INVESTIGADORES
CRISTOBAL Adrian Alberto
congresos y reuniones científicas
Título:
FEASIBILITY OF USING CORNCOBS AS PORE FORMER IN CERAMIC MATERIALS
Autor/es:
NANCY E. QUARANTA; MARTA G. CALIGARIS; ROMINA S. VAROLI; ADRIÁN A. CRISTÓBAL
Reunión:
Simposio; ISGC 3rd international symposium on green chemistry; 2015
Resumen:
The generation of industrial wastes from biomass processes has increased in recent years. These wastes include products of agriculture, forests, aquatic plants, municipal wastes, animal and vegetable products, by-products of food industry, etc. Different studies have been conducted to analyze the feasibility of reuse industrial biomass residues. With regards to food industry residues, numerous works were found, mainly involving its use as a fuel, called biomass-energy processes, proposing the use of different residues, including corncobs [1]. The biomass residues have been characterized for other possible uses, like in the manufacture of useful materials that can be directly applied in the construction industry. For example, in order to obtain lightweight bricks, rice hulls have been studied [2]. The aim of this work is to characterize corncob wastes and analyze the feasibility of their use as a pore-forming material in the manufacture of lightweight ceramics for the civil construction industry. Ground residual material, particle size less than 2mm, has been characterized by diverse techniques: electron diffraction analysis X-ray (XRD), differential and gravimetric thermal analyses (DTA-TGA), among others. DTA-TGA analysis of corncobs is shown in Figure 1. In the range 20°-250ºC a small loss in TGA curve is observed. It is assigned to the H2O loss and the release of light adsorbed gases. Exothermic peaks corresponding to degradation and decomposition reactions are observed between 250°-500°C [3]. Within this range, a pyrolytic thermal decomposition of cellulose and hemicellulose takes place. The XRD pattern of the corncob shows the profile of noncrystalline organic samples. Small ridge characteristic of silica at low angles is observed. Figure 2 shows de FTIR spectra of the corncob sample. A strong broad absorbance band is observed at 3300 cm-1, due to O-H stretching vibration. A weaker O-H stretching vibration band is seen at 1600 cm-1. Both adsorbed water and surface OH groups contribute to these bands. One band present at about 2900 cm-1 was attributed to the stretching vibration of CH3 group. The band at 1035 cm-1 was probably relative to the stretching vibration of C-O and C-C, or the complex form of the glycosidic bond (C-O-C) of hemicellulose, according to Cheng et al. [4]. This band has a small shoulder at 1100 cm-1 probably due to the Si-O-Si fundamental vibration. The results of these characterizations lead to the conclusion that it is highly feasible to use these waste materials as pore formers in ceramic pieces, because during the firing process they are burned remaining in very small proportion in the ceramic matrix, without changes in the main oxides of the clay used, which determine the firing temperature. FIG1 LEGEND DTA-TGA curves of ground corncobs FIG2 LEGEND FTIR of residual material KEYWORDS corncobs | lighweight ceramic | biomass REFERENCES [1] N. Rohmah, G. Pikra, A. Salim. Energy Procedia, 2013, 32, 200-208. [2] G. Gorhan, O. Simsek. Construction and Building Materials, 2013, 40, 390-396. [3] X. Liu, Y. Zhang, Z. Li, R. Feng, Y. Zhang. Bioresource Technology, 2014, 170, 76-82. [4] L. Cheng, H. Liu, Y. Cui, N. Xue, W. Ding. J. of Energy Chemistry, 2014, 23, 43-49.