(316e) Transesterification of Triglycerides for Biodiesel Over Selected Zeolite Catalysts

Transesterification of triglycerides in excess methanol to biodiesel using selected zeolite catalysts has been carried out. Various zeolites, such as beta-zeolite, zeolite Y and Mordenite, doped with alkali metals either by ion-exchange or impregnation, are employed to catalyze the transesterification at a relatively lower temperature around 60°C. A faster transesterification rate and higher conversion efficiency would be achieved with appropriate pretreatment on catalysts. Under a reaction temperature at 60°C, conversion efficiency of triglycerides to biodiesel as high as 97.3% was obtained. Cyclic durability of zeolite catalyst has been examined by running the same zeolite catalysts for 6 cycles of transesterification of triglyceride in methanol. It is found that catalyzed conversion efficiency of triglycerides did not differ significantly during the first 3 cycles. Additionally, regeneration on spent zeolite catalysts has been attempted as well. The zeolite catalyst can be recycled at least for four times without significant deterioration in terms of conversion efficiency of triglycerides.