2.3. Transesterification reaction
According to analysis of commercial grade Jatropha oil carried
out at Nirma University and as shown in Table 2, Jatropha oil
had 185 mg KOH/g oil of saponification value, 25.320 g iodine/
100 g oil of iodine value, 10.586 mg KOH/g oil of acid value and
5.29% of FFA. The average molecular weight was 870 g/mol, calculated
from the saponification value. As shown in Fig. 1 a 500 ml
three necked glass flask with a water-cooled condenser at the
top was charged with 50 g of oil, different volume of anhydrous
methanol and varied amounts of catalyst. Each mixture was vigorously
stirred and refluxed for the required reaction time. After several
hours, the reaction mixture was cooled and separated by
filtration. The filtrate was allowed to settle down to separate into
two layers. The oil phase consisted of methyl esters and unreacted
triglycerides, while the aqueous phase mainly contained methanol
and glycerol. The residual methanol was separated from the liquid
phase by distillation. Experiments were carried out by changing
different parameters like methanol/oil molar ratio, reaction time,
catalyst amount, temperature and mixing intensity. Glycerol
formed after the reaction was weighted and moles were calculated.
This mole value of glycerol is compared with theoretical value and
based on this difference conversion of triglyceride was found out.