molar ratio) and 1.5 g NaOH. The reaction was carried
out for 2 h under reflux at 60 C while stirring. The reaction
was carried out using 100% excess methanol, i.e. molar
ratio of methanol to oil is 6:1 and catalyst concentration of
0.5%. The reactor was equipped with reflux condenser to
condense back the methanol escaping from the reaction
mixture. The reaction mixture was then allowed to stand
overnight and the methyl ester layer was separated from
the glycerol layer using separatory funnel. After completion
of reaction, crude glycerol was separated by gravity.
The catalyst was removed by hot water washings. Phenolphthalein
indicator checked the complete removal of the
catalyst. Traces of moisture and unreacted methanol were
removed by vacuum distillation. The distillation was continued
until the loss in weight of ester was constant thus
confirming the complete removal of moisture and unreacted
methanol. The crude methyl ester was further purified
by distilling-off the unreacted methanol under normal
atmospheric pressure, washing several times with water,
centrifugation and drying with vacuum destigator.