Acceleration of Acid-catalyzed Transesterification Reaction by Minimizing Glycerol to Fatty Acid Methyl Ester Ratio

This work aimed to study the acceleration of a slow acid catalyzed transesterification process, retarded by poor blending of two components in a liquid-liquid reaction. Reducing the solution viscosity was achieved by adding fatty acid methyl ester (FAME) into refined palm oil at the beginning of the reaction could improve miscibility and enhance the conversion of triglyceride to FAME. The study also focused on glycerol to FAME ratio on adding FAME. The results show that a lower glycerol to FAME ratio in a conventional reactor increases FAME generation. This can be applied in the two-step transesterification process by maintaining a low glycerol to FAME ratio. To achieve the required ester content of greater than 96.5%, the proposed second step transesterification in a multistage reactor with glycerol removal can reduce the reaction time by up to 91.2% in the second step using heterogeneous acid catalyst, or by 57.5% using acid catalyst in a conventional reactor, respectively.