Zeólitas ácidas aplicadas na esterificação catalítica

Abstract

With respect the sugarcane sector expansion in Brazil, significant quantities of by-products have been generated, among them the fusel oil with potential for reuse due to the high volume produced and its rich isopentanol alcohol composition. An alternative of reuse is the transformation of this alcohol into ester, in this case, isopentyl acetate widely used in industries as flavors, solvents and others. In this context, the objective of the work was to apply commercial Si zeolites Si / Al = 15 and MFI with ratios (11.5, 15 and 25) in the protonated form as catalysts for the catalytic esterification of acetic acid the alcohols isopentanol and 1pentanol, in order to investigate the influence of the acidity, structure, and particle size of the catalysts in the catalytic activity. For this, the catalysts were characterized by: thermogravimetric analysis (ATG), X-ray diffractometry (DRX), nitrogen adsorption, scanning electron microscopy (MEV), desorption of ammonia at program temperature (DTP-NH3), spectroscopy energy dispersion (EDS) and X-ray fluorescence (FRX). By using the characterization techniques, it was found that commercially purchased materials corresponded to the one reported by the manufacturer. In addition, the characterization of samples with MFI structure showed that the Si / Al ratio has influence on shape, particle size, and acidity. In the catalytic tests, it was found that when comparing the MFI and USY structures with Si / Al = 15, it is not possible to identify which parameter had an influence on the catalytic activity, due to the number of variables. However, an improvement in the performance of the catalysts with the MFI structure with the increase of the Si / Al ratio was observed, this fact was attributed to the increase of the external surface.