The weak
reusability of the CaOeLa2O3 was influenced by the leaching of
active Ca2þ in the first run reaction. However, the catalyst's reusability
was stable for the next 4 cycles with reduced of Ca2þ ion
leaching into the acid reaction medium. The leaching of the Ca2þ
was due to the partially soluble of free CaO that did not bind in the
binary system. This lead to the unfavorable neutralization of FFA
with base Ca2þ species and resulted in white layer Ca soap
formation.
Acknowledgment
The authors acknowledge the financial support of the National