EFFECTS OF CALCINATION TEMPERATURE ON THE CATALYTIC ACTIVITY OF CAOSYNTHESIZED BY ALKALINE PRECIPITATION IN THE TRANSESTERIFICATION REACTION

Environmental issues and the scarcity of fossil fuel have motivated the development of research on alternative fuels such as biodiesel and ethanol. These have the advantage of being renewable and less harmful totheenvironment.Biodiesel has been widely studied due to its propertiessimilartofossildiesel.Itisobtainedthroughthetransesterificationreaction using vegetable oil or animal fat, alcohol and catalyst. The aim of this work is to synthesize calcium oxide catalyst and verifyits catalytic activity in the transesterification reaction. Alkaline precipitation from an aqueous solution of calcium chloridewas used to prepare crystalline calcium oxide. Samples calcined at 750, 850, and 950 oC were tested in three reaction cycles for the synthesis of fatty acid methyl esters. All the obtained ceramic powders showed catalytic activity, and methyl ester yields reached 65-91% in all three syntheses. In terms of reusability, the catalyst calcined at 850 oC showed methyl ester yields higher than 85%, proving advantageous over the other samples. These results were associated with the loss of active species by leaching and with the dissolution of CaO. Kinematic viscosity values in the range of 1.9-6.0 mm2/s at 40 oC were obtained, except for methyl ester produced with CaO calcined at 750 oC. The catalytic activity analysis confirmed the superiority of CaO calcined at 850 oC to produce methyl esters.