In order to study the effect of the loading of CE on RHA, a series of synthesized catalysts with various loadings ranging from 20 wt.% to 50 wt.% were prepared and the catalysts were employed to catalyze the transesterification reaction.
The results were presented in Fig. 4. It was shown that the biodiesel yields of three types of ash supported catalysts were substantially improved when the loading of CE increased from 20 wt.% to 30 wt.%, and further increase in loading from 30 wt.% to 50 wt.% reduced the biodiesel yield.