Synthesis of nanometric crystals of sodium and calcium zirconates as solid heterogeneous catalyst for biodiesel production.

Diesel varieties are mainly produced from two different sources oil and biomass. In the first case, oil is a non-renewable resource while diesel produced by biomass it is called biodiesel.  A better sustainable way to produce biodiesel is to take advantage of the availability of wasted cooking oil, when it has been discarded from the food industry, as it is found in large quantities. Our work was synthetize sodium and calcium zirconates (1:1), NZO and CZO. Obtain nano-solid heterogeneous catalyst of NZO and CZO. Via solid-state reaction used to obtain each zirconate. Reagent purities were studied by XRD, SDT and TEM. As a pretreatment process, sodium and calcium carbonate reagents were dehydrated by 10 min and zirconate oxide by 20 min both at 100 °C, to be sure that the stoichiometry does not vary. Sodium carbonate was hydrated (XRD PDF 01-072-1152), so it was left overnight at the right temperature to obtain the carbonate, without decomposing. Calcium carbonate PDF  After the solid-state reaction, it is observed by XRD and TEM confirm the zirconates formed (900 °C/1h). For CZO indicate, one impurity compound and unreacted reactants and NZO monophase. Nanocrystal sizes fabrication was done by mechanically mixed with aqueous medium room air atmosphere. We clarify that the wet grinding process does not favor the formation of hydroxides, detected by XRD (1-3 %) and TEM. Interestingly, metallic calcium was observed by TEM in CZO, this indicates that it must decrease the time and temperatures used, when the CZO manufacturing process is repeated. The crystal sizes calculate by Sherrer equation of CZO around 17– 78 nm. TEM analysis observes 20– 27 nm for CZO, with metallic calcium in another shade and NZO show 10 -33 nm crystals dimension. Nano-materials as catalysts remain to be tested.