Influence of different catalysts on transesterification reaction between oil and glycerol

Key words:  ionic liquids  transesterification reaction  soybean oil  fatty acid monoglyceride

Abstract:

Two imidazole basic ionic liquids, OH and Im, were synthesized. The structures of the two ionic liquids were characterized by nuclear magnetic resonance (NMR). Also, their thermal stability was determined and analyzed by thermogravimetric analysis. Then, the catalytic performance of the two ionic liquids and NaOH for the synthesis of fatty acid monoglyceride by the transesterification reaction between soybean oil and glycerol was conducted and compared. The results demonstrate that the thermal stability of Im is much better than that of OH. OH cannot catalyze the transesterification reaction efficiently due to the bad stability. Im has dual functions of alkali catalyst and phase transfer catalyst, which has the most efficiency among the three catalysts. The yield of fatty acid monoglyceride can reach 64.46% which is much higher than NaOH as the catalyst at the following conditions:temperature 190 ℃, reaction time 3 h, dosage of catalyst 10 % and molar ratio of glycerol and oil 6∶1.