Conjugation
between CaO and metal oxides with different basicity/acidity is
able to enhance the basicity or provides acidebase active sites for
transesterification process. Currently, some of the heterogeneous
mixed metal oxides are reported to be active in transesterification
reaction because they are tolerance to high FFAs and water in
vegetable oil. Previously, we have successfully established that the
improvement of basicity and catalyst's stability by integrated CaO
with MgO or ZnO. The mixed metal oxide (CaOeMgO and
CaOeZnO) by ameliorate the basicity were highly active in transesterification
of low grade jatropha oil. Furthermore, strong stability
of these binary metal oxide system provide higher quality
biodiesel yield with less leaching of active metal ion, better reusability
and highly tolerance to FFA as compare to pure CaO