Effects of Particle Size on the Preparation of Biomass Samples for Structural Characterization

This study evaluates the effects of particle size on the preparation of sugarcane bagasse, banana pseudostem, and orange bagasse for Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and x-ray diffraction (XRD) analyses. The biomasses were selected from five different granulometry, namely 850, 600, 425, 250, and 106 mu m, and analyzed in natura form, extractive-free, and extractive/pectin-free materials. According to the results, particle size influenced the extractive content mainly between 850 and 106 mu m, with variations of 8.40% for orange bagasse (OB), 33.96% for sugarcane bagasse (SB), and 44.72% for banana pseudostem (BP). There was a significant influence on the pectin removal between 850- and 425-mu m particles of 24.14% and 25.86%, respectively. The FTIR spectra showed an increase in the intensity of the bands when the particle size was reduced. The SEM images showed typical surfaces of lignocellulosic materials and modifications after extractives removal. From the XRD analysis, it was observed a high influence of granulometry on the crystallinity, mainly for SB samples. Overall, the particle size effects are more significant for materials with a large granulometry range, which is advantageous for industrial processes since no grinding is necessary for more homogeneous materials.