Síntese e caracterização do ZnAl2O4 impregnado com CuO e KI para obtenção de biodiesel.

Abstract

The following paper aimed to synthesize the spinel ZnAbCU by using three different heating sources, evaluate the influence of external heating in structural, morphological and catalytic properties of the samples, impregnate these samples with potassium and copper and also evaluate the influence of impregnated metal in the methylic transesterification and esterification process of soybean oil into biodiesel. The samples were tested as synthesized after impregnation with copper and potassium incipient-wetness. The structural and morphological characteristics of the samples were evaluated by X-ray diffraction (XRD), x-ray fluorescence (XRF), Fourier transform infrared (FT1R), particle size analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), thermogravimetric analysis (TGA), carbon content and textural analysis (BET). The bench catalytic tests were conducted using moral ratio 6/1 oil/methanol in transesterification and 4/1 fatty acid/methanol in esterification, using 1% by weight of catalyst in all reactions, the reaction product was characterized by gas chromatography and acid number. The values of surface area found from samples were between 8.6 and 57.3m2/g with mesoporous characteristic and morphology consisted of agglomerate with irregular plate shape and density, with nanoparticles clusters consisting of lower than 50 nm. Results showed that the three heating sources were effective in obtaining the spinel ZnAI204, however, as single phase the spinel was achieved only by using the microwave oven and electrical resistance with the use of crucible. From the results found it can be concluded that the type of heating did not cause significant change in the samples' morphology and structure. The catalytic tests showed that external heating type did not influence the catalytic potential of samples when in reactions of esterification and transesterification. The conversion results of impregnated samples showed that the impregnation was efficient in increasing 20% of biodiesel conversion in the process of esterification. The impregnated sample with potassium showed superior yield in the remaining 4% when in the transesterification process.