Transesterification of the crude oil of rapeseed with NaOH in supercritical and subcritical methanol

Transesterification reaction of the crude oil of rapeseed with supercritical/subcritical methanol in the presence of a relatively low amount of NaOH was successfully carried out, where soap formation didn't occur. The main factors affecting the methyl ester yield during the transesterification reaction were the catalyst content, the reaction temperature, the molar ratio of alcohol to oil and the water content. High methyl ester yield and fast reaction rate could be obtained even if the reaction pressure was relatively low. In addition, kinetics of the transesterification reaction was also discussed.