The maximum biodiesel yield of 83%
(w/w to the esterified oil) was achieved at 0.9% catalyst concentration
and 120 min of reaction time. Biodiesel yield was found to
decrease when the oil was treated with the catalyst concentration
above at 0.9%. The catalyst dose beyond the optimum level led to
increase in soap formation and decrease in biodiesel yield. This
could be due to the addition of excess alkaline catalyst which
was causing precipitation of triglycerides in the saponification
reaction resulting in the production of high amounts of soap.
From this study it can be concluded that the catalyst concentration
of 0.9% and reaction time of 120 min were considered ideal for biodiesel
conversion. The alga E. compressa recorded maximum biodiesel
yield of 90.6% which was achieved by employing optimum
conditions of 1% NaOH and 60 C for base transesterification reaction
[51]. Reaction temperature is another important factor that
will affect the formation of the methyl ester conversion. In the present
study, to increase the conversion yield, different reaction