The transesterification of non-edible jatropha oil with methanol
can be actively catalyzed using bifunctional acidebase CaOeLa2O3
catalysts. CaO is a suitable basic compound to be integrated with
La2O3 as a highly active and stable catalyst for biodiesel production.
Co-precipitation of La with Ca promoted the CaO dispersion and
thus, increased the surface acidic and basic sites rather than bulk
CaO and La2O3 metal oxide. The presence of acidity and basicity in
the active sites of CaOeLa2O3 was found to enhance the esterification
and transesterification reaction of high FFA Jatropha oil. The
effect of Ca/La atomic ratio ranging from 0.5 to 10.0 towards the
transesterification activity was investigated. Among the series of
CaOeLa2O3 catalysts, Ca/La with 8.0 atomic ratio rendered the
highest biodiesel yield (98.76%) at the transesterification condition
of 160 C, 3 h, 25 methanol/oil molar ratio and 3 wt.%. 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.