. Optimization of the glycerol settling rate and yield of biodiesel is required to define the optimum methanol concentration.
One can conclude that optimum concentration of Methanol for this particularly case seems to be in region of 30-40 vol.% having reasonable glycerol settling rate.
The yields corresponding to the amount of methanol used to produce biodiesel from used vegetable oil are summarized in Table 1.
Table 1 also shows that the yield increased from 86ml to 90ml by increasing the methanol concentration from 20% to 40%.
Further increase of methanol concentration from 40% to 50% produces a similar yield of 90ml biodiesel.
One can conclude that, the optimum concentration of methanol for this particularly case seems to be in region of 30-40 %, which produces a high yield (90ml) of biodiesel having reasonable glycerol settling rate.