Effects of pretreatment applied to sugarcane bagasse on composition and morphology of cellulosic fractions

Abstract

Due to the growing demand for renewable energy, the energy based on biomass plays an important role in energy policies of countries all over the world. Seven different pretreatments were performed on SCB to obtain yields, chemical composition, particle sizes and crystallinity indexes. The tools used to study the effects of pretreatments on SCB were X-ray diffraction (change in crystalline and amorphous regions) and SEM images. The application of microwave-assisted irradiation allowed the obtaining of the lowest cellulose removal with the fractions PT-6 and PT-7. FTIR spectra showed the removal of hemicellulose and lignin content during pretreatments. DP values decreased significantly suggesting higher digestibility of the seven cellulosic fractions by cellulolytic enzymes. In the present work, the presence of cellulose, hemicellulose and lignin structures in the sample of sugarcane bagasse and cellulosic fractions were indicated by the characteristic absorption bands (cm−1) of groups shown by the FTIR spectrum for hemicellulose and lignin. SEM images showed extensive degradation of the buddle of fibers of some cellulosic fractions. Mass loss (ML) obtained with SCB and cellulosic fractions were much greater under O2 atmosphere than under N2 atmosphere. The most relevant novelty of the present research was the use of chemical and physical methodologies to characterize sugarcane bagasse and their cellulosic fractions. The objective of this work was to determine the chemical composition and physical characteristics such as particle sizes as well as the removal of components resulting from seven different pretreatments. Nevertheless, future work is greatly required for improvement in this area.