Catalizadores de óxidos de metales de transición soportados para transesterificación de aceites

D. MARTÍN ALONSO; M. LÓPEZ GRANADOS; R. MARISCAL; J.C. YORI; C.R. VERA; J.M. GRAU

La Plata, Argentina

Congreso; XV Congreso Argentino de Catálisis - 4° Congreso de Catálisis del Mercosur; 2007

CONACA/CINDECA

ZrO2 and TiO2 supported over a wide pore silica were synthesized by means of a surface reaction technique involving hydrolizable precursors and OH groups of the support. These catalysts and their sulfated counterparts were tested in the reaction of transesterification of soybean oil with methanol in order to produce biodiesel. The results indicate that the most adequate silica support is that one with the biggest mean pore radius. This is attributed to the diffusional restrictions to mass transfer imposed by the big size of the triglyceride molecules. Sulfation has a weak promoting effect on the activity of the zirconia supported simples but quite a marked one in the case of titania. Sulfated titania catalysts are much more active than the unsulfated ones. In 2 h reaction time (200 °C, metanol:oil molar ratio=6, 2% catalyst) silica supported titania yields a conversion of 30% while sulfated titania yields a value of 50%. This last value corresponds to about 60% of the thermodynamic limit conversión. This shows the promising attributes of this new material.