The effect of alkaline-autoclaving delignification on chemical component changes of sugarcane trash

Abstract

Sugarcane trash (ST) is lignocellulosic biomass that available abundantly during the sugarcane is harvested as a side product of sugarcane plantation. Several research groups have already reported their ST delignification. However, there is still needs to find a suitable delignification technique for improving recovery of cellulose and eliminate lignin and hemicellulose from a complex structure of ST. One of the methods for delignification is used alkaline with a high temperature. Hence, the research aim is to investigate the effect of alkaline-autoclaving delignification method on chemical component changes of ST. The different sample of ST including washing process and microwave-assisted maleic acid pretreatment prior to the delignification process with 2% NaOH combine with autoclaving in 121°C temperature was used in this study compare with the initial sample. The chemical composition changes in pretreated solid fractions and reducing sugar in pretreated liquid were analyzed. The functional properties were also analyzed using Fourier Transform Infrared (FTIR). The results showed that microwave-assisted maleic acid pretreatment before delignification was the effective treatment in this study to eliminate lignin (88.11%) and hemicellulose (44.07%) and cellulose recovery (78.40%) than that other treatment. Besides, the reducing sugar obtained from microwave-assisted maleic acid pretreatment 3.2 times and 3.6 times higher than that initial biomass and washing treatment, respectively. The FTIR spectra showed that washing treatment affects increasing absorbance of hydroxyl group while the maleic acid pretreatment was also increasing absorbance of carbonyl and the aromatic group that is a feature of lignin compound.