The biodiesel
quality standard was satisfied with a BD yield of 95.6% and FAME
content of 96.6% when ultrasonically irradiated for 50 min. When
using ethanol, Fig. 2(b) shows a higher BD yield and FAME content
than using methanol for the same ultrasonic irradiation time, and
the biodiesel quality standard was satisfied with a BD yield of
95.8% and FAEE content of 97.0% at an ultrasonic irradiation time of
50 min. The reason why FAEE is larger than FAME is that the
ultrasonic irradiation energy effect of ethanol is higher than
methanol.