Fig. 11. (A) XRD patterns of 20% CaO/n-Al2O3 collected at different reaction times: (a) after 30 min, (b) after 2 h, (c) after 6 h, (d) after 10 h and (e) CDG/n-Al2O3. (B) Catalytic activity of 20% CaO/n-Al2O3 and calcium CDG/n-Al2O3 for the transesterification of soybean oil. Reaction conditions: temperature 150 ◦C, methanol/oil mole ratio 9:1, catalyst concentration 3 wt%, 500 rpm.