The biodiesel yield catalyzed by different catalysts supported by RHA400, RHA600 and RHA800 with different CE loadings and calcination temperatures was illustrated in Fig. 4. More specifically, when the RH treatment temperature increased from 400 °C to 800 °C, the activity of catalyst significantly enhanced.
The RHA800 supported catalysts gave the highest biodiesel yield, up to 91.5%when the CE loading percentage was 30 wt.% and calcination temperature was 800 °C.
Thus, among the supports, RHA800 emerged as the most promising one, and the optimum treatment temperature for RH was 800 °C.