OXIDATION OF FURFURAL USING IMPREGNATED ACTIVATED ALUMINA CATALYSTS

Abstract

The oxidation of furfural is of interest in more than one aspect. Furfural is the simplest compound of a class of cellulose secondary pyrolysis products which are cyclic, hydrogen deficient, and oxygenated, and is therefore relevant to biomass combustion. It is of interest as a heterocyclic compound, since it posses cyclic, ether, and diene character, and because of its aromatic character and greater reactivity compared to other aromatic compounds. The aim of this thesis is to study oxidation of furfural using iron-oxide and alum impregnated activated alumina as catalysts. Characterization of impregnated catalysts was carried out using standard procedures. Scanning electron microscope (SEM), energy dispersive x-ray (EDX), and Fourier transform infrared spectroscopy (FTIR) studies were performed to understand the mechanism of oxidation of furfural. Formation of 2-furancarboxylic acid was confirmed from the peak obtained at 245 urn (maximum absorbance wavelength for 2- furancarboxylic acid) from UV-spectrometric analysis. The present study concerns about oxidation of furfural using iron oxide impregnated activated alumina (IOIAA) and alum impregnated alumina (AIAA) which leads to the formation of 2-Furancarboxylic acid (also called furoic acid). The reaction was carried out in a batch reactor with a magnetic stirrer and effect of operational parameters on the reaction is observed. The parameters studied are catalytic ratio (CR):1-9%, temperature (T): 40-70 °C, initial concentration (Co): 0.1-0.5M, and time (t): 0.5-7.5 h. The individual and interactive effects of the above mentioned parameters have been studied using Box-Behnken design. Pareto analysis of variance (ANOVA) of the results showed a high coefficient of determination value ( R2 was equal to 0.8384 and 0.8973 for IOIAA and AIAA respectively). Fisher F-value of 34.65 for IOIAA and 55.10 for AIAA showed satisfactory prediction for second order regression model. The highest conversion of furfural to acid was obtained with CR= 5%, T=70 °C, Co= 0.3M and t=7 h. AIAA (81%) was found to give greater yield of acid than IOIAA (72%).