Fractionation of cellulose and lignin from sugarcane bagasse via the alkaline and acid chemical process

This research aimed to fractionate cellulose and lignin from sugarcane bagasse (SCB) using the alkaline and acid chemical process. Sulphuric acid (H2SO4) and Sodium hydroxide (NaOH) were selected as the pretreatment chemical solvents. After pretreatment, the cellulose content and lignin were 98.5% and 79.2%, respectively. Fourier Transform Infrared (FTIR) Spectroscopy, 1H and 13C Nuclear Magnetic Resonance (NMR), and Scanning Electron Microscopy (SEM) were employed to analyse the material. Raw SCB shows the vibration absorption peaks of O-H and C-H stretching at 338.23 and 2897.37 cm-1, which are correlated with cellulose, hemicellulose, and lignin molecules. The vibration of O-H and C-H functional groups was observed on extracted cellulose and lignin biopolymers. However, the intensity of vibration peaks decreased, especially for lignin biopolymer. The absorption band observed at 1603.74 and 1541 cm-1 was attributed to the aromatic (C=O, C=C) structure. 1H and 13C NMR spectra detected the presence of both the aromatic regions and the sidechain regions on raw SCB and SCB-lignin. However, only the sidechain regions were detected on SCB-cellulose. SEM analysis reveals that the surfaces of raw SCB, SCB-cellulose, and SCB-lignin exhibit smooth, irregular, and uneven shapes, respectively. The results show that cellulose and lignin were simultaneously recovered from SCB.