Shown in Fig. 1 is the effect of the methanol/oil ratio on the conversion
of biodiesel at a temperature of 30 C in the presence of
0.75 wt% KOH. The conversion reached a value of above 50% in just
20 min. Increasing the ratio from 5:1 to 8:1 increased the conversion.
It rose from 50% for the ratio of 5:1 to 64% for the ratio of 8:1.
The difference in the conversion between the ratios of 5:1 and 8:1
was about 24% in the first 60 min and slightly decreased to 13–16%
for the last 60 min. The difference in the conversion was less than
2% when the methanol/WCO ratio increased from 8:1 to 9:1.