Catalytic transesterification of crude rapeseed oil by liquid organic amine and co-catalyst in supercritical methanol

Abstract

Liquid organic amines, Ethylenediamine (EDA), Diethylamine (DEA) or Triethylamine (TEA), could speed up the production of methyl ester from crude rapeseed oil in supercritical methanol. The order of the catalytic activity was EDA > DEA > TEA. Acyl amine appeared in the products when EDA or DEA was used as the catalyst; however, this phenomenon didn’t occur when TEA was used. With Propylene oxide as the co-catalyst, the catalytic activity of TEA was greatly improved. In 10 min, the yield of methyl ester could reach 89.5%, which was seven times faster than that without the co-catalyst. Optimum molar ratio of methanol to crude rapeseed oil should not be lower than 24:1.