Síntese e caracterização de óxidos a base de cobre disperso em suportes com características ácidas para reações de desidratação de glicerol em fase gás

Abstract

The use of excess glycerol by catalytic conversion to higher value-added products has been widely studied to give a nobler destination this co-product, by valuing the biodiesel production chain. Among the glycerol catalytic conversion processes is the dehydration that stands out. To evaluate the effect of inclusion of acid oxides (zirconium oxide and tungsten oxide) in the catalytic activity for glycerol dehydration reaction in gas phase, catalysts were synthesized by the polymeric precursor method and impregnation wet. The synthesized catalyst (Al2O3; WO3/Al2O3; CuO/WO3/Al2O3; ZrO2/Al2O3; CuO/ZrO2/Al2O3) were characterized by fluorescent X-ray (XRF), N2 isotherms adsorption, pyridine isotherms adsorption, X-ray diffraction (XRD) and temperature programed reduction (TPR), scanning electron microscopy (SEM). After the catalytic tests, the samples were subjected to thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The catalytic tests were conducted in a continuous flow reactor at 250 ° C under N2 and H2 environments. The catalysts obtained were active in glycerol dehydration at gas phase and the selective acetol presenting best conversion results in a reducing atmosphere. The addition of zirconium oxide and tungsten oxide led to the formation of more active catalysts, improved conversions of pure alumina. The copper oxide contributed to the increased selectivity of the catalysts acetol.