Abstract:
Solid base heterogeneous catalysts are one of the promising materials for the transesterification of vegetable
oils because these catalysts are generally more reactive than solid acid catalysts which require
very severe operating conditions. Calcium oxide has shown good catalytic activity due to its high basicity
which is required for transesterification of triacylglycerides (TAGs). In the present study, the transesterification
of non-edible, high free fatty acid containing Jatropha and Karanja oils was studied by using
waste chicken egg shell derived calcium (i.e. CaO(cesp)) based mixed metal oxides (M-CaO; M = ZnO,
MnO2, Fe2O3 and Al2O3) as heterogeneous catalyst. A comparison was also made on the catalytic performance
of these prepared catalysts. The catalyst characterizations were done by XRD, SEM, TGA, FT-IR and
BET techniques. The effectiveness of the catalysts was highly influenced by the calcination temperature.
ZnO–CaO(cesp) catalyst was found to be the most efficient catalyst among all. The maximum conversion
for the transesterification of Jatropha and Karanja oils were achieved using 5 wt% catalyst, 65 C temperature
and 12:1 methanol/oil ratio. The catalyst could be re-used effectively during four cycles. Use of the
CaO(cesp) based mixed oxides made the process more environmental benign and economical. The biodiesel
prepared has shown good fuel characteristics as per EN, ASTM and IS standards.
