Estudo da desidratação de glicerol sobre CuO/SiO2 reduzidos em diferentes temperaturas

Abstract

Due to population growth and industrial development, the need for energy sources that meet this current demand has also increased. Among them, biodiesel has become more prominent because it is more sustainable when compared to other fossil fuels such as commercial diesel. However, large-scale biodiesel production generates glycerol. Therefore, several studies and applications have been made to increase the added value of this co-product. In this work, a silica-dispersed copper (CuO/SiO2) based catalyst, reduced at different temperatures to dehydrate glycerol, was synthesized. The synthesis was carried out by the Polymeric Precursors Method (Pechini) and the catalyst was previously characterized by the XRay Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). From the initial XRD it was possible to confirm that the synthesis of the catalyst was successful. Subsequently, catalytic tests were carried out at 180, 250 and 300°C, aiming to verify the effect of in situ reduction on the conversion and selectivity of glycerol. Thus, the catalytic performance was evaluated by the techniques of Gas Chromatography Flame Ionization (GC-FID), Gas Chromatography-Mass Spectrometry (GC-MS) and XRD. The obtained results identified the generation of 1,2-propanediol and acetol from the conversion of glycerol. In both generated products, the conversion was low, however, the selectivity for 1,2-propanediol was high. Furthermore, the diffractograms obtained after the catalytic tests showed that the copper reduction under the conditions of 250 and 300 °C occurred almost completely. Thus, the study carried out for the preparation of this work proved that the use of CuO/SiO2 as a catalyst for the dehydration of glycerol is an interesting route because it attributes greater added value to the by-product and serves as a basis for other alternative applications.