Authors: E. Leal, K.M.S. Viana, R.H.G.A. Kiminami, S.M.P. Meneghetti, A.C.F.M. Costa, H.L. Lira
Affilation: Universidade Federal de Campina Grande, Brazil
Pages: 502 - 505
Keywords: zinc aluminate, combustion reaction, catalytic support
The aim of this work is to evaluate the esterification activity of ZnAl2O4 catalysts obtained by different ways of heating (IU-plate, IIU-muffle furnace and IIIU-microwave oven) during the combustion synthesis using urea as reducing agent, and nitrates of zinc and aluminum as oxidants. During the synthesis were measured the parameters of combustion flame time and temperature. All samples were structural and morphologically characterized by XRD, particle size distribution, nitrogen adsorption (BET/BJH) and SEM, and then, they were forwarded to the catalytic tests on the biodiesel esterification. XRD results showed that even using different heating ways, all of them led to the formation of a cubic structure of ZnAl2O4 spinel. The heating way had a great influence on the structural and textural features of ZnAl2O4, such as crystallite size and surface area, whose values were of 27, 35 and 16nm, and15, 9 and 57m2/g for the samples IU, IIU and IIIU, respectively. All the samples presented morphology in irregular plates shape (SEM). These samples also showed the formation of particle agglomerates with a narrow size distribution. It was observed that the esterification reaction conducted in the presence of IIU catalyst had a slight increase in the percentage of biodiesel produced.