Acid catalysed transesterification of animal waste fat

Rendering plant fat (RPF) was collected and different conditions were used for transesterification. The course of transesterification of RPF was compared with that of transesterification of lard under the same conditions. Significant diffe-rences were found between transesterification of RPF and that of lard. Optimum methanol excess for lard transesterification was found to be 30-fold, for RPF 10-fold, optimum sulfuric acid concentration was 1% for lard, 2.5% for RPF. Optimum temperature as well as optimum reaction time were similar in both cases. The fatty acid composition is similar but not identical in both fats. RPF contains a higher amount of free acid which could be the reason for the differences observed.