies as a possible alternative, the use of different bivalent metals. The most active catalysts have been individuated and a correlation of the activities with the cation acidity has been found.